From patchwork Wed Mar 31 21:27:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 12176423 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 39D7CC433ED for ; Wed, 31 Mar 2021 21:28:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DEEF961056 for ; Wed, 31 Mar 2021 21:28:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232429AbhCaV1e (ORCPT ); Wed, 31 Mar 2021 17:27:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51714 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231974AbhCaV11 (ORCPT ); Wed, 31 Mar 2021 17:27:27 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C1529C06175F for ; Wed, 31 Mar 2021 14:27:26 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id v6so3644493ybk.9 for ; Wed, 31 Mar 2021 14:27:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc:content-transfer-encoding; bh=MD7gEDamITC1CAlAt7dxOxGSXpVHYTo3DV9/y5T2kDg=; b=MreWT4S/JEbqWGV58Ig1eiLvQUzfcOc6o6DgrD0r7unPSHwoxWoS6hhBLkxusZWKMG VlsDxlRQVQFVDcG7D6c/cEQ0MU5QkDiTdjnISoy0CSpdPMCGdATyXwdgcC7Ud1tO82jJ MBx6UDkpA3cDklJuB9ALf9Z9tumx2gYd/YwbV76TwqpBlBD988in9bdminI4JrT1Br3q MEuzpMzsrneY/6vlfckqk8KQppP95MazdTHW/XFkAMGrvc/ISqGNGUxww8sSf6viY6aB Ha1MLKu6umCYEy8umFHw4HpoixwR0sFsWghrmb0M98p+mHXQVR9A7wIG0NHH3F2g0hXs Ixgw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc:content-transfer-encoding; bh=MD7gEDamITC1CAlAt7dxOxGSXpVHYTo3DV9/y5T2kDg=; b=kCLMfCZJFnIcVRJM3xCBabcSWWOGdgASeOQ/ZFde0eO2+biJydPugis/SI2yWCnTg5 xMMzvwo6pOPLZD3E9+ZBrc5SUYSCZbdSZv09+sy+Tf5mtmLDoMqSKKO35YIYQ+w/ZhDs NoSz4xyiNN/Lau88JatUTApZg36V98sT/d21003uPLVcxP3u4QK35eq9wbV8Mq94G45A NhdZpd01UYsBG9SHkyouLk0urLt93lSKtlVT2UV1y/NXMS3zFZnYGwr0dMhKN6/os9ld x4mng61aR1IFjw2V1h1G7Z1h0cY1EqFNk2vzTVR7Dy/PF7yUfQzDlk7VhwcXNhsgkHYP 8spQ== X-Gm-Message-State: AOAM530r0+qdsSA70lRXT2wdweSIrBOcWpz5O1v1l0Rcr6RckO9hguAt PN7mDQTc1PrAeViyYQGVl0DrFFPXxZvz5/qgTxY= X-Google-Smtp-Source: ABdhPJz+Szi3CUmrhkkKMjuhVK2a/MFyX3ttk7+uAN2tT92szooe9x6SYIvOYOng0jbOFOOXmEiJcNATGXxeNFt/APg= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:7933:7015:a5d5:3835]) (user=samitolvanen job=sendgmr) by 2002:a25:accd:: with SMTP id x13mr7714590ybd.88.1617226045965; Wed, 31 Mar 2021 14:27:25 -0700 (PDT) Date: Wed, 31 Mar 2021 14:27:05 -0700 In-Reply-To: <20210331212722.2746212-1-samitolvanen@google.com> Message-Id: <20210331212722.2746212-2-samitolvanen@google.com> Mime-Version: 1.0 References: <20210331212722.2746212-1-samitolvanen@google.com> X-Mailer: git-send-email 2.31.0.291.g576ba9dcdaf-goog Subject: [PATCH v4 01/17] add support for Clang CFI From: Sami Tolvanen To: Kees Cook Cc: Nathan Chancellor , Nick Desaulniers , Masahiro Yamada , Will Deacon , Jessica Yu , Arnd Bergmann , Tejun Heo , "Paul E. McKenney" , Christoph Hellwig , Peter Zijlstra , Sedat Dilek , bpf@vger.kernel.org, linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org This change adds support for Clang’s forward-edge Control Flow Integrity (CFI) checking. With CONFIG_CFI_CLANG, the compiler injects a runtime check before each indirect function call to ensure the target is a valid function with the correct static type. This restricts possible call targets and makes it more difficult for an attacker to exploit bugs that allow the modification of stored function pointers. For more details, see: https://clang.llvm.org/docs/ControlFlowIntegrity.html Clang requires CONFIG_LTO_CLANG to be enabled with CFI to gain visibility to possible call targets. Kernel modules are supported with Clang’s cross-DSO CFI mode, which allows checking between independently compiled components. With CFI enabled, the compiler injects a __cfi_check() function into the kernel and each module for validating local call targets. For cross-module calls that cannot be validated locally, the compiler calls the global __cfi_slowpath_diag() function, which determines the target module and calls the correct __cfi_check() function. This patch includes a slowpath implementation that uses __module_address() to resolve call targets, and with CONFIG_CFI_CLANG_SHADOW enabled, a shadow map that speeds up module look-ups by ~3x. Clang implements indirect call checking using jump tables and offers two methods of generating them. With canonical jump tables, the compiler renames each address-taken function to .cfi and points the original symbol to a jump table entry, which passes __cfi_check() validation. This isn’t compatible with stand-alone assembly code, which the compiler doesn’t instrument, and would result in indirect calls to assembly code to fail. Therefore, we default to using non-canonical jump tables instead, where the compiler generates a local jump table entry .cfi_jt for each address-taken function, and replaces all references to the function with the address of the jump table entry. Note that because non-canonical jump table addresses are local to each component, they break cross-module function address equality. Specifically, the address of a global function will be different in each module, as it's replaced with the address of a local jump table entry. If this address is passed to a different module, it won’t match the address of the same function taken there. This may break code that relies on comparing addresses passed from other components. CFI checking can be disabled in a function with the __nocfi attribute. Additionally, CFI can be disabled for an entire compilation unit by filtering out CC_FLAGS_CFI. By default, CFI failures result in a kernel panic to stop a potential exploit. CONFIG_CFI_PERMISSIVE enables a permissive mode, where the kernel prints out a rate-limited warning instead, and allows execution to continue. This option is helpful for locating type mismatches, but should only be enabled during development. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- Makefile | 17 ++ arch/Kconfig | 45 ++++ include/asm-generic/bug.h | 16 ++ include/asm-generic/vmlinux.lds.h | 20 +- include/linux/cfi.h | 41 ++++ include/linux/compiler-clang.h | 2 + include/linux/compiler_types.h | 4 + include/linux/init.h | 2 +- include/linux/module.h | 13 +- init/Kconfig | 2 +- kernel/Makefile | 4 + kernel/cfi.c | 329 ++++++++++++++++++++++++++++++ kernel/module.c | 43 ++++ scripts/Makefile.modfinal | 2 +- 14 files changed, 534 insertions(+), 6 deletions(-) create mode 100644 include/linux/cfi.h create mode 100644 kernel/cfi.c diff --git a/Makefile b/Makefile index 73add16f9898..4a9c1ff420b6 100644 --- a/Makefile +++ b/Makefile @@ -920,6 +920,23 @@ KBUILD_AFLAGS += -fno-lto export CC_FLAGS_LTO endif +ifdef CONFIG_CFI_CLANG +CC_FLAGS_CFI := -fsanitize=cfi \ + -fsanitize-cfi-cross-dso \ + -fno-sanitize-cfi-canonical-jump-tables \ + -fno-sanitize-trap=cfi \ + -fno-sanitize-blacklist + +ifdef CONFIG_CFI_PERMISSIVE +CC_FLAGS_CFI += -fsanitize-recover=cfi +endif + +# If LTO flags are filtered out, we must also filter out CFI. +CC_FLAGS_LTO += $(CC_FLAGS_CFI) +KBUILD_CFLAGS += $(CC_FLAGS_CFI) +export CC_FLAGS_CFI +endif + ifdef CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_32B KBUILD_CFLAGS += -falign-functions=32 endif diff --git a/arch/Kconfig b/arch/Kconfig index ecfd3520b676..f6a85ba6cba2 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -692,6 +692,51 @@ config LTO_CLANG_THIN If unsure, say Y. endchoice +config ARCH_SUPPORTS_CFI_CLANG + bool + help + An architecture should select this option if it can support Clang's + Control-Flow Integrity (CFI) checking. + +config CFI_CLANG + bool "Use Clang's Control Flow Integrity (CFI)" + depends on LTO_CLANG && ARCH_SUPPORTS_CFI_CLANG + # Clang >= 12: + # - https://bugs.llvm.org/show_bug.cgi?id=46258 + # - https://bugs.llvm.org/show_bug.cgi?id=47479 + depends on CLANG_VERSION >= 120000 + select KALLSYMS + help + This option enables Clang’s forward-edge Control Flow Integrity + (CFI) checking, where the compiler injects a runtime check to each + indirect function call to ensure the target is a valid function with + the correct static type. This restricts possible call targets and + makes it more difficult for an attacker to exploit bugs that allow + the modification of stored function pointers. More information can be + found from Clang's documentation: + + https://clang.llvm.org/docs/ControlFlowIntegrity.html + +config CFI_CLANG_SHADOW + bool "Use CFI shadow to speed up cross-module checks" + default y + depends on CFI_CLANG && MODULES + help + If you select this option, the kernel builds a fast look-up table of + CFI check functions in loaded modules to reduce performance overhead. + + If unsure, say Y. + +config CFI_PERMISSIVE + bool "Use CFI in permissive mode" + depends on CFI_CLANG + help + When selected, Control Flow Integrity (CFI) violations result in a + warning instead of a kernel panic. This option should only be used + for finding indirect call type mismatches during development. + + If unsure, say N. + config HAVE_ARCH_WITHIN_STACK_FRAMES bool help diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h index 76a10e0dca9f..b402494883b6 100644 --- a/include/asm-generic/bug.h +++ b/include/asm-generic/bug.h @@ -241,6 +241,22 @@ void __warn(const char *file, int line, void *caller, unsigned taint, # define WARN_ON_SMP(x) ({0;}) #endif +/* + * WARN_ON_FUNCTION_MISMATCH() warns if a value doesn't match a + * function address, and can be useful for catching issues with + * callback functions, for example. + * + * With CONFIG_CFI_CLANG, the warning is disabled because the + * compiler replaces function addresses taken in C code with + * local jump table addresses, which breaks cross-module function + * address equality. + */ +#if defined(CONFIG_CFI_CLANG) && defined(CONFIG_MODULES) +# define WARN_ON_FUNCTION_MISMATCH(x, fn) ({ 0; }) +#else +# define WARN_ON_FUNCTION_MISMATCH(x, fn) WARN_ON_ONCE((x) != (fn)) +#endif + #endif /* __ASSEMBLY__ */ #endif diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 0331d5d49551..40a9c101565e 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -544,6 +544,22 @@ . = ALIGN((align)); \ __end_rodata = .; + +/* + * .text..L.cfi.jumptable.* contain Control-Flow Integrity (CFI) + * jump table entries. + */ +#ifdef CONFIG_CFI_CLANG +#define TEXT_CFI_JT \ + . = ALIGN(PMD_SIZE); \ + __cfi_jt_start = .; \ + *(.text..L.cfi.jumptable .text..L.cfi.jumptable.*) \ + . = ALIGN(PMD_SIZE); \ + __cfi_jt_end = .; +#else +#define TEXT_CFI_JT +#endif + /* * Non-instrumentable text section */ @@ -570,6 +586,7 @@ NOINSTR_TEXT \ *(.text..refcount) \ *(.ref.text) \ + TEXT_CFI_JT \ MEM_KEEP(init.text*) \ MEM_KEEP(exit.text*) \ @@ -974,7 +991,8 @@ * keep any .init_array.* sections. * https://bugs.llvm.org/show_bug.cgi?id=46478 */ -#if defined(CONFIG_GCOV_KERNEL) || defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KCSAN) +#if defined(CONFIG_GCOV_KERNEL) || defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KCSAN) || \ + defined(CONFIG_CFI_CLANG) # ifdef CONFIG_CONSTRUCTORS # define SANITIZER_DISCARDS \ *(.eh_frame) diff --git a/include/linux/cfi.h b/include/linux/cfi.h new file mode 100644 index 000000000000..879744aaa6e0 --- /dev/null +++ b/include/linux/cfi.h @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Clang Control Flow Integrity (CFI) support. + * + * Copyright (C) 2021 Google LLC + */ +#ifndef _LINUX_CFI_H +#define _LINUX_CFI_H + +#ifdef CONFIG_CFI_CLANG +typedef void (*cfi_check_fn)(uint64_t id, void *ptr, void *diag); + +/* Compiler-generated function in each module, and the kernel */ +extern void __cfi_check(uint64_t id, void *ptr, void *diag); + +/* + * Force the compiler to generate a CFI jump table entry for a function + * and store the jump table address to __cfi_jt_. + */ +#define __CFI_ADDRESSABLE(fn, __attr) \ + const void *__cfi_jt_ ## fn __visible __attr = (void *)&fn + +#ifdef CONFIG_CFI_CLANG_SHADOW + +extern void cfi_module_add(struct module *mod, unsigned long base_addr); +extern void cfi_module_remove(struct module *mod, unsigned long base_addr); + +#else + +static inline void cfi_module_add(struct module *mod, unsigned long base_addr) {} +static inline void cfi_module_remove(struct module *mod, unsigned long base_addr) {} + +#endif /* CONFIG_CFI_CLANG_SHADOW */ + +#else /* !CONFIG_CFI_CLANG */ + +#define __CFI_ADDRESSABLE(fn, __attr) + +#endif /* CONFIG_CFI_CLANG */ + +#endif /* _LINUX_CFI_H */ diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h index d217c382b02d..6de9d0c9377e 100644 --- a/include/linux/compiler-clang.h +++ b/include/linux/compiler-clang.h @@ -61,3 +61,5 @@ #if __has_feature(shadow_call_stack) # define __noscs __attribute__((__no_sanitize__("shadow-call-stack"))) #endif + +#define __nocfi __attribute__((__no_sanitize__("cfi"))) diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index e5dd5a4ae946..796935a37e37 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -242,6 +242,10 @@ struct ftrace_likely_data { # define __noscs #endif +#ifndef __nocfi +# define __nocfi +#endif + #ifndef asm_volatile_goto #define asm_volatile_goto(x...) asm goto(x) #endif diff --git a/include/linux/init.h b/include/linux/init.h index 31f54de58429..b3ea15348fbd 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -47,7 +47,7 @@ /* These are for everybody (although not all archs will actually discard it in modules) */ -#define __init __section(".init.text") __cold __latent_entropy __noinitretpoline +#define __init __section(".init.text") __cold __latent_entropy __noinitretpoline __nocfi #define __initdata __section(".init.data") #define __initconst __section(".init.rodata") #define __exitdata __section(".exit.data") diff --git a/include/linux/module.h b/include/linux/module.h index da4b6fbe8ebe..8100bb477d86 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -26,6 +26,7 @@ #include #include #include +#include #include #include @@ -128,13 +129,17 @@ extern void cleanup_module(void); #define module_init(initfn) \ static inline initcall_t __maybe_unused __inittest(void) \ { return initfn; } \ - int init_module(void) __copy(initfn) __attribute__((alias(#initfn))); + int init_module(void) __copy(initfn) \ + __attribute__((alias(#initfn))); \ + __CFI_ADDRESSABLE(init_module, __initdata); /* This is only required if you want to be unloadable. */ #define module_exit(exitfn) \ static inline exitcall_t __maybe_unused __exittest(void) \ { return exitfn; } \ - void cleanup_module(void) __copy(exitfn) __attribute__((alias(#exitfn))); + void cleanup_module(void) __copy(exitfn) \ + __attribute__((alias(#exitfn))); \ + __CFI_ADDRESSABLE(cleanup_module, __exitdata); #endif @@ -376,6 +381,10 @@ struct module { const s32 *crcs; unsigned int num_syms; +#ifdef CONFIG_CFI_CLANG + cfi_check_fn cfi_check; +#endif + /* Kernel parameters. */ #ifdef CONFIG_SYSFS struct mutex param_lock; diff --git a/init/Kconfig b/init/Kconfig index 5f5c776ef192..5babea38e346 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -2296,7 +2296,7 @@ endif # MODULES config MODULES_TREE_LOOKUP def_bool y - depends on PERF_EVENTS || TRACING + depends on PERF_EVENTS || TRACING || CFI_CLANG config INIT_ALL_POSSIBLE bool diff --git a/kernel/Makefile b/kernel/Makefile index 320f1f3941b7..e8a6715f38dc 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -41,6 +41,9 @@ KCSAN_SANITIZE_kcov.o := n UBSAN_SANITIZE_kcov.o := n CFLAGS_kcov.o := $(call cc-option, -fno-conserve-stack) -fno-stack-protector +# Don't instrument error handlers +CFLAGS_REMOVE_cfi.o := $(CC_FLAGS_CFI) + obj-y += sched/ obj-y += locking/ obj-y += power/ @@ -111,6 +114,7 @@ obj-$(CONFIG_BPF) += bpf/ obj-$(CONFIG_KCSAN) += kcsan/ obj-$(CONFIG_SHADOW_CALL_STACK) += scs.o obj-$(CONFIG_HAVE_STATIC_CALL_INLINE) += static_call.o +obj-$(CONFIG_CFI_CLANG) += cfi.o obj-$(CONFIG_PERF_EVENTS) += events/ diff --git a/kernel/cfi.c b/kernel/cfi.c new file mode 100644 index 000000000000..e17a56639766 --- /dev/null +++ b/kernel/cfi.c @@ -0,0 +1,329 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Clang Control Flow Integrity (CFI) error and slowpath handling. + * + * Copyright (C) 2021 Google LLC + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* Compiler-defined handler names */ +#ifdef CONFIG_CFI_PERMISSIVE +#define cfi_failure_handler __ubsan_handle_cfi_check_fail +#else +#define cfi_failure_handler __ubsan_handle_cfi_check_fail_abort +#endif + +static inline void handle_cfi_failure(void *ptr) +{ + if (IS_ENABLED(CONFIG_CFI_PERMISSIVE)) + WARN_RATELIMIT(1, "CFI failure (target: %pS):\n", ptr); + else + panic("CFI failure (target: %pS)\n", ptr); +} + +#ifdef CONFIG_MODULES +#ifdef CONFIG_CFI_CLANG_SHADOW +/* + * Index type. A 16-bit index can address at most (2^16)-2 pages (taking + * into account SHADOW_INVALID), i.e. ~256M with 4k pages. + */ +typedef u16 shadow_t; +#define SHADOW_INVALID ((shadow_t)~0UL) + +struct cfi_shadow { + /* Page index for the beginning of the shadow */ + unsigned long base; + /* An array of __cfi_check locations (as indices to the shadow) */ + shadow_t shadow[1]; +} __packed; + +/* + * The shadow covers ~128M from the beginning of the module region. If + * the region is larger, we fall back to __module_address for the rest. + */ +#define __SHADOW_RANGE (_UL(SZ_128M) >> PAGE_SHIFT) + +/* The in-memory size of struct cfi_shadow, always at least one page */ +#define __SHADOW_PAGES ((__SHADOW_RANGE * sizeof(shadow_t)) >> PAGE_SHIFT) +#define SHADOW_PAGES max(1UL, __SHADOW_PAGES) +#define SHADOW_SIZE (SHADOW_PAGES << PAGE_SHIFT) + +/* The actual size of the shadow array, minus metadata */ +#define SHADOW_ARR_SIZE (SHADOW_SIZE - offsetof(struct cfi_shadow, shadow)) +#define SHADOW_ARR_SLOTS (SHADOW_ARR_SIZE / sizeof(shadow_t)) + +static DEFINE_MUTEX(shadow_update_lock); +static struct cfi_shadow __rcu *cfi_shadow __read_mostly; + +/* Returns the index in the shadow for the given address */ +static inline int ptr_to_shadow(const struct cfi_shadow *s, unsigned long ptr) +{ + unsigned long index; + unsigned long page = ptr >> PAGE_SHIFT; + + if (unlikely(page < s->base)) + return -1; /* Outside of module area */ + + index = page - s->base; + + if (index >= SHADOW_ARR_SLOTS) + return -1; /* Cannot be addressed with shadow */ + + return (int)index; +} + +/* Returns the page address for an index in the shadow */ +static inline unsigned long shadow_to_ptr(const struct cfi_shadow *s, + int index) +{ + if (unlikely(index < 0 || index >= SHADOW_ARR_SLOTS)) + return 0; + + return (s->base + index) << PAGE_SHIFT; +} + +/* Returns the __cfi_check function address for the given shadow location */ +static inline unsigned long shadow_to_check_fn(const struct cfi_shadow *s, + int index) +{ + if (unlikely(index < 0 || index >= SHADOW_ARR_SLOTS)) + return 0; + + if (unlikely(s->shadow[index] == SHADOW_INVALID)) + return 0; + + /* __cfi_check is always page aligned */ + return (s->base + s->shadow[index]) << PAGE_SHIFT; +} + +static void prepare_next_shadow(const struct cfi_shadow __rcu *prev, + struct cfi_shadow *next) +{ + int i, index, check; + + /* Mark everything invalid */ + memset(next->shadow, 0xFF, SHADOW_ARR_SIZE); + + if (!prev) + return; /* No previous shadow */ + + /* If the base address didn't change, an update is not needed */ + if (prev->base == next->base) { + memcpy(next->shadow, prev->shadow, SHADOW_ARR_SIZE); + return; + } + + /* Convert the previous shadow to the new address range */ + for (i = 0; i < SHADOW_ARR_SLOTS; ++i) { + if (prev->shadow[i] == SHADOW_INVALID) + continue; + + index = ptr_to_shadow(next, shadow_to_ptr(prev, i)); + if (index < 0) + continue; + + check = ptr_to_shadow(next, + shadow_to_check_fn(prev, prev->shadow[i])); + if (check < 0) + continue; + + next->shadow[index] = (shadow_t)check; + } +} + +static void add_module_to_shadow(struct cfi_shadow *s, struct module *mod, + unsigned long min_addr, unsigned long max_addr) +{ + int check_index; + unsigned long check = (unsigned long)mod->cfi_check; + unsigned long ptr; + + if (unlikely(!PAGE_ALIGNED(check))) { + pr_warn("cfi: not using shadow for module %s\n", mod->name); + return; + } + + check_index = ptr_to_shadow(s, check); + if (check_index < 0) + return; /* Module not addressable with shadow */ + + /* For each page, store the check function index in the shadow */ + for (ptr = min_addr; ptr <= max_addr; ptr += PAGE_SIZE) { + int index = ptr_to_shadow(s, ptr); + + if (index >= 0) { + /* Each page must only contain one module */ + WARN_ON_ONCE(s->shadow[index] != SHADOW_INVALID); + s->shadow[index] = (shadow_t)check_index; + } + } +} + +static void remove_module_from_shadow(struct cfi_shadow *s, struct module *mod, + unsigned long min_addr, unsigned long max_addr) +{ + unsigned long ptr; + + for (ptr = min_addr; ptr <= max_addr; ptr += PAGE_SIZE) { + int index = ptr_to_shadow(s, ptr); + + if (index >= 0) + s->shadow[index] = SHADOW_INVALID; + } +} + +typedef void (*update_shadow_fn)(struct cfi_shadow *, struct module *, + unsigned long min_addr, unsigned long max_addr); + +static void update_shadow(struct module *mod, unsigned long base_addr, + update_shadow_fn fn) +{ + struct cfi_shadow *prev; + struct cfi_shadow *next; + unsigned long min_addr, max_addr; + + next = vmalloc(SHADOW_SIZE); + + mutex_lock(&shadow_update_lock); + prev = rcu_dereference_protected(cfi_shadow, + mutex_is_locked(&shadow_update_lock)); + + if (next) { + next->base = base_addr >> PAGE_SHIFT; + prepare_next_shadow(prev, next); + + min_addr = (unsigned long)mod->core_layout.base; + max_addr = min_addr + mod->core_layout.text_size; + fn(next, mod, min_addr & PAGE_MASK, max_addr & PAGE_MASK); + + set_memory_ro((unsigned long)next, SHADOW_PAGES); + } + + rcu_assign_pointer(cfi_shadow, next); + mutex_unlock(&shadow_update_lock); + synchronize_rcu(); + + if (prev) { + set_memory_rw((unsigned long)prev, SHADOW_PAGES); + vfree(prev); + } +} + +void cfi_module_add(struct module *mod, unsigned long base_addr) +{ + update_shadow(mod, base_addr, add_module_to_shadow); +} + +void cfi_module_remove(struct module *mod, unsigned long base_addr) +{ + update_shadow(mod, base_addr, remove_module_from_shadow); +} + +static inline cfi_check_fn ptr_to_check_fn(const struct cfi_shadow __rcu *s, + unsigned long ptr) +{ + int index; + + if (unlikely(!s)) + return NULL; /* No shadow available */ + + index = ptr_to_shadow(s, ptr); + if (index < 0) + return NULL; /* Cannot be addressed with shadow */ + + return (cfi_check_fn)shadow_to_check_fn(s, index); +} + +static inline cfi_check_fn find_shadow_check_fn(unsigned long ptr) +{ + cfi_check_fn fn; + + rcu_read_lock_sched(); + fn = ptr_to_check_fn(rcu_dereference_sched(cfi_shadow), ptr); + rcu_read_unlock_sched(); + + return fn; +} + +#else /* !CONFIG_CFI_CLANG_SHADOW */ + +static inline cfi_check_fn find_shadow_check_fn(unsigned long ptr) +{ + return NULL; +} + +#endif /* CONFIG_CFI_CLANG_SHADOW */ + +static inline cfi_check_fn find_module_check_fn(unsigned long ptr) +{ + cfi_check_fn fn = NULL; + struct module *mod; + + rcu_read_lock_sched(); + mod = __module_address(ptr); + if (mod) + fn = mod->cfi_check; + rcu_read_unlock_sched(); + + return fn; +} + +static inline cfi_check_fn find_check_fn(unsigned long ptr) +{ + cfi_check_fn fn = NULL; + + if (is_kernel_text(ptr)) + return __cfi_check; + + /* + * Indirect call checks can happen when RCU is not watching. Both + * the shadow and __module_address use RCU, so we need to wake it + * up if necessary. + */ + RCU_NONIDLE({ + if (IS_ENABLED(CONFIG_CFI_CLANG_SHADOW)) + fn = find_shadow_check_fn(ptr); + + if (!fn) + fn = find_module_check_fn(ptr); + }); + + return fn; +} + +void __cfi_slowpath_diag(uint64_t id, void *ptr, void *diag) +{ + cfi_check_fn fn = find_check_fn((unsigned long)ptr); + + if (likely(fn)) + fn(id, ptr, diag); + else /* Don't allow unchecked modules */ + handle_cfi_failure(ptr); +} +EXPORT_SYMBOL(__cfi_slowpath_diag); + +#else /* !CONFIG_MODULES */ + +void __cfi_slowpath_diag(uint64_t id, void *ptr, void *diag) +{ + handle_cfi_failure(ptr); /* No modules */ +} +EXPORT_SYMBOL(__cfi_slowpath_diag); + +#endif /* CONFIG_MODULES */ + +void cfi_failure_handler(void *data, void *ptr, void *vtable) +{ + handle_cfi_failure(ptr); +} +EXPORT_SYMBOL(cfi_failure_handler); diff --git a/kernel/module.c b/kernel/module.c index 30479355ab85..20fb004e7d8d 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2146,6 +2146,8 @@ void __weak module_arch_freeing_init(struct module *mod) { } +static void cfi_cleanup(struct module *mod); + /* Free a module, remove from lists, etc. */ static void free_module(struct module *mod) { @@ -2187,6 +2189,9 @@ static void free_module(struct module *mod) synchronize_rcu(); mutex_unlock(&module_mutex); + /* Clean up CFI for the module. */ + cfi_cleanup(mod); + /* This may be empty, but that's OK */ module_arch_freeing_init(mod); module_memfree(mod->init_layout.base); @@ -3866,6 +3871,8 @@ static int unknown_module_param_cb(char *param, char *val, const char *modname, return 0; } +static void cfi_init(struct module *mod); + /* * Allocate and load the module: note that size of section 0 is always * zero, and we rely on this for optional sections. @@ -3997,6 +4004,9 @@ static int load_module(struct load_info *info, const char __user *uargs, flush_module_icache(mod); + /* Setup CFI for the module. */ + cfi_init(mod); + /* Now copy in args */ mod->args = strndup_user(uargs, ~0UL >> 1); if (IS_ERR(mod->args)) { @@ -4070,6 +4080,7 @@ static int load_module(struct load_info *info, const char __user *uargs, synchronize_rcu(); kfree(mod->args); free_arch_cleanup: + cfi_cleanup(mod); module_arch_cleanup(mod); free_modinfo: free_modinfo(mod); @@ -4415,6 +4426,38 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, #endif /* CONFIG_LIVEPATCH */ #endif /* CONFIG_KALLSYMS */ +static void cfi_init(struct module *mod) +{ +#ifdef CONFIG_CFI_CLANG + initcall_t *init; + exitcall_t *exit; + + rcu_read_lock_sched(); + mod->cfi_check = (cfi_check_fn) + find_kallsyms_symbol_value(mod, "__cfi_check"); + init = (initcall_t *) + find_kallsyms_symbol_value(mod, "__cfi_jt_init_module"); + exit = (exitcall_t *) + find_kallsyms_symbol_value(mod, "__cfi_jt_cleanup_module"); + rcu_read_unlock_sched(); + + /* Fix init/exit functions to point to the CFI jump table */ + if (init) + mod->init = *init; + if (exit) + mod->exit = *exit; + + cfi_module_add(mod, module_addr_min); +#endif +} + +static void cfi_cleanup(struct module *mod) +{ +#ifdef CONFIG_CFI_CLANG + cfi_module_remove(mod, module_addr_min); +#endif +} + /* Maximum number of characters written by module_flags() */ #define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4) diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal index 735e11e9041b..dd87cea9fba7 100644 --- a/scripts/Makefile.modfinal +++ b/scripts/Makefile.modfinal @@ -23,7 +23,7 @@ modname = $(notdir $(@:.mod.o=)) part-of-module = y quiet_cmd_cc_o_c = CC [M] $@ - cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< + cmd_cc_o_c = $(CC) $(filter-out $(CC_FLAGS_CFI), $(c_flags)) -c -o $@ $< %.mod.o: %.mod.c FORCE $(call if_changed_dep,cc_o_c) From patchwork Wed Mar 31 21:27:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 12176425 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5F345C43616 for ; Wed, 31 Mar 2021 21:28:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4140C61075 for ; Wed, 31 Mar 2021 21:28:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230291AbhCaV1e (ORCPT ); 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McKenney" , Christoph Hellwig , Peter Zijlstra , Sedat Dilek , bpf@vger.kernel.org, linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org With CONFIG_CFI_CLANG, the compiler replaces a function address taken in C code with the address of a local jump table entry, which passes runtime indirect call checks. However, the compiler won't replace addresses taken in assembly code, which will result in a CFI failure if we later jump to such an address in instrumented C code. The code generated for the non-canonical jump table looks this: : /* In C, &noncanonical points here */ jmp noncanonical ... : /* function body */ ... This change adds the __cficanonical attribute, which tells the compiler to use a canonical jump table for the function instead. This means the compiler will rename the actual function to .cfi and points the original symbol to the jump table entry instead: : /* jump table entry */ jmp canonical.cfi ... : /* function body */ ... As a result, the address taken in assembly, or other non-instrumented code always points to the jump table and therefore, can be used for indirect calls in instrumented code without tripping CFI checks. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook Acked-by: Bjorn Helgaas # pci.h --- include/linux/compiler-clang.h | 1 + include/linux/compiler_types.h | 4 ++++ include/linux/init.h | 4 ++-- include/linux/pci.h | 4 ++-- 4 files changed, 9 insertions(+), 4 deletions(-) diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h index 6de9d0c9377e..adbe76b203e2 100644 --- a/include/linux/compiler-clang.h +++ b/include/linux/compiler-clang.h @@ -63,3 +63,4 @@ #endif #define __nocfi __attribute__((__no_sanitize__("cfi"))) +#define __cficanonical __attribute__((__cfi_canonical_jump_table__)) diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index 796935a37e37..d29bda7f6ebd 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -246,6 +246,10 @@ struct ftrace_likely_data { # define __nocfi #endif +#ifndef __cficanonical +# define __cficanonical +#endif + #ifndef asm_volatile_goto #define asm_volatile_goto(x...) asm goto(x) #endif diff --git a/include/linux/init.h b/include/linux/init.h index b3ea15348fbd..045ad1650ed1 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -220,8 +220,8 @@ extern bool initcall_debug; __initcall_name(initstub, __iid, id) #define __define_initcall_stub(__stub, fn) \ - int __init __stub(void); \ - int __init __stub(void) \ + int __init __cficanonical __stub(void); \ + int __init __cficanonical __stub(void) \ { \ return fn(); \ } \ diff --git a/include/linux/pci.h b/include/linux/pci.h index 86c799c97b77..39684b72db91 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1944,8 +1944,8 @@ enum pci_fixup_pass { #ifdef CONFIG_LTO_CLANG #define __DECLARE_PCI_FIXUP_SECTION(sec, name, vendor, device, class, \ class_shift, hook, stub) \ - void stub(struct pci_dev *dev); \ - void stub(struct pci_dev *dev) \ + void __cficanonical stub(struct pci_dev *dev); \ + void __cficanonical stub(struct pci_dev *dev) \ { \ hook(dev); \ } \ From patchwork Wed Mar 31 21:27:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 12176427 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 96054C43460 for ; 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Wed, 31 Mar 2021 14:27:29 -0700 (PDT) Date: Wed, 31 Mar 2021 14:27:07 -0700 In-Reply-To: <20210331212722.2746212-1-samitolvanen@google.com> Message-Id: <20210331212722.2746212-4-samitolvanen@google.com> Mime-Version: 1.0 References: <20210331212722.2746212-1-samitolvanen@google.com> X-Mailer: git-send-email 2.31.0.291.g576ba9dcdaf-goog Subject: [PATCH v4 03/17] mm: add generic function_nocfi macro From: Sami Tolvanen To: Kees Cook Cc: Nathan Chancellor , Nick Desaulniers , Masahiro Yamada , Will Deacon , Jessica Yu , Arnd Bergmann , Tejun Heo , "Paul E. McKenney" , Christoph Hellwig , Peter Zijlstra , Sedat Dilek , bpf@vger.kernel.org, linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org With CONFIG_CFI_CLANG, the compiler replaces function addresses in instrumented C code with jump table addresses. This means that __pa_symbol(function) returns the physical address of the jump table entry instead of the actual function, which may not work as the jump table code will immediately jump to a virtual address that may not be mapped. To avoid this address space confusion, this change adds a generic definition for function_nocfi(), which architectures that support CFI can override. The typical implementation of would use inline assembly to take the function address, which avoids compiler instrumentation. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- include/linux/mm.h | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index 8ba434287387..22cce9c7dd05 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -124,6 +124,16 @@ extern int mmap_rnd_compat_bits __read_mostly; #define lm_alias(x) __va(__pa_symbol(x)) #endif +/* + * With CONFIG_CFI_CLANG, the compiler replaces function addresses in + * instrumented C code with jump table addresses. Architectures that + * support CFI can define this macro to return the actual function address + * when needed. + */ +#ifndef function_nocfi +#define function_nocfi(x) (x) +#endif + /* * To prevent common memory management code establishing * a zero page mapping on a read fault. From patchwork Wed Mar 31 21:27:08 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 12176431 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B78A7C43618 for ; Wed, 31 Mar 2021 21:28:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 992B861041 for ; Wed, 31 Mar 2021 21:28:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232419AbhCaV2N (ORCPT ); Wed, 31 Mar 2021 17:28:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51774 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232101AbhCaV1f (ORCPT ); Wed, 31 Mar 2021 17:27:35 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 86701C0613D8 for ; Wed, 31 Mar 2021 14:27:32 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id x8so3714552ybo.6 for ; Wed, 31 Mar 2021 14:27:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=lJzARyoTFHSeDeqATvX4eu9oF56GjO0aovkcTYMeCXE=; b=EkwKQyMZdT5HfDUmkAZVrW7DWLH3qdU+R/FHZTPqq5IKj3NSExJ7rO5G826Zfp25Du 4SeLWwQdtvXJZTK7h4ZZ28yesbAdVRYaYD0+nkzkzzHCLmsSAl5G+DxlpNEm8A2HbV14 tjDJKbgnnBAN8zUjWqqu5EfJrrMMTPcc3Vp3MbyGSfKz3w+5QkjRKPTYJiaUHVyIfGAH Uw2KSLbyUziDQJrTtbRd5qayoZXfFGV/ul1u7MZ+aVnD/YxBbkoVM8AG04ixf/ZBdxFM lnSgkOrXFZ4W6piai3EFaSnpzVwD5YS8KMAEeWGT9UwcCv3eo8BVkIjR90//1hltbdO1 WtJQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=lJzARyoTFHSeDeqATvX4eu9oF56GjO0aovkcTYMeCXE=; b=JN32OE6jKttxQHS7F3PA2gj5JBBy43GLA7ZBFyjcCtb4m20Z30+Tlx+nzAWWQm9Ykl 3FHma3gmOf9aYBSGwgJAP/g3LLKuVdr3GGK+gIsJZJZYv3CzIJHQeryL9UvlMCxolEM1 D55w458+UKKZGrK4llZ3s03lAmfy+dRPcJGgLNfC9bc4haSCm1cMfpVMWJ2w92BWsqLz pmlpXbZSiEbq/ocj0MslJiXM3kry6HdtGQkQEbqtIiEgs1TMnnORJxjV6siqD4YTQuev 07TUyR+yE92iJHMPlZ8TIIR+IkLQt9y8EGt/7Np3fdygt+WJ0797AwA1tkBdBjc4Fohk 5u+w== X-Gm-Message-State: AOAM5328V8/kfnIn3xcU+5QRB9v+FM+dNVFHp+rLgAgvIRQhrvxu71Eg 0KsBbW3VAXqpbPrDkYJIQzkafOjxd5obXM0s854= X-Google-Smtp-Source: ABdhPJyd8HcE5E535kHQ1N5nE+6FNp3+tY1VY7IhXOwntRLaet3Jq1vErDdNDQFRye3uE6pJ+4BkgjDjLB/yQDl1VBo= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:7933:7015:a5d5:3835]) (user=samitolvanen job=sendgmr) by 2002:a25:5006:: with SMTP id e6mr7725488ybb.109.1617226051633; Wed, 31 Mar 2021 14:27:31 -0700 (PDT) Date: Wed, 31 Mar 2021 14:27:08 -0700 In-Reply-To: <20210331212722.2746212-1-samitolvanen@google.com> Message-Id: <20210331212722.2746212-5-samitolvanen@google.com> Mime-Version: 1.0 References: <20210331212722.2746212-1-samitolvanen@google.com> X-Mailer: git-send-email 2.31.0.291.g576ba9dcdaf-goog Subject: [PATCH v4 04/17] module: ensure __cfi_check alignment From: Sami Tolvanen To: Kees Cook Cc: Nathan Chancellor , Nick Desaulniers , Masahiro Yamada , Will Deacon , Jessica Yu , Arnd Bergmann , Tejun Heo , "Paul E. McKenney" , Christoph Hellwig , Peter Zijlstra , Sedat Dilek , bpf@vger.kernel.org, linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org CONFIG_CFI_CLANG_SHADOW assumes the __cfi_check() function is page aligned and at the beginning of the .text section. While Clang would normally align the function correctly, it fails to do so for modules with no executable code. This change ensures the correct __cfi_check() location and alignment. It also discards the .eh_frame section, which Clang can generate with certain sanitizers, such as CFI. Link: https://bugs.llvm.org/show_bug.cgi?id=46293 Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook Acked-by: Jessica Yu --- scripts/module.lds.S | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/scripts/module.lds.S b/scripts/module.lds.S index 168cd27e6122..2ba9e5ce71df 100644 --- a/scripts/module.lds.S +++ b/scripts/module.lds.S @@ -3,10 +3,21 @@ * Archs are free to supply their own linker scripts. ld will * combine them automatically. */ +#include + +#ifdef CONFIG_CFI_CLANG +# define ALIGN_CFI ALIGN(PAGE_SIZE) +# define SANITIZER_DISCARDS *(.eh_frame) +#else +# define ALIGN_CFI +# define SANITIZER_DISCARDS +#endif + SECTIONS { /DISCARD/ : { *(.discard) *(.discard.*) + SANITIZER_DISCARDS } __ksymtab 0 : { *(SORT(___ksymtab+*)) } @@ -40,7 +51,14 @@ SECTIONS { *(.rodata..L*) } - .text : { *(.text .text.[0-9a-zA-Z_]*) } + /* + * With CONFIG_CFI_CLANG, we assume __cfi_check is at the beginning + * of the .text section, and is aligned to PAGE_SIZE. + */ + .text : ALIGN_CFI { + *(.text.__cfi_check) + *(.text .text.[0-9a-zA-Z_]* .text..L.cfi*) + } } /* bring in arch-specific sections */ From patchwork Wed Mar 31 21:27:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 12176433 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C335C4363C for ; Wed, 31 Mar 2021 21:28:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E4E461073 for ; Wed, 31 Mar 2021 21:28:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232532AbhCaV2P (ORCPT ); Wed, 31 Mar 2021 17:28:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51782 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229486AbhCaV1g (ORCPT ); Wed, 31 Mar 2021 17:27:36 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6583CC0613DF for ; Wed, 31 Mar 2021 14:27:34 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id l83so3642032ybf.22 for ; Wed, 31 Mar 2021 14:27:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=83qC35j0sT8ux3EecZ4JSXTBbnC5lT5vvU8jPpy+oIo=; b=qW9htz+1Xajlr5ZlOCWPOGJSyd0/TSkn9e+fyiCr0KHqJua+AlwezhJkvGAUtb8Uus /S4mbwz/r+yDh70gtjVoZeS/Cd8Df/jmcs1PuDY46slrmp+4SqG+psUv2O+ksbCIJsku dIjxKPRi0/bBYhrdnimd0IFEXoBehXd1rxYwYKk6jnrMrv5BJOu5sLPElKsXeAOfL2IR FSzBya2A/E7j+p3qdkcoVeUbSlTHPrCr/FWByGn48UAf6x3/qZaErXzEP1jQigQ+9zTl SKBo2HTMUqAJmQOe4IT5KuTYEDd90h1ZV8EwZpReysv+MJnRxHy6JXArwTScE9I12WVL 7/4Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=83qC35j0sT8ux3EecZ4JSXTBbnC5lT5vvU8jPpy+oIo=; b=SjDfa9QIDCedIqOXvCOv39ehH8ZWQRwprQu983yaWGBIfdQG+ncY3VTKIwHmNWM0OK +Lt5z4fjMQGbp5VVHXmFOogJAnsYAZBxIu495S4UyjOqrBxHW2PlVCfNcdgXr9g70SHH R6G9eA9zfAOIAm7HHrGuGMDr8gH7C+KThpIBPBS5ynP4EJAeKWA9wWCg+rfUtPFIucjD TbvMnht3WqISOluuj4uoYaFxNgQil+eAgnnega7NtBpRgco38Gn5qKPSu7kd9S0vVS5a Ny3WJB9j7EbcRMLI596lIOuXMRX0GAd/84TZsrgXSh4KuGb87Q32JdGsG/eHWQ5jVHeO o5Sw== X-Gm-Message-State: AOAM533k72VQXUWOtV7jAH2qZQLVaS4W6MBXJAHsA7h1uVaLkH6AT8EE FBgMEcC+GjLYlcdwIJplj6JwPf3MsF22inUEGPc= X-Google-Smtp-Source: ABdhPJyr002SQuA6HZqmBTDomHGBVa4bvwCOQ/KoKLmk8qBxdNaaMWAdSxUHR/bPNxVIO6iowtKoA+CrI/FQIGDGCn4= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:7933:7015:a5d5:3835]) (user=samitolvanen job=sendgmr) by 2002:a25:3801:: with SMTP id f1mr7850920yba.353.1617226053546; Wed, 31 Mar 2021 14:27:33 -0700 (PDT) Date: Wed, 31 Mar 2021 14:27:09 -0700 In-Reply-To: <20210331212722.2746212-1-samitolvanen@google.com> Message-Id: <20210331212722.2746212-6-samitolvanen@google.com> Mime-Version: 1.0 References: <20210331212722.2746212-1-samitolvanen@google.com> X-Mailer: git-send-email 2.31.0.291.g576ba9dcdaf-goog Subject: [PATCH v4 05/17] workqueue: use WARN_ON_FUNCTION_MISMATCH From: Sami Tolvanen To: Kees Cook Cc: Nathan Chancellor , Nick Desaulniers , Masahiro Yamada , Will Deacon , Jessica Yu , Arnd Bergmann , Tejun Heo , "Paul E. McKenney" , Christoph Hellwig , Peter Zijlstra , Sedat Dilek , bpf@vger.kernel.org, linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org With CONFIG_CFI_CLANG, a callback function passed to __queue_delayed_work from a module points to a jump table entry defined in the module instead of the one used in the core kernel, which breaks function address equality in this check: WARN_ON_ONCE(timer->function != delayed_work_timer_fn); Use WARN_ON_FUNCTION_MISMATCH() instead to disable the warning when CFI and modules are both enabled. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- kernel/workqueue.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 0d150da252e8..03fe07d2f39f 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1630,7 +1630,7 @@ static void __queue_delayed_work(int cpu, struct workqueue_struct *wq, struct work_struct *work = &dwork->work; WARN_ON_ONCE(!wq); - WARN_ON_ONCE(timer->function != delayed_work_timer_fn); + WARN_ON_FUNCTION_MISMATCH(timer->function, delayed_work_timer_fn); WARN_ON_ONCE(timer_pending(timer)); WARN_ON_ONCE(!list_empty(&work->entry)); From patchwork Wed Mar 31 21:27:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 12176429 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 28DE0C43600 for ; Wed, 31 Mar 2021 21:28:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0E72361041 for ; Wed, 31 Mar 2021 21:28:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232101AbhCaV2O (ORCPT ); Wed, 31 Mar 2021 17:28:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51766 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232600AbhCaV1h (ORCPT ); Wed, 31 Mar 2021 17:27:37 -0400 Received: from mail-qk1-x749.google.com (mail-qk1-x749.google.com [IPv6:2607:f8b0:4864:20::749]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5AEDCC06175F for ; Wed, 31 Mar 2021 14:27:36 -0700 (PDT) Received: by mail-qk1-x749.google.com with SMTP id c131so2349422qkg.21 for ; Wed, 31 Mar 2021 14:27:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=w0Ob8x2IVOI0uzzuSsD4k6M727ovkcvMuqyZX5oqc8o=; b=nI+ENEyWz/rNq3xP8nhiHUSZWps3bzcuJMrVtvPjR+rwBVB/lrPv3BQxv4E6KMlKot N2LsEQni14VlVAHF8qnHU7viK/ziWMDnF+LjsDhRC5aIyL3jNfHcFkfBZOz7gp9DHK/O 0JRF/cYTuekKimF/7nWHkbZejho/mozDnjz14/sUDrLrCY52H9gqZiseo5bvX4tsLE3n UInjiRYKcOH12CVIEai20isk8gmvkqMy8DVUqR4KnBFv6jve3oIB8g21fppaRejyMB3V etjDn4nUdij5fV9SBqoW9glwdBH2VxhLNg9QBaiZB4SRwbU9iQX2g4S5jS1L/Ej7xHUS tYmQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=w0Ob8x2IVOI0uzzuSsD4k6M727ovkcvMuqyZX5oqc8o=; b=SHqU9zllXeREHndNHD3izR1AiJkC6NFjTM4xRCRJRHyZSRxcTWlpuf0mImBtZ6xZXs RdPkgC/9LxtKcgMeAPE+7egj0xaWvjtf/rMy7LOZvouoNh6FZXvgtul2pM+pRW7ZwT1T 0sH09fZbEzU/h5XQvNEtM+KwIDaVPg7hHSOrGPCejgn5rsxY7xsO0tzepyV9TpVxOTdk KTleUTRk8Q8ngbkFYKL3DFzWAPPquGWQOPEymaqzBtrg89n6sLw1OmA5UOAcl/AH+KMT VNXXUU+rZLDESsb5SZvXulN/7betd9Z67NF8HJcRrQvsVoYamBxR2McKix3IrmttLVjP rUtg== X-Gm-Message-State: AOAM530vc75ocjbrZbnFYeF+tl3tx/RPrVfuPJKonRpbH/ytaZOpnNxD twc8YccmLK6aLQpXvhXMVoehtGy9Isj8LtnEJAk= X-Google-Smtp-Source: ABdhPJxyRXN3znqnAe5t9dUQhGAL9s70gMe95fSLJFpd13x9D/1BXHdz4usqL4E5etbu055EIK7g6ge4pYkRTaLFmpw= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:7933:7015:a5d5:3835]) (user=samitolvanen job=sendgmr) by 2002:a0c:cb0c:: with SMTP id o12mr5070670qvk.54.1617226055502; Wed, 31 Mar 2021 14:27:35 -0700 (PDT) Date: Wed, 31 Mar 2021 14:27:10 -0700 In-Reply-To: <20210331212722.2746212-1-samitolvanen@google.com> Message-Id: <20210331212722.2746212-7-samitolvanen@google.com> Mime-Version: 1.0 References: <20210331212722.2746212-1-samitolvanen@google.com> X-Mailer: git-send-email 2.31.0.291.g576ba9dcdaf-goog Subject: [PATCH v4 06/17] kthread: use WARN_ON_FUNCTION_MISMATCH From: Sami Tolvanen To: Kees Cook Cc: Nathan Chancellor , Nick Desaulniers , Masahiro Yamada , Will Deacon , Jessica Yu , Arnd Bergmann , Tejun Heo , "Paul E. McKenney" , Christoph Hellwig , Peter Zijlstra , Sedat Dilek , bpf@vger.kernel.org, linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org With CONFIG_CFI_CLANG, a callback function passed to __kthread_queue_delayed_work from a module points to a jump table entry defined in the module instead of the one used in the core kernel, which breaks function address equality in this check: WARN_ON_ONCE(timer->function != ktead_delayed_work_timer_fn); Use WARN_ON_FUNCTION_MISMATCH() instead to disable the warning when CFI and modules are both enabled. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- kernel/kthread.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/kthread.c b/kernel/kthread.c index 1578973c5740..a1972eba2917 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -963,7 +963,8 @@ static void __kthread_queue_delayed_work(struct kthread_worker *worker, struct timer_list *timer = &dwork->timer; struct kthread_work *work = &dwork->work; - WARN_ON_ONCE(timer->function != kthread_delayed_work_timer_fn); + WARN_ON_FUNCTION_MISMATCH(timer->function, + kthread_delayed_work_timer_fn); /* * If @delay is 0, queue @dwork->work immediately. This is for From patchwork Wed Mar 31 21:27:11 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 12176437 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 01940C001B3 for ; Wed, 31 Mar 2021 21:28:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DFD1E61041 for ; Wed, 31 Mar 2021 21:28:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232661AbhCaV2Q (ORCPT ); Wed, 31 Mar 2021 17:28:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51758 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232672AbhCaV1i (ORCPT ); Wed, 31 Mar 2021 17:27:38 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2D3B6C061765 for ; Wed, 31 Mar 2021 14:27:38 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id a19so3691908ybg.10 for ; Wed, 31 Mar 2021 14:27:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=i1PxfqvHNAZaUSY0Wt2J9hLbKLkB/NragVXsh/CJXkk=; b=CgrLOqIhy6I4HPpgcvaJ2Kf5auntmv+ua+he8hCf1xZOx39XpJXZZQKDjnLwMtvYdc Coi9ppbfXIt+chJQ+QAqS+uMcGf3PwWgeivSHwdv4kpzv+rr2THIbfrCVVg6whJabjHV 2SJxgs1puZMWys7KvUR5E+GbWAG2gwUT/GVAk45+lS65j4BBiznnMwegCCuQHsgryS2u QzL22ZL9lFhVWUNp8q+UhG8SLH8hbhdY0GCTNzBAfacJ68xebK4pOQ0ZV2n5FHyUqPaj SKhOoLjlOqVTxE7XxST/QkBjkfCEkkv080ZLYXfJXOwteQgLmCab9Xy/VvS1MHxuU5DN Wx1g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=i1PxfqvHNAZaUSY0Wt2J9hLbKLkB/NragVXsh/CJXkk=; b=A2SzXLo9sc4LN/HGdfD/v+Wwgr/tDQm/Lp4hHgHT65M1jg9fC4ysSNwiZjP54Tt5k/ kOmB47QAsUqWEs3W/QZ8VDS9lzGXUHh0iImTdjJbyWOCa0L+UXZukMVNbp1iaDCv6xH5 1/fd7QBpilqW1Tx78ipq8nAZRhtybQhSFKkDYOIx/JdVDSAkwUmQTdgNpG8/XmszZ6OO hK/eiWIRcmq/U3Y1Qr9LhpddUcjwGIucW5CLyBlozwoEWpXHA3MsuWEIRYKxkgcgl+CF XzzXN2fI0rTCUUifpA0WIAX7Em1VC5T7MxoBx1tCZN1QWYhpdihX2qU5QoS2QvR/lAZV L2Iw== X-Gm-Message-State: AOAM533fzR/7yXKsdsv+C6/xuAIfygOQANoGCIuNJw7Mwy28nQQa8Y42 wv+tia1hb9Xcki+O3jBhNBUEa/uF7AB9/uOqiyo= X-Google-Smtp-Source: ABdhPJwLdAoVrfnuDHDuevSolHBmZu5plw9zwt9KPh0wtZT3FBVDe5eapKH2T6ID9dt0hQP3DBYLyas9XQhdZJ5fFFM= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:7933:7015:a5d5:3835]) (user=samitolvanen job=sendgmr) by 2002:a5b:5c7:: with SMTP id w7mr7418520ybp.164.1617226057459; Wed, 31 Mar 2021 14:27:37 -0700 (PDT) Date: Wed, 31 Mar 2021 14:27:11 -0700 In-Reply-To: <20210331212722.2746212-1-samitolvanen@google.com> Message-Id: <20210331212722.2746212-8-samitolvanen@google.com> Mime-Version: 1.0 References: <20210331212722.2746212-1-samitolvanen@google.com> X-Mailer: git-send-email 2.31.0.291.g576ba9dcdaf-goog Subject: [PATCH v4 07/17] kallsyms: strip ThinLTO hashes from static functions From: Sami Tolvanen To: Kees Cook Cc: Nathan Chancellor , Nick Desaulniers , Masahiro Yamada , Will Deacon , Jessica Yu , Arnd Bergmann , Tejun Heo , "Paul E. McKenney" , Christoph Hellwig , Peter Zijlstra , Sedat Dilek , bpf@vger.kernel.org, linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org With CONFIG_CFI_CLANG and ThinLTO, Clang appends a hash to the names of all static functions not marked __used. This can break userspace tools that don't expect the function name to change, so strip out the hash from the output. Suggested-by: Jack Pham Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- kernel/kallsyms.c | 55 ++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 50 insertions(+), 5 deletions(-) diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 8043a90aa50e..c851ca0ed357 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -161,6 +161,27 @@ static unsigned long kallsyms_sym_address(int idx) return kallsyms_relative_base - 1 - kallsyms_offsets[idx]; } +#if defined(CONFIG_CFI_CLANG) && defined(CONFIG_LTO_CLANG_THIN) +/* + * LLVM appends a hash to static function names when ThinLTO and CFI are + * both enabled, i.e. foo() becomes foo$707af9a22804d33c81801f27dcfe489b. + * This causes confusion and potentially breaks user space tools, so we + * strip the suffix from expanded symbol names. + */ +static inline bool cleanup_symbol_name(char *s) +{ + char *res; + + res = strrchr(s, '$'); + if (res) + *res = '\0'; + + return res != NULL; +} +#else +static inline bool cleanup_symbol_name(char *s) { return false; } +#endif + /* Lookup the address for this symbol. Returns 0 if not found. */ unsigned long kallsyms_lookup_name(const char *name) { @@ -173,6 +194,9 @@ unsigned long kallsyms_lookup_name(const char *name) if (strcmp(namebuf, name) == 0) return kallsyms_sym_address(i); + + if (cleanup_symbol_name(namebuf) && strcmp(namebuf, name) == 0) + return kallsyms_sym_address(i); } return module_kallsyms_lookup_name(name); } @@ -303,7 +327,9 @@ const char *kallsyms_lookup(unsigned long addr, namebuf, KSYM_NAME_LEN); if (modname) *modname = NULL; - return namebuf; + + ret = namebuf; + goto found; } /* See if it's in a module or a BPF JITed image. */ @@ -316,11 +342,16 @@ const char *kallsyms_lookup(unsigned long addr, if (!ret) ret = ftrace_mod_address_lookup(addr, symbolsize, offset, modname, namebuf); + +found: + cleanup_symbol_name(namebuf); return ret; } int lookup_symbol_name(unsigned long addr, char *symname) { + int res; + symname[0] = '\0'; symname[KSYM_NAME_LEN - 1] = '\0'; @@ -331,15 +362,23 @@ int lookup_symbol_name(unsigned long addr, char *symname) /* Grab name */ kallsyms_expand_symbol(get_symbol_offset(pos), symname, KSYM_NAME_LEN); - return 0; + goto found; } /* See if it's in a module. */ - return lookup_module_symbol_name(addr, symname); + res = lookup_module_symbol_name(addr, symname); + if (res) + return res; + +found: + cleanup_symbol_name(symname); + return 0; } int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name) { + int res; + name[0] = '\0'; name[KSYM_NAME_LEN - 1] = '\0'; @@ -351,10 +390,16 @@ int lookup_symbol_attrs(unsigned long addr, unsigned long *size, kallsyms_expand_symbol(get_symbol_offset(pos), name, KSYM_NAME_LEN); modname[0] = '\0'; - return 0; + goto found; } /* See if it's in a module. */ - return lookup_module_symbol_attrs(addr, size, offset, modname, name); + res = lookup_module_symbol_attrs(addr, size, offset, modname, name); + if (res) + return res; + +found: + cleanup_symbol_name(name); + return 0; } /* Look up a kernel symbol and return it in a text buffer. */ From patchwork Wed Mar 31 21:27:12 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 12176435 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E3BCBC433B4 for ; Wed, 31 Mar 2021 21:28:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CD25261077 for ; Wed, 31 Mar 2021 21:28:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232682AbhCaV2Q (ORCPT ); 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a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=VrfRHkoNzR+0/b/OZROtS1u75H9EO8EEUwf0vNpKXW4=; b=ZWTIDhCAxGaPq+pvzISUyMcEXVr8xMt1WRygCE9UvevqJPlbZFBlE8kybg7Cj6Yoq1 KQOJm+jMe6W7I+ekY/5DCcGWdGtZeOV1GXHZNIxaZJEvMUS/Kwb3FQeqGCzRYhGq/mA+ QMT7Zsy+ub+2VH8+FujATlIsJwH+v4rraiMeG0yVf+ZoOnca9oORU2gbqR1hjEnW3ZPX rTW8h/lwMRkIkpa5AEDSmCis8/7yzeI3AZSOcQ//1WRDLRj+kbhpSw3hlhpX3Ywe5v4/ /Tn3YaWsMowrb0u1eb7/hhW+5J1QBOAY65F/raewIgUCKxepfCg8PF6wyczzI0A7mD4u hiZQ== X-Gm-Message-State: AOAM5322jwoUIsCIZruPTQyZygSxMCrpT/4LJIM+2bJYwEt2BDH5wY1z 0b/iHOYtnlCM9+VRooToIb1b8gNMH5RioaBLCDA= X-Google-Smtp-Source: ABdhPJwxA0CtxdkWc6M/jwZJvtoqXk9nSdTKxmLyT5rwl9B6GB5FZIGHnM0kBXshVGaK6mnJ+f6IJx8IAQpBxGRL/Bk= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:7933:7015:a5d5:3835]) (user=samitolvanen job=sendgmr) by 2002:a25:bb49:: with SMTP id b9mr8136529ybk.350.1617226059304; Wed, 31 Mar 2021 14:27:39 -0700 (PDT) Date: Wed, 31 Mar 2021 14:27:12 -0700 In-Reply-To: <20210331212722.2746212-1-samitolvanen@google.com> Message-Id: <20210331212722.2746212-9-samitolvanen@google.com> Mime-Version: 1.0 References: <20210331212722.2746212-1-samitolvanen@google.com> X-Mailer: git-send-email 2.31.0.291.g576ba9dcdaf-goog Subject: [PATCH v4 08/17] bpf: disable CFI in dispatcher functions From: Sami Tolvanen To: Kees Cook Cc: Nathan Chancellor , Nick Desaulniers , Masahiro Yamada , Will Deacon , Jessica Yu , Arnd Bergmann , Tejun Heo , "Paul E. McKenney" , Christoph Hellwig , Peter Zijlstra , Sedat Dilek , bpf@vger.kernel.org, linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net BPF dispatcher functions are patched at runtime to perform direct instead of indirect calls. Disable CFI for the dispatcher functions to avoid conflicts. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- include/linux/bpf.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 3625f019767d..2f46f98479e1 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -650,7 +650,7 @@ struct bpf_dispatcher { struct bpf_ksym ksym; }; -static __always_inline unsigned int bpf_dispatcher_nop_func( +static __always_inline __nocfi unsigned int bpf_dispatcher_nop_func( const void *ctx, const struct bpf_insn *insnsi, unsigned int (*bpf_func)(const void *, @@ -678,7 +678,7 @@ void bpf_trampoline_put(struct bpf_trampoline *tr); } #define DEFINE_BPF_DISPATCHER(name) \ - noinline unsigned int bpf_dispatcher_##name##_func( \ + noinline __nocfi unsigned int bpf_dispatcher_##name##_func( \ const void *ctx, \ const struct bpf_insn *insnsi, \ unsigned int (*bpf_func)(const void *, \ From patchwork Wed Mar 31 21:27:13 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 12176443 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DD504C001B9 for ; Wed, 31 Mar 2021 21:28:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CA22661075 for ; Wed, 31 Mar 2021 21:28:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232786AbhCaV2R (ORCPT ); Wed, 31 Mar 2021 17:28:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51778 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232782AbhCaV1m (ORCPT ); Wed, 31 Mar 2021 17:27:42 -0400 Received: from mail-qk1-x749.google.com (mail-qk1-x749.google.com [IPv6:2607:f8b0:4864:20::749]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1C589C061762 for ; Wed, 31 Mar 2021 14:27:42 -0700 (PDT) Received: by mail-qk1-x749.google.com with SMTP id g18so2361021qki.15 for ; Wed, 31 Mar 2021 14:27:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=2279HN6zfl1Rfzm2qS23THJziTytoOMrM35pX63yR8c=; b=NETrkMv/qY3YnOmqaEUZEZaJO+BzieYp5l9dFABnBTIJd1SkpmUXwk1kMTdOa9ZUF2 BnC4GfN6ucOtxQqdSSxajFRoHmce7QMD5IA1koEB2EB1IKPDWUcDCKSadgSAt92Cwuye ZUQpXmQixB39Ee0kNCo8xiagscTgu+V6ASY8dir5lgN9oTTDDrPC9E7A4Fcdf9VFnY/6 5EKg3eqvqC6g5AJ6Mqh2sDyKH1FG7hV0c3vJe630xUlBGQ2o09fnGdni+9pCujn977qf z3E7jXtCHSmeaFzXJ1tToRGltSSEWuVO/4izf03xxwP4xAI7BStKtRMuui/1N2OxJaCJ bNBg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=2279HN6zfl1Rfzm2qS23THJziTytoOMrM35pX63yR8c=; b=OSjgI8V/slIBYcSZCGJ4mPPdeWKcRRsUk1HDDUo5eOVKz3VZyQJimMB71GxhTM+njL TA2zm/lVKb6lXWIsfKQzGpTkems2l93mizSTz+hNDkh/MXUPJ+f/tWquXzKbDLLuBXyE 24Jn7OkXwt6WRULZAr3zR7eQ8C3xeNGvKEmOzopRty6ItibrH1w6onkoYtuntfVMhbvk 0VfyhbAjjWwUIJIDRxUzNQjMknwlM+0zH5KOQt9eBsoEll0lyWgB+bQERsDptZSLLjob k2WrsFZlXyJmuEC2yY5od/BCczmjxnbs+I2PuS8muy/a0IQUJfhkQ4ot/zx6PlvUanAJ 5u4A== X-Gm-Message-State: AOAM533fowvuCkISRahT8Bp2B15xlOqZvBtWbdrtkWXXpEsf6KjNonxO +3iYc5z7SA3otSJZChFWCt5TuT/Cj4SPBNIORqE= X-Google-Smtp-Source: ABdhPJwIDN9evwiyPhBaJw8x+Q++kVngpgGwvV4OECPLBJsZ+VusLLrQixAz+r0xZJ17vw5/QexsUzioIlnWWiZUs2M= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:7933:7015:a5d5:3835]) (user=samitolvanen job=sendgmr) by 2002:a05:6214:80d:: with SMTP id df13mr5126439qvb.55.1617226061273; Wed, 31 Mar 2021 14:27:41 -0700 (PDT) Date: Wed, 31 Mar 2021 14:27:13 -0700 In-Reply-To: <20210331212722.2746212-1-samitolvanen@google.com> Message-Id: <20210331212722.2746212-10-samitolvanen@google.com> Mime-Version: 1.0 References: <20210331212722.2746212-1-samitolvanen@google.com> X-Mailer: git-send-email 2.31.0.291.g576ba9dcdaf-goog Subject: [PATCH v4 09/17] treewide: Change list_sort to use const pointers From: Sami Tolvanen To: Kees Cook Cc: Nathan Chancellor , Nick Desaulniers , Masahiro Yamada , Will Deacon , Jessica Yu , Arnd Bergmann , Tejun Heo , "Paul E. McKenney" , Christoph Hellwig , Peter Zijlstra , Sedat Dilek , bpf@vger.kernel.org, linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org list_sort() internally casts the comparison function passed to it to a different type with constant struct list_head pointers, and uses this pointer to call the functions, which trips indirect call Control-Flow Integrity (CFI) checking. Instead of removing the consts, this change defines the list_cmp_func_t type and changes the comparison function types of all list_sort() callers to use const pointers, thus avoiding type mismatches. Suggested-by: Nick Desaulniers Signed-off-by: Sami Tolvanen Reviewed-by: Nick Desaulniers Tested-by: Nick Desaulniers Reviewed-by: Christoph Hellwig Reviewed-by: Kees Cook --- arch/arm64/kvm/vgic/vgic-its.c | 8 ++++---- arch/arm64/kvm/vgic/vgic.c | 3 ++- block/blk-mq-sched.c | 3 ++- block/blk-mq.c | 3 ++- drivers/acpi/nfit/core.c | 3 ++- drivers/acpi/numa/hmat.c | 3 ++- drivers/clk/keystone/sci-clk.c | 4 ++-- drivers/gpu/drm/drm_modes.c | 3 ++- drivers/gpu/drm/i915/gt/intel_engine_user.c | 3 ++- drivers/gpu/drm/i915/gvt/debugfs.c | 2 +- drivers/gpu/drm/i915/selftests/i915_gem_gtt.c | 3 ++- drivers/gpu/drm/radeon/radeon_cs.c | 4 ++-- .../hw/usnic/usnic_uiom_interval_tree.c | 3 ++- drivers/interconnect/qcom/bcm-voter.c | 2 +- drivers/md/raid5.c | 3 ++- drivers/misc/sram.c | 4 ++-- drivers/nvme/host/core.c | 3 ++- .../pci/controller/cadence/pcie-cadence-host.c | 3 ++- drivers/spi/spi-loopback-test.c | 3 ++- fs/btrfs/raid56.c | 3 ++- fs/btrfs/tree-log.c | 3 ++- fs/btrfs/volumes.c | 3 ++- fs/ext4/fsmap.c | 4 ++-- fs/gfs2/glock.c | 3 ++- fs/gfs2/log.c | 2 +- fs/gfs2/lops.c | 3 ++- fs/iomap/buffered-io.c | 3 ++- fs/ubifs/gc.c | 7 ++++--- fs/ubifs/replay.c | 4 ++-- fs/xfs/scrub/bitmap.c | 4 ++-- fs/xfs/xfs_bmap_item.c | 4 ++-- fs/xfs/xfs_buf.c | 6 +++--- fs/xfs/xfs_extent_busy.c | 4 ++-- fs/xfs/xfs_extent_busy.h | 3 ++- fs/xfs/xfs_extfree_item.c | 4 ++-- fs/xfs/xfs_refcount_item.c | 4 ++-- fs/xfs/xfs_rmap_item.c | 4 ++-- include/linux/list_sort.h | 7 ++++--- lib/list_sort.c | 17 ++++++----------- lib/test_list_sort.c | 3 ++- net/tipc/name_table.c | 4 ++-- 41 files changed, 90 insertions(+), 72 deletions(-) diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c index 40cbaca81333..b9518f94bd43 100644 --- a/arch/arm64/kvm/vgic/vgic-its.c +++ b/arch/arm64/kvm/vgic/vgic-its.c @@ -2190,8 +2190,8 @@ static int vgic_its_restore_ite(struct vgic_its *its, u32 event_id, return offset; } -static int vgic_its_ite_cmp(void *priv, struct list_head *a, - struct list_head *b) +static int vgic_its_ite_cmp(void *priv, const struct list_head *a, + const struct list_head *b) { struct its_ite *itea = container_of(a, struct its_ite, ite_list); struct its_ite *iteb = container_of(b, struct its_ite, ite_list); @@ -2329,8 +2329,8 @@ static int vgic_its_restore_dte(struct vgic_its *its, u32 id, return offset; } -static int vgic_its_device_cmp(void *priv, struct list_head *a, - struct list_head *b) +static int vgic_its_device_cmp(void *priv, const struct list_head *a, + const struct list_head *b) { struct its_device *deva = container_of(a, struct its_device, dev_list); struct its_device *devb = container_of(b, struct its_device, dev_list); diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c index 1c597c9885fa..15b666200f0b 100644 --- a/arch/arm64/kvm/vgic/vgic.c +++ b/arch/arm64/kvm/vgic/vgic.c @@ -255,7 +255,8 @@ static struct kvm_vcpu *vgic_target_oracle(struct vgic_irq *irq) * Return negative if "a" sorts before "b", 0 to preserve order, and positive * to sort "b" before "a". */ -static int vgic_irq_cmp(void *priv, struct list_head *a, struct list_head *b) +static int vgic_irq_cmp(void *priv, const struct list_head *a, + const struct list_head *b) { struct vgic_irq *irqa = container_of(a, struct vgic_irq, ap_list); struct vgic_irq *irqb = container_of(b, struct vgic_irq, ap_list); diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index e1e997af89a0..3ebd6f10f728 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -75,7 +75,8 @@ void blk_mq_sched_restart(struct blk_mq_hw_ctx *hctx) blk_mq_run_hw_queue(hctx, true); } -static int sched_rq_cmp(void *priv, struct list_head *a, struct list_head *b) +static int sched_rq_cmp(void *priv, const struct list_head *a, + const struct list_head *b) { struct request *rqa = container_of(a, struct request, queuelist); struct request *rqb = container_of(b, struct request, queuelist); diff --git a/block/blk-mq.c b/block/blk-mq.c index d4d7c1caa439..4e3a70ab5be1 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1895,7 +1895,8 @@ void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, spin_unlock(&ctx->lock); } -static int plug_rq_cmp(void *priv, struct list_head *a, struct list_head *b) +static int plug_rq_cmp(void *priv, const struct list_head *a, + const struct list_head *b) { struct request *rqa = container_of(a, struct request, queuelist); struct request *rqb = container_of(b, struct request, queuelist); diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index 8c5dde628405..d15e3ee93b5b 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -1195,7 +1195,8 @@ static int __nfit_mem_init(struct acpi_nfit_desc *acpi_desc, return 0; } -static int nfit_mem_cmp(void *priv, struct list_head *_a, struct list_head *_b) +static int nfit_mem_cmp(void *priv, const struct list_head *_a, + const struct list_head *_b) { struct nfit_mem *a = container_of(_a, typeof(*a), list); struct nfit_mem *b = container_of(_b, typeof(*b), list); diff --git a/drivers/acpi/numa/hmat.c b/drivers/acpi/numa/hmat.c index cb73a5d6ea76..137a5dd880c2 100644 --- a/drivers/acpi/numa/hmat.c +++ b/drivers/acpi/numa/hmat.c @@ -558,7 +558,8 @@ static bool hmat_update_best(u8 type, u32 value, u32 *best) return updated; } -static int initiator_cmp(void *priv, struct list_head *a, struct list_head *b) +static int initiator_cmp(void *priv, const struct list_head *a, + const struct list_head *b) { struct memory_initiator *ia; struct memory_initiator *ib; diff --git a/drivers/clk/keystone/sci-clk.c b/drivers/clk/keystone/sci-clk.c index aaf31abe1c8f..7e1b136e71ae 100644 --- a/drivers/clk/keystone/sci-clk.c +++ b/drivers/clk/keystone/sci-clk.c @@ -503,8 +503,8 @@ static int ti_sci_scan_clocks_from_fw(struct sci_clk_provider *provider) #else -static int _cmp_sci_clk_list(void *priv, struct list_head *a, - struct list_head *b) +static int _cmp_sci_clk_list(void *priv, const struct list_head *a, + const struct list_head *b) { struct sci_clk *ca = container_of(a, struct sci_clk, node); struct sci_clk *cb = container_of(b, struct sci_clk, node); diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c index 1ac67d4505e0..6662d0457ad6 100644 --- a/drivers/gpu/drm/drm_modes.c +++ b/drivers/gpu/drm/drm_modes.c @@ -1290,7 +1290,8 @@ EXPORT_SYMBOL(drm_mode_prune_invalid); * Negative if @lh_a is better than @lh_b, zero if they're equivalent, or * positive if @lh_b is better than @lh_a. */ -static int drm_mode_compare(void *priv, struct list_head *lh_a, struct list_head *lh_b) +static int drm_mode_compare(void *priv, const struct list_head *lh_a, + const struct list_head *lh_b) { struct drm_display_mode *a = list_entry(lh_a, struct drm_display_mode, head); struct drm_display_mode *b = list_entry(lh_b, struct drm_display_mode, head); diff --git a/drivers/gpu/drm/i915/gt/intel_engine_user.c b/drivers/gpu/drm/i915/gt/intel_engine_user.c index 34e6096f196e..da21d2a10cc9 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_user.c +++ b/drivers/gpu/drm/i915/gt/intel_engine_user.c @@ -49,7 +49,8 @@ static const u8 uabi_classes[] = { [VIDEO_ENHANCEMENT_CLASS] = I915_ENGINE_CLASS_VIDEO_ENHANCE, }; -static int engine_cmp(void *priv, struct list_head *A, struct list_head *B) +static int engine_cmp(void *priv, const struct list_head *A, + const struct list_head *B) { const struct intel_engine_cs *a = container_of((struct rb_node *)A, typeof(*a), uabi_node); diff --git a/drivers/gpu/drm/i915/gvt/debugfs.c b/drivers/gpu/drm/i915/gvt/debugfs.c index 62e6a14ad58e..9f1c209d9251 100644 --- a/drivers/gpu/drm/i915/gvt/debugfs.c +++ b/drivers/gpu/drm/i915/gvt/debugfs.c @@ -41,7 +41,7 @@ struct diff_mmio { /* Compare two diff_mmio items. */ static int mmio_offset_compare(void *priv, - struct list_head *a, struct list_head *b) + const struct list_head *a, const struct list_head *b) { struct diff_mmio *ma; struct diff_mmio *mb; diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c index c1adea8765a9..52b9c39e0155 100644 --- a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c @@ -1076,7 +1076,8 @@ static int igt_ppgtt_shrink_boom(void *arg) return exercise_ppgtt(arg, shrink_boom); } -static int sort_holes(void *priv, struct list_head *A, struct list_head *B) +static int sort_holes(void *priv, const struct list_head *A, + const struct list_head *B) { struct drm_mm_node *a = list_entry(A, typeof(*a), hole_stack); struct drm_mm_node *b = list_entry(B, typeof(*b), hole_stack); diff --git a/drivers/gpu/drm/radeon/radeon_cs.c b/drivers/gpu/drm/radeon/radeon_cs.c index 35e937d39b51..1a5c3db1d53b 100644 --- a/drivers/gpu/drm/radeon/radeon_cs.c +++ b/drivers/gpu/drm/radeon/radeon_cs.c @@ -393,8 +393,8 @@ int radeon_cs_parser_init(struct radeon_cs_parser *p, void *data) return 0; } -static int cmp_size_smaller_first(void *priv, struct list_head *a, - struct list_head *b) +static int cmp_size_smaller_first(void *priv, const struct list_head *a, + const struct list_head *b) { struct radeon_bo_list *la = list_entry(a, struct radeon_bo_list, tv.head); struct radeon_bo_list *lb = list_entry(b, struct radeon_bo_list, tv.head); diff --git a/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.c b/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.c index d399523206c7..29d71267af78 100644 --- a/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.c +++ b/drivers/infiniband/hw/usnic/usnic_uiom_interval_tree.c @@ -83,7 +83,8 @@ usnic_uiom_interval_node_alloc(long int start, long int last, int ref_cnt, return interval; } -static int interval_cmp(void *priv, struct list_head *a, struct list_head *b) +static int interval_cmp(void *priv, const struct list_head *a, + const struct list_head *b) { struct usnic_uiom_interval_node *node_a, *node_b; diff --git a/drivers/interconnect/qcom/bcm-voter.c b/drivers/interconnect/qcom/bcm-voter.c index 1cc565bce2f4..d1591a28b743 100644 --- a/drivers/interconnect/qcom/bcm-voter.c +++ b/drivers/interconnect/qcom/bcm-voter.c @@ -39,7 +39,7 @@ struct bcm_voter { u32 tcs_wait; }; -static int cmp_vcd(void *priv, struct list_head *a, struct list_head *b) +static int cmp_vcd(void *priv, const struct list_head *a, const struct list_head *b) { const struct qcom_icc_bcm *bcm_a = list_entry(a, struct qcom_icc_bcm, list); const struct qcom_icc_bcm *bcm_b = list_entry(b, struct qcom_icc_bcm, list); diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 5d57a5bd171f..841e1c1aa5e6 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -953,7 +953,8 @@ static void dispatch_bio_list(struct bio_list *tmp) submit_bio_noacct(bio); } -static int cmp_stripe(void *priv, struct list_head *a, struct list_head *b) +static int cmp_stripe(void *priv, const struct list_head *a, + const struct list_head *b) { const struct r5pending_data *da = list_entry(a, struct r5pending_data, sibling); diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c index 6c1a23cb3e8c..202bf951e909 100644 --- a/drivers/misc/sram.c +++ b/drivers/misc/sram.c @@ -144,8 +144,8 @@ static void sram_free_partitions(struct sram_dev *sram) } } -static int sram_reserve_cmp(void *priv, struct list_head *a, - struct list_head *b) +static int sram_reserve_cmp(void *priv, const struct list_head *a, + const struct list_head *b) { struct sram_reserve *ra = list_entry(a, struct sram_reserve, list); struct sram_reserve *rb = list_entry(b, struct sram_reserve, list); diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 0896e21642be..5eaaa51a5e30 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -3855,7 +3855,8 @@ static int nvme_init_ns_head(struct nvme_ns *ns, unsigned nsid, return ret; } -static int ns_cmp(void *priv, struct list_head *a, struct list_head *b) +static int ns_cmp(void *priv, const struct list_head *a, + const struct list_head *b) { struct nvme_ns *nsa = container_of(a, struct nvme_ns, list); struct nvme_ns *nsb = container_of(b, struct nvme_ns, list); diff --git a/drivers/pci/controller/cadence/pcie-cadence-host.c b/drivers/pci/controller/cadence/pcie-cadence-host.c index 73dcf8cf98fb..ae1c55503513 100644 --- a/drivers/pci/controller/cadence/pcie-cadence-host.c +++ b/drivers/pci/controller/cadence/pcie-cadence-host.c @@ -345,7 +345,8 @@ static int cdns_pcie_host_bar_config(struct cdns_pcie_rc *rc, return 0; } -static int cdns_pcie_host_dma_ranges_cmp(void *priv, struct list_head *a, struct list_head *b) +static int cdns_pcie_host_dma_ranges_cmp(void *priv, const struct list_head *a, + const struct list_head *b) { struct resource_entry *entry1, *entry2; diff --git a/drivers/spi/spi-loopback-test.c b/drivers/spi/spi-loopback-test.c index df981e55c24c..f1cf2232f0b5 100644 --- a/drivers/spi/spi-loopback-test.c +++ b/drivers/spi/spi-loopback-test.c @@ -454,7 +454,8 @@ struct rx_ranges { u8 *end; }; -static int rx_ranges_cmp(void *priv, struct list_head *a, struct list_head *b) +static int rx_ranges_cmp(void *priv, const struct list_head *a, + const struct list_head *b) { struct rx_ranges *rx_a = list_entry(a, struct rx_ranges, list); struct rx_ranges *rx_b = list_entry(b, struct rx_ranges, list); diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c index 8c31357f08ed..f4139de63b2e 100644 --- a/fs/btrfs/raid56.c +++ b/fs/btrfs/raid56.c @@ -1634,7 +1634,8 @@ struct btrfs_plug_cb { /* * rbios on the plug list are sorted for easier merging. */ -static int plug_cmp(void *priv, struct list_head *a, struct list_head *b) +static int plug_cmp(void *priv, const struct list_head *a, + const struct list_head *b) { struct btrfs_raid_bio *ra = container_of(a, struct btrfs_raid_bio, plug_list); diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c index 92a368627791..00a88bd8105e 100644 --- a/fs/btrfs/tree-log.c +++ b/fs/btrfs/tree-log.c @@ -4136,7 +4136,8 @@ static noinline int copy_items(struct btrfs_trans_handle *trans, return ret; } -static int extent_cmp(void *priv, struct list_head *a, struct list_head *b) +static int extent_cmp(void *priv, const struct list_head *a, + const struct list_head *b) { struct extent_map *em1, *em2; diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 1c6810bbaf8b..912dd8b9f156 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1224,7 +1224,8 @@ static int open_fs_devices(struct btrfs_fs_devices *fs_devices, return 0; } -static int devid_cmp(void *priv, struct list_head *a, struct list_head *b) +static int devid_cmp(void *priv, const struct list_head *a, + const struct list_head *b) { struct btrfs_device *dev1, *dev2; diff --git a/fs/ext4/fsmap.c b/fs/ext4/fsmap.c index 4c2a9fe30067..4493ef0c715e 100644 --- a/fs/ext4/fsmap.c +++ b/fs/ext4/fsmap.c @@ -354,8 +354,8 @@ static unsigned int ext4_getfsmap_find_sb(struct super_block *sb, /* Compare two fsmap items. */ static int ext4_getfsmap_compare(void *priv, - struct list_head *a, - struct list_head *b) + const struct list_head *a, + const struct list_head *b) { struct ext4_fsmap *fa; struct ext4_fsmap *fb; diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c index 9567520d79f7..c06a6cdf05de 100644 --- a/fs/gfs2/glock.c +++ b/fs/gfs2/glock.c @@ -1732,7 +1732,8 @@ void gfs2_glock_complete(struct gfs2_glock *gl, int ret) spin_unlock(&gl->gl_lockref.lock); } -static int glock_cmp(void *priv, struct list_head *a, struct list_head *b) +static int glock_cmp(void *priv, const struct list_head *a, + const struct list_head *b) { struct gfs2_glock *gla, *glb; diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c index 6410281546f9..88649b43fcff 100644 --- a/fs/gfs2/log.c +++ b/fs/gfs2/log.c @@ -695,7 +695,7 @@ void log_flush_wait(struct gfs2_sbd *sdp) } } -static int ip_cmp(void *priv, struct list_head *a, struct list_head *b) +static int ip_cmp(void *priv, const struct list_head *a, const struct list_head *b) { struct gfs2_inode *ipa, *ipb; diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c index a82f4747aa8d..b4809967efc6 100644 --- a/fs/gfs2/lops.c +++ b/fs/gfs2/lops.c @@ -634,7 +634,8 @@ static void gfs2_check_magic(struct buffer_head *bh) kunmap_atomic(kaddr); } -static int blocknr_cmp(void *priv, struct list_head *a, struct list_head *b) +static int blocknr_cmp(void *priv, const struct list_head *a, + const struct list_head *b) { struct gfs2_bufdata *bda, *bdb; diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 414769a6ad11..0129e6bab985 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -1155,7 +1155,8 @@ iomap_ioend_try_merge(struct iomap_ioend *ioend, struct list_head *more_ioends, EXPORT_SYMBOL_GPL(iomap_ioend_try_merge); static int -iomap_ioend_compare(void *priv, struct list_head *a, struct list_head *b) +iomap_ioend_compare(void *priv, const struct list_head *a, + const struct list_head *b) { struct iomap_ioend *ia = container_of(a, struct iomap_ioend, io_list); struct iomap_ioend *ib = container_of(b, struct iomap_ioend, io_list); diff --git a/fs/ubifs/gc.c b/fs/ubifs/gc.c index a4aaeea63893..dc3e26e9ed7b 100644 --- a/fs/ubifs/gc.c +++ b/fs/ubifs/gc.c @@ -102,7 +102,8 @@ static int switch_gc_head(struct ubifs_info *c) * This function compares data nodes @a and @b. Returns %1 if @a has greater * inode or block number, and %-1 otherwise. */ -static int data_nodes_cmp(void *priv, struct list_head *a, struct list_head *b) +static int data_nodes_cmp(void *priv, const struct list_head *a, + const struct list_head *b) { ino_t inuma, inumb; struct ubifs_info *c = priv; @@ -145,8 +146,8 @@ static int data_nodes_cmp(void *priv, struct list_head *a, struct list_head *b) * first and sorted by length in descending order. Directory entry nodes go * after inode nodes and are sorted in ascending hash valuer order. */ -static int nondata_nodes_cmp(void *priv, struct list_head *a, - struct list_head *b) +static int nondata_nodes_cmp(void *priv, const struct list_head *a, + const struct list_head *b) { ino_t inuma, inumb; struct ubifs_info *c = priv; diff --git a/fs/ubifs/replay.c b/fs/ubifs/replay.c index 0f8a6a16421b..4d17e5382b74 100644 --- a/fs/ubifs/replay.c +++ b/fs/ubifs/replay.c @@ -298,8 +298,8 @@ static int apply_replay_entry(struct ubifs_info *c, struct replay_entry *r) * entries @a and @b by comparing their sequence numer. Returns %1 if @a has * greater sequence number and %-1 otherwise. */ -static int replay_entries_cmp(void *priv, struct list_head *a, - struct list_head *b) +static int replay_entries_cmp(void *priv, const struct list_head *a, + const struct list_head *b) { struct ubifs_info *c = priv; struct replay_entry *ra, *rb; diff --git a/fs/xfs/scrub/bitmap.c b/fs/xfs/scrub/bitmap.c index f88694f22d05..813b5f219113 100644 --- a/fs/xfs/scrub/bitmap.c +++ b/fs/xfs/scrub/bitmap.c @@ -63,8 +63,8 @@ xbitmap_init( static int xbitmap_range_cmp( void *priv, - struct list_head *a, - struct list_head *b) + const struct list_head *a, + const struct list_head *b) { struct xbitmap_range *ap; struct xbitmap_range *bp; diff --git a/fs/xfs/xfs_bmap_item.c b/fs/xfs/xfs_bmap_item.c index 2344757ede63..e3a691937e92 100644 --- a/fs/xfs/xfs_bmap_item.c +++ b/fs/xfs/xfs_bmap_item.c @@ -265,8 +265,8 @@ xfs_trans_log_finish_bmap_update( static int xfs_bmap_update_diff_items( void *priv, - struct list_head *a, - struct list_head *b) + const struct list_head *a, + const struct list_head *b) { struct xfs_bmap_intent *ba; struct xfs_bmap_intent *bb; diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index 37a1d12762d8..592800c8852f 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -2124,9 +2124,9 @@ xfs_buf_delwri_queue( */ static int xfs_buf_cmp( - void *priv, - struct list_head *a, - struct list_head *b) + void *priv, + const struct list_head *a, + const struct list_head *b) { struct xfs_buf *ap = container_of(a, struct xfs_buf, b_list); struct xfs_buf *bp = container_of(b, struct xfs_buf, b_list); diff --git a/fs/xfs/xfs_extent_busy.c b/fs/xfs/xfs_extent_busy.c index ef17c1f6db32..a4075685d9eb 100644 --- a/fs/xfs/xfs_extent_busy.c +++ b/fs/xfs/xfs_extent_busy.c @@ -629,8 +629,8 @@ xfs_extent_busy_wait_all( int xfs_extent_busy_ag_cmp( void *priv, - struct list_head *l1, - struct list_head *l2) + const struct list_head *l1, + const struct list_head *l2) { struct xfs_extent_busy *b1 = container_of(l1, struct xfs_extent_busy, list); diff --git a/fs/xfs/xfs_extent_busy.h b/fs/xfs/xfs_extent_busy.h index 990ab3891971..8aea07100092 100644 --- a/fs/xfs/xfs_extent_busy.h +++ b/fs/xfs/xfs_extent_busy.h @@ -58,7 +58,8 @@ void xfs_extent_busy_wait_all(struct xfs_mount *mp); int -xfs_extent_busy_ag_cmp(void *priv, struct list_head *a, struct list_head *b); +xfs_extent_busy_ag_cmp(void *priv, const struct list_head *a, + const struct list_head *b); static inline void xfs_extent_busy_sort(struct list_head *list) { diff --git a/fs/xfs/xfs_extfree_item.c b/fs/xfs/xfs_extfree_item.c index 93223ebb3372..2424230ca2c3 100644 --- a/fs/xfs/xfs_extfree_item.c +++ b/fs/xfs/xfs_extfree_item.c @@ -397,8 +397,8 @@ xfs_trans_free_extent( static int xfs_extent_free_diff_items( void *priv, - struct list_head *a, - struct list_head *b) + const struct list_head *a, + const struct list_head *b) { struct xfs_mount *mp = priv; struct xfs_extent_free_item *ra; diff --git a/fs/xfs/xfs_refcount_item.c b/fs/xfs/xfs_refcount_item.c index 07ebccbbf4df..746f4eda724c 100644 --- a/fs/xfs/xfs_refcount_item.c +++ b/fs/xfs/xfs_refcount_item.c @@ -269,8 +269,8 @@ xfs_trans_log_finish_refcount_update( static int xfs_refcount_update_diff_items( void *priv, - struct list_head *a, - struct list_head *b) + const struct list_head *a, + const struct list_head *b) { struct xfs_mount *mp = priv; struct xfs_refcount_intent *ra; diff --git a/fs/xfs/xfs_rmap_item.c b/fs/xfs/xfs_rmap_item.c index 49cebd68b672..dc4f0c9f0897 100644 --- a/fs/xfs/xfs_rmap_item.c +++ b/fs/xfs/xfs_rmap_item.c @@ -337,8 +337,8 @@ xfs_trans_log_finish_rmap_update( static int xfs_rmap_update_diff_items( void *priv, - struct list_head *a, - struct list_head *b) + const struct list_head *a, + const struct list_head *b) { struct xfs_mount *mp = priv; struct xfs_rmap_intent *ra; diff --git a/include/linux/list_sort.h b/include/linux/list_sort.h index 20f178c24e9d..453105f74e05 100644 --- a/include/linux/list_sort.h +++ b/include/linux/list_sort.h @@ -6,8 +6,9 @@ struct list_head; +typedef int __attribute__((nonnull(2,3))) (*list_cmp_func_t)(void *, + const struct list_head *, const struct list_head *); + __attribute__((nonnull(2,3))) -void list_sort(void *priv, struct list_head *head, - int (*cmp)(void *priv, struct list_head *a, - struct list_head *b)); +void list_sort(void *priv, struct list_head *head, list_cmp_func_t cmp); #endif diff --git a/lib/list_sort.c b/lib/list_sort.c index 52f0c258c895..a926d96ffd44 100644 --- a/lib/list_sort.c +++ b/lib/list_sort.c @@ -7,16 +7,13 @@ #include #include -typedef int __attribute__((nonnull(2,3))) (*cmp_func)(void *, - struct list_head const *, struct list_head const *); - /* * Returns a list organized in an intermediate format suited * to chaining of merge() calls: null-terminated, no reserved or * sentinel head node, "prev" links not maintained. */ __attribute__((nonnull(2,3,4))) -static struct list_head *merge(void *priv, cmp_func cmp, +static struct list_head *merge(void *priv, list_cmp_func_t cmp, struct list_head *a, struct list_head *b) { struct list_head *head, **tail = &head; @@ -52,7 +49,7 @@ static struct list_head *merge(void *priv, cmp_func cmp, * throughout. */ __attribute__((nonnull(2,3,4,5))) -static void merge_final(void *priv, cmp_func cmp, struct list_head *head, +static void merge_final(void *priv, list_cmp_func_t cmp, struct list_head *head, struct list_head *a, struct list_head *b) { struct list_head *tail = head; @@ -185,9 +182,7 @@ static void merge_final(void *priv, cmp_func cmp, struct list_head *head, * 2^(k+1) - 1 (second merge of case 5 when x == 2^(k-1) - 1). */ __attribute__((nonnull(2,3))) -void list_sort(void *priv, struct list_head *head, - int (*cmp)(void *priv, struct list_head *a, - struct list_head *b)) +void list_sort(void *priv, struct list_head *head, list_cmp_func_t cmp) { struct list_head *list = head->next, *pending = NULL; size_t count = 0; /* Count of pending */ @@ -227,7 +222,7 @@ void list_sort(void *priv, struct list_head *head, if (likely(bits)) { struct list_head *a = *tail, *b = a->prev; - a = merge(priv, (cmp_func)cmp, b, a); + a = merge(priv, cmp, b, a); /* Install the merged result in place of the inputs */ a->prev = b->prev; *tail = a; @@ -249,10 +244,10 @@ void list_sort(void *priv, struct list_head *head, if (!next) break; - list = merge(priv, (cmp_func)cmp, pending, list); + list = merge(priv, cmp, pending, list); pending = next; } /* The final merge, rebuilding prev links */ - merge_final(priv, (cmp_func)cmp, head, pending, list); + merge_final(priv, cmp, head, pending, list); } EXPORT_SYMBOL(list_sort); diff --git a/lib/test_list_sort.c b/lib/test_list_sort.c index 1f017d3b610e..00daaf23316f 100644 --- a/lib/test_list_sort.c +++ b/lib/test_list_sort.c @@ -56,7 +56,8 @@ static int __init check(struct debug_el *ela, struct debug_el *elb) return 0; } -static int __init cmp(void *priv, struct list_head *a, struct list_head *b) +static int __init cmp(void *priv, const struct list_head *a, + const struct list_head *b) { struct debug_el *ela, *elb; diff --git a/net/tipc/name_table.c b/net/tipc/name_table.c index ee5ac40ea2b6..f8141443f2e2 100644 --- a/net/tipc/name_table.c +++ b/net/tipc/name_table.c @@ -397,8 +397,8 @@ static struct publication *tipc_service_remove_publ(struct service_range *sr, * Code reused: time_after32() for the same purpose */ #define publication_after(pa, pb) time_after32((pa)->id, (pb)->id) -static int tipc_publ_sort(void *priv, struct list_head *a, - struct list_head *b) +static int tipc_publ_sort(void *priv, const struct list_head *a, + const struct list_head *b) { struct publication *pa, *pb; 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a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=LhQny/aeJmeAJ3bCETNM8gy3/qff2yzp1+GBUrzrBDs=; b=Gaz3np9DIfMyC97vKYVyUOx7ArQhNqKLL3SX7uqAqrlgLhLE+t3+T71DTz/0Dmu9d9 8qvjxHbI3u5wVdu/3wZxcrU8p+/xDWMAMxT4XJ1lf6sDrNsH4z4vRIt7OvuEOYGBHBP6 1FqbGY6ijg+dDEUkx3Fndmtw3qmbfnZReuhS1JxDtSnF/U9pOp39/4U3W6J+vpV6jyo4 OXrCUz9cdc6P/ML625kcnIWpgNP5JHMkHOyQoSZsMUQm/Y9PbIlS60/el+AFado4soeO 7Ajx9t3GzUI+BUau6sFtUyKoip/LvlBq1D1sLcILJLpLMRBf9ZWQ7O8WdenlbA7FeDWy khlA== X-Gm-Message-State: AOAM531aGed4Y+eRh7wiliCh/DwcIc12rE95gyVXyyWp4+BD6w2JQM8W arO1N5D7lmrt07FBvD+lCGQMBj4RjUt2DbtDQYE= X-Google-Smtp-Source: ABdhPJwLju6B+haVkuwTRD6OTE7Kj+Fskb9zJBbkaGFlIanyE03asSCx14sDc0Ys7LCvhLw3MkN686iAQEZQHDgH42E= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:7933:7015:a5d5:3835]) (user=samitolvanen job=sendgmr) by 2002:a25:38c6:: with SMTP id f189mr7492638yba.183.1617226063121; Wed, 31 Mar 2021 14:27:43 -0700 (PDT) Date: Wed, 31 Mar 2021 14:27:14 -0700 In-Reply-To: <20210331212722.2746212-1-samitolvanen@google.com> Message-Id: <20210331212722.2746212-11-samitolvanen@google.com> Mime-Version: 1.0 References: <20210331212722.2746212-1-samitolvanen@google.com> X-Mailer: git-send-email 2.31.0.291.g576ba9dcdaf-goog Subject: [PATCH v4 10/17] lkdtm: use function_nocfi From: Sami Tolvanen To: Kees Cook Cc: Nathan Chancellor , Nick Desaulniers , Masahiro Yamada , Will Deacon , Jessica Yu , Arnd Bergmann , Tejun Heo , "Paul E. McKenney" , Christoph Hellwig , Peter Zijlstra , Sedat Dilek , bpf@vger.kernel.org, linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org To ensure we take the actual address of a function in kernel text, use function_nocfi. Otherwise, with CONFIG_CFI_CLANG, the compiler replaces the address with a pointer to the CFI jump table, which is actually in the module when compiled with CONFIG_LKDTM=m. Signed-off-by: Sami Tolvanen Acked-by: Kees Cook --- drivers/misc/lkdtm/usercopy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/misc/lkdtm/usercopy.c b/drivers/misc/lkdtm/usercopy.c index 109e8d4302c1..15d220ef35a5 100644 --- a/drivers/misc/lkdtm/usercopy.c +++ b/drivers/misc/lkdtm/usercopy.c @@ -314,7 +314,7 @@ void lkdtm_USERCOPY_KERNEL(void) pr_info("attempting bad copy_to_user from kernel text: %px\n", vm_mmap); - if (copy_to_user((void __user *)user_addr, vm_mmap, + if (copy_to_user((void __user *)user_addr, function_nocfi(vm_mmap), unconst + PAGE_SIZE)) { pr_warn("copy_to_user failed, but lacked Oops\n"); goto free_user; From patchwork Wed Mar 31 21:27:15 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 12176439 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AF2B6C43460 for ; Wed, 31 Mar 2021 21:28:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 95B4A61077 for ; Wed, 31 Mar 2021 21:28:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232825AbhCaV2T (ORCPT ); Wed, 31 Mar 2021 17:28:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51844 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232816AbhCaV1q (ORCPT ); Wed, 31 Mar 2021 17:27:46 -0400 Received: from mail-qt1-x84a.google.com (mail-qt1-x84a.google.com [IPv6:2607:f8b0:4864:20::84a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EC6C5C06174A for ; Wed, 31 Mar 2021 14:27:45 -0700 (PDT) Received: by mail-qt1-x84a.google.com with SMTP id b18so1923803qte.21 for ; Wed, 31 Mar 2021 14:27:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=u3sb7mCURY4VtmyE6zoVQ18sx7nW16pIZYxJrlMzk+o=; b=eMFe9houa2XuN05SOLsaOm1Hewi7pJ9LNis+2l70Pybgv0BDjfh3Tdjx0LeKuDts/8 5TrWVPttIn2hlb4FWOkPJvsI+3pl4WmXqShOicHoGuBx+x06lTjU0PYmzEkX1eUIZZYm 2UbSefvKGG4w1T/hAXOi65BNTP7V932xjjIwsFszWbETMcndQAgg2J1lQsmkLEDmJ1uu 1cOK+xgl4cg4yXyncFGUWYT9T4R4JW24KVZEyJFf3MUxdM4Swj6k/74eJaTzZZDQWuQc XORxfZubOGWv8Du+0NlGMiued0fd4ATF8owIEc3jR7W1F5csKMraVh8dIC3NwYQXtmwR qYrQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=u3sb7mCURY4VtmyE6zoVQ18sx7nW16pIZYxJrlMzk+o=; b=EjPLxRadX/7zgGeRzzCd0Udql9WcpJwymFnpDmIw20iD8sIVg/7n0u8rWlWzDSYuQN gIDxBecJGOvCs7UZZSq3PyZdlU+qi+h51l2SFWzFoWstuFrrMO1hwh6WxKD0SciOSoBx lg4G0oSMCIpsgE6yirddczaDrGG/0/xSOZMXQX41dqzTNc5QbCIkOtwKWJMvD0x3KtN9 Yf/C758MzNfThBq8jcOZPsy7Gh4c5Q5THG6A5jhg56H/Yv+17vEQq82xqN/c8+F9qV6A rocsNnWBO9L2P9TetF1wnOcIYdvPJDaYEXI1eLHQjoDl0mHVfONK3fZwtoW/zg1gJSPi uMmQ== X-Gm-Message-State: AOAM533ZdG3RNzsQfVUwYsVdXi71oV8bYBwmiDeSqJMEq+Vb+dz3DLb9 UMHMek/0FslSrxIEgMVUMETaHEcrpLC7PUqSd0M= X-Google-Smtp-Source: ABdhPJzrA9aIb2BbE0lWagI3+XE0XKAg7qn3gSUlNS0HnH2/8JbM1k1enyP7wLr7bRTJVSNLjEIoy9fiEcRhnF0cjM8= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:7933:7015:a5d5:3835]) (user=samitolvanen job=sendgmr) by 2002:a05:6214:945:: with SMTP id dn5mr4904341qvb.3.1617226065111; Wed, 31 Mar 2021 14:27:45 -0700 (PDT) Date: Wed, 31 Mar 2021 14:27:15 -0700 In-Reply-To: <20210331212722.2746212-1-samitolvanen@google.com> Message-Id: <20210331212722.2746212-12-samitolvanen@google.com> Mime-Version: 1.0 References: <20210331212722.2746212-1-samitolvanen@google.com> X-Mailer: git-send-email 2.31.0.291.g576ba9dcdaf-goog Subject: [PATCH v4 11/17] psci: use function_nocfi for cpu_resume From: Sami Tolvanen To: Kees Cook Cc: Nathan Chancellor , Nick Desaulniers , Masahiro Yamada , Will Deacon , Jessica Yu , Arnd Bergmann , Tejun Heo , "Paul E. McKenney" , Christoph Hellwig , Peter Zijlstra , Sedat Dilek , bpf@vger.kernel.org, linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org With CONFIG_CFI_CLANG, the compiler replaces function pointers with jump table addresses, which results in __pa_symbol returning the physical address of the jump table entry. As the jump table contains an immediate jump to an EL1 virtual address, this typically won't work as intended. Use function_nocfi to get the actual address of cpu_resume. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- drivers/firmware/psci/psci.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c index f5fc429cae3f..64344e84bd63 100644 --- a/drivers/firmware/psci/psci.c +++ b/drivers/firmware/psci/psci.c @@ -325,8 +325,9 @@ static int __init psci_features(u32 psci_func_id) static int psci_suspend_finisher(unsigned long state) { u32 power_state = state; + phys_addr_t pa_cpu_resume = __pa_symbol(function_nocfi(cpu_resume)); - return psci_ops.cpu_suspend(power_state, __pa_symbol(cpu_resume)); + return psci_ops.cpu_suspend(power_state, pa_cpu_resume); } int psci_cpu_suspend_enter(u32 state) @@ -344,8 +345,10 @@ int psci_cpu_suspend_enter(u32 state) static int psci_system_suspend(unsigned long unused) { + phys_addr_t pa_cpu_resume = __pa_symbol(function_nocfi(cpu_resume)); + return invoke_psci_fn(PSCI_FN_NATIVE(1_0, SYSTEM_SUSPEND), - __pa_symbol(cpu_resume), 0, 0); + pa_cpu_resume, 0, 0); } static int psci_system_suspend_enter(suspend_state_t state) From patchwork Wed Mar 31 21:27:16 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 12176447 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B23C3C001E4 for ; Wed, 31 Mar 2021 21:28:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8A8996108C for ; Wed, 31 Mar 2021 21:28:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232847AbhCaV2U (ORCPT ); Wed, 31 Mar 2021 17:28:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51860 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232835AbhCaV1s (ORCPT ); Wed, 31 Mar 2021 17:27:48 -0400 Received: from mail-qt1-x849.google.com (mail-qt1-x849.google.com [IPv6:2607:f8b0:4864:20::849]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 485CDC061574 for ; Wed, 31 Mar 2021 14:27:48 -0700 (PDT) Received: by mail-qt1-x849.google.com with SMTP id l13so1941717qtu.6 for ; Wed, 31 Mar 2021 14:27:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=RWJ9aQhTl20nw/R5RXPJl7NDj1C/UnL5LrldsenTslw=; b=OI2BXN7KaQv0FSebUTwCneDYkgM3EAclc0LW8tfWF13e9tAHbT6S7IOhSWAvQZLEnM JINs3HBpLvp6Qvodp3XPXwpa2AY4B6TKaD777pUzRWtoTAYeD1ocUHZu2HycU4zx1Kmv TNPKwT23uSIbpB+4L8uGbr3k4clT4tWUBKmb6FlOF1Rr6P3NPk9yRjsBi/8/WqNqXQ91 l8FNow8wvarKsgb5E8LUZNePMtfEnTyG4gLYP5Kv+xRbrPTbyVM2AH1BrU969hKl7202 it/AECGlU/1SsjxKqzkPukkeE7jMpt1aJJc+o2/Ob3guLAV3RI2sN0Iy2pgsPxnRnjo4 2KMg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=RWJ9aQhTl20nw/R5RXPJl7NDj1C/UnL5LrldsenTslw=; b=fWWdhGJYOpZESy3PeS1fCPLA5Tw+dc0FPprlBYYiT931Dv08e0qHuuXgPFMrx6k6KX vPEqFTEufWaVLtqL85n8G0At5O2uzwkOBRtJYumVYvjdEjP2XSYGoDx853nf/4GmakTI 876sEgySE2AS9m0nCAERaflDoPkEE72nSuoDUpw4jIunVXJOj9x4oNXP6lvYIFsuTbv8 2acceJ8P20rNt6L2i89mpSr/3+h3HHzh6rR4LQqX4eQuW6I4d8mxxrKNprzB8fHaTNUc lydIIcWzuFyWOtcHUCfPOYvtC/OGHeiRPtTQFDIJADs0ZL2jhhmSvIjAjqpqNIsRfQPj WTHw== X-Gm-Message-State: AOAM531HB7IquUfEQOOxQSI8eriijBGvLyEi6EF8WTtpF5SpS5kNxj2m cOevVCmmVUYOo9K2+3yhfwRj205kzLlIrH84luo= X-Google-Smtp-Source: ABdhPJwgeYfpiU4TaL+sNYk8JQhgUoPaRCwg5+9HCoLujfPlRhTT1jZ0jK2Sqbbps882JdAhQwjOAlmdak1l08CL8Lw= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:7933:7015:a5d5:3835]) (user=samitolvanen job=sendgmr) by 2002:a0c:b410:: with SMTP id u16mr5255799qve.8.1617226067444; Wed, 31 Mar 2021 14:27:47 -0700 (PDT) Date: Wed, 31 Mar 2021 14:27:16 -0700 In-Reply-To: <20210331212722.2746212-1-samitolvanen@google.com> Message-Id: <20210331212722.2746212-13-samitolvanen@google.com> Mime-Version: 1.0 References: <20210331212722.2746212-1-samitolvanen@google.com> X-Mailer: git-send-email 2.31.0.291.g576ba9dcdaf-goog Subject: [PATCH v4 12/17] arm64: implement function_nocfi From: Sami Tolvanen To: Kees Cook Cc: Nathan Chancellor , Nick Desaulniers , Masahiro Yamada , Will Deacon , Jessica Yu , Arnd Bergmann , Tejun Heo , "Paul E. McKenney" , Christoph Hellwig , Peter Zijlstra , Sedat Dilek , bpf@vger.kernel.org, linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org With CONFIG_CFI_CLANG, the compiler replaces function addresses in instrumented C code with jump table addresses. This change implements the function_nocfi() macro, which returns the actual function address instead. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- arch/arm64/include/asm/memory.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 0aabc3be9a75..b55410afd3d1 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -321,6 +321,21 @@ static inline void *phys_to_virt(phys_addr_t x) #define virt_to_pfn(x) __phys_to_pfn(__virt_to_phys((unsigned long)(x))) #define sym_to_pfn(x) __phys_to_pfn(__pa_symbol(x)) +#ifdef CONFIG_CFI_CLANG +/* + * With CONFIG_CFI_CLANG, the compiler replaces function address + * references with the address of the function's CFI jump table + * entry. The function_nocfi macro always returns the address of the + * actual function instead. + */ +#define function_nocfi(x) ({ \ + void *addr; \ + asm("adrp %0, " __stringify(x) "\n\t" \ + "add %0, %0, :lo12:" __stringify(x) : "=r" (addr)); \ + addr; \ +}) +#endif + /* * virt_to_page(x) convert a _valid_ virtual address to struct page * * virt_addr_valid(x) indicates whether a virtual address is valid From patchwork Wed Mar 31 21:27:17 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 12176445 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2D54AC43461 for ; Wed, 31 Mar 2021 21:28:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0CB226108E for ; Wed, 31 Mar 2021 21:28:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232882AbhCaV2V (ORCPT ); Wed, 31 Mar 2021 17:28:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51884 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232866AbhCaV1u (ORCPT ); Wed, 31 Mar 2021 17:27:50 -0400 Received: from mail-qv1-xf4a.google.com (mail-qv1-xf4a.google.com [IPv6:2607:f8b0:4864:20::f4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 75733C061760 for ; Wed, 31 Mar 2021 14:27:50 -0700 (PDT) Received: by mail-qv1-xf4a.google.com with SMTP id i1so2102942qvu.12 for ; Wed, 31 Mar 2021 14:27:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=o64BOrDovMhhQ8PDB1l0LcOi9/iKBCLRb9E2FXFROjI=; b=ab418U9t+zO8emXNBH+5SJoSatco1/BYXVKCp5kR9oJ4dCv4FBJ0DOAzFZKeLUfkKl fUgBhHFjNoA5jCgHMBVfISQPsfcV4tkglm8aql2tpBWv1K2SMJ8MWoOGLzJPhln2pjXI eI+Ck2AwY62ZFKL8TjPFZCLps9vUFzJCE+ArU7q1Fo9x7ck10a0C6NDV6lTmVy3ixwTP j1cIlkUHSzwrbxv1RSH3dhf3h2++UXcP0MsAZZuh8hj5TBYXvM2vkFDpZuKWR9E72a/m dvx4zQ1yue18RyXHSDL196mNCqIFEk3eJZZCew9nQBGiqOzbz27VX+tJlmmN3ytfTX8r O0ZQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=o64BOrDovMhhQ8PDB1l0LcOi9/iKBCLRb9E2FXFROjI=; b=cCpDZegk+hZqLhnVVP/PMA0dO+PhYOYImzj8j0zNUYiUS5ZdowwzRGJ6bG7nhSWOEc IDwMzq5RgPNprTH34RfPCTaAPq+vDkKKwIHX1K/N6UYYAbqTsG6FFaFAojOlYFAOEcXT z9hlJLyv42lzRpXVTEm8i4Hrc+EZDbB160hadf0DySgnu56pL5gTsIT4kq4wyU2luPU9 zGn2EchI78W6umN+ri62hHR6td/eqRlCQYZ46Oqs5xAMVTaQoj/Vhp0UdEz8an1KxCe7 Ji5MqRQUMLJp14ud5s3R4egNKEykJGxe/HYQJKdy+/auBqZIngluxS8xcSAD8edIA1gl fLnw== X-Gm-Message-State: AOAM533KplrCpOESJVd7/WErx2ndWkRScS6KJLmzAsz+xmx0//b7CK5C 08wjQPIVymtFVgxU9KNksaSycGqbkYNcbgdnw8k= X-Google-Smtp-Source: ABdhPJxPk8zktx7csSixwhB9+NXChBwJxthJyO98xdq2NpEvdMcuq8rD1w1wRNUqI7dcjJv+2zZININi7HzUKUAKx3Y= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:7933:7015:a5d5:3835]) (user=samitolvanen job=sendgmr) by 2002:a0c:a5a5:: with SMTP id z34mr5299257qvz.4.1617226069635; Wed, 31 Mar 2021 14:27:49 -0700 (PDT) Date: Wed, 31 Mar 2021 14:27:17 -0700 In-Reply-To: <20210331212722.2746212-1-samitolvanen@google.com> Message-Id: <20210331212722.2746212-14-samitolvanen@google.com> Mime-Version: 1.0 References: <20210331212722.2746212-1-samitolvanen@google.com> X-Mailer: git-send-email 2.31.0.291.g576ba9dcdaf-goog Subject: [PATCH v4 13/17] arm64: use function_nocfi with __pa_symbol From: Sami Tolvanen To: Kees Cook Cc: Nathan Chancellor , Nick Desaulniers , Masahiro Yamada , Will Deacon , Jessica Yu , Arnd Bergmann , Tejun Heo , "Paul E. McKenney" , Christoph Hellwig , Peter Zijlstra , Sedat Dilek , bpf@vger.kernel.org, linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org With CONFIG_CFI_CLANG, the compiler replaces function address references with the address of the function's CFI jump table entry. This means that __pa_symbol(function) returns the physical address of the jump table entry, which can lead to address space confusion as the jump table points to the function's virtual address. Therefore, use the function_nocfi() macro to ensure we are always taking the address of the actual function instead. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- arch/arm64/include/asm/mmu_context.h | 2 +- arch/arm64/kernel/acpi_parking_protocol.c | 3 ++- arch/arm64/kernel/cpu-reset.h | 2 +- arch/arm64/kernel/cpufeature.c | 2 +- arch/arm64/kernel/psci.c | 3 ++- arch/arm64/kernel/smp_spin_table.c | 3 ++- 6 files changed, 9 insertions(+), 6 deletions(-) diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h index bd02e99b1a4c..386b96400a57 100644 --- a/arch/arm64/include/asm/mmu_context.h +++ b/arch/arm64/include/asm/mmu_context.h @@ -140,7 +140,7 @@ static inline void cpu_replace_ttbr1(pgd_t *pgdp) ttbr1 |= TTBR_CNP_BIT; } - replace_phys = (void *)__pa_symbol(idmap_cpu_replace_ttbr1); + replace_phys = (void *)__pa_symbol(function_nocfi(idmap_cpu_replace_ttbr1)); cpu_install_idmap(); replace_phys(ttbr1); diff --git a/arch/arm64/kernel/acpi_parking_protocol.c b/arch/arm64/kernel/acpi_parking_protocol.c index e7c941d8340d..bfeeb5319abf 100644 --- a/arch/arm64/kernel/acpi_parking_protocol.c +++ b/arch/arm64/kernel/acpi_parking_protocol.c @@ -99,7 +99,8 @@ static int acpi_parking_protocol_cpu_boot(unsigned int cpu) * that read this address need to convert this address to the * Boot-Loader's endianness before jumping. */ - writeq_relaxed(__pa_symbol(secondary_entry), &mailbox->entry_point); + writeq_relaxed(__pa_symbol(function_nocfi(secondary_entry)), + &mailbox->entry_point); writel_relaxed(cpu_entry->gic_cpu_id, &mailbox->cpu_id); arch_send_wakeup_ipi_mask(cpumask_of(cpu)); diff --git a/arch/arm64/kernel/cpu-reset.h b/arch/arm64/kernel/cpu-reset.h index ed50e9587ad8..f3adc574f969 100644 --- a/arch/arm64/kernel/cpu-reset.h +++ b/arch/arm64/kernel/cpu-reset.h @@ -22,7 +22,7 @@ static inline void __noreturn cpu_soft_restart(unsigned long entry, unsigned long el2_switch = !is_kernel_in_hyp_mode() && is_hyp_mode_available(); - restart = (void *)__pa_symbol(__cpu_soft_restart); + restart = (void *)__pa_symbol(function_nocfi(__cpu_soft_restart)); cpu_install_idmap(); restart(el2_switch, entry, arg0, arg1, arg2); diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 2a5d9854d664..ac616c59ae92 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1463,7 +1463,7 @@ kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused) if (arm64_use_ng_mappings) return; - remap_fn = (void *)__pa_symbol(idmap_kpti_install_ng_mappings); + remap_fn = (void *)__pa_symbol(function_nocfi(idmap_kpti_install_ng_mappings)); cpu_install_idmap(); remap_fn(cpu, num_online_cpus(), __pa_symbol(swapper_pg_dir)); diff --git a/arch/arm64/kernel/psci.c b/arch/arm64/kernel/psci.c index 62d2bda7adb8..e74bcb57559b 100644 --- a/arch/arm64/kernel/psci.c +++ b/arch/arm64/kernel/psci.c @@ -38,7 +38,8 @@ static int __init cpu_psci_cpu_prepare(unsigned int cpu) static int cpu_psci_cpu_boot(unsigned int cpu) { - int err = psci_ops.cpu_on(cpu_logical_map(cpu), __pa_symbol(secondary_entry)); + int err = psci_ops.cpu_on(cpu_logical_map(cpu), + __pa_symbol(function_nocfi(secondary_entry))); if (err) pr_err("failed to boot CPU%d (%d)\n", cpu, err); diff --git a/arch/arm64/kernel/smp_spin_table.c b/arch/arm64/kernel/smp_spin_table.c index 056772c26098..4c4e36ded4aa 100644 --- a/arch/arm64/kernel/smp_spin_table.c +++ b/arch/arm64/kernel/smp_spin_table.c @@ -88,7 +88,8 @@ static int smp_spin_table_cpu_prepare(unsigned int cpu) * boot-loader's endianness before jumping. This is mandated by * the boot protocol. */ - writeq_relaxed(__pa_symbol(secondary_holding_pen), release_addr); + writeq_relaxed(__pa_symbol(function_nocfi(secondary_holding_pen)), + release_addr); __flush_dcache_area((__force void *)release_addr, sizeof(*release_addr)); From patchwork Wed Mar 31 21:27:18 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 12176453 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C3FE6C41538 for ; Wed, 31 Mar 2021 21:28:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A787861078 for ; Wed, 31 Mar 2021 21:28:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232866AbhCaV2W (ORCPT ); Wed, 31 Mar 2021 17:28:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51896 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232874AbhCaV1x (ORCPT ); Wed, 31 Mar 2021 17:27:53 -0400 Received: from mail-qk1-x74a.google.com (mail-qk1-x74a.google.com [IPv6:2607:f8b0:4864:20::74a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AAE7AC061574 for ; Wed, 31 Mar 2021 14:27:52 -0700 (PDT) Received: by mail-qk1-x74a.google.com with SMTP id t24so2381030qkg.3 for ; Wed, 31 Mar 2021 14:27:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=qCxq1N1gA7TwxAMFKmL7hLg9EO4lnSukatZLoaD+FFE=; b=KeQedqCHSppeGUQMSB3qvddKepeNQHx1p1/VSfzMSylvv0LONVB89TrLW3prq8oZLd GBGSMaPvGJnxYeqpyXqf46YXoIA4BadxdCS+/OCujIT/cSSW4RH6HuseJGcAaYs/B2h0 VPCq2Yot/QxDNIrN078Op8TpVyvUgNLnqtUsZWFs4jkRLeq3QIubrq+hsNm8jw0/sNbu x6ydT94rlxQyzBBmMXhSg1nR2cT5jJEpSyTDeTKaFhRS7JORrsdmSYdEe1cmftX7I5J0 WBiVyhSq+sZPQBRPdqZ0g2ebTLAodY/JCdgVHrXBLyUi190r5xfaOS+yUqmC2AQgYhO3 ejSg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=qCxq1N1gA7TwxAMFKmL7hLg9EO4lnSukatZLoaD+FFE=; b=SzeJcrJumguPqioKdnXqSTfB4gMzmAdfJuZf6KxVJXV3KFO4/AjF6YFfEkf9B/cJ8t UgSNR+XSTep0XupOHnAoz/LP07UFDe90oif9aXYfqWWWvJChMXckwdeqZlBNrW3LVjLu dv6XoG3dAESrg12vSPy+FxRLqrQM3ZSt8tMvtBLr3HjHiKkTzysqJ3n0v6Nc+n6240Xd kx0XdFZ9lzxwFmvI5rM0xgWgeVFxYiWvaG/ZsaZ5pwHVi2g6jEGo+LqVkKRkSE/FLgW0 t9YVRxYeLozZQXCtw5P70HrCmuLIEGkI3idI7P1vUkUxxUTw4+PpEg3CApYqu6azmvGG hEqA== X-Gm-Message-State: AOAM531j+euJsz7pmqUUqRUwrsYUoc+n2pJz/5sY7EOch7/5SosEC1IG wHzYTlDgQigQMdYndzB/dwt6cNxUdWcQk44rDpI= X-Google-Smtp-Source: ABdhPJx7XX2KOGLVRiBBOLjdMcWGg8SbFNRL+HOjMTa79TjDOvRh955y/RHVoyp83P6xuYihqrO7IRPK/3G0aLsMx0w= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:7933:7015:a5d5:3835]) (user=samitolvanen job=sendgmr) by 2002:a05:6214:b04:: with SMTP id u4mr5243055qvj.0.1617226071830; Wed, 31 Mar 2021 14:27:51 -0700 (PDT) Date: Wed, 31 Mar 2021 14:27:18 -0700 In-Reply-To: <20210331212722.2746212-1-samitolvanen@google.com> Message-Id: <20210331212722.2746212-15-samitolvanen@google.com> Mime-Version: 1.0 References: <20210331212722.2746212-1-samitolvanen@google.com> X-Mailer: git-send-email 2.31.0.291.g576ba9dcdaf-goog Subject: [PATCH v4 14/17] arm64: add __nocfi to functions that jump to a physical address From: Sami Tolvanen To: Kees Cook Cc: Nathan Chancellor , Nick Desaulniers , Masahiro Yamada , Will Deacon , Jessica Yu , Arnd Bergmann , Tejun Heo , "Paul E. McKenney" , Christoph Hellwig , Peter Zijlstra , Sedat Dilek , bpf@vger.kernel.org, linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Disable CFI checking for functions that switch to linear mapping and make an indirect call to a physical address, since the compiler only understands virtual addresses and the CFI check for such indirect calls would always fail. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- arch/arm64/include/asm/mmu_context.h | 2 +- arch/arm64/kernel/cpu-reset.h | 8 ++++---- arch/arm64/kernel/cpufeature.c | 2 +- 3 files changed, 6 insertions(+), 6 deletions(-) diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h index 386b96400a57..d3cef9133539 100644 --- a/arch/arm64/include/asm/mmu_context.h +++ b/arch/arm64/include/asm/mmu_context.h @@ -119,7 +119,7 @@ static inline void cpu_install_idmap(void) * Atomically replaces the active TTBR1_EL1 PGD with a new VA-compatible PGD, * avoiding the possibility of conflicting TLB entries being allocated. */ -static inline void cpu_replace_ttbr1(pgd_t *pgdp) +static inline void __nocfi cpu_replace_ttbr1(pgd_t *pgdp) { typedef void (ttbr_replace_func)(phys_addr_t); extern ttbr_replace_func idmap_cpu_replace_ttbr1; diff --git a/arch/arm64/kernel/cpu-reset.h b/arch/arm64/kernel/cpu-reset.h index f3adc574f969..9a7b1262ef17 100644 --- a/arch/arm64/kernel/cpu-reset.h +++ b/arch/arm64/kernel/cpu-reset.h @@ -13,10 +13,10 @@ void __cpu_soft_restart(unsigned long el2_switch, unsigned long entry, unsigned long arg0, unsigned long arg1, unsigned long arg2); -static inline void __noreturn cpu_soft_restart(unsigned long entry, - unsigned long arg0, - unsigned long arg1, - unsigned long arg2) +static inline void __noreturn __nocfi cpu_soft_restart(unsigned long entry, + unsigned long arg0, + unsigned long arg1, + unsigned long arg2) { typeof(__cpu_soft_restart) *restart; diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index ac616c59ae92..1cd7877deada 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1446,7 +1446,7 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry, } #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 -static void +static void __nocfi kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused) { typedef void (kpti_remap_fn)(int, int, phys_addr_t); From patchwork Wed Mar 31 21:27:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 12176451 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8C13AC001EB for ; 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Wed, 31 Mar 2021 14:27:54 -0700 (PDT) Date: Wed, 31 Mar 2021 14:27:19 -0700 In-Reply-To: <20210331212722.2746212-1-samitolvanen@google.com> Message-Id: <20210331212722.2746212-16-samitolvanen@google.com> Mime-Version: 1.0 References: <20210331212722.2746212-1-samitolvanen@google.com> X-Mailer: git-send-email 2.31.0.291.g576ba9dcdaf-goog Subject: [PATCH v4 15/17] arm64: add __nocfi to __apply_alternatives From: Sami Tolvanen To: Kees Cook Cc: Nathan Chancellor , Nick Desaulniers , Masahiro Yamada , Will Deacon , Jessica Yu , Arnd Bergmann , Tejun Heo , "Paul E. McKenney" , Christoph Hellwig , Peter Zijlstra , Sedat Dilek , bpf@vger.kernel.org, linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org __apply_alternatives makes indirect calls to functions whose address is taken in assembly code using the alternative_cb macro. With non-canonical CFI, the compiler won't replace these function references with the jump table addresses, which trips CFI. Disable CFI checking in the function to work around the issue. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- arch/arm64/kernel/alternative.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/alternative.c b/arch/arm64/kernel/alternative.c index 1184c44ea2c7..abc84636af07 100644 --- a/arch/arm64/kernel/alternative.c +++ b/arch/arm64/kernel/alternative.c @@ -133,8 +133,8 @@ static void clean_dcache_range_nopatch(u64 start, u64 end) } while (cur += d_size, cur < end); } -static void __apply_alternatives(void *alt_region, bool is_module, - unsigned long *feature_mask) +static void __nocfi __apply_alternatives(void *alt_region, bool is_module, + unsigned long *feature_mask) { struct alt_instr *alt; struct alt_region *region = alt_region; From patchwork Wed Mar 31 21:27:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 12176449 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1A987C001E6 for ; Wed, 31 Mar 2021 21:28:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EACD061041 for ; Wed, 31 Mar 2021 21:28:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232923AbhCaV2X (ORCPT ); Wed, 31 Mar 2021 17:28:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51942 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232927AbhCaV16 (ORCPT ); Wed, 31 Mar 2021 17:27:58 -0400 Received: from mail-qv1-xf49.google.com (mail-qv1-xf49.google.com [IPv6:2607:f8b0:4864:20::f49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0D991C061763 for ; Wed, 31 Mar 2021 14:27:57 -0700 (PDT) Received: by mail-qv1-xf49.google.com with SMTP id r5so2095802qvc.11 for ; Wed, 31 Mar 2021 14:27:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=tNWRsiiEAfetheYG6qtDYdd6Zu2YM8DJGmENfE26Aac=; b=ubXheP2brktumzheoRlwOGBaDAhJZCw5NjiWWseiWXm7uPGHPIEhQNkw1vclDXilyC T58HwhxWmupp1FHmmbm/one9xjzW1zyEIjkTSSxxlsem3MjSEZyOYyr2rhKeCFRUkd1c yGspf/krXoZV1aO23JrXpEBnl0Y82WLgsZPob752XnnEkvdLJpCAqDdeG+QPej4XPSZi CCDXPydG6+7wL9MGmLynGahaXHCtSa4TMIRQo0YgQK5KW48jFUEOkg9RmceaiJf2wbgY lIMNbUBaPlDMhK4s8fFJq1GcJptaYswx+mQ1VL7I/WglifRbnqfcOPmIuT0hvWr13KAr jjYw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=tNWRsiiEAfetheYG6qtDYdd6Zu2YM8DJGmENfE26Aac=; b=nSJriqq0tuuo1pS6ZFK5+7DbEIQewUtaH4KTlit8u0t89WgQfKc4Ya10nInKaGKLF2 /bSltFY+8TCVXunUvAA5wPuqIinEF/A3gaRlwD8WR6UeVnHx/6gBJTe0VOmRhKWqgN8h rVYvIqavE1Ak8jIzpyoAG8bysAu84z5i/mZKUDsNFnUXsnjFtNLI3k/Yf00+A5H+bIg3 l2qnTXfNI1enHHD8Vv3a8h/iMx+MGfFE5OhpDhN4RBh1PBJPQz41H+KEAgWiPZ1NqRvK 1JEeFcCj/aS3W8qb7mv/PlWnWxjf7DWT0YvQu+yKqXhFUTPmDRL1kF7/R8dm+AELmIwy mdPw== X-Gm-Message-State: AOAM531kQA/PyzjnnrY6turrleOuIu8LfbNaieMnqWbB2XIGwO29ycYF i28J54z7eiZsQpRAJiOJoRdHQWbnQ5VlIPybYac= X-Google-Smtp-Source: ABdhPJzZWP60rNMcikFQnnnMLQ3nIFchg+3t6XyAeYS/TMwgF+id2xc8kKag8yrH4KJDKMnacT9UMf7IYNlFmwHArxk= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:7933:7015:a5d5:3835]) (user=samitolvanen job=sendgmr) by 2002:a0c:f349:: with SMTP id e9mr4952920qvm.59.1617226076143; Wed, 31 Mar 2021 14:27:56 -0700 (PDT) Date: Wed, 31 Mar 2021 14:27:20 -0700 In-Reply-To: <20210331212722.2746212-1-samitolvanen@google.com> Message-Id: <20210331212722.2746212-17-samitolvanen@google.com> Mime-Version: 1.0 References: <20210331212722.2746212-1-samitolvanen@google.com> X-Mailer: git-send-email 2.31.0.291.g576ba9dcdaf-goog Subject: [PATCH v4 16/17] KVM: arm64: Disable CFI for nVHE From: Sami Tolvanen To: Kees Cook Cc: Nathan Chancellor , Nick Desaulniers , Masahiro Yamada , Will Deacon , Jessica Yu , Arnd Bergmann , Tejun Heo , "Paul E. McKenney" , Christoph Hellwig , Peter Zijlstra , Sedat Dilek , bpf@vger.kernel.org, linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Disable CFI for the nVHE code to avoid address space confusion. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- arch/arm64/kvm/hyp/nvhe/Makefile | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile index a6707df4f6c0..fb24a0f022ad 100644 --- a/arch/arm64/kvm/hyp/nvhe/Makefile +++ b/arch/arm64/kvm/hyp/nvhe/Makefile @@ -75,9 +75,9 @@ quiet_cmd_hyprel = HYPREL $@ quiet_cmd_hypcopy = HYPCOPY $@ cmd_hypcopy = $(OBJCOPY) --prefix-symbols=__kvm_nvhe_ $< $@ -# Remove ftrace and Shadow Call Stack CFLAGS. -# This is equivalent to the 'notrace' and '__noscs' annotations. -KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS), $(KBUILD_CFLAGS)) +# Remove ftrace, Shadow Call Stack, and CFI CFLAGS. +# This is equivalent to the 'notrace', '__noscs', and '__nocfi' annotations. +KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS) $(CC_FLAGS_CFI), $(KBUILD_CFLAGS)) # KVM nVHE code is run at a different exception code with a different map, so # compiler instrumentation that inserts callbacks or checks into the code may From patchwork Wed Mar 31 21:27:21 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 12176455 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4F0E7C0032E for ; Wed, 31 Mar 2021 21:28:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2919361075 for ; Wed, 31 Mar 2021 21:28:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232404AbhCaV2X (ORCPT ); Wed, 31 Mar 2021 17:28:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51906 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232954AbhCaV17 (ORCPT ); Wed, 31 Mar 2021 17:27:59 -0400 Received: from mail-qk1-x74a.google.com (mail-qk1-x74a.google.com [IPv6:2607:f8b0:4864:20::74a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 47060C061761 for ; Wed, 31 Mar 2021 14:27:59 -0700 (PDT) Received: by mail-qk1-x74a.google.com with SMTP id k68so2377501qke.2 for ; Wed, 31 Mar 2021 14:27:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=lk8inZlzo7fNLcnXaQ1bMqH+Yl1xnIiMxwLQYqKIvN0=; b=Vn+IV2jTMQ3qfrTZI0BaCIvipMQjXnOyPVdlyPeO2A1ydhmBtiQ0/KPQbFLprUQsKz XEsE22KBNeTSVCxLa9BdhULZj1AuDO/PaWmw/EF9j8xlXX10FsmT0+B+8p/x/fbzZqXB ioPa4cOo0iYeLpwms5O94L4r44baMvUxEDLYiQ4o+KUu+SAM7a1CX7s/NWI/L7SfPxrM Ua/5ZcXDAjzY32eJHiQGKkogawbLWhdKE06AvSW60VNJY10icae6GpzRlVISoSMCZyJ1 ZgYMtg4qfAmuFnaNGf+3dlT/SZspW5x0yX39FkVTOC7fQmzwrn8FU2ClEoHTyE8AdE0d Bd6Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=lk8inZlzo7fNLcnXaQ1bMqH+Yl1xnIiMxwLQYqKIvN0=; b=rUmqOjnTtoXrCiUjvTv7kdB64AH3fZhUEXpw0wB8pnclGYI4laADwyYHNluLrkWUQy nfrh+iesTgICBvb9Ej2U/rmy7MIowt1sR0r/xxXwY578YsFFWR3qD3tPtUI7ScJSW9WG 2zdXA/mnF8l4twE+t6L9OZzbkVIdCKdT5cylF6JjvPXZNYzbVI9lEdH6IKuYtUn6cGph 1/j96H78+mrJFTJlXBuA6Y13/OLL70GMbmqqW8Py7/XHp7TYgUm/dgT0cP2hfsB+uOF2 RrF6367bY0WGKml9Av3w8Rtwo4BTfdOf2nV2OlRJSDZf7Nabb0C4fBS4vXoR4uf5aC46 lQlQ== X-Gm-Message-State: AOAM530DGZAsFY7+1eep7FjY028+/qoCKRyCPxMkjet8PwgSsJt8yfJu Wi25/KtLyeyLarjUrTUSbKXDq/1UQnusMdEHA2U= X-Google-Smtp-Source: ABdhPJxbLnYVkEE3SX2BDreH5/lfjqbV3qQJ9QM78vYg3uiCL7YeQbGCVkgbIG/Qv+7aSalIOwO+SwFDW3TO97SD7KU= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:7933:7015:a5d5:3835]) (user=samitolvanen job=sendgmr) by 2002:a0c:e148:: with SMTP id c8mr5184451qvl.56.1617226078315; Wed, 31 Mar 2021 14:27:58 -0700 (PDT) Date: Wed, 31 Mar 2021 14:27:21 -0700 In-Reply-To: <20210331212722.2746212-1-samitolvanen@google.com> Message-Id: <20210331212722.2746212-18-samitolvanen@google.com> Mime-Version: 1.0 References: <20210331212722.2746212-1-samitolvanen@google.com> X-Mailer: git-send-email 2.31.0.291.g576ba9dcdaf-goog Subject: [PATCH v4 17/17] arm64: allow CONFIG_CFI_CLANG to be selected From: Sami Tolvanen To: Kees Cook Cc: Nathan Chancellor , Nick Desaulniers , Masahiro Yamada , Will Deacon , Jessica Yu , Arnd Bergmann , Tejun Heo , "Paul E. McKenney" , Christoph Hellwig , Peter Zijlstra , Sedat Dilek , bpf@vger.kernel.org, linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Select ARCH_SUPPORTS_CFI_CLANG to allow CFI to be enabled. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook --- arch/arm64/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index e4e1b6550115..d7395772b6b8 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -75,6 +75,7 @@ config ARM64 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN select ARCH_SUPPORTS_LTO_CLANG_THIN + select ARCH_SUPPORTS_CFI_CLANG select ARCH_SUPPORTS_ATOMIC_RMW select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && (GCC_VERSION >= 50000 || CC_IS_CLANG) select ARCH_SUPPORTS_NUMA_BALANCING