From patchwork Thu Jun 1 10:12:57 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Rapoport X-Patchwork-Id: 13263393 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 87EFA20999; Thu, 1 Jun 2023 10:15:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 881EDC433A8; Thu, 1 Jun 2023 10:15:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1685614514; bh=KP9HX6DBOdeXbh1b+aKLs5zgkX2POLO57m2Kdhv+uBE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PpK9bveSqvpewvjbyZorKqSi3Q/F2n/LjJbM2xuj27cyV2j16y21onV4vnPjeZgTl zE9e28Ev7BFmducrk1/4dDKq3oOIJdBaX0QRyCLXbMWkq7hyE5K3/dP7zLmKJI/u+J lhU+vPxA/p2Jf8kS/aFYDSo6FeVktlpcm+nCEuVDQIry8EXyK9YUnYblgPqXCgLqeR 2j1GLCveGyj3OVEyE2BDq2GHbbfSv+yRuLfu/Nry87svP0BgLxAfXOGT4DOJSO+sz1 hW3iK555Pl8OaMr8Z+t77LXxqmLIyxUXr+Y3h+YIQv8TpNf780OllbwDGe20NNxSf6 l3zqIrjNIFEhQ== From: Mike Rapoport To: linux-kernel@vger.kernel.org Cc: Andrew Morton , Catalin Marinas , Christophe Leroy , "David S. Miller" , Dinh Nguyen , Heiko Carstens , Helge Deller , Huacai Chen , Kent Overstreet , Luis Chamberlain , Michael Ellerman , Mike Rapoport , "Naveen N. Rao" , Palmer Dabbelt , Russell King , Song Liu , Steven Rostedt , Thomas Bogendoerfer , Thomas Gleixner , Will Deacon , bpf@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, linux-modules@vger.kernel.org, linux-parisc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, loongarch@lists.linux.dev, netdev@vger.kernel.org, sparclinux@vger.kernel.org, x86@kernel.org Subject: [PATCH 13/13] x86/jitalloc: make memory allocated for code ROX Date: Thu, 1 Jun 2023 13:12:57 +0300 Message-Id: <20230601101257.530867-14-rppt@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20230601101257.530867-1-rppt@kernel.org> References: <20230601101257.530867-1-rppt@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: "Mike Rapoport (IBM)" When STRICT_KERNEL_RWX or STRICT_MODULE_RWX is enabled, force text allocations to use KERNEL_PAGE_ROX. Signed-off-by: Mike Rapoport (IBM) --- arch/Kconfig | 3 +++ arch/x86/Kconfig | 1 + arch/x86/kernel/ftrace.c | 3 --- arch/x86/mm/init.c | 6 ++++++ include/linux/jitalloc.h | 2 ++ mm/jitalloc.c | 21 +++++++++++++++++++++ 6 files changed, 33 insertions(+), 3 deletions(-) diff --git a/arch/Kconfig b/arch/Kconfig index 479a7b8be191..e7c4b01307d7 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -1307,6 +1307,9 @@ config STRICT_MODULE_RWX and non-text memory will be made non-executable. This provides protection against certain security exploits (e.g. writing to text) +config ARCH_HAS_TEXT_POKE + def_bool n + # select if the architecture provides an asm/dma-direct.h header config ARCH_HAS_PHYS_TO_DMA bool diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index fac4add6ce16..e1a512f557de 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -96,6 +96,7 @@ config X86 select ARCH_HAS_SET_DIRECT_MAP select ARCH_HAS_STRICT_KERNEL_RWX select ARCH_HAS_STRICT_MODULE_RWX + select ARCH_HAS_TEXT_POKE select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE select ARCH_HAS_SYSCALL_WRAPPER select ARCH_HAS_UBSAN_SANITIZE_ALL diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index d50595f2c1a6..bd4dd8974ee6 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -313,7 +313,6 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size) unsigned long call_offset; unsigned long jmp_offset; unsigned long offset; - unsigned long npages; unsigned long size; unsigned long *ptr; void *trampoline; @@ -350,7 +349,6 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size) return 0; *tramp_size = size + RET_SIZE + sizeof(void *); - npages = DIV_ROUND_UP(*tramp_size, PAGE_SIZE); /* Copy ftrace_caller onto the trampoline memory */ ret = text_poke_copy(trampoline, (void *)start_offset, size); @@ -416,7 +414,6 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size) /* ALLOC_TRAMP flags lets us know we created it */ ops->flags |= FTRACE_OPS_FL_ALLOC_TRAMP; - set_memory_rox((unsigned long)trampoline, npages); return (unsigned long)trampoline; fail: tramp_free(trampoline); diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index ffaf9a3840ce..c314738991fa 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -1127,6 +1127,12 @@ struct jit_alloc_params *jit_alloc_arch_params(void) jit_alloc_params.text.start = MODULES_VADDR + get_jit_load_offset(); jit_alloc_params.text.end = MODULES_END; + if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX) || + IS_ENABLED(CONFIG_STRICT_MODULE_RWX)) { + jit_alloc_params.text.pgprot = PAGE_KERNEL_ROX; + jit_alloc_params.flags |= JIT_ALLOC_USE_TEXT_POKE; + } + return &jit_alloc_params; } #endif /* CONFIG_JIT_ALLOC */ diff --git a/include/linux/jitalloc.h b/include/linux/jitalloc.h index 0ba5ef785a85..0e29e87acefe 100644 --- a/include/linux/jitalloc.h +++ b/include/linux/jitalloc.h @@ -15,9 +15,11 @@ /** * enum jit_alloc_flags - options for executable memory allocations * @JIT_ALLOC_KASAN_SHADOW: allocate kasan shadow + * @JIT_ALLOC_USE_TEXT_POKE: use text poking APIs to update memory */ enum jit_alloc_flags { JIT_ALLOC_KASAN_SHADOW = (1 << 0), + JIT_ALLOC_USE_TEXT_POKE = (1 << 1), }; /** diff --git a/mm/jitalloc.c b/mm/jitalloc.c index a8ae64364d56..15d1067faf3f 100644 --- a/mm/jitalloc.c +++ b/mm/jitalloc.c @@ -7,6 +7,26 @@ static struct jit_alloc_params jit_alloc_params; +#ifdef CONFIG_ARCH_HAS_TEXT_POKE +#include + +static inline void jit_text_poke_copy(void *dst, const void *src, size_t len) +{ + if (jit_alloc_params.flags & JIT_ALLOC_USE_TEXT_POKE) + text_poke_copy(dst, src, len); + else + memcpy(dst, src, len); +} + +static inline void jit_text_poke_set(void *addr, int c, size_t len) +{ + if (jit_alloc_params.flags & JIT_ALLOC_USE_TEXT_POKE) + text_poke_set(addr, c, len); + else + memset(addr, c, len); +} + +#else static inline void jit_text_poke_copy(void *dst, const void *src, size_t len) { memcpy(dst, src, len); @@ -16,6 +36,7 @@ static inline void jit_text_poke_set(void *addr, int c, size_t len) { memset(addr, c, len); } +#endif static void *jit_alloc(size_t len, unsigned int alignment, pgprot_t pgprot, unsigned long start, unsigned long end,