From patchwork Sat Aug 5 14:58:12 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 13342612 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B4ACC001DB for ; Sat, 5 Aug 2023 14:58:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229848AbjHEO6Z (ORCPT ); Sat, 5 Aug 2023 10:58:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54616 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229884AbjHEO6X (ORCPT ); Sat, 5 Aug 2023 10:58:23 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B2181F3; Sat, 5 Aug 2023 07:58:19 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 2F2E160B18; Sat, 5 Aug 2023 14:58:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E9CC9C433C7; Sat, 5 Aug 2023 14:58:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1691247498; bh=kTo/aoefVKctIuXm1UMj2MsQELVZD2xl3Ne2+DS37E0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Kv+kjjWME/gela2qJFapSDl5WTptMVpqdyKyi/pQOiiSyqTJHqEDqg/8VpUm3p3P+ g/+WLdRfqqsOhkwMec7FtEPbAum/T2ESapKHGluRM7LlNA6zyQNQ62dOwZFSF24nYP 9GXLEld7Zva96ge445ZM1y4jIjUf3L1TrT+9tCTITw6yDEE6o376slWsBw/j4IHFlx TknB5eVNwnJY6voEQ3RlfoZAL9J2KWps0MIcux8a5UynAHGQVDovEcg/Z2LxJysU4O dMqPvPgxQbyoUqDTSiVVvkZsZoOo/TRMoQaT0GSq98wuVgb2wCLWRlJ2rL04lQtwKc CWnDCCoRVqM9g== From: "Masami Hiramatsu (Google)" To: Alexei Starovoitov , Steven Rostedt , Florent Revest Cc: linux-trace-kernel@vger.kernel.org, LKML , Martin KaFai Lau , bpf , Sven Schnelle , Alexei Starovoitov , Jiri Olsa , Arnaldo Carvalho de Melo , Daniel Borkmann , Alan Maguire , Mark Rutland , Peter Zijlstra , Thomas Gleixner Subject: [RFC PATCH 2/5] fprobe: rethook: Use fprobe_regs in fprobe exit handler and rethook Date: Sat, 5 Aug 2023 23:58:12 +0900 Message-Id: <169124749229.186149.1426658495303367593.stgit@devnote2> X-Mailer: git-send-email 2.34.1 In-Reply-To: <169124746774.186149.2326708176801468806.stgit@devnote2> References: <169124746774.186149.2326708176801468806.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org From: Masami Hiramatsu (Google) Change the fprobe exit handler and rethook to use ftrace_regs data structure instead of pt_regs. This also introduce HAVE_FTRACE_REGS_COMPATIBLE_WITH_PT_REGS which means the ftrace_regs is equal to the pt_regs so that those are compatible. Only if it is enabled, kretprobe will use rethook since kretprobe requires pt_regs for backward compatibility. This means the archs which currently implement rethook for kretprobes needs to set that flag and it must ensure struct ftrace_regs is same as pt_regs. If not, it must be either disabling kretprobe or implementing kretprobe trampoline separately from rethook trampoline. Signed-off-by: Masami Hiramatsu (Google) --- arch/Kconfig | 1 + arch/loongarch/Kconfig | 1 + arch/s390/Kconfig | 1 + arch/x86/Kconfig | 1 + arch/x86/kernel/rethook.c | 9 ++++++--- include/linux/fprobe.h | 2 +- include/linux/rethook.h | 11 ++++++----- kernel/kprobes.c | 9 +++++++-- kernel/trace/Kconfig | 7 +++++++ kernel/trace/bpf_trace.c | 6 +++++- kernel/trace/fprobe.c | 6 +++--- kernel/trace/rethook.c | 16 ++++++++-------- kernel/trace/trace_fprobe.c | 6 +++++- lib/test_fprobe.c | 6 +++--- samples/fprobe/fprobe_example.c | 2 +- 15 files changed, 56 insertions(+), 28 deletions(-) diff --git a/arch/Kconfig b/arch/Kconfig index aff2746c8af2..e321bdb8b22b 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -201,6 +201,7 @@ config KRETPROBE_ON_RETHOOK def_bool y depends on HAVE_RETHOOK depends on KRETPROBES + depends on HAVE_PT_REGS_COMPAT_FTRACE_REGS || !HAVE_DYNAMIC_FTRACE_WITH_ARGS select RETHOOK config USER_RETURN_NOTIFIER diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index e55511af4c77..93a4336b0a94 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -102,6 +102,7 @@ config LOONGARCH select HAVE_DMA_CONTIGUOUS select HAVE_DYNAMIC_FTRACE select HAVE_DYNAMIC_FTRACE_WITH_ARGS + select HAVE_PT_REGS_COMPAT_FTRACE_REGS select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS select HAVE_DYNAMIC_FTRACE_WITH_REGS select HAVE_EBPF_JIT diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 5b39918b7042..299ba17d3316 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -165,6 +165,7 @@ config S390 select HAVE_DMA_CONTIGUOUS select HAVE_DYNAMIC_FTRACE select HAVE_DYNAMIC_FTRACE_WITH_ARGS + select HAVE_PT_REGS_COMPAT_FTRACE_REGS select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS select HAVE_DYNAMIC_FTRACE_WITH_REGS select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 7422db409770..df1b7a2791e8 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -207,6 +207,7 @@ config X86 select HAVE_DYNAMIC_FTRACE select HAVE_DYNAMIC_FTRACE_WITH_REGS select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64 + select HAVE_PT_REGS_COMPAT_FTRACE_REGS if X86_64 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS select HAVE_SAMPLE_FTRACE_DIRECT if X86_64 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI if X86_64 diff --git a/arch/x86/kernel/rethook.c b/arch/x86/kernel/rethook.c index 8a1c0111ae79..79a52bfde562 100644 --- a/arch/x86/kernel/rethook.c +++ b/arch/x86/kernel/rethook.c @@ -83,7 +83,8 @@ __used __visible void arch_rethook_trampoline_callback(struct pt_regs *regs) * arch_rethook_fixup_return() which called from this * rethook_trampoline_handler(). */ - rethook_trampoline_handler(regs, (unsigned long)frame_pointer); + rethook_trampoline_handler((struct ftrace_regs *)regs, + (unsigned long)frame_pointer); /* * Copy FLAGS to 'pt_regs::ss' so that arch_rethook_trapmoline() @@ -104,9 +105,10 @@ NOKPROBE_SYMBOL(arch_rethook_trampoline_callback); STACK_FRAME_NON_STANDARD_FP(arch_rethook_trampoline); /* This is called from rethook_trampoline_handler(). */ -void arch_rethook_fixup_return(struct pt_regs *regs, +void arch_rethook_fixup_return(struct ftrace_regs *fregs, unsigned long correct_ret_addr) { + struct pt_regs *regs = ftrace_get_regs(fregs); unsigned long *frame_pointer = (void *)(regs + 1); /* Replace fake return address with real one. */ @@ -114,8 +116,9 @@ void arch_rethook_fixup_return(struct pt_regs *regs, } NOKPROBE_SYMBOL(arch_rethook_fixup_return); -void arch_rethook_prepare(struct rethook_node *rh, struct pt_regs *regs, bool mcount) +void arch_rethook_prepare(struct rethook_node *rh, struct ftrace_regs *fregs, bool mcount) { + struct pt_regs *regs = ftrace_get_regs(fregs); unsigned long *stack = (unsigned long *)regs->sp; rh->ret_addr = stack[0]; diff --git a/include/linux/fprobe.h b/include/linux/fprobe.h index 36c0595f7b93..b9c0c216dedb 100644 --- a/include/linux/fprobe.h +++ b/include/linux/fprobe.h @@ -38,7 +38,7 @@ struct fprobe { unsigned long ret_ip, struct ftrace_regs *regs, void *entry_data); void (*exit_handler)(struct fprobe *fp, unsigned long entry_ip, - unsigned long ret_ip, struct pt_regs *regs, + unsigned long ret_ip, struct ftrace_regs *regs, void *entry_data); }; diff --git a/include/linux/rethook.h b/include/linux/rethook.h index 26b6f3c81a76..138d64c8b67b 100644 --- a/include/linux/rethook.h +++ b/include/linux/rethook.h @@ -7,6 +7,7 @@ #include #include +#include #include #include #include @@ -14,7 +15,7 @@ struct rethook_node; -typedef void (*rethook_handler_t) (struct rethook_node *, void *, unsigned long, struct pt_regs *); +typedef void (*rethook_handler_t) (struct rethook_node *, void *, unsigned long, struct ftrace_regs *); /** * struct rethook - The rethook management data structure. @@ -64,12 +65,12 @@ void rethook_free(struct rethook *rh); void rethook_add_node(struct rethook *rh, struct rethook_node *node); struct rethook_node *rethook_try_get(struct rethook *rh); void rethook_recycle(struct rethook_node *node); -void rethook_hook(struct rethook_node *node, struct pt_regs *regs, bool mcount); +void rethook_hook(struct rethook_node *node, struct ftrace_regs *regs, bool mcount); unsigned long rethook_find_ret_addr(struct task_struct *tsk, unsigned long frame, struct llist_node **cur); /* Arch dependent code must implement arch_* and trampoline code */ -void arch_rethook_prepare(struct rethook_node *node, struct pt_regs *regs, bool mcount); +void arch_rethook_prepare(struct rethook_node *node, struct ftrace_regs *regs, bool mcount); void arch_rethook_trampoline(void); /** @@ -84,11 +85,11 @@ static inline bool is_rethook_trampoline(unsigned long addr) } /* If the architecture needs to fixup the return address, implement it. */ -void arch_rethook_fixup_return(struct pt_regs *regs, +void arch_rethook_fixup_return(struct ftrace_regs *regs, unsigned long correct_ret_addr); /* Generic trampoline handler, arch code must prepare asm stub */ -unsigned long rethook_trampoline_handler(struct pt_regs *regs, +unsigned long rethook_trampoline_handler(struct ftrace_regs *regs, unsigned long frame); #ifdef CONFIG_RETHOOK diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 1fc6095d502d..ccbe41c961c3 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -2120,7 +2120,7 @@ static int pre_handler_kretprobe(struct kprobe *p, struct pt_regs *regs) if (rp->entry_handler && rp->entry_handler(ri, regs)) rethook_recycle(rhn); else - rethook_hook(rhn, regs, kprobe_ftrace(p)); + rethook_hook(rhn, (struct ftrace_regs *)regs, kprobe_ftrace(p)); return 0; } @@ -2128,12 +2128,17 @@ NOKPROBE_SYMBOL(pre_handler_kretprobe); static void kretprobe_rethook_handler(struct rethook_node *rh, void *data, unsigned long ret_addr, - struct pt_regs *regs) + struct ftrace_regs *fregs) { struct kretprobe *rp = (struct kretprobe *)data; + struct pt_regs *regs = ftrace_get_regs(fregs); struct kretprobe_instance *ri; struct kprobe_ctlblk *kcb; + /* This is bug because this depends on HAVE_PT_REGS_COMPAT_FTRACE_REGS */ + if (WARN_ON_ONCE(!regs)) + return; + /* The data must NOT be null. This means rethook data structure is broken. */ if (WARN_ON_ONCE(!data) || !rp->handler) return; diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 976fd594b446..7d6abb5bd861 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -57,6 +57,13 @@ config HAVE_DYNAMIC_FTRACE_WITH_ARGS This allows for use of ftrace_regs_get_argument() and ftrace_regs_get_stack_pointer(). +config HAVE_PT_REGS_COMPAT_FTRACE_REGS + bool + help + If this is set, the ftrace_regs data structure is compatible + with the pt_regs. So it is possible to be converted by + ftrace_get_regs(). + config HAVE_DYNAMIC_FTRACE_NO_PATCHABLE bool help diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 51573eaa04c4..99c5f95360f9 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2668,10 +2668,14 @@ kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, static void kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip, - unsigned long ret_ip, struct pt_regs *regs, + unsigned long ret_ip, struct ftrace_regs *fregs, void *data) { struct bpf_kprobe_multi_link *link; + struct pt_regs *regs = ftrace_get_regs(fregs); + + if (!regs) + return; link = container_of(fp, struct bpf_kprobe_multi_link, fp); kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c index 15a2aef92733..70b9c493e52d 100644 --- a/kernel/trace/fprobe.c +++ b/kernel/trace/fprobe.c @@ -53,7 +53,7 @@ static inline void __fprobe_handler(unsigned long ip, unsigned long parent_ip, if (ret) rethook_recycle(rh); else - rethook_hook(rh, ftrace_get_regs(fregs), true); + rethook_hook(rh, fregs, true); } } @@ -120,7 +120,7 @@ static void fprobe_kprobe_handler(unsigned long ip, unsigned long parent_ip, } static void fprobe_exit_handler(struct rethook_node *rh, void *data, - unsigned long ret_ip, struct pt_regs *regs) + unsigned long ret_ip, struct ftrace_regs *fregs) { struct fprobe *fp = (struct fprobe *)data; struct fprobe_rethook_node *fpr; @@ -141,7 +141,7 @@ static void fprobe_exit_handler(struct rethook_node *rh, void *data, return; } - fp->exit_handler(fp, fpr->entry_ip, ret_ip, regs, + fp->exit_handler(fp, fpr->entry_ip, ret_ip, fregs, fp->entry_data_size ? (void *)fpr->data : NULL); ftrace_test_recursion_unlock(bit); } diff --git a/kernel/trace/rethook.c b/kernel/trace/rethook.c index 5eb9b598f4e9..7c5cf9d5910c 100644 --- a/kernel/trace/rethook.c +++ b/kernel/trace/rethook.c @@ -189,7 +189,7 @@ NOKPROBE_SYMBOL(rethook_try_get); /** * rethook_hook() - Hook the current function return. * @node: The struct rethook node to hook the function return. - * @regs: The struct pt_regs for the function entry. + * @fregs: The struct ftrace_regs for the function entry. * @mcount: True if this is called from mcount(ftrace) context. * * Hook the current running function return. This must be called when the @@ -199,9 +199,9 @@ NOKPROBE_SYMBOL(rethook_try_get); * from the real function entry (e.g. kprobes) @mcount must be set false. * This is because the way to hook the function return depends on the context. */ -void rethook_hook(struct rethook_node *node, struct pt_regs *regs, bool mcount) +void rethook_hook(struct rethook_node *node, struct ftrace_regs *fregs, bool mcount) { - arch_rethook_prepare(node, regs, mcount); + arch_rethook_prepare(node, fregs, mcount); __llist_add(&node->llist, ¤t->rethooks); } NOKPROBE_SYMBOL(rethook_hook); @@ -269,7 +269,7 @@ unsigned long rethook_find_ret_addr(struct task_struct *tsk, unsigned long frame } NOKPROBE_SYMBOL(rethook_find_ret_addr); -void __weak arch_rethook_fixup_return(struct pt_regs *regs, +void __weak arch_rethook_fixup_return(struct ftrace_regs *fregs, unsigned long correct_ret_addr) { /* @@ -281,7 +281,7 @@ void __weak arch_rethook_fixup_return(struct pt_regs *regs, } /* This function will be called from each arch-defined trampoline. */ -unsigned long rethook_trampoline_handler(struct pt_regs *regs, +unsigned long rethook_trampoline_handler(struct ftrace_regs *fregs, unsigned long frame) { struct llist_node *first, *node = NULL; @@ -295,7 +295,7 @@ unsigned long rethook_trampoline_handler(struct pt_regs *regs, BUG_ON(1); } - instruction_pointer_set(regs, correct_ret_addr); + ftrace_regs_set_instruction_pointer(fregs, correct_ret_addr); /* * These loops must be protected from rethook_free_rcu() because those @@ -315,7 +315,7 @@ unsigned long rethook_trampoline_handler(struct pt_regs *regs, handler = READ_ONCE(rhn->rethook->handler); if (handler) handler(rhn, rhn->rethook->data, - correct_ret_addr, regs); + correct_ret_addr, fregs); if (first == node) break; @@ -323,7 +323,7 @@ unsigned long rethook_trampoline_handler(struct pt_regs *regs, } /* Fixup registers for returning to correct address. */ - arch_rethook_fixup_return(regs, correct_ret_addr); + arch_rethook_fixup_return(fregs, correct_ret_addr); /* Unlink used shadow stack */ first = current->rethooks.first; diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c index 4d3ae79f036e..f440c97e050f 100644 --- a/kernel/trace/trace_fprobe.c +++ b/kernel/trace/trace_fprobe.c @@ -341,10 +341,14 @@ static int fentry_dispatcher(struct fprobe *fp, unsigned long entry_ip, NOKPROBE_SYMBOL(fentry_dispatcher); static void fexit_dispatcher(struct fprobe *fp, unsigned long entry_ip, - unsigned long ret_ip, struct pt_regs *regs, + unsigned long ret_ip, struct ftrace_regs *fregs, void *entry_data) { struct trace_fprobe *tf = container_of(fp, struct trace_fprobe, fp); + struct pt_regs *regs = ftrace_get_regs(fregs); + + if (!regs) + return; if (trace_probe_test_flag(&tf->tp, TP_FLAG_TRACE)) fexit_trace_func(tf, entry_ip, ret_ip, regs); diff --git a/lib/test_fprobe.c b/lib/test_fprobe.c index ff607babba18..d1e80653bf0c 100644 --- a/lib/test_fprobe.c +++ b/lib/test_fprobe.c @@ -59,9 +59,9 @@ static notrace int fp_entry_handler(struct fprobe *fp, unsigned long ip, static notrace void fp_exit_handler(struct fprobe *fp, unsigned long ip, unsigned long ret_ip, - struct pt_regs *regs, void *data) + struct ftrace_regs *fregs, void *data) { - unsigned long ret = regs_return_value(regs); + unsigned long ret = ftrace_regs_return_value(fregs); KUNIT_EXPECT_FALSE(current_test, preemptible()); if (ip != target_ip) { @@ -89,7 +89,7 @@ static notrace int nest_entry_handler(struct fprobe *fp, unsigned long ip, static notrace void nest_exit_handler(struct fprobe *fp, unsigned long ip, unsigned long ret_ip, - struct pt_regs *regs, void *data) + struct ftrace_regs *fregs, void *data) { KUNIT_EXPECT_FALSE(current_test, preemptible()); KUNIT_EXPECT_EQ(current_test, ip, target_nest_ip); diff --git a/samples/fprobe/fprobe_example.c b/samples/fprobe/fprobe_example.c index 1545a1aac616..d476d1f07538 100644 --- a/samples/fprobe/fprobe_example.c +++ b/samples/fprobe/fprobe_example.c @@ -67,7 +67,7 @@ static int sample_entry_handler(struct fprobe *fp, unsigned long ip, } static void sample_exit_handler(struct fprobe *fp, unsigned long ip, - unsigned long ret_ip, struct pt_regs *regs, + unsigned long ret_ip, struct ftrace_regs *regs, void *data) { unsigned long rip = ret_ip;