From patchwork Fri Jan 12 10:16:08 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 13518251 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 7D4F864AB0; Fri, 12 Jan 2024 10:16:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Z9alAlbr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A7B41C433F1; Fri, 12 Jan 2024 10:16:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1705054574; bh=oiJYB2UuFrGS8fIQt3vASzn+Wih9LPxEKlaTTe/MYC0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Z9alAlbrPpR2TPX3Rf1N0YUGuI8mZozN9VoTkscMHXFEY/Y3LgLoPdJ6wpbvglyji CJNiL4VxTvngtiGXgvG2DwtoFq+WP1NoVOHfox5vnbnkSnT2zXc6Ji4JoCf8SjUIjs +8CqVBk7K6GAxre9giB5k5mdHJoXF85nJ2l+6YPrXc3sWSOIinnWS7gkvyNH8nL+5O pjbUk5GROADwXdu/hWlXnhplgRC9iB57RF9GG7mbltwqQCsYdj8DOAAfKuamluFLWC j6L+Wc3LtqYvFLWK1XCUPaxdxP02ibrd53Ieh6hR8HVk3dlUMalK3AqzFMSZ+1vcxC 322emnmUo/EPg== 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 , Guo Ren Subject: [PATCH v6 27/36] fprobe: Use ftrace_regs in fprobe exit handler Date: Fri, 12 Jan 2024 19:16:08 +0900 Message-Id: <170505456827.459169.5071371071652498082.stgit@devnote2> X-Mailer: git-send-email 2.34.1 In-Reply-To: <170505424954.459169.10630626365737237288.stgit@devnote2> References: <170505424954.459169.10630626365737237288.stgit@devnote2> User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Masami Hiramatsu (Google) Change the fprobe exit handler to use ftrace_regs structure instead of pt_regs. This also introduce HAVE_PT_REGS_TO_FTRACE_REGS_CAST which means the ftrace_regs's memory layout is equal to the pt_regs so that those are able to cast. Fprobe introduces a new dependency with that. Signed-off-by: Masami Hiramatsu (Google) --- Changes in v3: - Use ftrace_regs_get_return_value() Changes from previous series: NOTHING, just forward ported. --- arch/loongarch/Kconfig | 1 + arch/s390/Kconfig | 1 + arch/x86/Kconfig | 1 + include/linux/fprobe.h | 2 +- include/linux/ftrace.h | 5 +++++ kernel/trace/Kconfig | 8 ++++++++ kernel/trace/bpf_trace.c | 6 +++++- kernel/trace/fprobe.c | 3 ++- kernel/trace/trace_fprobe.c | 6 +++++- lib/test_fprobe.c | 6 +++--- samples/fprobe/fprobe_example.c | 2 +- 11 files changed, 33 insertions(+), 8 deletions(-) diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index ee123820a476..b0bd252aefe8 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -108,6 +108,7 @@ config LOONGARCH select HAVE_DMA_CONTIGUOUS select HAVE_DYNAMIC_FTRACE select HAVE_DYNAMIC_FTRACE_WITH_ARGS + select HAVE_PT_REGS_TO_FTRACE_REGS_CAST 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 d5d8f99d1f25..5736c1970f49 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -168,6 +168,7 @@ config S390 select HAVE_DMA_CONTIGUOUS select HAVE_DYNAMIC_FTRACE select HAVE_DYNAMIC_FTRACE_WITH_ARGS + select HAVE_PT_REGS_TO_FTRACE_REGS_CAST 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 375ad280ee75..1a8b5d447e85 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -209,6 +209,7 @@ 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_TO_FTRACE_REGS_CAST 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/include/linux/fprobe.h b/include/linux/fprobe.h index 36c0595f7b93..879a30956009 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 *fregs, void *entry_data); }; diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index da2a23f5a9ed..a72a2eaec576 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -159,6 +159,11 @@ struct ftrace_regs { #define ftrace_regs_set_instruction_pointer(fregs, ip) do { } while (0) #endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */ +#ifdef CONFIG_HAVE_PT_REGS_TO_FTRACE_REGS_CAST + +static_assert(sizeof(struct pt_regs) == sizeof(struct ftrace_regs)); + +#endif /* CONFIG_HAVE_PT_REGS_TO_FTRACE_REGS_CAST */ static __always_inline struct pt_regs *ftrace_get_regs(struct ftrace_regs *fregs) { diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 805d72ab77c6..1a2544712690 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -60,6 +60,13 @@ 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_TO_FTRACE_REGS_CAST + bool + help + If this is set, the memory layout of the ftrace_regs data structure + is the same as the pt_regs. So the pt_regs is possible to be casted + to ftrace_regs. + config HAVE_DYNAMIC_FTRACE_NO_PATCHABLE bool help @@ -291,6 +298,7 @@ config FPROBE bool "Kernel Function Probe (fprobe)" depends on FUNCTION_TRACER depends on DYNAMIC_FTRACE_WITH_REGS || DYNAMIC_FTRACE_WITH_ARGS + depends on HAVE_PT_REGS_TO_FTRACE_REGS_CAST || !HAVE_DYNAMIC_FTRACE_WITH_ARGS depends on HAVE_RETHOOK select RETHOOK default n diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index d3f8745d8ead..efb792f8f2ea 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2749,10 +2749,14 @@ 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 a932c3a79e8f..31210423efc3 100644 --- a/kernel/trace/fprobe.c +++ b/kernel/trace/fprobe.c @@ -124,6 +124,7 @@ static void fprobe_exit_handler(struct rethook_node *rh, void *data, { struct fprobe *fp = (struct fprobe *)data; struct fprobe_rethook_node *fpr; + struct ftrace_regs *fregs = (struct ftrace_regs *)regs; int bit; if (!fp || fprobe_disabled(fp)) @@ -141,7 +142,7 @@ 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/trace_fprobe.c b/kernel/trace/trace_fprobe.c index ef6b36fd05ae..3982626c82e6 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..271ce0caeec0 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_get_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;