From patchwork Sun Aug 18 12:49:16 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: 13767408 X-Patchwork-Delegate: bpf@iogearbox.net 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 A1A8A286A3; Sun, 18 Aug 2024 12:49:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723985361; cv=none; b=icv6X0pgLNAUui1Gx+BoJVFYtQTcJqChgRl580v82WsIvOQBUL8f/y4u88NyNcqBU7n/qe0smlatiaUuH0D3H3tUP6TJNg94i+nr5A61rXAt5MrGSuuFip1pMkz8PkbBCvJUZfuyCshrFTWUiiJY7BX/skTD0H/2wZtaCm8bcy4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723985361; c=relaxed/simple; bh=HIuUHRP2bZeiOHc7iM1LDG4JhKapAaol6dDufhclus4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=eXxk8MsXCcI30a43f4AvgN9e9RBUTiYzui/5KS0ImB62wSqLsbKDxooTVpyuJWquSJ8UdgLJH6WzPd4rOocY/946cEBpZwfXt5llicUpud1zcNnfuo+FFjQw29ndBilvUvwNTXhsbQ5JglRU4jDWE9ydp+bQ/5ZPVwOfXrf1zus= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=n8n1fStl; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="n8n1fStl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 408D1C4AF0B; Sun, 18 Aug 2024 12:49:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1723985361; bh=HIuUHRP2bZeiOHc7iM1LDG4JhKapAaol6dDufhclus4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=n8n1fStluPMtVJhJiBjJc8bWpLwvAvt0dc4Lv0HwHpsIpmgos9kBMsFqeabEHjG0T dhN2Ve1d/bv/GKnSGEHrhKC9RPXXOO9iG8kObS/xM5kDOM4usIfESec5rkof53rfiL 7UKz3P0Bnb8DwZ0/ULmQGgz2/tqfCbAPTvHQ7XfPuUDJFabXvqMsJUXBIHKR/fWzxq AH9gRe2MchCcfwzI6lGslJIkL2t4UdCDVYoGAvNUrwccqvjrD8K/7UfoTWajSk6obl oijj33BdilayIwh4Ps+ljwHMD3uJgLaD2WpRepWiL3SuBbzc7d0/TBh7jGbaKmmrKw AQw5L09zk/iUA== 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 v13 08/20] fprobe: Use ftrace_regs in fprobe exit handler Date: Sun, 18 Aug 2024 21:49:16 +0900 Message-Id: <172398535633.293426.2157498788084697864.stgit@devnote2> X-Mailer: git-send-email 2.34.1 In-Reply-To: <172398527264.293426.2050093948411376857.stgit@devnote2> References: <172398527264.293426.2050093948411376857.stgit@devnote2> User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: bpf@iogearbox.net 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 | 6 ++++++ 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, 34 insertions(+), 8 deletions(-) diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index 974f08f65f63..73cb657496c8 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -122,6 +122,7 @@ 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 12e942cfbcde..eebc299f424b 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -175,6 +175,7 @@ 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 047384e4d93a..59788d8b220e 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -218,6 +218,7 @@ 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 ca64ee5e45d2..ef609bcca0f9 100644 --- a/include/linux/fprobe.h +++ b/include/linux/fprobe.h @@ -14,7 +14,7 @@ typedef int (*fprobe_entry_cb)(struct fprobe *fp, unsigned long entry_ip, void *entry_data); typedef void (*fprobe_exit_cb)(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/ftrace.h b/include/linux/ftrace.h index e7c41d9988e1..a1b2ef492c7f 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -162,6 +162,12 @@ 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) { if (!fregs) diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 0c6a03554c13..2e2b39699542 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_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 @@ -288,6 +295,7 @@ 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 947808a002d0..cdba9981b048 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2874,10 +2874,14 @@ 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, true, data); diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c index 3d3789283873..90a3c8e2bbdf 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 b2c20d4fdfd7..273cdf3cf70c 100644 --- a/kernel/trace/trace_fprobe.c +++ b/kernel/trace/trace_fprobe.c @@ -359,10 +359,14 @@ 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, entry_data); 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 c234afae52d6..bfe98ce826f3 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;