[v13,08/20] fprobe: Use ftrace_regs in fprobe exit handler

Message ID	172398535633.293426.2157498788084697864.stgit@devnote2 (mailing list archive)
State	Superseded
Headers	show 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) From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> To: Alexei Starovoitov <alexei.starovoitov@gmail.com>, Steven Rostedt <rostedt@goodmis.org>, Florent Revest <revest@chromium.org> Cc: linux-trace-kernel@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>, Martin KaFai Lau <martin.lau@linux.dev>, bpf <bpf@vger.kernel.org>, Sven Schnelle <svens@linux.ibm.com>, Alexei Starovoitov <ast@kernel.org>, Jiri Olsa <jolsa@kernel.org>, Arnaldo Carvalho de Melo <acme@kernel.org>, Daniel Borkmann <daniel@iogearbox.net>, Alan Maguire <alan.maguire@oracle.com>, Mark Rutland <mark.rutland@arm.com>, Peter Zijlstra <peterz@infradead.org>, Thomas Gleixner <tglx@linutronix.de>, Guo Ren <guoren@kernel.org> 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> In-Reply-To: <172398527264.293426.2050093948411376857.stgit@devnote2> References: <172398527264.293426.2050093948411376857.stgit@devnote2> User-Agent: StGit/0.19 Precedence: bulk MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit
Series	tracing: fprobe: function_graph: Multi-function graph and fprobe on fgraph \| expand [v13,00/20] tracing: fprobe: function_graph: Multi-function graph and fprobe on fgraph [v13,01/20] tracing: fgraph: Fix to add new fgraph_ops to array after ftrace_startup_subops() [v13,02/20] tracing: Add a comment about ftrace_regs definition [v13,03/20] tracing: Rename ftrace_regs_return_value to ftrace_regs_get_return_value [v13,04/20] function_graph: Pass ftrace_regs to entryfunc [v13,05/20] function_graph: Replace fgraph_ret_regs with ftrace_regs [v13,06/20] function_graph: Pass ftrace_regs to retfunc [v13,07/20] fprobe: Use ftrace_regs in fprobe entry handler [v13,08/20] fprobe: Use ftrace_regs in fprobe exit handler [v13,09/20] tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs [v13,10/20] tracing: Add ftrace_fill_perf_regs() for perf event [v13,11/20] tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS [v13,12/20] bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled [v13,13/20] ftrace: Add CONFIG_HAVE_FTRACE_GRAPH_FUNC [v13,14/20] fprobe: Rewrite fprobe on function-graph tracer [v13,15/20] tracing: Fix function timing profiler to initialize hashtable [v13,16/20] tracing/fprobe: Remove nr_maxactive from fprobe [v13,17/20] selftests: ftrace: Remove obsolate maxactive syntax check [v13,18/20] selftests/ftrace: Add a test case for repeating register/unregister fprobe [v13,19/20] Documentation: probes: Update fprobe on function-graph tracer [v13,20/20] fgraph: Skip recording calltime/rettime if it is not nneeded

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;

[v13,08/20] fprobe: Use ftrace_regs in fprobe exit handler

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