From nobody Fri Feb 13 06:06:25 2026 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 46A2E39ADD; Sun, 2 Jun 2024 03:37:27 +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=1717299447; cv=none; b=U1lqT3oULC9pXXwn/SZtjWP00CDgNANfJXiAFiHiGOmpQbyCXJIiJ3T3li5GfftbO9VYzzjb1szfUe27eON1lT2jzVD51i3Yo4L/AXyEUur3GC78X6IrKSiOpZKUBUxR/s3pZzuuD6DUs47geodpfPQ9nyGPsQKxVms1o9iaEg8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717299447; c=relaxed/simple; bh=3l/gu/FYcbjCAMjbkxPSB7XC3G/80oVuZGVp8xWdyDQ=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=j2CCrdSVEjio8JsNjBZZYAQia0THaYy3o5UAITzQCJd31TI37NCYBoO4yEXql4k6Ptdyq8cBeVPiHReafTfl9KLrAMKRnJTBh92n9NHvDWOenNDml0MuMgV2X4YKOrcKnsvZ6LV6I602Cm9ZEYP4IEkxNrZdHgnSj35/lGEp7O4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2E529C4AF0A; Sun, 2 Jun 2024 03:37:27 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.97) (envelope-from ) id 1sDc3G-000000094Sx-21ou; Sat, 01 Jun 2024 23:38:34 -0400 Message-ID: <20240602033834.343037522@goodmis.org> User-Agent: quilt/0.68 Date: Sat, 01 Jun 2024 23:38:04 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Alexei Starovoitov , Florent Revest , Martin KaFai Lau , bpf , Sven Schnelle , Alexei Starovoitov , Jiri Olsa , Arnaldo Carvalho de Melo , Daniel Borkmann , Alan Maguire , Peter Zijlstra , Thomas Gleixner , Guo Ren Subject: [PATCH v2 20/27] function_graph: Add selftest for passing local variables References: <20240602033744.563858532@goodmis.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: "Steven Rostedt (VMware)" Add boot up selftest that passes variables from a function entry to a function exit, and make sure that they do get passed around. Co-developed with Masami Hiramatsu: Link: https://lore.kernel.org/linux-trace-kernel/171509110271.162236.110475= 51496319744627.stgit@devnote2 Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_selftest.c | 169 ++++++++++++++++++++++++++++++++++ 1 file changed, 169 insertions(+) diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index f8f55fd79e53..fcdc744c245e 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -756,6 +756,173 @@ trace_selftest_startup_function(struct tracer *trace,= struct trace_array *tr) =20 #ifdef CONFIG_FUNCTION_GRAPH_TRACER =20 +#ifdef CONFIG_DYNAMIC_FTRACE + +#define BYTE_NUMBER 123 +#define SHORT_NUMBER 12345 +#define WORD_NUMBER 1234567890 +#define LONG_NUMBER 1234567890123456789LL + +static int fgraph_store_size __initdata; +static const char *fgraph_store_type_name __initdata; +static char *fgraph_error_str __initdata; +static char fgraph_error_str_buf[128] __initdata; + +static __init int store_entry(struct ftrace_graph_ent *trace, + struct fgraph_ops *gops) +{ + const char *type =3D fgraph_store_type_name; + int size =3D fgraph_store_size; + void *p; + + p =3D fgraph_reserve_data(gops->idx, size); + if (!p) { + snprintf(fgraph_error_str_buf, sizeof(fgraph_error_str_buf), + "Failed to reserve %s\n", type); + fgraph_error_str =3D fgraph_error_str_buf; + return 0; + } + + switch (fgraph_store_size) { + case 1: + *(char *)p =3D BYTE_NUMBER; + break; + case 2: + *(short *)p =3D SHORT_NUMBER; + break; + case 4: + *(int *)p =3D WORD_NUMBER; + break; + case 8: + *(long long *)p =3D LONG_NUMBER; + break; + } + + return 1; +} + +static __init void store_return(struct ftrace_graph_ret *trace, + struct fgraph_ops *gops) +{ + const char *type =3D fgraph_store_type_name; + long long expect =3D 0; + long long found =3D -1; + int size; + char *p; + + p =3D fgraph_retrieve_data(gops->idx, &size); + if (!p) { + snprintf(fgraph_error_str_buf, sizeof(fgraph_error_str_buf), + "Failed to retrieve %s\n", type); + fgraph_error_str =3D fgraph_error_str_buf; + return; + } + if (fgraph_store_size > size) { + snprintf(fgraph_error_str_buf, sizeof(fgraph_error_str_buf), + "Retrieved size %d is smaller than expected %d\n", + size, (int)fgraph_store_size); + fgraph_error_str =3D fgraph_error_str_buf; + return; + } + + switch (fgraph_store_size) { + case 1: + expect =3D BYTE_NUMBER; + found =3D *(char *)p; + break; + case 2: + expect =3D SHORT_NUMBER; + found =3D *(short *)p; + break; + case 4: + expect =3D WORD_NUMBER; + found =3D *(int *)p; + break; + case 8: + expect =3D LONG_NUMBER; + found =3D *(long long *)p; + break; + } + + if (found !=3D expect) { + snprintf(fgraph_error_str_buf, sizeof(fgraph_error_str_buf), + "%s returned not %lld but %lld\n", type, expect, found); + fgraph_error_str =3D fgraph_error_str_buf; + return; + } + fgraph_error_str =3D NULL; +} + +static struct fgraph_ops store_bytes __initdata =3D { + .entryfunc =3D store_entry, + .retfunc =3D store_return, +}; + +static int __init test_graph_storage_type(const char *name, int size) +{ + char *func_name; + int len; + int ret; + + fgraph_store_type_name =3D name; + fgraph_store_size =3D size; + + snprintf(fgraph_error_str_buf, sizeof(fgraph_error_str_buf), + "Failed to execute storage %s\n", name); + fgraph_error_str =3D fgraph_error_str_buf; + + pr_cont("PASSED\n"); + pr_info("Testing fgraph storage of %d byte%s: ", size, size > 1 ? "s" : "= "); + + func_name =3D "*" __stringify(DYN_FTRACE_TEST_NAME); + len =3D strlen(func_name); + + ret =3D ftrace_set_filter(&store_bytes.ops, func_name, len, 1); + if (ret && ret !=3D -ENODEV) { + pr_cont("*Could not set filter* "); + return -1; + } + + ret =3D register_ftrace_graph(&store_bytes); + if (ret) { + pr_warn("Failed to init store_bytes fgraph tracing\n"); + return -1; + } + + DYN_FTRACE_TEST_NAME(); + + unregister_ftrace_graph(&store_bytes); + + if (fgraph_error_str) { + pr_cont("*** %s ***", fgraph_error_str); + return -1; + } + + return 0; +} +/* Test the storage passed across function_graph entry and return */ +static __init int test_graph_storage(void) +{ + int ret; + + ret =3D test_graph_storage_type("byte", 1); + if (ret) + return ret; + ret =3D test_graph_storage_type("short", 2); + if (ret) + return ret; + ret =3D test_graph_storage_type("word", 4); + if (ret) + return ret; + ret =3D test_graph_storage_type("long long", 8); + if (ret) + return ret; + return 0; +} +#else +static inline int test_graph_storage(void) { return 0; } +#endif /* CONFIG_DYNAMIC_FTRACE */ + /* Maximum number of functions to trace before diagnosing a hang */ #define GRAPH_MAX_FUNC_TEST 100000000 =20 @@ -913,6 +1080,8 @@ trace_selftest_startup_function_graph(struct tracer *t= race, ftrace_set_global_filter(NULL, 0, 1); #endif =20 + ret =3D test_graph_storage(); + /* Don't test dynamic tracing, the function tracer already did */ out: /* Stop it if we failed */ --=20 2.43.0