From patchwork Wed Nov 8 14:27:49 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: 13450177 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 26F02199DA; Wed, 8 Nov 2023 14:27:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="h3ABJQPl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8AA58C433C8; Wed, 8 Nov 2023 14:27:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699453675; bh=scic1c4AReJm5CEswQdYp93zWYtdZAuoXxQCoLn6I6Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=h3ABJQPlkE6/AKdvVMkBmcx0aETkZahLXURssP/FG1i4MXurleseWQe6qWAMEiUUO DFb3KvNhWrA5K5aLE74PMg2BsIDOJ+riHUiGvmD/BixGjml2YInSgLP3XaTVYPa30r gYOJrHO1WPZnl2Gc5257simUaDO/bJ2NtkCr+lbDcQM9gEjBQgBPuCwD/qHSbEHZ/l 5BYD/Ox4tnP8r69TdBfDTiRJxNskWAjxMxclF1lCq1+j3/XsE9oILBnMYh8ALO2CSt YI9Z5pL14IVahVz+O2QxX9R68uEh6YK3O2h8hUAMcABWbo0kqdoDarAK+udErwqQRP 5b6S1nGs25WWw== 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: [RFC PATCH v2 18/31] function_graph: Add selftest for passing local variables Date: Wed, 8 Nov 2023 23:27:49 +0900 Message-Id: <169945366902.55307.16626453640949225005.stgit@devnote2> X-Mailer: git-send-email 2.34.1 In-Reply-To: <169945345785.55307.5003201137843449313.stgit@devnote2> References: <169945345785.55307.5003201137843449313.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-State: RFC 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. Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v2: - Add reserved size test. - Use pr_*() instead of printk(KERN_*). --- 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 f0758afa2f7d..601e9d475546 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) #ifdef CONFIG_FUNCTION_GRAPH_TRACER +#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 = fgraph_store_type_name; + int size = fgraph_store_size; + void *p; + + p = fgraph_reserve_data(size); + if (!p) { + snprintf(fgraph_error_str_buf, sizeof(fgraph_error_str_buf), + "Failed to reserve %s\n", type); + fgraph_error_str = fgraph_error_str_buf; + return 0; + } + + switch (fgraph_store_size) { + case 1: + *(char *)p = BYTE_NUMBER; + break; + case 2: + *(short *)p = SHORT_NUMBER; + break; + case 4: + *(int *)p = WORD_NUMBER; + break; + case 8: + *(long long *)p = LONG_NUMBER; + break; + } + + return 1; +} + +static __init void store_return(struct ftrace_graph_ret *trace, + struct fgraph_ops *gops) +{ + const char *type = fgraph_store_type_name; + long long expect = 0; + long long found = -1; + int size; + char *p; + + p = fgraph_retrieve_data(&size); + if (!p) { + snprintf(fgraph_error_str_buf, sizeof(fgraph_error_str_buf), + "Failed to retrieve %s\n", type); + fgraph_error_str = 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 = fgraph_error_str_buf; + return; + } + + switch (fgraph_store_size) { + case 1: + expect = BYTE_NUMBER; + found = *(char *)p; + break; + case 2: + expect = SHORT_NUMBER; + found = *(short *)p; + break; + case 4: + expect = WORD_NUMBER; + found = *(int *)p; + break; + case 8: + expect = LONG_NUMBER; + found = *(long long *)p; + break; + } + + if (found != expect) { + snprintf(fgraph_error_str_buf, sizeof(fgraph_error_str_buf), + "%s returned not %lld but %lld\n", type, expect, found); + fgraph_error_str = fgraph_error_str_buf; + return; + } + fgraph_error_str = NULL; +} + +static struct fgraph_ops store_bytes __initdata = { + .entryfunc = store_entry, + .retfunc = 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 = name; + fgraph_store_size = size; + + snprintf(fgraph_error_str_buf, sizeof(fgraph_error_str_buf), + "Failed to execute storage %s\n", name); + fgraph_error_str = fgraph_error_str_buf; + + pr_cont("PASSED\n"); + pr_info("Testing fgraph storage of %d byte%s: ", size, size > 1 ? "s" : ""); + + func_name = "*" __stringify(DYN_FTRACE_TEST_NAME); + len = strlen(func_name); + + ret = ftrace_set_filter(&store_bytes.ops, func_name, len, 1); + if (ret && ret != -ENODEV) { + pr_cont("*Could not set filter* "); + return -1; + } + + ret = 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 = test_graph_storage_type("byte", 1); + if (ret) + return ret; + ret = test_graph_storage_type("short", 2); + if (ret) + return ret; + ret = test_graph_storage_type("word", 4); + if (ret) + return ret; + ret = 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 @@ -913,6 +1080,8 @@ trace_selftest_startup_function_graph(struct tracer *trace, ftrace_set_global_filter(NULL, 0, 1); #endif + ret = test_graph_storage(); + /* Don't test dynamic tracing, the function tracer already did */ out: /* Stop it if we failed */