From patchwork Thu Dec 28 20:35:32 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 13506199 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 A4E9C107BB for ; Thu, 28 Dec 2023 20:36:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0E7E4C433D9; Thu, 28 Dec 2023 20:36:26 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.97) (envelope-from ) id 1rIx7z-00000000DtA-3H5G; Thu, 28 Dec 2023 15:37:15 -0500 From: Steven Rostedt To: linux-trace-devel@vger.kernel.org Cc: "Steven Rostedt (Google)" Subject: [PATCH 10/23] libtracefs: Add tracefs_instance_file_write_number() Date: Thu, 28 Dec 2023 15:35:32 -0500 Message-ID: <20231228203714.53294-11-rostedt@goodmis.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231228203714.53294-1-rostedt@goodmis.org> References: <20231228203714.53294-1-rostedt@goodmis.org> Precedence: bulk X-Mailing-List: linux-trace-devel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: "Steven Rostedt (Google)" Add the helper function to write a number into a tracefs file. As tracefs files require writing strings and not binary numbers, this is a helper function that does the conversion to string followed by a tracefs_instance_file_write() on that string. Signed-off-by: Steven Rostedt (Google) --- .../libtracefs-instances-file-manip.txt | 9 +++++- Documentation/libtracefs.txt | 1 + include/tracefs.h | 2 ++ src/tracefs-instance.c | 21 +++++++++++++ utest/tracefs-utest.c | 30 ++++++++++++++++++- 5 files changed, 61 insertions(+), 2 deletions(-) diff --git a/Documentation/libtracefs-instances-file-manip.txt b/Documentation/libtracefs-instances-file-manip.txt index 8c04240523d3..bb1b36e36c3e 100644 --- a/Documentation/libtracefs-instances-file-manip.txt +++ b/Documentation/libtracefs-instances-file-manip.txt @@ -5,7 +5,7 @@ NAME ---- tracefs_instance_file_open, -tracefs_instance_file_write, tracefs_instance_file_append, tracefs_instance_file_clear, +tracefs_instance_file_write, tracefs_instance_file_write_number, tracefs_instance_file_append, tracefs_instance_file_clear, tracefs_instance_file_read, tracefs_instance_file_read_number - Work with files in tracing instances. SYNOPSIS @@ -16,6 +16,7 @@ SYNOPSIS int *tracefs_instance_file_open*(struct tracefs_instance pass:[*]_instance_, const char pass:[*]_file_, int _mode_); int *tracefs_instance_file_write*(struct tracefs_instance pass:[*]_instance_, const char pass:[*]_file_, const char pass:[*]_str_); +int *tracefs_instance_file_write_number*(struct tracefs_instance pass:[*]_instance_, const char pass:[*]_file_, size_t _val_); int *tracefs_instance_file_append*(struct tracefs_instance pass:[*]_instance_, const char pass:[*]_file_, const char pass:[*]_str_); int *tracefs_instance_file_clear*(struct tracefs_instance pass:[*]_instance_, const char pass:[*]_file_); char pass:[*]*tracefs_instance_file_read*(struct tracefs_instance pass:[*]_instance_, const char pass:[*]_file_, int pass:[*]_psize_); @@ -38,6 +39,10 @@ The *tracefs_instance_file_write()* function writes a string _str_ in a _file_ f the given _instance_, without the terminating NULL character. When opening the file, this function tries to truncates the size of the file to zero, which clears all previously existing settings. +The *tracefs_instance_file_write_number()* function converts _val_ into a string +and then writes it to the given file. This is a helper function that does the number +conversion to string and then calls *tracefs_instance_file_write()*. + The *tracefs_instance_file_append()* function writes a string _str_ in a _file_ from the given _instance_, without the terminating NULL character. This function is similar to *tracefs_instance_file_write()*, but the existing content of the is not cleared. Thus the @@ -61,6 +66,8 @@ closed with *close*(3). In case of an error, -1 is returned. The *tracefs_instance_file_write()* function returns the number of written bytes, or -1 in case of an error. +The *tracefs_instance_file_write_number()* function returns 0 on success and -1 on error. + The *tracefs_instance_file_append()* function returns the number of written bytes, or -1 in case of an error. diff --git a/Documentation/libtracefs.txt b/Documentation/libtracefs.txt index 850118302ab2..11ff576e826c 100644 --- a/Documentation/libtracefs.txt +++ b/Documentation/libtracefs.txt @@ -33,6 +33,7 @@ Trace instances: char pass:[*]*tracefs_instance_get_dir*(struct tracefs_instance pass:[*]_instance_); int *tracefs_instance_file_open*(struct tracefs_instance pass:[*]_instance_, const char pass:[*]_file_, int _mode_); int *tracefs_instance_file_write*(struct tracefs_instance pass:[*]_instance_, const char pass:[*]_file_, const char pass:[*]_str_); + int *tracefs_instance_file_write_number*(struct tracefs_instance pass:[*]_instance_, const char pass:[*]_file_, size_t _val_); int *tracefs_instance_file_append*(struct tracefs_instance pass:[*]_instance_, const char pass:[*]_file_, const char pass:[*]_str_); int *tracefs_instance_file_clear*(struct tracefs_instance pass:[*]_instance_, const char pass:[*]_file_); char pass:[*]*tracefs_instance_file_read*(struct tracefs_instance pass:[*]_instance_, const char pass:[*]_file_, int pass:[*]_psize_); diff --git a/include/tracefs.h b/include/tracefs.h index 25429a30c028..0971d54dd7c7 100644 --- a/include/tracefs.h +++ b/include/tracefs.h @@ -36,6 +36,8 @@ tracefs_instance_get_file(struct tracefs_instance *instance, const char *file); char *tracefs_instance_get_dir(struct tracefs_instance *instance); int tracefs_instance_file_write(struct tracefs_instance *instance, const char *file, const char *str); +int tracefs_instance_file_write_number(struct tracefs_instance *instance, + const char *file, size_t val); int tracefs_instance_file_append(struct tracefs_instance *instance, const char *file, const char *str); int tracefs_instance_file_clear(struct tracefs_instance *instance, diff --git a/src/tracefs-instance.c b/src/tracefs-instance.c index 2efcc75dfd98..b019836333a3 100644 --- a/src/tracefs-instance.c +++ b/src/tracefs-instance.c @@ -493,6 +493,27 @@ int tracefs_instance_file_write(struct tracefs_instance *instance, return instance_file_write(instance, file, str, O_WRONLY | O_TRUNC); } +/** + * tracefs_instance_file_write_number - Write integer from a trace file. + * @instance: ftrace instance, can be NULL for the top instance + * @file: name of the file + * @res: The integer to write to @file + * + * Returns 0 if the write succeeds, -1 on error. + */ +int tracefs_instance_file_write_number(struct tracefs_instance *instance, + const char *file, size_t val) +{ + char buf[64]; + int ret; + + snprintf(buf, 64, "%zd\n", val); + + ret = tracefs_instance_file_write(instance, file, buf); + + return ret > 1 ? 0 : -1; +} + /** * tracefs_instance_file_append - Append to a trace file of specific instance. * @instance: ftrace instance, can be NULL for the top instance. diff --git a/utest/tracefs-utest.c b/utest/tracefs-utest.c index 492e5c05551f..98cfd322b171 100644 --- a/utest/tracefs-utest.c +++ b/utest/tracefs-utest.c @@ -488,7 +488,7 @@ static int setup_trace_cpu(struct tracefs_instance *instance, struct test_cpu_da if (!data->buf) goto fail; - data->kbuf = kbuffer_alloc(sizeof(long) == 8, !tep_is_bigendian()); + data->kbuf = tep_kbuffer(data->tep); CU_TEST(data->kbuf != NULL); if (!data->kbuf) goto fail; @@ -2127,6 +2127,7 @@ static void test_instance_file_fd(struct tracefs_instance *instance) const char *name = get_rand_str(); const char *tdir = tracefs_instance_get_trace_dir(instance); long long res = -1; + long long res2; char rd[2]; int fd; @@ -2146,7 +2147,34 @@ static void test_instance_file_fd(struct tracefs_instance *instance) CU_TEST(read(fd, &rd, 1) == 1); rd[1] = 0; CU_TEST(res == atoi(rd)); + close(fd); + + /* Inverse tracing_on and test changing it with write_number */ + res ^= 1; + CU_TEST(tracefs_instance_file_write_number(instance, TRACE_ON, (size_t)res) == 0); + + CU_TEST(tracefs_instance_file_read_number(instance, TRACE_ON, &res2) == 0); + CU_TEST(res2 == res); + fd = tracefs_instance_file_open(instance, TRACE_ON, O_RDONLY); + CU_TEST(fd >= 0); + CU_TEST(read(fd, &rd, 1) == 1); + rd[1] = 0; + CU_TEST(res2 == atoi(rd)); + close(fd); + + /* Put back the result of tracing_on */ + res ^= 1; + + CU_TEST(tracefs_instance_file_write_number(instance, TRACE_ON, (size_t)res) == 0); + + CU_TEST(tracefs_instance_file_read_number(instance, TRACE_ON, &res2) == 0); + CU_TEST(res2 == res); + fd = tracefs_instance_file_open(instance, TRACE_ON, O_RDONLY); + CU_TEST(fd >= 0); + CU_TEST(read(fd, &rd, 1) == 1); + rd[1] = 0; + CU_TEST(res2 == atoi(rd)); close(fd); }