From 44b58e06e8e3872b6741e5aee59a7a93dfe3834a Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Tue, 20 Jun 2017 12:19:16 -0300 Subject: [PATCH] perf tools: Do parameter validation earlier on fetch_kernel_version() While trying to reduce util.[ch] I noticed that fetch_kernel_version() and fetch_ubuntu_kernel_version() do lots of operations only to check if they are needed, i.e. it checks if the pointer where to return the kernel version is NULL only after obtaining the kernel version from /proc/version_signature or by parsing the results from uname(). Do it earlier not to confuse people reading this code in the future :-) Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-i94qwyekk4tzbu0b9ce1r1mz@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/util.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c index 3cd4299..988111e 100644 --- a/tools/perf/util/util.c +++ b/tools/perf/util/util.c @@ -350,8 +350,12 @@ fetch_ubuntu_kernel_version(unsigned int *puint) size_t line_len = 0; char *ptr, *line = NULL; int version, patchlevel, sublevel, err; - FILE *vsig = fopen("/proc/version_signature", "r"); + FILE *vsig; + if (!puint) + return 0; + + vsig = fopen("/proc/version_signature", "r"); if (!vsig) { pr_debug("Open /proc/version_signature failed: %s\n", strerror(errno)); @@ -381,8 +385,7 @@ fetch_ubuntu_kernel_version(unsigned int *puint) goto errout; } - if (puint) - *puint = (version << 16) + (patchlevel << 8) + sublevel; + *puint = (version << 16) + (patchlevel << 8) + sublevel; err = 0; errout: free(line); @@ -409,6 +412,9 @@ fetch_kernel_version(unsigned int *puint, char *str, str[str_size - 1] = '\0'; } + if (!puint || int_ver_ready) + return 0; + err = sscanf(utsname.release, "%d.%d.%d", &version, &patchlevel, &sublevel); @@ -418,8 +424,7 @@ fetch_kernel_version(unsigned int *puint, char *str, return -1; } - if (puint && !int_ver_ready) - *puint = (version << 16) + (patchlevel << 8) + sublevel; + *puint = (version << 16) + (patchlevel << 8) + sublevel; return 0; } -- 2.7.4