[PATCH 06/11] perf tools: Make fetch_kernel_version() publicly available

From: Arnaldo Carvalho de Melo
Date: Fri Nov 06 2015 - 15:57:08 EST


From: Wang Nan <wangnan0@xxxxxxxxxx>

There are 2 places in llvm-utils.c which find kernel version information
through uname. This patch extracts the uname related code into a
fetch_kernel_version() function and puts it into util.h so it can be
reused.

Signed-off-by: Wang Nan <wangnan0@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Zefan Li <lizefan@xxxxxxxxxx>
Cc: pi3orama@xxxxxxx
Link: http://lkml.kernel.org/r/1446818135-87310-1-git-send-email-wangnan0@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/util/llvm-utils.c | 49 +++++++++++++++-----------------------------
tools/perf/util/util.c | 30 +++++++++++++++++++++++++++
tools/perf/util/util.h | 3 +++
3 files changed, 49 insertions(+), 33 deletions(-)

diff --git a/tools/perf/util/llvm-utils.c b/tools/perf/util/llvm-utils.c
index 8ee25bea1b24..00724d496d38 100644
--- a/tools/perf/util/llvm-utils.c
+++ b/tools/perf/util/llvm-utils.c
@@ -4,7 +4,6 @@
*/

#include <stdio.h>
-#include <sys/utsname.h>
#include "util.h"
#include "debug.h"
#include "llvm-utils.h"
@@ -216,18 +215,19 @@ static int detect_kbuild_dir(char **kbuild_dir)
const char *suffix_dir = "";

char *autoconf_path;
- struct utsname utsname;

int err;

if (!test_dir) {
- err = uname(&utsname);
- if (err) {
- pr_warning("uname failed: %s\n", strerror(errno));
+ /* _UTSNAME_LENGTH is 65 */
+ char release[128];
+
+ err = fetch_kernel_version(NULL, release,
+ sizeof(release));
+ if (err)
return -EINVAL;
- }

- test_dir = utsname.release;
+ test_dir = release;
prefix_dir = "/lib/modules/";
suffix_dir = "/build";
}
@@ -325,38 +325,18 @@ get_kbuild_opts(char **kbuild_dir, char **kbuild_include_opts)
pr_debug("include option is set to %s\n", *kbuild_include_opts);
}

-static unsigned long
-fetch_kernel_version(void)
-{
- struct utsname utsname;
- int version, patchlevel, sublevel, err;
-
- if (uname(&utsname))
- return 0;
-
- err = sscanf(utsname.release, "%d.%d.%d",
- &version, &patchlevel, &sublevel);
-
- if (err != 3) {
- pr_debug("Unablt to get kernel version from uname '%s'\n",
- utsname.release);
- return 0;
- }
-
- return (version << 16) + (patchlevel << 8) + sublevel;
-}
-
int llvm__compile_bpf(const char *path, void **p_obj_buf,
size_t *p_obj_buf_sz)
{
+ size_t obj_buf_sz;
+ void *obj_buf = NULL;
int err, nr_cpus_avail;
- char clang_path[PATH_MAX], nr_cpus_avail_str[64];
+ unsigned int kernel_version;
char linux_version_code_str[64];
const char *clang_opt = llvm_param.clang_opt;
- const char *template = llvm_param.clang_bpf_cmd_template;
+ char clang_path[PATH_MAX], nr_cpus_avail_str[64];
char *kbuild_dir = NULL, *kbuild_include_opts = NULL;
- void *obj_buf = NULL;
- size_t obj_buf_sz;
+ const char *template = llvm_param.clang_bpf_cmd_template;

if (!template)
template = CLANG_BPF_CMD_DEFAULT_TEMPLATE;
@@ -388,8 +368,11 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf,
snprintf(nr_cpus_avail_str, sizeof(nr_cpus_avail_str), "%d",
nr_cpus_avail);

+ if (fetch_kernel_version(&kernel_version, NULL, 0))
+ kernel_version = 0;
+
snprintf(linux_version_code_str, sizeof(linux_version_code_str),
- "0x%lx", fetch_kernel_version());
+ "0x%x", kernel_version);

force_set_env("NR_CPUS", nr_cpus_avail_str);
force_set_env("LINUX_VERSION_CODE", linux_version_code_str);
diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index cd12c25e4ea4..47b1e36c7ea0 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -3,6 +3,7 @@
#include "debug.h"
#include <api/fs/fs.h>
#include <sys/mman.h>
+#include <sys/utsname.h>
#ifdef HAVE_BACKTRACE_SUPPORT
#include <execinfo.h>
#endif
@@ -665,3 +666,32 @@ bool find_process(const char *name)
closedir(dir);
return ret ? false : true;
}
+
+int
+fetch_kernel_version(unsigned int *puint, char *str,
+ size_t str_size)
+{
+ struct utsname utsname;
+ int version, patchlevel, sublevel, err;
+
+ if (uname(&utsname))
+ return -1;
+
+ if (str && str_size) {
+ strncpy(str, utsname.release, str_size);
+ str[str_size - 1] = '\0';
+ }
+
+ err = sscanf(utsname.release, "%d.%d.%d",
+ &version, &patchlevel, &sublevel);
+
+ if (err != 3) {
+ pr_debug("Unablt to get kernel version from uname '%s'\n",
+ utsname.release);
+ return -1;
+ }
+
+ if (puint)
+ *puint = (version << 16) + (patchlevel << 8) + sublevel;
+ return 0;
+}
diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index 4cfb913aa9e0..2665126267dc 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -350,4 +350,7 @@ static inline char *asprintf_expr_not_in_ints(const char *var, size_t nints, int

int get_stack_size(const char *str, unsigned long *_size);

+int fetch_kernel_version(unsigned int *puint,
+ char *str, size_t str_sz);
+
#endif /* GIT_COMPAT_UTIL_H */
--
2.1.0

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