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authorWang Nan <wangnan0@huawei.com>2016-11-15 04:05:44 +0000
committerArnaldo Carvalho de Melo <acme@redhat.com>2016-11-25 11:00:30 -0300
commitd18acd15c6dfb669f0463afa31ac5343594d2fe2 (patch)
tree518a4ddf76295a74020dd5ec8a9a1282bd2d8beb /tools/perf/util
parent8388deb3ba4d36ffcae91a2a01cb2ea6f27553e6 (diff)
perf tools: Fix kernel version error in ubuntu
On ubuntu the internal kernel version code is different from what can be retrived from uname: $ uname -r 4.4.0-47-generic $ cat /lib/modules/`uname -r`/build/include/generated/uapi/linux/version.h #define LINUX_VERSION_CODE 263192 #define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c)) $ cat /lib/modules/`uname -r`/build/include/generated/utsrelease.h #define UTS_RELEASE "4.4.0-47-generic" #define UTS_UBUNTU_RELEASE_ABI 47 $ cat /proc/version_signature Ubuntu 4.4.0-47.68-generic 4.4.24 The macro LINUX_VERSION_CODE is set to 4.4.24 (263192 == 0x40418), but `uname -r` reports 4.4.0. This mismatch causes LINUX_VERSION_CODE macro passed to BPF script become an incorrect value, results in magic failure in BPF loading: $ sudo ./buildperf/perf record -e ./tools/perf/tests/bpf-script-example.c ls event syntax error: './tools/perf/tests/bpf-script-example.c' \___ Failed to load program for unknown reason According to Ubuntu document (https://wiki.ubuntu.com/Kernel/FAQ), the correct kernel version can be retrived through /proc/version_signature, which is ubuntu specific. This patch checks the existance of /proc/version_signature, and returns version number through parsing this file instead of uname. Version string is untouched (value returns from uname) because `uname -r` is required to be consistence with path of kbuild directory in /lib/module. Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Alexei Starovoitov <ast@fb.com> Cc: He Kuang <hekuang@huawei.com> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/20161115040617.69788-2-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util')
-rw-r--r--tools/perf/util/util.c55
1 files changed, 53 insertions, 2 deletions
diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index 5bbd1f609f1f..67ac765da27a 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -637,12 +637,63 @@ bool find_process(const char *name)
return ret ? false : true;
}
+static int
+fetch_ubuntu_kernel_version(unsigned int *puint)
+{
+ ssize_t len;
+ size_t line_len = 0;
+ char *ptr, *line = NULL;
+ int version, patchlevel, sublevel, err;
+ FILE *vsig = fopen("/proc/version_signature", "r");
+
+ if (!vsig) {
+ pr_debug("Open /proc/version_signature failed: %s\n",
+ strerror(errno));
+ return -1;
+ }
+
+ len = getline(&line, &line_len, vsig);
+ fclose(vsig);
+ err = -1;
+ if (len <= 0) {
+ pr_debug("Reading from /proc/version_signature failed: %s\n",
+ strerror(errno));
+ goto errout;
+ }
+
+ ptr = strrchr(line, ' ');
+ if (!ptr) {
+ pr_debug("Parsing /proc/version_signature failed: %s\n", line);
+ goto errout;
+ }
+
+ err = sscanf(ptr + 1, "%d.%d.%d",
+ &version, &patchlevel, &sublevel);
+ if (err != 3) {
+ pr_debug("Unable to get kernel version from /proc/version_signature '%s'\n",
+ line);
+ goto errout;
+ }
+
+ if (puint)
+ *puint = (version << 16) + (patchlevel << 8) + sublevel;
+ err = 0;
+errout:
+ free(line);
+ return err;
+}
+
int
fetch_kernel_version(unsigned int *puint, char *str,
size_t str_size)
{
struct utsname utsname;
int version, patchlevel, sublevel, err;
+ bool int_ver_ready = false;
+
+ if (access("/proc/version_signature", R_OK) == 0)
+ if (!fetch_ubuntu_kernel_version(puint))
+ int_ver_ready = true;
if (uname(&utsname))
return -1;
@@ -656,12 +707,12 @@ fetch_kernel_version(unsigned int *puint, char *str,
&version, &patchlevel, &sublevel);
if (err != 3) {
- pr_debug("Unablt to get kernel version from uname '%s'\n",
+ pr_debug("Unable to get kernel version from uname '%s'\n",
utsname.release);
return -1;
}
- if (puint)
+ if (puint && !int_ver_ready)
*puint = (version << 16) + (patchlevel << 8) + sublevel;
return 0;
}