perf symbols: Check kptr_restrict for root

If kptr_restrict is set to 2, even root is not allowed to see pointers.
This patch checks kptr_restrict even if euid == 0. For root, report
error if kptr_restrict is 2.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1464081688-167940-1-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Wang Nan 2016-05-24 09:21:27 +00:00 committed by Arnaldo Carvalho de Melo
parent 275ae411e5
commit 38272dc4f1

View file

@ -1933,17 +1933,17 @@ int setup_intlist(struct intlist **list, const char *list_str,
static bool symbol__read_kptr_restrict(void)
{
bool value = false;
FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
if (geteuid() != 0) {
FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
if (fp != NULL) {
char line[8];
if (fp != NULL) {
char line[8];
if (fgets(line, sizeof(line), fp) != NULL)
value = atoi(line) != 0;
if (fgets(line, sizeof(line), fp) != NULL)
value = (geteuid() != 0) ?
(atoi(line) != 0) :
(atoi(line) == 2);
fclose(fp);
}
fclose(fp);
}
return value;