From: Wang Nan <wangn...@huawei.com> 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 <wangn...@huawei.com> Tested-by: Arnaldo Carvalho de Melo <a...@redhat.com> Cc: Zefan Li <lize...@huawei.com> Cc: pi3or...@163.com Link: http://lkml.kernel.org/r/1464081688-167940-1-git-send-email-wangn...@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- tools/perf/util/symbol.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 20f9cb32b703..54c4ff2b1cee 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -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; -- 2.5.5
