From 1638b8f096ca165965189b9626564c933c79fe63 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 21 Oct 2019 12:07:15 +0200 Subject: [PATCH] lib/vdso: Make clock_getres() POSIX compliant again A recent commit removed the NULL pointer check from the clock_getres() implementation causing a test case to fault. POSIX requires an explicit NULL pointer check for clock_getres() aside of the validity check of the clock_id argument for obscure reasons. Add it back for both 32bit and 64bit. Note, this is only a partial revert of the offending commit which does not bring back the broken fallback invocation in the the 32bit compat implementations of clock_getres() and clock_gettime(). Fixes: a9446a906f52 ("lib/vdso/32: Remove inconsistent NULL pointer checks") Reported-by: Andreas Schwab Signed-off-by: Thomas Gleixner Tested-by: Christophe Leroy Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1910211202260.1904@nanos.tec.linutronix.de --- lib/vdso/gettimeofday.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c index e630e7ff57f1..45f57fd2db64 100644 --- a/lib/vdso/gettimeofday.c +++ b/lib/vdso/gettimeofday.c @@ -214,9 +214,10 @@ int __cvdso_clock_getres_common(clockid_t clock, struct __kernel_timespec *res) return -1; } - res->tv_sec = 0; - res->tv_nsec = ns; - + if (likely(res)) { + res->tv_sec = 0; + res->tv_nsec = ns; + } return 0; } @@ -245,7 +246,7 @@ __cvdso_clock_getres_time32(clockid_t clock, struct old_timespec32 *res) ret = clock_getres_fallback(clock, &ts); #endif - if (likely(!ret)) { + if (likely(!ret && res)) { res->tv_sec = ts.tv_sec; res->tv_nsec = ts.tv_nsec; }