Re: [PATCH 06/14] vdso/gettimeofday: Return bool from clock_gettime() helpers
From: Thomas Weißschuh <hidden>
Date: 2025-07-09 07:34:29
Also in:
linux-arch, linux-kselftest, lkml
Hi Marek, On Tue, Jul 08, 2025 at 05:49:18PM +0200, Marek Szyprowski wrote:
On 08.07.2025 17:17, Marek Szyprowski wrote:quoted
On 01.07.2025 10:58, Thomas Weißschuh wrote:quoted
The internal helpers are effectively using boolean results, while pretending to use error numbers. Switch the return type to bool for more clarity. Signed-off-by: Thomas Weißschuh <redacted> --- lib/vdso/gettimeofday.c | 58 +++++++++++++++++++++++++------------------------ 1 file changed, 30 insertions(+), 28 deletions(-)This patch landed in today's linux-next as commit fcc8e46f768f ("vdso/gettimeofday: Return bool from clock_gettime() helpers"). In my tests I found that it causes serious problem with hwclock operation on some of my ARM 32bit test boards. I observe that calling "hwclock -w -f /dev/rtc0" never ends on those boards. Disabling vdso support (by removing ARM architected timer) fixes this issue.I spent some time analyzing the code refactored in this patch and it looks that the following change is missing:
Thanks for the report and investigation!
quoted hunk ↗ jump to hunk
diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c index c5266532a097..7e79b02839b0 100644 --- a/lib/vdso/gettimeofday.c +++ b/lib/vdso/gettimeofday.c@@ -344,7 +344,7 @@ __cvdso_gettimeofday_data(const structvdso_time_data *vd, if (likely(tv != NULL)) { struct __kernel_timespec ts; - if (do_hres(vd, &vc[CS_HRES_COARSE], CLOCK_REALTIME, &ts)) + if (!do_hres(vd, &vc[CS_HRES_COARSE], CLOCK_REALTIME, &ts)) return gettimeofday_fallback(tv, tz); tv->tv_sec = ts.tv_sec; In my tests this fixed the hwclock issue on the mentioned boards.
This fix looks correct to me. tglx: Are you going to fold the fix into the commit or do you want a proper patch? Marek: If a new patch is required, do you want to send it? You found and fixed the issue after all. If not, I'll take care of it. Thomas