On 09/11/2021 09:52, André Almeida via Libc-alpha wrote: > Hi Vasily, > > Às 08:18 de 09/11/21, Vasily Gorbik escreveu: >> On Thu, Sep 23, 2021 at 02:11:09PM -0300, André Almeida wrote: >>> Test if the futex_waitv timeout is working as expected, using the >>> supported clockid options. >> >>> + /* futex_waitv with CLOCK_MONOTONIC */ >>> + if (futex_get_abs_timeout(CLOCK_MONOTONIC, &to, timeout_ns)) >>> + return RET_FAIL; >>> + res = futex_waitv(&waitv, 1, 0, &to, CLOCK_MONOTONIC); >>> + test_timeout(res, &ret, "futex_waitv monotonic", ETIMEDOUT); >>> + >>> + /* futex_waitv with CLOCK_REALTIME */ >>> + if (futex_get_abs_timeout(CLOCK_REALTIME, &to, timeout_ns)) >>> + return RET_FAIL; >>> + res = futex_waitv(&waitv, 1, 0, &to, CLOCK_REALTIME); >>> + test_timeout(res, &ret, "futex_waitv realtime", ETIMEDOUT); >> >> Hi André, >> >> when built with -m32 and run as compat this two futex_waitv calls hang >> on x86 and s390 (noticed while wiring up futex_waitv). The rest of the >> futex selftests pass. This suggests some common compat issue? Any ideas? > > The issue is that futex_waitv() only accepts struct timespec that uses > 64bit members. When using -m32, glibc will give you a 32bit timespec, > thus the timeout won't wort. Someday glibc will provide 64bit timespec > to 32bit userspace, given that this is affected by y2038 bug. We do since glibc 2.34, but you need to opt-in by defining -D_TIME_SIZE=64. The default might change in a future release, so hopefully we will have both LFS and 64-bit as the default ABI. > > In previous submissions I added a workaround for that in the > selftest[0]. Search for "Y2038 section for 32-bit applications" in that > link. I'll submit something like that for futex_waitv() timeout test. > > [0] > https://lore.kernel.org/lkml/20210709001328.329716-6-andrealmeid@xxxxxxxxxxxxx/ >
