lkml.org 
[lkml]   [2023]   [May]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 1/2] selftests/nolibc: add new gettimeofday test cases
On 2023-05-30 19:28:06+0800, Zhangjin Wu wrote:
> > On 2023-05-30 14:37:49+0800, Zhangjin Wu wrote:
> > > These 3 test cases are added to cover the normal using scenes of
> > > gettimeofday().
> > >
> > > They have been used to trigger and fix up such issue:
> > >
> > > nolibc-test.c:(.text.gettimeofday+0x54): undefined reference to `__aeabi_ldivmod'
> > >
> > > This issue happens while there is no "unsigned int" conversion in the
> > > new clock_gettime / clock_gettime64 syscall path of gettimeofday():
> > >
> > > tv->tv_usec = ts.tv_nsec / 1000;
> > >
> > > Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
> > > ---
> > > tools/testing/selftests/nolibc/nolibc-test.c | 5 +++++
> > > 1 file changed, 5 insertions(+)
> > >
> > > diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
> > > index 8ba8c2fc71a0..20d184da9a2b 100644
> > > --- a/tools/testing/selftests/nolibc/nolibc-test.c
> > > +++ b/tools/testing/selftests/nolibc/nolibc-test.c
> > > @@ -533,6 +533,8 @@ static int test_stat_timestamps(void)
> > > */
> > > int run_syscall(int min, int max)
> > > {
> > > + struct timeval tv;
> > > + struct timezone tz;
> > > struct stat stat_buf;
> > > int euid0;
> > > int proc;
> > > @@ -588,6 +590,9 @@ int run_syscall(int min, int max)
> > > CASE_TEST(getdents64_root); EXPECT_SYSNE(1, test_getdents64("/"), -1); break;
> > > CASE_TEST(getdents64_null); EXPECT_SYSER(1, test_getdents64("/dev/null"), -1, ENOTDIR); break;
> > > CASE_TEST(gettimeofday_null); EXPECT_SYSZR(1, gettimeofday(NULL, NULL)); break;
> > > + CASE_TEST(gettimeofday_tv); EXPECT_SYSZR(1, gettimeofday(&tv, NULL)); break;
> > > + CASE_TEST(gettimeofday_tz); EXPECT_SYSZR(1, gettimeofday(NULL, &tz)); break;
> >
> > Calling gettimeofday(NULL, ...) will actually segfault on glibc.
> > It works when calling through the VDSO, but not the logic in glibc
> > itself, which is guess is allowed by POSIX.
> >
>
> In low level gettimeofday syscall, it should be ok, will check the non-vdso
> code of glibc later. in musl, it returns 0 when it is NULL
> (src/time/gettimeofday.c).

It's fine for the Linux syscall, vdso, musl and nolibc.
It's not fine for glibc and gnulib.

> > I propose to avoid doing it :-)
>
> Just checked it again, these two cases can also detect the issues (1):
>
> CASE_TEST(gettimeofday_tv); EXPECT_SYSZR(1, gettimeofday(&tv, NULL)); break;
> CASE_TEST(gettimeofday_tv_tz);EXPECT_SYSZR(1, gettimeofday(&tv, &tz)); break;
>
> (1) nolibc-test.c:(.text.gettimeofday+0x54): undefined reference to `__aeabi_ldivmod'

To be honest this does not look like a nolibc issue, more a compiler
setup problem. GCC generates calls to a function in libgcc that is not
linked for some reason.

Can you provide reproduction steps?

Also I guess a testcase that tests at runtime that the compilation has
worked is of limited use :-)
It either works or it never executes.

> we can directly remove the second one ;-)
>
> >
> > Either we gate the existing test in #ifdef NOLIBC or we remove it.
>
> so, we still need to check the original gettimeofday_null test case for glibc?

The original testcase also needs adaption, yes.

> Thanks,
> Zhangjin
>
> >
> > > + CASE_TEST(gettimeofday_tv_tz);EXPECT_SYSZR(1, gettimeofday(&tv, &tz)); break;
> > > CASE_TEST(getpagesize); EXPECT_SYSZR(1, test_getpagesize()); break;
> > > CASE_TEST(ioctl_tiocinq); EXPECT_SYSZR(1, ioctl(0, TIOCINQ, &tmp)); break;
> > > CASE_TEST(ioctl_tiocinq); EXPECT_SYSZR(1, ioctl(0, TIOCINQ, &tmp)); break;

\
 
 \ /
  Last update: 2023-05-30 13:56    [W:0.092 / U:0.492 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site