time: Skip overflow itimer tests on 32-bit systems

Message ID 20210607131851.4015661-1-shorne@gmail.com
State New
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  • time: Skip overflow itimer tests on 32-bit systems
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Commit Message

Adhemerval Zanella via Libc-alpha June 7, 2021, 1:18 p.m.
On the port of OpenRISC I am working on and it appears the rv32 port
we have sets __TIMESIZE == 64 && __WORDSIZE == 32.  This causes the
size of time_t to be 8 bytes, but the tv_sec in the kernel is still 32-bit
causing truncation.

The truncations are unavoidable on these systems so skip the
testing/failures by guarding with __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64.
---

I am open to other suggestions, this seemed the most correct to me.

Cc: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Cc: Alistair Francis <alistair.francis@wdc.com>

 time/tst-itimer.c | 2 ++
 1 file changed, 2 insertions(+)

-- 
2.31.1

Comments

Adhemerval Zanella via Libc-alpha June 9, 2021, 1:50 p.m. | #1
On 07/06/2021 10:18, Stafford Horne wrote:
> On the port of OpenRISC I am working on and it appears the rv32 port

> we have sets __TIMESIZE == 64 && __WORDSIZE == 32.  This causes the

> size of time_t to be 8 bytes, but the tv_sec in the kernel is still 32-bit

> causing truncation.

> 

> The truncations are unavoidable on these systems so skip the

> testing/failures by guarding with __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64.


Sigh, I was hoping that we won't need to handle this situation (glibc 
support only 64-bit time_t, but kernel still providing some 32-bit 
syscall).

> ---

> 

> I am open to other suggestions, this seemed the most correct to me.

> 

> Cc: Adhemerval Zanella <adhemerval.zanella@linaro.org>

> Cc: Alistair Francis <alistair.francis@wdc.com>

> 

>  time/tst-itimer.c | 2 ++

>  1 file changed, 2 insertions(+)

> 

> diff --git a/time/tst-itimer.c b/time/tst-itimer.c

> index 929c2b74c7..0c99d46d7e 100644

> --- a/time/tst-itimer.c

> +++ b/time/tst-itimer.c

> @@ -89,6 +89,7 @@ do_test (void)

>        TEST_COMPARE (it.it_interval.tv_sec, it_old.it_interval.tv_sec);

>        TEST_COMPARE (it.it_interval.tv_usec, it_old.it_interval.tv_usec);

>  

> +#if __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64

>        if (sizeof (time_t) == 4)

>  	continue;

>  

> @@ -146,6 +147,7 @@ do_test (void)

>  	  TEST_COMPARE (setitimer (timers[i], &it, NULL), -1);

>  	  TEST_COMPARE (errno, EOVERFLOW);

>  	}

> +#endif

>    }

>  

>    {

> 


Instead of disabling, I think it would be better to use
__KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64 instead of __time_t sizeof
(so we can still tests the EOVERFLOW):

diff --git a/time/tst-itimer.c b/time/tst-itimer.c
index 929c2b74c7..bd7d7afe83 100644
--- a/time/tst-itimer.c
+++ b/time/tst-itimer.c
@@ -100,7 +100,7 @@ do_test (void)

       /* Linux does not provide 64 bit time_t support for getitimer and
         setitimer on architectures with 32 bit time_t support.  */
-      if (sizeof (__time_t) == 8)
+      if (__KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64)
        { 
          TEST_COMPARE (setitimer (timers[i], &it, NULL), 0);
          TEST_COMPARE (setitimer (timers[i], &(struct itimerval) { 0 },
@@ -131,7 +131,7 @@ do_test (void)
       it.it_interval.tv_usec = 20;
       it.it_value.tv_sec = 30;
       it.it_value.tv_usec = 40;
-      if (sizeof (__time_t) == 8)
+      if (__KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64)
        { 
          TEST_COMPARE (setitimer (timers[i], &it, NULL), 0);
Adhemerval Zanella via Libc-alpha June 9, 2021, 9:38 p.m. | #2
On Wed, Jun 09, 2021 at 10:50:23AM -0300, Adhemerval Zanella wrote:
> 

> 

> On 07/06/2021 10:18, Stafford Horne wrote:

> > On the port of OpenRISC I am working on and it appears the rv32 port

> > we have sets __TIMESIZE == 64 && __WORDSIZE == 32.  This causes the

> > size of time_t to be 8 bytes, but the tv_sec in the kernel is still 32-bit

> > causing truncation.

> > 

> > The truncations are unavoidable on these systems so skip the

> > testing/failures by guarding with __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64.

> 

> Sigh, I was hoping that we won't need to handle this situation (glibc 

> support only 64-bit time_t, but kernel still providing some 32-bit 

> syscall).

> 

> > ---

> > 

> > I am open to other suggestions, this seemed the most correct to me.

> > 

> > Cc: Adhemerval Zanella <adhemerval.zanella@linaro.org>

> > Cc: Alistair Francis <alistair.francis@wdc.com>

> > 

> >  time/tst-itimer.c | 2 ++

> >  1 file changed, 2 insertions(+)

> > 

> > diff --git a/time/tst-itimer.c b/time/tst-itimer.c

> > index 929c2b74c7..0c99d46d7e 100644

> > --- a/time/tst-itimer.c

> > +++ b/time/tst-itimer.c

> > @@ -89,6 +89,7 @@ do_test (void)

> >        TEST_COMPARE (it.it_interval.tv_sec, it_old.it_interval.tv_sec);

> >        TEST_COMPARE (it.it_interval.tv_usec, it_old.it_interval.tv_usec);

> >  

> > +#if __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64

> >        if (sizeof (time_t) == 4)

> >  	continue;

> >  

> > @@ -146,6 +147,7 @@ do_test (void)

> >  	  TEST_COMPARE (setitimer (timers[i], &it, NULL), -1);

> >  	  TEST_COMPARE (errno, EOVERFLOW);

> >  	}

> > +#endif

> >    }

> >  

> >    {

> > 

> 

> Instead of disabling, I think it would be better to use

> __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64 instead of __time_t sizeof

> (so we can still tests the EOVERFLOW):

> 

> diff --git a/time/tst-itimer.c b/time/tst-itimer.c

> index 929c2b74c7..bd7d7afe83 100644

> --- a/time/tst-itimer.c

> +++ b/time/tst-itimer.c

> @@ -100,7 +100,7 @@ do_test (void)

> 

>        /* Linux does not provide 64 bit time_t support for getitimer and

>          setitimer on architectures with 32 bit time_t support.  */

> -      if (sizeof (__time_t) == 8)

> +      if (__KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64)

>         { 

>           TEST_COMPARE (setitimer (timers[i], &it, NULL), 0);

>           TEST_COMPARE (setitimer (timers[i], &(struct itimerval) { 0 },

> @@ -131,7 +131,7 @@ do_test (void)

>        it.it_interval.tv_usec = 20;

>        it.it_value.tv_sec = 30;

>        it.it_value.tv_usec = 40;

> -      if (sizeof (__time_t) == 8)

> +      if (__KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64)

>         { 

>           TEST_COMPARE (setitimer (timers[i], &it, NULL), 0);


This looks good to me, I can update to this, test and resend the patch when I
get some time.  Probably later tonight.

-Strafford
Adhemerval Zanella via Libc-alpha June 12, 2021, 9:19 a.m. | #3
On Thu, Jun 10, 2021 at 06:38:04AM +0900, Stafford Horne wrote:
> On Wed, Jun 09, 2021 at 10:50:23AM -0300, Adhemerval Zanella wrote:

> > 

> > 

> > On 07/06/2021 10:18, Stafford Horne wrote:

> > > On the port of OpenRISC I am working on and it appears the rv32 port

> > > we have sets __TIMESIZE == 64 && __WORDSIZE == 32.  This causes the

> > > size of time_t to be 8 bytes, but the tv_sec in the kernel is still 32-bit

> > > causing truncation.

> > > 

> > > The truncations are unavoidable on these systems so skip the

> > > testing/failures by guarding with __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64.

> > 

> > Sigh, I was hoping that we won't need to handle this situation (glibc 

> > support only 64-bit time_t, but kernel still providing some 32-bit 

> > syscall).

> > 

> > > ---

> > > 

> > > I am open to other suggestions, this seemed the most correct to me.

> > > 

> > > Cc: Adhemerval Zanella <adhemerval.zanella@linaro.org>

> > > Cc: Alistair Francis <alistair.francis@wdc.com>

> > > 

> > >  time/tst-itimer.c | 2 ++

> > >  1 file changed, 2 insertions(+)

> > > 

> > > diff --git a/time/tst-itimer.c b/time/tst-itimer.c

> > > index 929c2b74c7..0c99d46d7e 100644

> > > --- a/time/tst-itimer.c

> > > +++ b/time/tst-itimer.c

> > > @@ -89,6 +89,7 @@ do_test (void)

> > >        TEST_COMPARE (it.it_interval.tv_sec, it_old.it_interval.tv_sec);

> > >        TEST_COMPARE (it.it_interval.tv_usec, it_old.it_interval.tv_usec);

> > >  

> > > +#if __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64

> > >        if (sizeof (time_t) == 4)

> > >  	continue;

> > >  

> > > @@ -146,6 +147,7 @@ do_test (void)

> > >  	  TEST_COMPARE (setitimer (timers[i], &it, NULL), -1);

> > >  	  TEST_COMPARE (errno, EOVERFLOW);

> > >  	}

> > > +#endif

> > >    }

> > >  

> > >    {

> > > 

> > 

> > Instead of disabling, I think it would be better to use

> > __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64 instead of __time_t sizeof

> > (so we can still tests the EOVERFLOW):

> > 

> > diff --git a/time/tst-itimer.c b/time/tst-itimer.c

> > index 929c2b74c7..bd7d7afe83 100644

> > --- a/time/tst-itimer.c

> > +++ b/time/tst-itimer.c

> > @@ -100,7 +100,7 @@ do_test (void)

> > 

> >        /* Linux does not provide 64 bit time_t support for getitimer and

> >          setitimer on architectures with 32 bit time_t support.  */

> > -      if (sizeof (__time_t) == 8)

> > +      if (__KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64)

> >         { 

> >           TEST_COMPARE (setitimer (timers[i], &it, NULL), 0);

> >           TEST_COMPARE (setitimer (timers[i], &(struct itimerval) { 0 },

> > @@ -131,7 +131,7 @@ do_test (void)

> >        it.it_interval.tv_usec = 20;

> >        it.it_value.tv_sec = 30;

> >        it.it_value.tv_usec = 40;

> > -      if (sizeof (__time_t) == 8)

> > +      if (__KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64)

> >         { 

> >           TEST_COMPARE (setitimer (timers[i], &it, NULL), 0);

> 

> This looks good to me, I can update to this, test and resend the patch when I

> get some time.  Probably later tonight.


I tested this and it exposes an issue in the linux setitimer wrapper.  On my
platform I get EINVAL instead of EOVERFLOW.

    FAIL: time/tst-itimer
    original exit status 1
    tst-itimer.c:125: numeric comparison failure
       left: 22 (0x16); from: errno
      right: 75 (0x4b); from: EOVERFLOW
    tst-itimer.c:147: numeric comparison failure
       left: 22 (0x16); from: errno
      right: 75 (0x4b); from: EOVERFLOW


It seems this is because sysdeps/unix/sysv/linux/setitimer.c, checks that
the incoming value is in the range of time_t.  The problem is that
that we need to fit the value in __int32_t not time_t.  When testing the time_t
range check does not detect the overflow and setitimer ends up passing a -1 to
the kernel causing EINVAL.

I can fix that, as per the patch below, but It will take me some time to audit
other places this might be an issue.



  if (! in_time_t_range (new_value->it_interval.tv_sec)
      || ! in_time_t_range (new_value->it_value.tv_sec))
    {
      __set_errno (EOVERFLOW);
      return -1;
    }
  new_value_32.it_interval
    = valid_timeval64_to_timeval32 (new_value->it_interval);
  new_value_32.it_value
    = valid_timeval64_to_timeval32 (new_value->it_value);




The below patch works for me, but there is probably a better thing to do then
create a new functrion.



diff --git a/include/time.h b/include/time.h
index 4372bfbd96..377a4a45ea 100644
--- a/include/time.h
+++ b/include/time.h
@@ -342,6 +342,14 @@ in_time_t_range (__time64_t t)
   return s == t;
 }
 
+/* Check whether T fits in a timeval32 (__int32_t).  */
+static inline bool
+in_timeval32_range (__time64_t t)
+{
+  __int32_t s = t;
+  return s == t;
+}
+
 /* Convert a known valid struct timeval into a struct __timespec64.  */
 static inline struct __timespec64
 valid_timeval_to_timespec64 (const struct timeval tv)
diff --git a/sysdeps/unix/sysv/linux/setitimer.c
b/sysdeps/unix/sysv/linux/setitimer.c
index 083a25cf35..bada30ba02 100644
--- a/sysdeps/unix/sysv/linux/setitimer.c
+++ b/sysdeps/unix/sysv/linux/setitimer.c
@@ -32,8 +32,8 @@ __setitimer64 (__itimer_which_t which,
 #else
   struct __itimerval32 new_value_32;
 
-  if (! in_time_t_range (new_value->it_interval.tv_sec)
-      || ! in_time_t_range (new_value->it_value.tv_sec))
+  if (! in_timeval32_range (new_value->it_interval.tv_sec)
+      || ! in_timeval32_range (new_value->it_value.tv_sec))
     {


-Stafford

Patch

diff --git a/time/tst-itimer.c b/time/tst-itimer.c
index 929c2b74c7..0c99d46d7e 100644
--- a/time/tst-itimer.c
+++ b/time/tst-itimer.c
@@ -89,6 +89,7 @@  do_test (void)
       TEST_COMPARE (it.it_interval.tv_sec, it_old.it_interval.tv_sec);
       TEST_COMPARE (it.it_interval.tv_usec, it_old.it_interval.tv_usec);
 
+#if __KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64
       if (sizeof (time_t) == 4)
 	continue;
 
@@ -146,6 +147,7 @@  do_test (void)
 	  TEST_COMPARE (setitimer (timers[i], &it, NULL), -1);
 	  TEST_COMPARE (errno, EOVERFLOW);
 	}
+#endif
   }
 
   {