[PATCH] powerpc/vdso: fix clock_gettime_fallback for vdso32

The second argument of __kernel_clock_gettime64 points to a struct
__kernel_timespec, with 64-bit time_t, so use the clock_gettime64 syscall
in the fallback function for the 32-bit vdso.  Similarily,
clock_getres_fallback should use the clock_getres_time64 syscall, though
it isn't yet called from the 32-bit vdso.

Signed-off-by: Andreas Schwab <redacted>
---
 arch/powerpc/include/asm/vdso/gettimeofday.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/powerpc/include/asm/vdso/gettimeofday.h b/arch/powerpc/include/asm/vdso/gettimeofday.h
index 81671aa365b3..a26c12df2c9a 100644
--- a/arch/powerpc/include/asm/vdso/gettimeofday.h
+++ b/arch/powerpc/include/asm/vdso/gettimeofday.h

@@ -106,13 +106,21 @@ int gettimeofday_fallback(struct __kernel_old_timeval *_tv, struct timezone *_tz
 static __always_inline
 int clock_gettime_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
 {
+#ifndef __powerpc64__
+	return do_syscall_2(__NR_clock_gettime64, _clkid, (unsigned long)_ts);
+#else
 	return do_syscall_2(__NR_clock_gettime, _clkid, (unsigned long)_ts);
+#endif
 }
 
 static __always_inline
 int clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
 {
+#ifndef __powerpc64__
+	return do_syscall_2(__NR_clock_getres_time64, _clkid, (unsigned long)_ts);
+#else
 	return do_syscall_2(__NR_clock_getres, _clkid, (unsigned long)_ts);
+#endif
 }
 
 #ifdef CONFIG_VDSO32

-- 
2.30.0


-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
"And now for something completely different."

Le 11/01/2021 à 16:18, Andreas Schwab a écrit :

The second argument of __kernel_clock_gettime64 points to a struct
__kernel_timespec, with 64-bit time_t, so use the clock_gettime64 syscall
in the fallback function for the 32-bit vdso.  Similarily,
clock_getres_fallback should use the clock_getres_time64 syscall, though
it isn't yet called from the 32-bit vdso.

Signed-off-by: Andreas Schwab <redacted>

Fixes: d0e3fc69d00d ("powerpc/vdso: Provide __kernel_clock_gettime64() on vdso32")

I think we should do like x86, create a second version of clock_gettime_fallback() inside the #ifdef 
CONFIG_VDSO32, and move that one in a matching (non existing yet) #else

+	return do_syscall_2(__NR_clock_gettime64, _clkid, (unsigned long)_ts);
+#else
  	return do_syscall_2(__NR_clock_gettime, _clkid, (unsigned long)_ts);
+#endif
  }
  
  static __always_inline
  int clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
  {
+#ifndef __powerpc64__

Same.

+	return do_syscall_2(__NR_clock_getres_time64, _clkid, (unsigned long)_ts);
+#else
  	return do_syscall_2(__NR_clock_getres, _clkid, (unsigned long)_ts);
+#endif
  }
  
  #ifdef CONFIG_VDSO32

Christophe