Re: [PATCH v2] powerpc/vdso: fix clock_gettime_fallback for vdso32

[Christophe Leroy]

Le 12/01/2021 à 02:13, Michael Ellerman a écrit :
Christophe Leroy <christophe.le...@csgroup.eu> writes:
From: Andreas Schwab <sch...@linux-m68k.org>

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 <sch...@linux-m68k.org>
[chleroy: Moved into the #ifdef CONFIG_VDSO32 block]

That doesn't build for 64-bit with compat VDSO. Should I just take
Andreas' version, or do you want to send a v3?

Yes, that #ifdef CONFIG_VDSO32 is crazy, should use __powerpc64__ instead, or __VDSO32__ but that 
one is defined in asflags-y so not sure we have it in C.

I sent v3 just before lunch.

Christophe


cheers

Fixes: d0e3fc69d00d ("powerpc/vdso: Provide __kernel_clock_gettime64() on 
vdso32")
Signed-off-by: Christophe Leroy <christophe.le...@csgroup.eu>
---
  arch/powerpc/include/asm/vdso/gettimeofday.h | 27 +++++++++++++++-----
  1 file changed, 21 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/include/asm/vdso/gettimeofday.h 
b/arch/powerpc/include/asm/vdso/gettimeofday.h
index 7a215cc5da77..3ecddd9c6302 100644
--- a/arch/powerpc/include/asm/vdso/gettimeofday.h
+++ b/arch/powerpc/include/asm/vdso/gettimeofday.h
@@ -102,22 +102,22 @@ int gettimeofday_fallback(struct __kernel_old_timeval 
*_tv, struct timezone *_tz
        return do_syscall_2(__NR_gettimeofday, (unsigned long)_tv, (unsigned 
long)_tz);
  }
  
+#ifdef CONFIG_VDSO32
+
+#define BUILD_VDSO32           1
+
  static __always_inline
  int clock_gettime_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
  {
-       return do_syscall_2(__NR_clock_gettime, _clkid, (unsigned long)_ts);
+       return do_syscall_2(__NR_clock_gettime64, _clkid, (unsigned long)_ts);
  }
  
  static __always_inline
  int clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
  {
-       return do_syscall_2(__NR_clock_getres, _clkid, (unsigned long)_ts);
+       return do_syscall_2(__NR_clock_getres_time64, _clkid, (unsigned 
long)_ts);
  }
  
-#ifdef CONFIG_VDSO32
-
-#define BUILD_VDSO32           1
-
  static __always_inline
  int clock_gettime32_fallback(clockid_t _clkid, struct old_timespec32 *_ts)
  {
@@ -129,6 +129,21 @@ int clock_getres32_fallback(clockid_t _clkid, struct 
old_timespec32 *_ts)
  {
        return do_syscall_2(__NR_clock_getres, _clkid, (unsigned long)_ts);
  }
+
+#else
+
+static __always_inline
+int clock_gettime_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
+{
+       return do_syscall_2(__NR_clock_gettime, _clkid, (unsigned long)_ts);
+}
+
+static __always_inline
+int clock_getres_fallback(clockid_t _clkid, struct __kernel_timespec *_ts)
+{
+       return do_syscall_2(__NR_clock_getres, _clkid, (unsigned long)_ts);
+}
+
  #endif
  
  static __always_inline u64 __arch_get_hw_counter(s32 clock_mode,
--
2.25.0