[20/23] linux: Use 64-bit time_t syscall on clock_getcputclockid

Message ID 20200713171025.3661832-20-adhemerval.zanella@linaro.org
State New
Headers show
Series
  • [01/23] linux: Simplify clock_adjtime
Related show

Commit Message

Will Deacon via Libc-alpha July 13, 2020, 5:10 p.m.
The syscall __NR_clock_getres_time64 (for 32-bit) or __NR_clock_getres
(for 64-bit) is used as default.  The 32-bit fallback is used iff
__ASSUME_TIME64_SYSCALLS is not defined, which assumes the kernel ABI
provides either __NR_rt_sigtimedwait (32-bit time_t).

Since the symbol does not use any type which might be affected by the
time_t, there is no need to add a 64-bit variant.

Checked on x86_64-linux-gnu and i686-linux-gnu (on 5.4 and on 4.15
kernel).
---
 sysdeps/unix/sysv/linux/clock_getcpuclockid.c | 37 ++++++++++++-------
 1 file changed, 24 insertions(+), 13 deletions(-)

-- 
2.25.1

Comments

Will Deacon via Libc-alpha Aug. 24, 2020, 6:33 p.m. | #1
Ping.

On 13/07/2020 14:10, Adhemerval Zanella wrote:
> The syscall __NR_clock_getres_time64 (for 32-bit) or __NR_clock_getres

> (for 64-bit) is used as default.  The 32-bit fallback is used iff

> __ASSUME_TIME64_SYSCALLS is not defined, which assumes the kernel ABI

> provides either __NR_rt_sigtimedwait (32-bit time_t).

> 

> Since the symbol does not use any type which might be affected by the

> time_t, there is no need to add a 64-bit variant.

> 

> Checked on x86_64-linux-gnu and i686-linux-gnu (on 5.4 and on 4.15

> kernel).

> ---

>  sysdeps/unix/sysv/linux/clock_getcpuclockid.c | 37 ++++++++++++-------

>  1 file changed, 24 insertions(+), 13 deletions(-)

> 

> diff --git a/sysdeps/unix/sysv/linux/clock_getcpuclockid.c b/sysdeps/unix/sysv/linux/clock_getcpuclockid.c

> index be1f477187..3c3bdd42ed 100644

> --- a/sysdeps/unix/sysv/linux/clock_getcpuclockid.c

> +++ b/sysdeps/unix/sysv/linux/clock_getcpuclockid.c

> @@ -22,6 +22,20 @@

>  #include "kernel-posix-cpu-timers.h"

>  #include <shlib-compat.h>

>  

> +static int

> +clock_getcpuclockid_return (int r, clockid_t pidclock, clockid_t *clock_id)

> +{

> +  if (r == 0)

> +    {

> +      *clock_id = pidclock;

> +      return 0;

> +    }

> +  if (r == -EINVAL)

> +    /* The clock_getres system call checked the PID for us.  */

> +    return ESRCH;

> +  return -r;

> +}

> +

>  int

>  __clock_getcpuclockid (pid_t pid, clockid_t *clock_id)

>  {

> @@ -30,20 +44,17 @@ __clock_getcpuclockid (pid_t pid, clockid_t *clock_id)

>  

>    const clockid_t pidclock = MAKE_PROCESS_CPUCLOCK (pid, CPUCLOCK_SCHED);

>  

> -  int r = INTERNAL_SYSCALL_CALL (clock_getres, pidclock, NULL);

> -  if (!INTERNAL_SYSCALL_ERROR_P (r))

> -    {

> -      *clock_id = pidclock;

> -      return 0;

> -    }

> +#ifndef __NR_clock_getres_time64

> +# define __NR_clock_getres_time64 __NR_clock_getres

> +#endif

> +  int r = INTERNAL_SYSCALL_CALL (clock_getres_time64, pidclock, NULL);

> +#ifndef __ASSUME_TIME64_SYSCALLS

> +  if (r == 0 && r != -ENOSYS)

> +    return clock_getcpuclockid_return (r, pidclock, clock_id);

>  

> -  if (INTERNAL_SYSCALL_ERRNO (r) == EINVAL)

> -    {

> -      /* The clock_getres system call checked the PID for us.  */

> -      return ESRCH;

> -    }

> -  else

> -    return INTERNAL_SYSCALL_ERRNO (r);

> +  r = INTERNAL_SYSCALL_CALL (clock_getres, pidclock, NULL);

> +#endif

> +  return clock_getcpuclockid_return (r, pidclock, clock_id);

>  }

>  

>  versioned_symbol (libc, __clock_getcpuclockid, clock_getcpuclockid, GLIBC_2_17);

>

Patch

diff --git a/sysdeps/unix/sysv/linux/clock_getcpuclockid.c b/sysdeps/unix/sysv/linux/clock_getcpuclockid.c
index be1f477187..3c3bdd42ed 100644
--- a/sysdeps/unix/sysv/linux/clock_getcpuclockid.c
+++ b/sysdeps/unix/sysv/linux/clock_getcpuclockid.c
@@ -22,6 +22,20 @@ 
 #include "kernel-posix-cpu-timers.h"
 #include <shlib-compat.h>
 
+static int
+clock_getcpuclockid_return (int r, clockid_t pidclock, clockid_t *clock_id)
+{
+  if (r == 0)
+    {
+      *clock_id = pidclock;
+      return 0;
+    }
+  if (r == -EINVAL)
+    /* The clock_getres system call checked the PID for us.  */
+    return ESRCH;
+  return -r;
+}
+
 int
 __clock_getcpuclockid (pid_t pid, clockid_t *clock_id)
 {
@@ -30,20 +44,17 @@  __clock_getcpuclockid (pid_t pid, clockid_t *clock_id)
 
   const clockid_t pidclock = MAKE_PROCESS_CPUCLOCK (pid, CPUCLOCK_SCHED);
 
-  int r = INTERNAL_SYSCALL_CALL (clock_getres, pidclock, NULL);
-  if (!INTERNAL_SYSCALL_ERROR_P (r))
-    {
-      *clock_id = pidclock;
-      return 0;
-    }
+#ifndef __NR_clock_getres_time64
+# define __NR_clock_getres_time64 __NR_clock_getres
+#endif
+  int r = INTERNAL_SYSCALL_CALL (clock_getres_time64, pidclock, NULL);
+#ifndef __ASSUME_TIME64_SYSCALLS
+  if (r == 0 && r != -ENOSYS)
+    return clock_getcpuclockid_return (r, pidclock, clock_id);
 
-  if (INTERNAL_SYSCALL_ERRNO (r) == EINVAL)
-    {
-      /* The clock_getres system call checked the PID for us.  */
-      return ESRCH;
-    }
-  else
-    return INTERNAL_SYSCALL_ERRNO (r);
+  r = INTERNAL_SYSCALL_CALL (clock_getres, pidclock, NULL);
+#endif
+  return clock_getcpuclockid_return (r, pidclock, clock_id);
 }
 
 versioned_symbol (libc, __clock_getcpuclockid, clock_getcpuclockid, GLIBC_2_17);