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authorLukasz Majewski <lukma@denx.de>2020-09-18 20:54:13 +0200
committerLukasz Majewski <lukma@denx.de>2020-10-15 09:35:43 +0200
commit29e9874a048f47e2d46c40253036c8d2de921548 (patch)
tree89bf596e3db06ad009bca5ba0b5ee947732d8f68 /sysdeps/nptl/futex-internal.c
parent9ebaabeaac1a96b0d91f52902ce1dbf4f5a562dd (diff)
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y2038: nptl: Convert pthread_mutex_{clock|timed}lock to support 64 bit
The pthread_mutex_clocklock and pthread_mutex_timedlock have been converted
to support 64 bit time.

This change uses:
- New __futex_clocklock_wait64 (instead of lll_timedwait)

from ./sysdeps/nptl/futex-helpers.c and

- New __futex_clocklock64 function (instead of lll_clocklock)
- New futex_lock_pi64

defined in sysdeps/nptl/futex-internal.h

The pthread_mutex_{clock|timed}lock only accepts absolute time.
Moreover, there is no need to check for NULL passed as *abstime pointer to the
syscalls as those calls have exported symbols marked with __nonull attribute
for abstime.

Some architectures - namely x86, powerpc and s390 - do support lock elision.
For those - adjustments have been made in arch specific elision-*.c files
to use __futex_clocklock64 instead of lll_clocklock.
The __lll_lock_elision (aliased to __lll_clocklock_elision in e.g.
sysdeps/unix/sysv/linux/s390/elision-timed.c) just uses, in this patch
provided, __futex_clocklock64.

For systems with __TIMESIZE != 64 && __WORDSIZE == 32:
- Conversions between 64 bit time to 32 bit are necessary
- Redirection to pthread_mutex_{clock|timed}lock will provide support for 64
bit time

Build tests:
./src/scripts/build-many-glibcs.py glibcs

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
Diffstat (limited to 'sysdeps/nptl/futex-internal.c')
-rw-r--r--sysdeps/nptl/futex-internal.c53
1 files changed, 53 insertions, 0 deletions
diff --git a/sysdeps/nptl/futex-internal.c b/sysdeps/nptl/futex-internal.c
index f418ed2dbb..2e1919f056 100644
--- a/sysdeps/nptl/futex-internal.c
+++ b/sysdeps/nptl/futex-internal.c
@@ -169,3 +169,56 @@ __futex_abstimed_wait64 (unsigned int* futex_word, unsigned int expected,
       futex_fatal_error ();
     }
 }
+
+int
+__futex_clocklock_wait64 (int *futex, int val, clockid_t clockid,
+                          const struct __timespec64 *abstime, int private)
+{
+  struct __timespec64 ts, *tsp = NULL;
+
+  if (abstime != NULL)
+    {
+      /* Reject invalid timeouts.  */
+      if (! valid_nanoseconds (abstime->tv_nsec))
+        return EINVAL;
+
+      /* Get the current time. This can only fail if clockid is not valid.  */
+      if (__glibc_unlikely (__clock_gettime64 (clockid, &ts) != 0))
+        return EINVAL;
+
+      /* Compute relative timeout.  */
+      ts.tv_sec = abstime->tv_sec - ts.tv_sec;
+      ts.tv_nsec = abstime->tv_nsec - ts.tv_nsec;
+      if (ts.tv_nsec < 0)
+        {
+	  ts.tv_nsec += 1000000000;
+	  --ts.tv_sec;
+        }
+
+      if (ts.tv_sec < 0)
+        return ETIMEDOUT;
+
+      tsp = &ts;
+    }
+
+  int err = INTERNAL_SYSCALL_CALL (futex_time64, futex,
+                                   __lll_private_flag (FUTEX_WAIT, private),
+                                   val, tsp);
+#ifndef __ASSUME_TIME64_SYSCALLS
+  if (err == -ENOSYS)
+    {
+      if (tsp != NULL && ! in_time_t_range (tsp->tv_sec))
+        return EOVERFLOW;
+
+      struct timespec ts32;
+      if (tsp != NULL)
+        ts32 = valid_timespec64_to_timespec (*tsp);
+
+      err = INTERNAL_SYSCALL_CALL (futex, futex,
+                                   __lll_private_flag (FUTEX_WAIT, private),
+                                   val, tsp != NULL ? &ts32 : NULL);
+    }
+#endif
+
+  return -err;
+}