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authorLukasz Majewski <lukma@denx.de>2020-07-20 15:50:12 +0200
committerLukasz Majewski <lukma@denx.de>2020-08-13 14:16:34 +0200
commit4a14cb87cad30bb15bb906e579089109874f3071 (patch)
tree4a5cdc2249d5c749985f5da2833e8e5a337d2573 /sysdeps/nptl/futex-internal.h
parent12b2fd0ef9f51642ad00646c1a2e3490e25f4a00 (diff)
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y2038: nptl: Convert pthread_{clock|timed}join_np to support 64 bit time
The pthread_clockjoin_np and pthread_timedjoin_np have been converted to
support 64 bit time.

This change introduces new futex_timed_wait_cancel64 function in
./sysdeps/nptl/futex-internal.h, which uses futex_time64 where possible
and tries to replace low-level preprocessor macros from
lowlevellock-futex.h
The pthread_{timed|clock}join_np only accept absolute time. Moreover,
there is no need to check for NULL passed as *abstime pointer as
clockwait_tid() always passes struct __timespec64.

For systems with __TIMESIZE != 64 && __WORDSIZE == 32:
- Conversions between 64 bit time to 32 bit are necessary
- Redirection to __pthread_{clock|timed}join_np64 will provide support
  for 64 bit time

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

Run-time tests:
- Run specific tests on ARM/x86 32bit systems (qemu):
  https://github.com/lmajewski/meta-y2038 and run tests:
  https://github.com/lmajewski/y2038-tests/commits/master

Above tests were performed with Y2038 redirection applied as well as without
to test the proper usage of both __pthread_{timed|clock}join_np64 and
__pthread_{timed|clock}join_np.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Diffstat (limited to 'sysdeps/nptl/futex-internal.h')
-rw-r--r--sysdeps/nptl/futex-internal.h52
1 files changed, 52 insertions, 0 deletions
diff --git a/sysdeps/nptl/futex-internal.h b/sysdeps/nptl/futex-internal.h
index d622122ddc..159aae82dc 100644
--- a/sysdeps/nptl/futex-internal.h
+++ b/sysdeps/nptl/futex-internal.h
@@ -467,4 +467,56 @@ futex_unlock_pi (unsigned int *futex_word, int private)
     }
 }
 
+#ifndef __NR_futex_time64
+# define __NR_futex_time64 __NR_futex
+#endif
+
+static __always_inline int
+futex_timed_wait_cancel64 (pid_t *tidp,  pid_t tid,
+                           const struct __timespec64 *timeout, int private)
+{
+  int err = INTERNAL_SYSCALL_CANCEL (futex_time64, tidp,
+                                     __lll_private_flag
+                                     (FUTEX_WAIT, private), tid, timeout);
+#ifndef __ASSUME_TIME64_SYSCALLS
+  if (err == -ENOSYS)
+    {
+      if (in_time_t_range (timeout->tv_sec))
+        {
+          struct timespec ts32 = valid_timespec64_to_timespec (*timeout);
+
+          err = INTERNAL_SYSCALL_CANCEL (futex, tidp,
+                                         __lll_private_flag (FUTEX_WAIT,
+                                                             private),
+                                         tid, &ts32);
+        }
+      else
+        err = -EOVERFLOW;
+    }
+#endif
+  switch (err)
+    {
+    case 0:
+    case -EAGAIN:
+    case -EINTR:
+    case -ETIMEDOUT:
+    case -EDEADLK:
+    case -ENOSYS:
+    case -EOVERFLOW:  /* Passed absolute timeout uses 64 bit time_t type, but
+                         underlying kernel does not support 64 bit time_t futex
+                         syscalls.  */
+    case -EPERM:  /*  The caller is not allowed to attach itself to the futex.
+		      Used to check if PI futexes are supported by the
+		      kernel.  */
+      return -err;
+
+    case -EINVAL: /* Either due to wrong alignment or due to the timeout not
+		     being normalized.  Must have been caused by a glibc or
+		     application bug.  */
+    case -EFAULT: /* Must have been caused by a glibc or application bug.  */
+    /* No other errors are documented at this time.  */
+    default:
+      futex_fatal_error ();
+    }
+}
 #endif  /* futex-internal.h */