lib/glibc
1
0
Fork 0
mirror of https://sourceware.org/git/glibc.git synced 2025-08-01 10:06:57 +03:00
Code Activity

y2038: nptl: Convert pthread_rwlock_{clock|timed}{rd|wr}lock to support 64 bit time

Browse Source 
The pthread_rwlock_clockrdlock, pthread_rwlock_clockwrlock,
pthread_rwlock_timedrdlock and pthread_rwlock_timedwrlock have been converted
to support 64 bit time.

This change uses new futex_abstimed_wait64 function in
./sysdeps/nptl/futex-helpers.c, which uses futex_time64 where possible.

The pthread_rwlock_{clock|timed}{rd|wr}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.

For systems with __TIMESIZE != 64 && __WORDSIZE == 32:
- Conversions between 64 bit time to 32 bit are necessary
- Redirection to pthread_rwlock_{clock|timed}{rd|wr}lock 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_rwlock_{clock|timed}{rd|wr}lock64
and __pthread_rwlock_{clock|timed}{rd|wr}lock.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
This commit is contained in:
Lukasz Majewski
2020-09-08 11:51:23 +02:00
parent b2cdadde4d
commit 3102e28bd1
8 changed files with 104 additions and 31 deletions
Download Patch File Download Diff File Expand all files Collapse all files

33
nptl/pthread_rwlock_common.c
View File

@ -278,9 +278,8 @@ __pthread_rwlock_rdunlock (pthread_rwlock_t *rwlock)
static __always_inline int
__pthread_rwlock_rdlock_full (pthread_rwlock_t *rwlock,
clockid_t clockid,
const struct timespec *abstime)
__pthread_rwlock_rdlock_full64 (pthread_rwlock_t *rwlock, clockid_t clockid,
const struct __timespec64 *abstime)
{
unsigned int r;
@ -330,8 +329,9 @@ __pthread_rwlock_rdlock_full (pthread_rwlock_t *rwlock,
& PTHREAD_RWLOCK_RWAITING) != 0)
{
int private = __pthread_rwlock_get_private (rwlock);
int err = futex_abstimed_wait (&rwlock->__data.__readers,
r, clockid, abstime, private);
int err = __futex_abstimed_wait64 (&rwlock->__data.__readers,
r, clockid, abstime,
private);
/* We ignore EAGAIN and EINTR. On time-outs, we can just
return because we don't need to clean up anything. */
if (err == ETIMEDOUT)
@ -457,9 +457,9 @@ __pthread_rwlock_rdlock_full (pthread_rwlock_t *rwlock,
(&rwlock->__data.__wrphase_futex,
&wpf, wpf | PTHREAD_RWLOCK_FUTEX_USED)))
continue;
int err = futex_abstimed_wait (&rwlock->__data.__wrphase_futex,
1 | PTHREAD_RWLOCK_FUTEX_USED,
clockid, abstime, private);
int err = __futex_abstimed_wait64 (&rwlock->__data.__wrphase_futex,
1 | PTHREAD_RWLOCK_FUTEX_USED,
clockid, abstime, private);
if (err == ETIMEDOUT)
{
/* If we timed out, we need to unregister. If no read phase
@ -585,9 +585,8 @@ __pthread_rwlock_wrunlock (pthread_rwlock_t *rwlock)
static __always_inline int
__pthread_rwlock_wrlock_full (pthread_rwlock_t *rwlock,
clockid_t clockid,
const struct timespec *abstime)
__pthread_rwlock_wrlock_full64 (pthread_rwlock_t *rwlock, clockid_t clockid,
const struct __timespec64 *abstime)
{
/* Make sure any passed in clockid and timeout value are valid. Note that
the previous implementation assumed that this check *must* not be
@ -728,9 +727,9 @@ __pthread_rwlock_wrlock_full (pthread_rwlock_t *rwlock,
share the flag, and another writer will wake one of the writers
in this group. */
may_share_futex_used_flag = true;
int err = futex_abstimed_wait (&rwlock->__data.__writers_futex,
1 | PTHREAD_RWLOCK_FUTEX_USED,
clockid, abstime, private);
int err = __futex_abstimed_wait64 (&rwlock->__data.__writers_futex,
1 | PTHREAD_RWLOCK_FUTEX_USED,
clockid, abstime, private);
if (err == ETIMEDOUT)
{
if (prefer_writer)
@ -827,9 +826,9 @@ __pthread_rwlock_wrlock_full (pthread_rwlock_t *rwlock,
(&rwlock->__data.__wrphase_futex, &wpf,
PTHREAD_RWLOCK_FUTEX_USED)))
continue;
int err = futex_abstimed_wait (&rwlock->__data.__wrphase_futex,
PTHREAD_RWLOCK_FUTEX_USED,
clockid, abstime, private);
int err = __futex_abstimed_wait64 (&rwlock->__data.__wrphase_futex,
PTHREAD_RWLOCK_FUTEX_USED,
clockid, abstime, private);
if (err == ETIMEDOUT)
{
if (rwlock->__data.__flags != PTHREAD_RWLOCK_PREFER_READER_NP)