From ce7eb0e90315eb1939ac29f656d39b3db858c092 Mon Sep 17 00:00:00 2001 From: Adhemerval Zanella Date: Thu, 10 May 2018 17:24:56 -0300 Subject: nptl: Cleanup cancellation macros This patch wraps all uses of *_{enable,disable}_asynccancel and and *_CANCEL_{ASYNC,RESET} in either already provided macros (lll_futex_timed_wait_cancel) or creates new ones if the functionality is not provided (SYSCALL_CANCEL_NCS, lll_futex_wait_cancel, and lll_futex_timed_wait_cancel). Also for some generic implementations, the direct call of the macros are removed since the underlying symbols are suppose to provide cancellation support. This is a priliminary patch intended to simplify the work required for BZ#12683 fix. It is a refactor change, no semantic changes are expected. Checked on x86_64-linux-gnu and i686-linux-gnu. * nptl/pthread_join_common.c (__pthread_timedjoin_ex): Use lll_wait_tid with timeout. * nptl/sem_wait.c (__old_sem_wait): Use lll_futex_wait_cancel. * sysdeps/nptl/aio_misc.h (AIO_MISC_WAIT): Use futex_reltimed_wait_cancelable for cancelabla mode. * sysdeps/nptl/gai_misc.h (GAI_MISC_WAIT): Likewise. * sysdeps/posix/open64.c (__libc_open64): Do not call cancelation macros. * sysdeps/posix/sigwait.c (__sigwait): Likewise. * sysdeps/posix/waitid.c (__sigwait): Likewise. * sysdeps/unix/sysdep.h (__SYSCALL_CANCEL_CALL, SYSCALL_CANCEL_NCS): New macro. * sysdeps/nptl/lowlevellock.h (lll_wait_tid): Add timeout argument. (lll_timedwait_tid): Remove macro. * sysdeps/unix/sysv/linux/i386/lowlevellock.h (lll_wait_tid): Likewise. (lll_timedwait_tid): Likewise. * sysdeps/unix/sysv/linux/sparc/lowlevellock.h (lll_wait_tid): Likewise. (lll_timedwait_tid): Likewise. * sysdeps/unix/sysv/linux/x86_64/lowlevellock.h (lll_wait_tid): Likewise. (lll_timedwait_tid): Likewise. * sysdeps/unix/sysv/linux/clock_nanosleep.c (__clock_nanosleep): Use INTERNAL_SYSCALL_CANCEL. * sysdeps/unix/sysv/linux/futex-internal.h (futex_reltimed_wait_cancelable): Use LIBC_CANCEL_{ASYNC,RESET} instead of __pthread_{enable,disable}_asynccancel. * sysdeps/unix/sysv/linux/lowlevellock-futex.h (lll_futex_wait_cancel): New macro. --- sysdeps/unix/sysv/linux/sparc/lowlevellock.h | 39 ++++++++++++++-------------- 1 file changed, 20 insertions(+), 19 deletions(-) (limited to 'sysdeps/unix/sysv/linux/sparc') diff --git a/sysdeps/unix/sysv/linux/sparc/lowlevellock.h b/sysdeps/unix/sysv/linux/sparc/lowlevellock.h index 47946c3eb5..5aed572d43 100644 --- a/sysdeps/unix/sysv/linux/sparc/lowlevellock.h +++ b/sysdeps/unix/sysv/linux/sparc/lowlevellock.h @@ -108,28 +108,29 @@ __lll_timedlock (int *futex, const struct timespec *abstime, int private) #define LLL_LOCK_INITIALIZER (0) #define LLL_LOCK_INITIALIZER_LOCKED (1) -/* The kernel notifies a process which uses CLONE_CHILD_CLEARTID via futex - wakeup when the clone terminates. The memory location contains the - thread ID while the clone is running and is reset to zero - afterwards. */ -#define lll_wait_tid(tid) \ - do \ - { \ - __typeof (tid) __tid; \ - while ((__tid = (tid)) != 0) \ - lll_futex_wait (&(tid), __tid, LLL_SHARED); \ - } \ - while (0) - extern int __lll_timedwait_tid (int *, const struct timespec *) attribute_hidden; -#define lll_timedwait_tid(tid, abstime) \ - ({ \ - int __res = 0; \ - if ((tid) != 0) \ - __res = __lll_timedwait_tid (&(tid), (abstime)); \ - __res; \ +/* The kernel notifies a process which uses CLONE_CHILD_CLEARTID via futex + wake-up when the clone terminates. The memory location contains the + thread ID while the clone is running and is reset to zero by the kernel + afterwards. The kernel up to version 3.16.3 does not use the private futex + operations for futex wake-up when the clone terminates. + If ABSTIME is not NULL, is used a timeout for futex call. If the timeout + occurs then return ETIMEOUT, if ABSTIME is invalid, return EINVAL. + The futex operation are issues with cancellable versions. */ +#define lll_wait_tid(tid, abstime) \ + ({ \ + int __res = 0; \ + __typeof (tid) __tid; \ + if (abstime != NULL) \ + __res = __lll_timedwait_tid (&(tid), (abstime)); \ + else \ + /* We need acquire MO here so that we synchronize with the \ + kernel's store to 0 when the clone terminates. (see above) */ \ + while ((__tid = atomic_load_acquire (&(tid))) != 0) \ + lll_futex_wait_cancel (&(tid), __tid, LLL_SHARED); \ + __res; \ }) #endif /* lowlevellock.h */ -- cgit v1.2.3-70-g09d2