diff options
Diffstat (limited to 'main/musl/fix-failure-to-obtain-EOWNERDEAD-status-for-process-shared-robust-mutexes.patch')
| -rw-r--r-- | main/musl/fix-failure-to-obtain-EOWNERDEAD-status-for-process-shared-robust-mutexes.patch | 69 |
1 files changed, 0 insertions, 69 deletions
diff --git a/main/musl/fix-failure-to-obtain-EOWNERDEAD-status-for-process-shared-robust-mutexes.patch b/main/musl/fix-failure-to-obtain-EOWNERDEAD-status-for-process-shared-robust-mutexes.patch deleted file mode 100644 index 445fa80455..0000000000 --- a/main/musl/fix-failure-to-obtain-EOWNERDEAD-status-for-process-shared-robust-mutexes.patch +++ /dev/null @@ -1,69 +0,0 @@ -commit 384d103d94dba0472a587861f67d7ed6e8955f86 -Author: Rich Felker <dalias@aerifal.cx> -Date: Mon Jun 27 15:18:13 2016 -0400 - - fix failure to obtain EOWNERDEAD status for process-shared robust mutexes - - Linux's documentation (robust-futex-ABI.txt) claims that, when a - process dies with a futex on the robust list, bit 30 (0x40000000) is - set to indicate the status. however, what actually happens is that - bits 0-30 are replaced with the value 0x40000000, i.e. bits 0-29 - (containing the old owner tid) are cleared at the same time bit 30 is - set. - - our userspace-side code for robust mutexes was written based on that - documentation, assuming that kernel would never produce a futex value - of 0x40000000, since the low (owner) bits would always be non-zero. - commit d338b506e39b1e2c68366b12be90704c635602ce introduced this - assumption explicitly while fixing another bug in how non-recoverable - status for robust mutexes was tracked. presumably the tests conducted - at that time only checked non-process-shared robust mutexes, which are - handled in pthread_exit (which implemented the documented kernel - protocol, not the actual one) rather than by the kernel. - - change pthread_exit robust list processing to match the kernel - behavior, clearing bits 0-29 while setting bit 30, and use the value - 0x7fffffff instead of 0x40000000 to encode non-recoverable status. the - choice of value here is arbitrary; any value with at least one of bits - 0-29 set should work just as well, - -diff --git a/src/thread/pthread_create.c b/src/thread/pthread_create.c -index e7df34a..9f6b98e 100644 ---- a/src/thread/pthread_create.c -+++ b/src/thread/pthread_create.c -@@ -79,7 +79,7 @@ _Noreturn void __pthread_exit(void *result) - int priv = (m->_m_type & 128) ^ 128; - self->robust_list.pending = rp; - self->robust_list.head = *rp; -- int cont = a_swap(&m->_m_lock, self->tid|0x40000000); -+ int cont = a_swap(&m->_m_lock, 0x40000000); - self->robust_list.pending = 0; - if (cont < 0 || waiters) - __wake(&m->_m_lock, 1, priv); -diff --git a/src/thread/pthread_mutex_trylock.c b/src/thread/pthread_mutex_trylock.c -index 0df3ce2..54876a6 100644 ---- a/src/thread/pthread_mutex_trylock.c -+++ b/src/thread/pthread_mutex_trylock.c -@@ -14,7 +14,7 @@ int __pthread_mutex_trylock_owner(pthread_mutex_t *m) - m->_m_count++; - return 0; - } -- if (own == 0x40000000) return ENOTRECOVERABLE; -+ if (own == 0x7fffffff) return ENOTRECOVERABLE; - - if (m->_m_type & 128) { - if (!self->robust_list.off) { -diff --git a/src/thread/pthread_mutex_unlock.c b/src/thread/pthread_mutex_unlock.c -index 02da92a..7dd00d2 100644 ---- a/src/thread/pthread_mutex_unlock.c -+++ b/src/thread/pthread_mutex_unlock.c -@@ -24,7 +24,7 @@ int __pthread_mutex_unlock(pthread_mutex_t *m) - if (next != &self->robust_list.head) *(volatile void *volatile *) - ((char *)next - sizeof(void *)) = prev; - } -- cont = a_swap(&m->_m_lock, (type & 8) ? 0x40000000 : 0); -+ cont = a_swap(&m->_m_lock, (type & 8) ? 0x7fffffff : 0); - if (type != PTHREAD_MUTEX_NORMAL && !priv) { - self->robust_list.pending = 0; - __vm_unlock(); - |