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author | Rich Felker <dalias@aerifal.cx> | 2011-05-07 23:23:58 -0400 |
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committer | Rich Felker <dalias@aerifal.cx> | 2011-05-07 23:23:58 -0400 |
commit | 99b8a25e941e54537bf39ca2f265c345f393f112 (patch) | |
tree | 758faba1a20af40b5d09221d008eddbc704636fa /src/thread/pthread_create.c | |
parent | 77f15d108ee021d4dfbeebe793661131c4470d4d (diff) | |
download | musl-99b8a25e941e54537bf39ca2f265c345f393f112.tar.gz musl-99b8a25e941e54537bf39ca2f265c345f393f112.tar.bz2 musl-99b8a25e941e54537bf39ca2f265c345f393f112.tar.xz musl-99b8a25e941e54537bf39ca2f265c345f393f112.zip |
overhaul implementation-internal signal protections
the new approach relies on the fact that the only ways to create
sigset_t objects without invoking UB are to use the sig*set()
functions, or from the masks returned by sigprocmask, sigaction, etc.
or in the ucontext_t argument to a signal handler. thus, as long as
sigfillset and sigaddset avoid adding the "protected" signals, there
is no way the application will ever obtain a sigset_t including these
bits, and thus no need to add the overhead of checking/clearing them
when sigprocmask or sigaction is called.
note that the old code actually *failed* to remove the bits from
sa_mask when sigaction was called.
the new implementations are also significantly smaller, simpler, and
faster due to ignoring the useless "GNU HURD signals" 65-1024, which
are not used and, if there's any sanity in the world, never will be
used.
Diffstat (limited to 'src/thread/pthread_create.c')
-rw-r--r-- | src/thread/pthread_create.c | 16 |
1 files changed, 4 insertions, 12 deletions
diff --git a/src/thread/pthread_create.c b/src/thread/pthread_create.c index 0d2c17bb..6545539b 100644 --- a/src/thread/pthread_create.c +++ b/src/thread/pthread_create.c @@ -34,7 +34,7 @@ void __pthread_unwind_next(struct __ptcb *cb) if (!n) exit(0); if (self->detached && self->map_base) { - __syscall(SYS_rt_sigprocmask, SIG_BLOCK, (long)(uint64_t[1]){-1},0,8); + __syscall(SYS_rt_sigprocmask, SIG_BLOCK, (uint64_t[]){-1},0,8); __unmapself(self->map_base, self->map_size); } @@ -44,12 +44,8 @@ void __pthread_unwind_next(struct __ptcb *cb) static int start(void *p) { struct pthread *self = p; - if (self->unblock_cancel) { - sigset_t set; - sigemptyset(&set); - sigaddset(&set, SIGCANCEL); - __libc_sigprocmask(SIG_UNBLOCK, &set, 0); - } + if (self->unblock_cancel) + __syscall(SYS_rt_sigprocmask, SIG_UNBLOCK, &SIGPT_SET, 0, 8); pthread_exit(self->start(self->start_arg)); return 0; } @@ -72,11 +68,7 @@ int pthread_create(pthread_t *res, const pthread_attr_t *attr, void *(*entry)(vo if (!self) return ENOSYS; if (!libc.threaded) { - sigset_t set; - sigemptyset(&set); - sigaddset(&set, SIGSYSCALL); - sigaddset(&set, SIGCANCEL); - __libc_sigprocmask(SIG_UNBLOCK, &set, 0); + __syscall(SYS_rt_sigprocmask, SIG_UNBLOCK, &SIGPT_SET, 0, 8); libc.threaded = 1; } |