diff options
| -rw-r--r-- | nptl/Versions | 3 | ||||
| -rw-r--r-- | nptl/pthreadP.h | 6 | ||||
| -rw-r--r-- | nptl/pthread_cancel.c | 49 | ||||
| -rw-r--r-- | nptl/pthread_create.c | 15 |
4 files changed, 28 insertions, 45 deletions
diff --git a/nptl/Versions b/nptl/Versions index b8b8299..d49dba9 100644 --- a/nptl/Versions +++ b/nptl/Versions @@ -403,7 +403,6 @@ libc { __nptl_free_tcb; __nptl_nthreads; __nptl_setxid_sighandler; - __nptl_sigcancel_handler; __nptl_stack_list_add; __nptl_stack_list_del; __pthread_attr_copy; @@ -522,4 +521,4 @@ ld { __nptl_initial_report_events; __nptl_set_robust_list_avail; } -}
\ No newline at end of file +} diff --git a/nptl/pthreadP.h b/nptl/pthreadP.h index 05f2bae..48d48e7 100644 --- a/nptl/pthreadP.h +++ b/nptl/pthreadP.h @@ -569,12 +569,6 @@ libc_hidden_proto (__pthread_attr_setsigmask_internal) extern __typeof (pthread_attr_getsigmask_np) __pthread_attr_getsigmask_np; libc_hidden_proto (__pthread_attr_getsigmask_np) -/* The cancellation signal handler defined alongside with - pthread_cancel. This is included in statically linked binaries - only if pthread_cancel is linked in. */ -void __nptl_sigcancel_handler (int sig, siginfo_t *si, void *ctx); -libc_hidden_proto (__nptl_sigcancel_handler) - /* Special versions which use non-exported functions. */ extern void __pthread_cleanup_push (struct _pthread_cleanup_buffer *buffer, void (*routine) (void *), void *arg); diff --git a/nptl/pthread_cancel.c b/nptl/pthread_cancel.c index 802c691..deb4046 100644 --- a/nptl/pthread_cancel.c +++ b/nptl/pthread_cancel.c @@ -28,11 +28,19 @@ #include <gnu/lib-names.h> #include <sys/single_threaded.h> -/* For asynchronous cancellation we use a signal. This is the core - logic of the signal handler. */ +/* For asynchronous cancellation we use a signal. */ static void -sigcancel_handler (void) +sigcancel_handler (int sig, siginfo_t *si, void *ctx) { + /* Safety check. It would be possible to call this function for + other signals and send a signal from another process. This is not + correct and might even be a security problem. Try to catch as + many incorrect invocations as possible. */ + if (sig != SIGCANCEL + || si->si_pid != __getpid() + || si->si_code != SI_TKILL) + return; + struct pthread *self = THREAD_SELF; int oldval = THREAD_GETMEM (self, cancelhandling); @@ -66,24 +74,6 @@ sigcancel_handler (void) } } -/* This is the actually installed SIGCANCEL handler. It adds some - safety checks before performing the cancellation. */ -void -__nptl_sigcancel_handler (int sig, siginfo_t *si, void *ctx) -{ - /* Safety check. It would be possible to call this function for - other signals and send a signal from another process. This is not - correct and might even be a security problem. Try to catch as - many incorrect invocations as possible. */ - if (sig != SIGCANCEL - || si->si_pid != __getpid() - || si->si_code != SI_TKILL) - return; - - sigcancel_handler (); -} -libc_hidden_def (__nptl_sigcancel_handler) - int __pthread_cancel (pthread_t th) { @@ -94,6 +84,17 @@ __pthread_cancel (pthread_t th) /* Not a valid thread handle. */ return ESRCH; + static int init_sigcancel = 0; + if (atomic_load_relaxed (&init_sigcancel) == 0) + { + struct sigaction sa; + sa.sa_sigaction = sigcancel_handler; + sa.sa_flags = SA_SIGINFO; + __sigemptyset (&sa.sa_mask); + __libc_sigaction (SIGCANCEL, &sa, NULL); + atomic_store_relaxed (&init_sigcancel, 1); + } + #ifdef SHARED /* Trigger an error if libgcc_s cannot be loaded. */ { @@ -134,7 +135,11 @@ __pthread_cancel (pthread_t th) call pthread_cancel (pthread_self ()) without calling pthread_create, so the signal handler may not have been set up for a self-cancel. */ - sigcancel_handler (); + { + THREAD_SETMEM (pd, result, PTHREAD_CANCELED); + if ((newval & CANCELTYPE_BITMASK) != 0) + __do_cancel (); + } else { /* The cancellation handler will take care of marking the diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c index 02892b1..72ecda8 100644 --- a/nptl/pthread_create.c +++ b/nptl/pthread_create.c @@ -67,21 +67,6 @@ late_init (void) struct sigaction sa; __sigemptyset (&sa.sa_mask); - /* Install the cancellation signal handler (in static builds only if - pthread_cancel has been linked in). If for some reason we cannot - install the handler we do not abort. Maybe we should, but it is - only asynchronous cancellation which is affected. */ -#ifndef SHARED - extern __typeof (__nptl_sigcancel_handler) __nptl_sigcancel_handler - __attribute__ ((weak)); - if (__nptl_sigcancel_handler != NULL) -#endif - { - sa.sa_sigaction = __nptl_sigcancel_handler; - sa.sa_flags = SA_SIGINFO; - (void) __libc_sigaction (SIGCANCEL, &sa, NULL); - } - /* Install the handle to change the threads' uid/gid. Use SA_ONSTACK because the signal may be sent to threads that are running with custom stacks. (This is less likely for |