diff options
| -rw-r--r-- | ChangeLog | 7 | ||||
| -rw-r--r-- | sysdeps/pthread/aio_notify.c | 33 |
2 files changed, 37 insertions, 3 deletions
@@ -1,3 +1,10 @@ +2002-12-08 Roland McGrath <roland@redhat.com> + + * sysdeps/pthread/aio_notify.c (notify_func_wrapper): Take a malloc'd + struct containing function ptr and value, free it. + (__aio_notify_only): Allocate that and copy values from SIGEV into it. + It's not safe to let the new thread use the SIGEV pointer. + 2001-10-20 Paul Eggert <eggert@twinsun.com> * misc/error.c (strerror_r): Do not declare unless [!_LIBC]. diff --git a/sysdeps/pthread/aio_notify.c b/sysdeps/pthread/aio_notify.c index 4537ca5aab..047b6314a0 100644 --- a/sysdeps/pthread/aio_notify.c +++ b/sysdeps/pthread/aio_notify.c @@ -25,11 +25,20 @@ #include "aio_misc.h" +struct notify_func + { + void (*func) (sigval_t); + sigval_t value; + }; + static void * notify_func_wrapper (void *arg) { - struct sigevent *sigev = arg; - sigev->sigev_notify_function (sigev->sigev_value); + struct notify_func *const n = arg; + void (*func) (sigval_t) = n->func; + sigval_t value = n->value; + free (n); + (*func) (value); return NULL; } @@ -55,8 +64,26 @@ __aio_notify_only (struct sigevent *sigev, pid_t caller_pid) pattr = &attr; } - if (pthread_create (&tid, pattr, notify_func_wrapper, sigev) < 0) + /* SIGEV may be freed as soon as we return, so we cannot let the + notification thread use that pointer. Even though a sigval_t is + only one word and the same size as a void *, we cannot just pass + the value through pthread_create as the argument and have the new + thread run the user's function directly, because on some machines + the calling convention for a union like sigval_t is different from + that for a pointer type like void *. */ + struct notify_func *nf = malloc (sizeof *nf); + if (nf == NULL) result = -1; + else + { + nf->func = sigev->sigev_notify_function; + nf->value = sigev->sigev_value; + if (pthread_create (&tid, pattr, notify_func_wrapper, nf) < 0) + { + free (nf); + result = -1; + } + } } else if (sigev->sigev_notify == SIGEV_SIGNAL) { |