From 66def4e776a0c6d68559309aa043163f77b148a5 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Sun, 3 Apr 2011 13:15:42 -0400 Subject: [PATCH] block all signals during rsyscall otherwise a signal handler could see an inconsistent and nonconformant program state where different threads have different uids/gids. --- src/thread/pthread_create.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/src/thread/pthread_create.c b/src/thread/pthread_create.c index 344b39f8..cdf36ff2 100644 --- a/src/thread/pthread_create.c +++ b/src/thread/pthread_create.c @@ -85,7 +85,7 @@ static void rsyscall_handler(int sig, siginfo_t *si, void *ctx) /* Threads which have already decremented themselves from the * thread count must not increment rs.cnt or otherwise act. */ if (self->dead) { - sigaddset(&((ucontext_t *)ctx)->uc_sigmask, SIGSYSCALL); + sigfillset(&((ucontext_t *)ctx)->uc_sigmask); return; } @@ -151,13 +151,18 @@ static void init_threads() libc.lockfile = __lockfile; libc.cancelpt = cancelpt; libc.rsyscall = rsyscall; + + sigfillset(&sa.sa_mask); + sa.sa_sigaction = rsyscall_handler; + __libc_sigaction(SIGSYSCALL, &sa, 0); + + sigemptyset(&sa.sa_mask); sa.sa_sigaction = cancel_handler; __libc_sigaction(SIGCANCEL, &sa, 0); + sigaddset(&sa.sa_mask, SIGSYSCALL); sigaddset(&sa.sa_mask, SIGCANCEL); - sa.sa_sigaction = rsyscall_handler; - __libc_sigaction(SIGSYSCALL, &sa, 0); - sigprocmask(SIG_UNBLOCK, &sa.sa_mask, 0); + __libc_sigprocmask(SIG_UNBLOCK, &sa.sa_mask, 0); } static int start(void *p) -- 2.25.1