From a1ed6b4cabb0109106490f501ba64c2f45fa84e5 Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Sat, 5 Jul 2003 06:18:19 +0000 Subject: [PATCH] (sigcancel_handler): Change parameters to match handler for SA_SIGACTION. Check signal number and code to recognize invalid invocations. --- nptl/init.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/nptl/init.c b/nptl/init.c index 3e041ed..abc7857 100644 --- a/nptl/init.c +++ b/nptl/init.c @@ -132,8 +132,19 @@ static struct pthread_functions pthread_functions = /* For asynchronous cancellation we use a signal. This is the handler. */ static void -sigcancel_handler (int sig __attribute ((unused))) +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 thread. 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_code != SI_TKILL) + /* XXX The Linux kernel currently does not report the correct PID + in the si->si_pid field. Once this is changed another test + will be added. */ + return; + struct pthread *self = THREAD_SELF; int oldval = THREAD_GETMEM (self, cancelhandling); @@ -209,8 +220,8 @@ __pthread_initialize_minimal_internal (void) cannot install the handler we do not abort. Maybe we should, but it is only asynchronous cancellation which is affected. */ struct sigaction sa; - sa.sa_handler = sigcancel_handler; - sa.sa_flags = 0; + sa.sa_sigaction = sigcancel_handler; + sa.sa_flags = SA_SIGINFO; sigemptyset (&sa.sa_mask); (void) __libc_sigaction (SIGCANCEL, &sa, NULL); -- 2.7.4