Changeset f3b5dc8

Timestamp:

Mar 25, 2011, 3:55:41 AM (13 years ago)

Author:

David Benjamin <davidben@mit.edu>

Children:

567de81

Parents:

8eb6068

git-author:

David Benjamin <davidben@mit.edu> (02/28/11 10:12:15)

git-committer:

David Benjamin <davidben@mit.edu> (03/25/11 03:55:41)

Message:

Reset signal dispositions and mask, in case our parent was lame

Also check return values more carefully.

Files:

• owl.c (modified) (1 diff)
• signal.c (modified) (3 diffs)

owl.c

@@ -389 +389 @@
 }
 
+#define CHECK_RESULT(s, syscall) \
+  G_STMT_START {                 \
+    if ((syscall) != 0) {        \
+      perror((s));               \
+      exit(1);                   \
+    }                            \
+  } G_STMT_END
+
 void owl_register_signal_handlers(void) {
-  struct sigaction ignore = { .sa_handler = SIG_IGN };
+  struct sigaction sig_ignore = { .sa_handler = SIG_IGN };
+  struct sigaction sig_default = { .sa_handler = SIG_DFL };
   sigset_t sigset;
+  int ret, i;
+  const int signals[] = { SIGABRT, SIGBUS, SIGCHLD, SIGFPE, SIGHUP, SIGILL,
+                          SIGINT, SIGQUIT, SIGSEGV, SIGTERM, SIGWINCH };
+
+  /* Sanitize our signals; the mask and dispositions from our parent
+   * aren't really useful. Signal list taken from equivalent code in
+   * Chromium. */
+  CHECK_RESULT("sigemptyset", sigemptyset(&sigset));
+  if ((ret = pthread_sigmask(SIG_SETMASK, &sigset, NULL)) != 0) {
+    errno = ret;
+    perror("pthread_sigmask");
+  }
+  for (i = 0; i < G_N_ELEMENTS(signals); i++) {
+    CHECK_RESULT("sigaction", sigaction(signals[i], &sig_default, NULL));
+  }
 
   /* Turn off SIGPIPE; we check the return value of write. */
-  sigaction(SIGPIPE, &ignore, NULL);
+  CHECK_RESULT("sigaction", sigaction(SIGPIPE, &sig_ignore, NULL));
 
   /* Register some signals with the signal thread. */
-  sigemptyset(&sigset);
-  sigaddset(&sigset, SIGWINCH);
-  sigaddset(&sigset, SIGTERM);
-  sigaddset(&sigset, SIGHUP);
-  sigaddset(&sigset, SIGINT);
+  CHECK_RESULT("sigaddset", sigaddset(&sigset, SIGWINCH));
+  CHECK_RESULT("sigaddset", sigaddset(&sigset, SIGTERM));
+  CHECK_RESULT("sigaddset", sigaddset(&sigset, SIGHUP));
+  CHECK_RESULT("sigaddset", sigaddset(&sigset, SIGINT));
   owl_signal_init(&sigset, sig_handler, g_main_context_default());
 }

signal.c

@@ -1 +1 @@
 #include <glib.h>
+#include <errno.h>
 #include <pthread.h>
 #include <signal.h>
@@ -21 +22 @@
 void owl_signal_init(const sigset_t *set, void (*callback)(int, void*), void *data) {
   GError *error = NULL;
+  int ret;
 
   signal_set = *set;
@@ -26 +28 @@
   signal_cbdata = data;
   /* Block these signals in all threads, so we can get them. */
-  pthread_sigmask(SIG_BLOCK, set, NULL);
+  if ((ret = pthread_sigmask(SIG_BLOCK, set, NULL)) != 0) {
+    errno = ret;
+    perror("pthread_sigmask");
+  }
   /* Spawn a dedicated thread to sigwait. */
   signal_thread = g_thread_create(signal_thread_func, NULL, FALSE, &error);