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[Ada] sigaction result not properly checked in __gnat_install_handler (QNX)

Message ID 20220516084314.GA3843704@adacore.com
State New
Headers show
Series [Ada] sigaction result not properly checked in __gnat_install_handler (QNX) | expand

Commit Message

Pierre-Marie de Rodat May 16, 2022, 8:43 a.m. UTC 
The QNX version of __gnat_install_handler calls sigaction for a number
of signals, and then prints an error message when the the call failed.
But unfortunately, except for the first call, we forgot to store
sigaction's return value, so the check that ensues uses a potentially
uninitialized variable, which the compiler does detect (this is how we
found this issue).

This change fixes this by make sure we store the result of each
sigaction call before checking it.

While at it, we noticed a thinko in the error messages all alerting
about the SIGFPE signal, rather than the signal it just tested.  Most
likely a copy/paste thinko. Fixed by this change as well.

Tested on x86_64-pc-linux-gnu, committed on trunk

gcc/ada/

	* init.c (__gnat_install_handler) [__QNX__]: Save sigaction's
	return value in err before checking err's value.  Fix incorrect
	signal names in perror messages.
diff mbox series

Patch

diff --git a/gcc/ada/init.c b/gcc/ada/init.c
--- a/gcc/ada/init.c
+++ b/gcc/ada/init.c
@@ -2625,26 +2625,26 @@  __gnat_install_handler (void)
     }
   }
   if (__gnat_get_interrupt_state (SIGILL) != 's') {
-    sigaction (SIGILL,  &act, NULL);
+    err = sigaction (SIGILL,  &act, NULL);
     if (err == -1) {
       err = errno;
-      perror ("error while attaching SIGFPE");
+      perror ("error while attaching SIGILL");
       perror (strerror (err));
     }
   }
   if (__gnat_get_interrupt_state (SIGSEGV) != 's') {
-    sigaction (SIGSEGV, &act, NULL);
+    err = sigaction (SIGSEGV, &act, NULL);
     if (err == -1) {
       err = errno;
-      perror ("error while attaching SIGFPE");
+      perror ("error while attaching SIGSEGV");
       perror (strerror (err));
     }
   }
   if (__gnat_get_interrupt_state (SIGBUS) != 's') {
-    sigaction (SIGBUS,  &act, NULL);
+    err = sigaction (SIGBUS,  &act, NULL);
     if (err == -1) {
       err = errno;
-      perror ("error while attaching SIGFPE");
+      perror ("error while attaching SIGBUS");
       perror (strerror (err));
     }
   }