Cleanup abort() so it behaves itself a bit better

libc/stdlib/abort.c

@@ -21,31 +21,86 @@ Cambridge, MA 02139, USA.  */
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
 #include <signal.h>
 #include <errno.h>
 
+
+/* Our last ditch effort to commit suicide */ 
+#if defined(__i386__)
+#define ABORT_INSTRUCTION asm ("hlt")
+#elif defined(__ia64__)
+#define ABORT_INSTRUCTION asm ("break 0")
+#elif defined(__mc68000__)
+#define ABORT_INSTRUCTION asm ("illegal")
+#elif defined(__mips__)
+#define ABORT_INSTRUCTION asm ("break 255")
+#elif defined(__s390__)
+#define ABORT_INSTRUCTION asm (".word 0")
+#elif defined(__sparc__)
+#define ABORT_INSTRUCTION asm ("unimp 0xf00")
+#elif defined(__x86_64__)
+#define ABORT_INSTRUCTION asm ("hlt")
+#else
+#define ABORT_INSTRUCTION
+#endif
+
 typedef void (*vfuncp) (void);
 extern vfuncp __uClibc_cleanup;
 extern void _exit __P((int __status)) __attribute__ ((__noreturn__));
+static int been_there_done_that = 0;
 
 /* Cause an abnormal program termination with core-dump.  */
 void abort(void)
 {
-	sigset_t sigset;
+    sigset_t sigset;
+
+    /* Unmask SIGABRT to be sure we can get it */
+    if (__sigemptyset(&sigset) == 0 && __sigaddset(&sigset, SIGABRT) == 0) {
+	sigprocmask(SIG_UNBLOCK, &sigset, (sigset_t *) NULL);
+    }
+
+    /* __uClibc_cleanup NULLs itself out after being called */
+    if (__uClibc_cleanup) {		
+	__uClibc_cleanup();
+    }
+
+    while (1) {
+	/* Try to suicide with a SIGABRT.  */
+	if (been_there_done_that == 0) {
+	    been_there_done_that++;
+	    raise(SIGABRT);
+	}
+
+	/* Still here?  Try to remove any signal handlers.  */
+	if (been_there_done_that == 1) {
+	    struct sigaction act;
 
-	if (sigemptyset(&sigset) == 0 && sigaddset(&sigset, SIGABRT) == 0) {
-		sigprocmask(SIG_UNBLOCK, &sigset, (sigset_t *) NULL);
+	    been_there_done_that++;
+	    memset (&act, '\0', sizeof (struct sigaction));
+	    act.sa_handler = SIG_DFL;
+	    __sigfillset (&act.sa_mask);
+	    act.sa_flags = 0;
+	    sigaction (SIGABRT, &act, NULL);
 	}
 
-	if (__uClibc_cleanup) {		/* Not already executing __uClibc_cleanup. */
-		__uClibc_cleanup();
+	/* Still here?  Try to suicide with an illegal instruction */
+	if (been_there_done_that == 2) {
+	    been_there_done_that++;
+	    ABORT_INSTRUCTION;
 	}
 
+	/* Still here?  Try to at least exit */
+	if (been_there_done_that == 3) {
+	    been_there_done_that++;
+	    _exit (127);
+	}
+
+	/* Still here?  We're screwed.  Sleepy time.  Good night */
 	while (1)
-		if (raise(SIGABRT))
-			/* If we can't signal ourselves, exit.  */
-			_exit(127);
-	/* If we signal ourselves and are still alive,
-	   or can't exit, loop forever.  */
+	    /* Try for ever and ever.  */
+	    ABORT_INSTRUCTION;
+    }
 }
+