X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;f=arch%2Fum%2Fos-Linux%2Fmain.c;h=685feaab65d239efa4931af9838e63b54f62d702;hb=ae5dd8e346efc25a5f9cc9d01bc0915c40eb38d9;hp=3a0ac38e978bffa982f68badb8e9dd1e168bd3f6;hpb=2bf9d6d0f2dadc2a6c13684719c67dc043b9ce67;p=powerpc.git

diff --git a/arch/um/os-Linux/main.c b/arch/um/os-Linux/main.c
index 3a0ac38e97..685feaab65 100644
--- a/arch/um/os-Linux/main.c
+++ b/arch/um/os-Linux/main.c
@@ -23,6 +23,7 @@
 #include "choose-mode.h"
 #include "uml-config.h"
 #include "os.h"
+#include "um_malloc.h"
 
 /* Set in set_stklim, which is called from main and __wrap_malloc.
  * __wrap_malloc only calls it if main hasn't started.
@@ -59,7 +60,7 @@ static __init void do_uml_initcalls(void)
 	initcall_t *call;
 
 	call = &__uml_initcall_start;
-	while (call < &__uml_initcall_end){;
+	while (call < &__uml_initcall_end){
 		(*call)();
 		call++;
 	}
@@ -67,13 +68,32 @@ static __init void do_uml_initcalls(void)
 
 static void last_ditch_exit(int sig)
 {
-	signal(SIGINT, SIG_DFL);
-	signal(SIGTERM, SIG_DFL);
-	signal(SIGHUP, SIG_DFL);
 	uml_cleanup();
 	exit(1);
 }
 
+static void install_fatal_handler(int sig)
+{
+	struct sigaction action;
+
+	/* All signals are enabled in this handler ... */
+	sigemptyset(&action.sa_mask);
+
+	/* ... including the signal being handled, plus we want the
+	 * handler reset to the default behavior, so that if an exit
+	 * handler is hanging for some reason, the UML will just die
+	 * after this signal is sent a second time.
+	 */
+	action.sa_flags = SA_RESETHAND | SA_NODEFER;
+	action.sa_restorer = NULL;
+	action.sa_handler = last_ditch_exit;
+	if(sigaction(sig, &action, NULL) < 0){
+		printf("failed to install handler for signal %d - errno = %d\n",
+		       errno);
+		exit(1);
+	}
+}
+
 #define UML_LIB_PATH	":/usr/lib/uml"
 
 static void setup_env_path(void)
@@ -158,9 +178,12 @@ int main(int argc, char **argv, char **envp)
 	}
 	new_argv[argc] = NULL;
 
-	set_handler(SIGINT, last_ditch_exit, SA_ONESHOT | SA_NODEFER, -1);
-	set_handler(SIGTERM, last_ditch_exit, SA_ONESHOT | SA_NODEFER, -1);
-	set_handler(SIGHUP, last_ditch_exit, SA_ONESHOT | SA_NODEFER, -1);
+	/* Allow these signals to bring down a UML if all other
+	 * methods of control fail.
+	 */
+	install_fatal_handler(SIGINT);
+	install_fatal_handler(SIGTERM);
+	install_fatal_handler(SIGHUP);
 
 	scan_elf_aux( envp);