X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fum%2Fos-Linux%2Fmain.c;fp=arch%2Fum%2Fos-Linux%2Fmain.c;h=685feaab65d239efa4931af9838e63b54f62d702;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=2878e89a674f0190108f4c527feb637de85ca6dc;hpb=76828883507a47dae78837ab5dec5a5b4513c667;p=linux-2.6.git

diff --git a/arch/um/os-Linux/main.c b/arch/um/os-Linux/main.c
index 2878e89a6..685feaab6 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 +68,60 @@ 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)
+{
+	char *new_path = NULL;
+	char *old_path = NULL;
+	int path_len = 0;
+
+	old_path = getenv("PATH");
+	/* if no PATH variable is set or it has an empty value
+	 * just use the default + /usr/lib/uml
+	 */
+	if (!old_path || (path_len = strlen(old_path)) == 0) {
+		putenv("PATH=:/bin:/usr/bin/" UML_LIB_PATH);
+		return;
+	}
+
+	/* append /usr/lib/uml to the existing path */
+	path_len += strlen("PATH=" UML_LIB_PATH) + 1;
+	new_path = malloc(path_len);
+	if (!new_path) {
+		perror("coudn't malloc to set a new PATH");
+		return;
+	}
+	snprintf(new_path, path_len, "PATH=%s" UML_LIB_PATH, old_path);
+	putenv(new_path);
+}
+
 extern int uml_exitcode;
 
 extern void scan_elf_aux( char **envp);
@@ -114,6 +162,8 @@ int main(int argc, char **argv, char **envp)
 
 	set_stklim();
 
+	setup_env_path();
+
 	new_argv = malloc((argc + 1) * sizeof(char *));
 	if(new_argv == NULL){
 		perror("Mallocing argv");
@@ -128,9 +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);