[PATCH] uml: search from uml_net in a more reasonable PATH

Append /usr/lib/uml to the existing PATH environment variable to let execvp()
search uml_net in FHS compliant locations.
Signed-off-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/um/os-Linux/main.c

@@ -74,6 +74,34 @@ static void last_ditch_exit(int sig)
 	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 +142,8 @@ 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");