handle suicide on late failure exits in execve() in search_binary_handler()

... rather than doing that in the guts of ->load_binary().
[updated to fix the bug spotted by Shentino - for SIGSEGV we really need
something stronger than send_sig_info(); again, better do that in one place]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/exec.c b/fs/exec.c
index a2b42a9..7302b75 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1372,18 +1372,23 @@
 		read_unlock(&binfmt_lock);
 		bprm->recursion_depth++;
 		retval = fmt->load_binary(bprm);
-		bprm->recursion_depth--;
-		if (retval >= 0 || retval != -ENOEXEC ||
-		    bprm->mm == NULL || bprm->file == NULL) {
-			put_binfmt(fmt);
-			return retval;
-		}
 		read_lock(&binfmt_lock);
 		put_binfmt(fmt);
+		bprm->recursion_depth--;
+		if (retval < 0 && !bprm->mm) {
+			/* we got to flush_old_exec() and failed after it */
+			read_unlock(&binfmt_lock);
+			force_sigsegv(SIGSEGV, current);
+			return retval;
+		}
+		if (retval != -ENOEXEC || !bprm->file) {
+			read_unlock(&binfmt_lock);
+			return retval;
+		}
 	}
 	read_unlock(&binfmt_lock);
 
-	if (need_retry && retval == -ENOEXEC) {
+	if (need_retry) {
 		if (printable(bprm->buf[0]) && printable(bprm->buf[1]) &&
 		    printable(bprm->buf[2]) && printable(bprm->buf[3]))
 			return retval;