From: Simon Ruderich <simon@ruderich.org>
Date: Thu, 23 Oct 2014 09:32:48 +0000 (+0200)
Subject: fix race condition in handle_wall()
X-Git-Url: https://ruderich.org/simon/gitweb/?p=wall-notify%2Fwall-notify.git;a=commitdiff_plain;h=bcd8ae1311102a644bd6d0dc0774d824169027b5

fix race condition in handle_wall()

If a signal occurred before the while loop is reached, it was lost.
---

diff --git a/src/wall-notify.c b/src/wall-notify.c
index 95c4d8f..efe5005 100644
--- a/src/wall-notify.c
+++ b/src/wall-notify.c
@@ -48,8 +48,13 @@
 #endif
 
 
+static sig_atomic_t signaled = 0;
+
+
 static void sig_handler(int signal) {
     (void)signal;
+
+    signaled = 1;
 }
 static void setup_signals(void) {
     struct sigaction action;
@@ -332,7 +337,7 @@ static void handle_wall(int fd, char **argv) {
     ssize_t r;
 
     assert(SSIZE_MAX <= SIZE_MAX);
-    while ((r = read(fd, buffer, sizeof(buffer))) > 0) {
+    while (!signaled && (r = read(fd, buffer, sizeof(buffer))) > 0) {
         size_t space;
         ssize_t r2;