Per discussion with Manuel, when we call __stdio_flush_buffers

from abort() and from _exit(), we need to ensure that flushing
will not cause us to block.  So use fcntl to set the fd's to
non-block mode...

1 files changed, 9 insertions, 1 deletions

diff --git a/libc/stdio/stdio.c b/libc/stdio/stdio.c
index 45cd0b8ec..eb2961f37 100644
--- a/libc/stdio/stdio.c
+++ b/libc/stdio/stdio.c
@@ -198,7 +198,15 @@ char _free_buffer_index = FIXED_BUFFERS;
  */
 void __stdio_flush_buffers(void)
 {
-	fflush(NULL);				/* Files will be closed on _exit call. */
+    FILE *fp;
+    for (fp = __IO_list; fp; fp = fp->next) {
+	if (WRITEABLE(fp)) {
+	    /* Set the underlying fd to non-block mode to ensure
+	     * that calls to _exit() and abort() will not block */
+	    fcntl(fp->fd, F_SETFL, O_NONBLOCK);
+	    fflush(fp);
+	}
+    }
 }
 
 /*