From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Sat, 23 Feb 2013 20:30:59 +0000 (-0500)
Subject: Don't write outside the requested range
X-Git-Url: http://git.efficios.com/?p=test-ssd.git;a=commitdiff_plain

Don't write outside the requested range

Ensure we don't spill BUFLEN outside of the requested length.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/test-ssd-write.c b/test-ssd-write.c
index 5b7c8c4..ea85248 100644
--- a/test-ssd-write.c
+++ b/test-ssd-write.c
@@ -146,13 +146,18 @@ static int rand_write(int fd, size_t len)
 	uint64_t valcount;
 	int ret;
 
+	if (len < BUFLEN) {
+		fprintf(stderr, "Error: File size needs to be at least %u\n", BUFLEN);
+		exit(EXIT_FAILURE);
+	}
+
 	memset(buf, 0, BUFLEN);
 
 	for (;;) {
 		if (len > UINT32_MAX) {
-			offset = (((size_t) rand() << 32) + (size_t) rand()) % len;
+			offset = (((size_t) rand() << 32) + (size_t) rand()) % (len - BUFLEN);
 		} else {
-			offset = rand() % len;
+			offset = rand() % (len - BUFLEN);
 		}
 
 		if ((offset >= validate_offset &&