From: Dmitry V. Levin <ldv@altlinux.org>
Date: Wed, 18 May 2016 09:14:12 +0000 (+0000)
Subject: tests/read-write.c: robustify against os specific issues
X-Git-Tag: v4.12~116
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=a8e820586ece77fe5430ca089b255f735a92cb6b;p=strace

tests/read-write.c: robustify against os specific issues

Do not assume that write syscall fails when only part of the specified
memory buffer is accessible.  With some kernels, one accessible byte
at the end of page is enough for write syscall to return 1.

* tests/read-write.c (main): Tweak the test that can lead to a partial
write.
---

diff --git a/tests/read-write.c b/tests/read-write.c
index 4efe1473..4d1e7302 100644
--- a/tests/read-write.c
+++ b/tests/read-write.c
@@ -152,12 +152,11 @@ main(void)
 		perror_msg_and_fail("write: expected 0, returned %ld", rc);
 	tprintf("write(1, \"\", 0) = 0\n");
 
-	rc = write(1, w, w_len + 1);
+	rc = write(1, efault, 1);
 	if (rc != -1)
 		perror_msg_and_fail("write: expected -1 EFAULT"
 				    ", returned %ld", rc);
-	tprintf("write(1, %p, %u) = -1 EFAULT (%m)\n",
-		w, w_len + 1);
+	tprintf("write(1, %p, 1) = -1 EFAULT (%m)\n", efault);
 
 	rc = write(1, w, w_len);
 	if (rc != (int) w_len)