From: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Date: Tue, 9 May 2017 19:46:35 +0000 (-0400)
Subject: Fix: COMPAT_EPOLL_PROC_PATH is available from Linux 2.6.28
X-Git-Tag: v2.8.7~12
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=811b2f150aae06ae0d211dc97416b847986798a3;p=lttng-tools.git

Fix: COMPAT_EPOLL_PROC_PATH is available from Linux 2.6.28

v2: Typo in commit message "per see" -> "per se"

Failing on opening [1] is not an error per se. [1] was
introduced in Linux 2.6.28 but epoll is available since
2.5.44. Hence, goto end and set a default value without
setting error return value.

[1] /proc/sys/fs/epoll/max_user_watches

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---

diff --git a/src/common/compat/compat-epoll.c b/src/common/compat/compat-epoll.c
index 6259fd389..f4befa1a2 100644
--- a/src/common/compat/compat-epoll.c
+++ b/src/common/compat/compat-epoll.c
@@ -259,7 +259,15 @@ int compat_epoll_set_max_size(void)
 
 	fd = open(COMPAT_EPOLL_PROC_PATH, O_RDONLY);
 	if (fd < 0) {
-		retval = -1;
+		/*
+		 * Failing on opening [1] is not an error per see. [1] was
+		 * introduced in Linux 2.6.28 but epoll is available since
+		 * 2.5.44. Hence, goto end and set a default value without
+		 * setting an error return value.
+		 *
+		 * [1] /proc/sys/fs/epoll/max_user_watches
+		 */
+		retval = 0;
 		goto end;
 	}