From: Serge Hallyn <serge.hallyn@ubuntu.com>
Date: Sun, 17 May 2015 20:14:13 +0000 (+0000)
Subject: proc update - don't assume we are pid 1
X-Git-Tag: lxc-2.0.0.beta1~267
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fe4478860810c6db680181e67f65c3a15e97fc15;p=thirdparty%2Flxc.git

proc update - don't assume we are pid 1

(I erred in the first patch, causing every lxc-attach to unmount the
container-'s /proc)

Since we now use mount_proc_if_needed() from attach, as opposed to only
from start, we cannot assume we are pid 1.  So fix the check for whether
to mount a new proc.

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>
---

diff --git a/src/lxc/utils.c b/src/lxc/utils.c
index ac00af3b5..467bc1b42 100644
--- a/src/lxc/utils.c
+++ b/src/lxc/utils.c
@@ -1417,6 +1417,7 @@ int mount_proc_if_needed(const char *rootfs)
 	char path[MAXPATHLEN];
 	char link[20];
 	int linklen, ret;
+	int mypid;
 
 	ret = snprintf(path, MAXPATHLEN, "%s/proc/self", rootfs);
 	if (ret < 0 || ret >= MAXPATHLEN) {
@@ -1425,12 +1426,12 @@ int mount_proc_if_needed(const char *rootfs)
 	}
 	memset(link, 0, 20);
 	linklen = readlink(path, link, 20);
-	INFO("I am %d, /proc/self points to '%s'", getpid(), link);
+	mypid = (int)getpid();
+	INFO("I am %d, /proc/self points to '%s'", mypid, link);
 	ret = snprintf(path, MAXPATHLEN, "%s/proc", rootfs);
 	if (linklen < 0) /* /proc not mounted */
 		goto domount;
-	/* can't be longer than rootfs/proc/1 */
-	if (strncmp(link, "1", linklen) != 0) {
+	if (atoi(link) != mypid) {
 		/* wrong /procs mounted */
 		umount2(path, MNT_DETACH); /* ignore failure */
 		goto domount;