From: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Date: Sat, 22 Oct 2016 20:11:41 +0000 (-0400)
Subject: tree-wide: use startswith return value to avoid hardcoded offset
X-Git-Tag: v233.3~178
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;ds=sidebyside;h=910c586574a52c6b4cbc6638193797008da076c7;p=elogind.git

tree-wide: use startswith return value to avoid hardcoded offset

I think it's an antipattern to have to count the number of bytes in
the prefix by hand. We should do this automatically to avoid wasting
programmer time, and possible errors. I didn't any offsets that were
wrong, so this change is mostly to make future development easier.
---

diff --git a/src/core/cgroup.c b/src/core/cgroup.c
index 9e4e99326..a524a4110 100644
--- a/src/core/cgroup.c
+++ b/src/core/cgroup.c
@@ -930,7 +930,7 @@ static void cgroup_context_apply(Unit *u, CGroupMask mask, ManagerState state) {
                 }
 
                 LIST_FOREACH(device_allow, a, c->device_allow) {
-                        char acc[4];
+                        char acc[4], *val;
                         unsigned k = 0;
 
                         if (a->r)
@@ -947,10 +947,10 @@ static void cgroup_context_apply(Unit *u, CGroupMask mask, ManagerState state) {
 
                         if (startswith(a->path, "/dev/"))
                                 whitelist_device(path, a->path, acc);
-                        else if (startswith(a->path, "block-"))
-                                whitelist_major(path, a->path + 6, 'b', acc);
-                        else if (startswith(a->path, "char-"))
-                                whitelist_major(path, a->path + 5, 'c', acc);
+                        else if ((val = startswith(a->path, "block-")))
+                                whitelist_major(path, val, 'b', acc);
+                        else if ((val = startswith(a->path, "char-")))
+                                whitelist_major(path, val, 'c', acc);
                         else
                                 log_unit_debug(u, "Ignoring device %s while writing cgroup attribute.", a->path);
                 }