From 3f62a020c48d5d812fb2898759b93a59dc24d310 Mon Sep 17 00:00:00 2001
From: Jeff Vander Stoep <jeffv@google.com>
Date: Thu, 23 Jul 2015 15:18:36 -0700
Subject: [PATCH] logd: allow logd to write to /dev/cpuset files

Required by logd on devices with USE_CPUSETS defined.

Make /dev/cpuset/background, /dev/cpuset/foreground and
/dev/cpuset/task writeable by system gid. Add logd to system
group for writing to cpuset files and to root group to avoid
regressions. When dropping privs, also drop supplementary groups.

Bug: 22699101
Change-Id: Icc01769b18b5e1f1649623da8325a8bfabc3a3f0
---
 logd/main.cpp   | 4 ++++
 rootdir/init.rc | 7 ++++---
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/logd/main.cpp b/logd/main.cpp
index 9b889838d..a3241d059 100644
--- a/logd/main.cpp
+++ b/logd/main.cpp
@@ -103,6 +103,10 @@ static int drop_privs() {
         return -1;
     }
 
+    if (setgroups(0, NULL) == -1) {
+        return -1;
+    }
+
     if (setgid(AID_LOGD) != 0) {
         return -1;
     }
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 7af2b7709..2ac182bed 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -145,9 +145,9 @@ on init
     chown system system /dev/cpuset/tasks
     chown system system /dev/cpuset/foreground/tasks
     chown system system /dev/cpuset/background/tasks
-    chmod 0644 /dev/cpuset/foreground/tasks
-    chmod 0644 /dev/cpuset/background/tasks
-    chmod 0644 /dev/cpuset/tasks
+    chmod 0664 /dev/cpuset/foreground/tasks
+    chmod 0664 /dev/cpuset/background/tasks
+    chmod 0664 /dev/cpuset/tasks
 
 
     # qtaguid will limit access to specific data based on group memberships.
@@ -523,6 +523,7 @@ service logd /system/bin/logd
     socket logd stream 0666 logd logd
     socket logdr seqpacket 0666 logd logd
     socket logdw dgram 0222 logd logd
+    group root system
 
 service logd-reinit /system/bin/logd --reinit
     oneshot