From 94e2a921cb38b586cfd34a6967b776474e1d6e91 Mon Sep 17 00:00:00 2001
From: Josh Gao <jmgao@google.com>
Date: Tue, 28 Mar 2017 13:09:37 -0700
Subject: [PATCH] Add /dev/kmsg_debug.
Add /dev/kmsg_debug on userdebug devices, to allow crash_dump to log
crashes to dmesg when logd isn't up yet (or is the one crashing).
Bug: http://b/36574794
Test: stop tombstoned; crasher; dmesg
Change-Id: I6ffe11bc613e88198893e82712719522b74fe1be
---
private/file_contexts | 1 +
public/crash_dump.te | 3 +++
public/device.te | 1 +
public/init.te | 4 ++++
4 files changed, 9 insertions(+)
diff --git a/private/file_contexts b/private/file_contexts
index 971c0801a..dcb09c1c3 100644
--- a/private/file_contexts
+++ b/private/file_contexts
@@ -105,6 +105,7 @@
/dev/ptmx u:object_r:ptmx_device:s0
/dev/pvrsrvkm u:object_r:gpu_device:s0
/dev/kmsg u:object_r:kmsg_device:s0
+/dev/kmsg_debug u:object_r:kmsg_debug_device:s0
/dev/null u:object_r:null_device:s0
/dev/nvhdcp1 u:object_r:video_device:s0
/dev/random u:object_r:random_device:s0
diff --git a/public/crash_dump.te b/public/crash_dump.te
index a0e278a13..0bab782f1 100644
--- a/public/crash_dump.te
+++ b/public/crash_dump.te
@@ -15,6 +15,9 @@ dontaudit crash_dump self:capability { sys_ptrace };
userdebug_or_eng(`
allow crash_dump logd:process { ptrace signal sigchld sigstop sigkill };
+
+ # Let crash_dump write to /dev/kmsg_debug crashes that happen before logd comes up.
+ allow crash_dump kmsg_debug_device:chr_file { open append };
')
# Use inherited file descriptors
diff --git a/public/device.te b/public/device.te
index 4a3bec91f..0f64bfabb 100644
--- a/public/device.te
+++ b/public/device.te
@@ -36,6 +36,7 @@ type mtp_device, dev_type, mlstrustedobject;
type nfc_device, dev_type;
type ptmx_device, dev_type, mlstrustedobject;
type kmsg_device, dev_type;
+type kmsg_debug_device, dev_type;
type null_device, dev_type, mlstrustedobject;
type random_device, dev_type, mlstrustedobject;
type sensors_device, dev_type;
diff --git a/public/init.te b/public/init.te
index b5c698e38..3223400b2 100644
--- a/public/init.te
+++ b/public/init.te
@@ -13,6 +13,10 @@ allow init tmpfs:chr_file { create setattr unlink rw_file_perms };
# /dev/kmsg
allow init tmpfs:chr_file relabelfrom;
allow init kmsg_device:chr_file { write relabelto };
+# /dev/kmsg_debug
+userdebug_or_eng(`
+ allow init kmsg_debug_device:chr_file { write relabelto };
+')
# /dev/__properties__
allow init properties_device:dir relabelto;
allow init properties_serial:file { write relabelto };
--
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