From a015186fab804b4cc8f7d26221451b5340db11ce Mon Sep 17 00:00:00 2001 From: Josh Gao 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: I249e11291c58fee77098dec3fd3271ea23363ac9 --- 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 4a392f1c2..adae7dcfd 100644 --- a/private/file_contexts +++ b/private/file_contexts @@ -104,6 +104,7 @@ /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 4b080464b..b36a00201 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 };