Merge "Ensure input has CAP_BLOCK_SUSPEND" (72f94e1d) · Commits · e / os / android_frameworks_native

services/inputflinger/reader/Android.bp

+1 −0

Original line number	Diff line number	Diff line
		@@ -50,6 +50,7 @@ cc_library_shared {

		shared_libs: [
		"libbase",
		"libcap",
		"libinputflinger_base",
		"libcrypto",
		"libcutils",

services/inputflinger/reader/EventHub.cpp

+43 −0

Original line number	Diff line number	Diff line
		@@ -24,6 +24,7 @@
		#include <stdio.h>
		#include <stdlib.h>
		#include <string.h>
		#include <sys/capability.h>
		#include <sys/epoll.h>
		#include <sys/inotify.h>
		#include <sys/ioctl.h>
		@@ -237,6 +238,47 @@ bool EventHub::Device::hasValidFd() {
		return !isVirtual && enabled;
		}

		/**
		* Get the capabilities for the current process.
		* Crashes the system if unable to create / check / destroy the capabilities object.
		*/
		class Capabilities final {
		public:
		explicit Capabilities() {
		mCaps = cap_get_proc();
		LOG_ALWAYS_FATAL_IF(mCaps == nullptr, "Could not get capabilities of the current process");
		}

		/**
		* Check whether the current process has a specific capability
		* in the set of effective capabilities.
		* Return CAP_SET if the process has the requested capability
		* Return CAP_CLEAR otherwise.
		*/
		cap_flag_value_t checkEffectiveCapability(cap_value_t capability) {
		cap_flag_value_t value;
		const int result = cap_get_flag(mCaps, capability, CAP_EFFECTIVE, &value);
		LOG_ALWAYS_FATAL_IF(result == -1, "Could not obtain the requested capability");
		return value;
		}

		~Capabilities() {
		const int result = cap_free(mCaps);
		LOG_ALWAYS_FATAL_IF(result == -1, "Could not release the capabilities structure");
		}

		private:
		cap_t mCaps;
		};

		static void ensureProcessCanBlockSuspend() {
		Capabilities capabilities;
		const bool canBlockSuspend =
		capabilities.checkEffectiveCapability(CAP_BLOCK_SUSPEND) == CAP_SET;
		LOG_ALWAYS_FATAL_IF(!canBlockSuspend,
		"Input must be able to block suspend to properly process events");
		}

		// --- EventHub ---

		const int EventHub::EPOLL_MAX_EVENTS;
		@@ -253,6 +295,7 @@ EventHub::EventHub(void)
		mPendingEventCount(0),
		mPendingEventIndex(0),
		mPendingINotify(false) {
		ensureProcessCanBlockSuspend();
		acquire_wake_lock(PARTIAL_WAKE_LOCK, WAKE_LOCK_ID);

		mEpollFd = epoll_create1(EPOLL_CLOEXEC);