Merge "crash_dump: during early boot, output to kmsg on userdebug." am: 72ca48e5cb (e80f6668) · Commits · e / os / android_system_core

debuggerd/libdebuggerd/utility.cpp

+45 −1

Original line number	Diff line number	Diff line
		@@ -22,16 +22,22 @@
		#include <signal.h>
		#include <string.h>
		#include <sys/ptrace.h>
		#include <sys/uio.h>
		#include <sys/wait.h>
		#include <unistd.h>

		#include <string>

		#include <android-base/logging.h>
		#include <android-base/properties.h>
		#include <android-base/stringprintf.h>
		#include <android-base/strings.h>
		#include <android-base/unique_fd.h>
		#include <backtrace/Backtrace.h>
		#include <log/log.h>

		using android::base::unique_fd;

		// Whitelist output desired in the logcat output.
		bool is_allowed_in_logcat(enum logtype ltype) {
		if ((ltype == HEADER)
		@@ -42,6 +48,19 @@ bool is_allowed_in_logcat(enum logtype ltype) {
		return false;
		}

		static bool should_write_to_kmsg() {
		// Write to kmsg if tombstoned isn't up, and we're able to do so.
		if (!android::base::GetBoolProperty("ro.debuggable", false)) {
		return false;
		}

		if (android::base::GetProperty("init.svc.tombstoned", "") == "running") {
		return false;
		}

		return true;
		}

		__attribute__((__weak__, visibility("default")))
		void _LOG(log_t* log, enum logtype ltype, const char* fmt, ...) {
		bool write_to_tombstone = (log->tfd != -1);
		@@ -49,6 +68,7 @@ void _LOG(log_t* log, enum logtype ltype, const char* fmt, ...) {
		&& log->crashed_tid != -1
		&& log->current_tid != -1
		&& (log->crashed_tid == log->current_tid);
		static bool write_to_kmsg = should_write_to_kmsg();

		char buf[512];
		va_list ap;
		@@ -70,6 +90,30 @@ void _LOG(log_t* log, enum logtype ltype, const char* fmt, ...) {
		if (log->amfd_data != nullptr) {
		*log->amfd_data += buf;
		}

		if (write_to_kmsg) {
		unique_fd kmsg_fd(open("/dev/kmsg_debug", O_WRONLY \| O_APPEND \| O_CLOEXEC));
		if (kmsg_fd.get() >= 0) {
		// Our output might contain newlines which would otherwise be handled by the android logger.
		// Split the lines up ourselves before sending to the kernel logger.
		if (buf[len - 1] == '\n') {
		buf[len - 1] = '\0';
		}

		std::vector<std::string> fragments = android::base::Split(buf, "\n");
		for (const std::string& fragment : fragments) {
		static constexpr char prefix[] = "<3>DEBUG: ";
		struct iovec iov[3];
		iov[0].iov_base = const_cast<char*>(prefix);
		iov[0].iov_len = strlen(prefix);
		iov[1].iov_base = const_cast<char*>(fragment.c_str());
		iov[1].iov_len = fragment.length();
		iov[2].iov_base = const_cast<char*>("\n");
		iov[2].iov_len = 1;
		TEMP_FAILURE_RETRY(writev(kmsg_fd.get(), iov, 3));
		}
		}
		}
		}
		}

		@@ -205,7 +249,7 @@ void dump_memory(log_t* log, Backtrace* backtrace, uintptr_t addr, const char* f
		}

		void read_with_default(const char* path, char* buf, size_t len, const char* default_value) {
		android::base::unique_fd fd(open(path, O_RDONLY));
		unique_fd fd(open(path, O_RDONLY \| O_CLOEXEC));
		if (fd != -1) {
		int rc = TEMP_FAILURE_RETRY(read(fd.get(), buf, len - 1));
		if (rc != -1) {

init/Android.mk

+4 −2

Original line number	Diff line number	Diff line
		@@ -8,12 +8,14 @@ ifneq (,$(filter userdebug eng,$(TARGET_BUILD_VARIANT)))
		init_options += \
		-DALLOW_LOCAL_PROP_OVERRIDE=1 \
		-DALLOW_PERMISSIVE_SELINUX=1 \
		-DREBOOT_BOOTLOADER_ON_PANIC=1
		-DREBOOT_BOOTLOADER_ON_PANIC=1 \
		-DWORLD_WRITABLE_KMSG=1
		else
		init_options += \
		-DALLOW_LOCAL_PROP_OVERRIDE=0 \
		-DALLOW_PERMISSIVE_SELINUX=0 \
		-DREBOOT_BOOTLOADER_ON_PANIC=0
		-DREBOOT_BOOTLOADER_ON_PANIC=0 \
		-DWORLD_WRITABLE_KMSG=0
		endif

		ifneq (,$(filter eng,$(TARGET_BUILD_VARIANT)))

init/init.cpp

+9 −0

Original line number	Diff line number	Diff line
		@@ -890,6 +890,9 @@ static void selinux_restore_context() {
		LOG(INFO) << "Running restorecon...";
		restorecon("/dev");
		restorecon("/dev/kmsg");
		if constexpr (WORLD_WRITABLE_KMSG) {
		restorecon("/dev/kmsg_debug");
		}
		restorecon("/dev/socket");
		restorecon("/dev/random");
		restorecon("/dev/urandom");
		@@ -1166,7 +1169,13 @@ int main(int argc, char** argv) {
		setgroups(arraysize(groups), groups);
		mount("sysfs", "/sys", "sysfs", 0, NULL);
		mount("selinuxfs", "/sys/fs/selinux", "selinuxfs", 0, NULL);

		mknod("/dev/kmsg", S_IFCHR \| 0600, makedev(1, 11));

		if constexpr (WORLD_WRITABLE_KMSG) {
		mknod("/dev/kmsg_debug", S_IFCHR \| 0622, makedev(1, 11));
		}

		mknod("/dev/random", S_IFCHR \| 0666, makedev(1, 8));
		mknod("/dev/urandom", S_IFCHR \| 0666, makedev(1, 9));