recovery: use __android_log_pmsg_file_write for log files
- Add call to __android_log_pmsg_file_write for recovery logging.
- Add call to refresh pmsg if we reboot back into recovery and then
allow overwrite of those logs.
- Add a new one-time executable recovery-refresh that refreshes pmsg
in post-fs phase of init. We rely on pmsg eventually scrolling off
to age the content after recovery-persist has done its job.
- Add a new one-time executable recovery-persist that transfers from
pmsg to /data/misc/recovery/ directory if /cache is not mounted
in post-fs-data phase of init.
- Build and appropriately trigger the above two as required if
BOARD_CACHEIMAGE_PARTITION_SIZE is undefined.
- Add some simple unit tests
NB: Test failure is expected on systems that do not deliver either
the recovery-persist or recovery-refresh executables, e.g. systems
with /cache. Tests also require a timely reboot sequence of test
to truly verify, tests provide guidance on stderr to direct.
Bug: 27176738
Change-Id: I17bb95980234984f6b2087fd5941b0a3126b706b
diff --git a/recovery-persist.cpp b/recovery-persist.cpp
new file mode 100644
index 0000000..8587e9a
--- /dev/null
+++ b/recovery-persist.cpp
@@ -0,0 +1,200 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "recovery-persist"
+
+//
+// Strictly to deal with reboot into system after OTA after /data
+// mounts to pull the last pmsg file data and place it
+// into /data/misc/recovery/ directory, rotating it in.
+//
+// Usage: recovery-persist [--force-persist]
+//
+// On systems without /cache mount, all file content representing in the
+// recovery/ directory stored in /sys/fs/pstore/pmsg-ramoops-0 in logger
+// format that reside in the LOG_ID_SYSTEM buffer at ANDROID_LOG_INFO
+// priority or higher is transfered to the /data/misc/recovery/ directory.
+// The content is matched and rotated in as need be.
+//
+// --force-persist ignore /cache mount, always rotate in the contents.
+//
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <string>
+
+#include <android/log.h> /* Android Log Priority Tags */
+#include <android-base/file.h>
+#include <log/log.h>
+#include <log/logger.h> /* Android Log packet format */
+#include <private/android_logger.h> /* private pmsg functions */
+
+static const char *LAST_LOG_FILE = "/data/misc/recovery/last_log";
+static const char *LAST_PMSG_FILE = "/sys/fs/pstore/pmsg-ramoops-0";
+static const char *LAST_KMSG_FILE = "/data/misc/recovery/last_kmsg";
+static const char *LAST_CONSOLE_FILE = "/sys/fs/pstore/console-ramoops-0";
+
+static const int KEEP_LOG_COUNT = 10;
+
+// close a file, log an error if the error indicator is set
+static void check_and_fclose(FILE *fp, const char *name) {
+ fflush(fp);
+ if (ferror(fp)) SLOGE("%s %s", name, strerror(errno));
+ fclose(fp);
+}
+
+static void copy_file(const char* source, const char* destination) {
+ FILE* dest_fp = fopen(destination, "w");
+ if (dest_fp == nullptr) {
+ SLOGE("%s %s", destination, strerror(errno));
+ } else {
+ FILE* source_fp = fopen(source, "r");
+ if (source_fp != nullptr) {
+ char buf[4096];
+ size_t bytes;
+ while ((bytes = fread(buf, 1, sizeof(buf), source_fp)) != 0) {
+ fwrite(buf, 1, bytes, dest_fp);
+ }
+ check_and_fclose(source_fp, source);
+ }
+ check_and_fclose(dest_fp, destination);
+ }
+}
+
+static bool rotated = false;
+
+// Rename last_log -> last_log.1 -> last_log.2 -> ... -> last_log.$max.
+// Similarly rename last_kmsg -> last_kmsg.1 -> ... -> last_kmsg.$max.
+// Overwrite any existing last_log.$max and last_kmsg.$max.
+static void rotate_logs(int max) {
+ // Logs should only be rotated once.
+
+ if (rotated) {
+ return;
+ }
+ rotated = true;
+
+ for (int i = max-1; i >= 0; --i) {
+ std::string old_log(LAST_LOG_FILE);
+ if (i > 0) {
+ old_log += "." + std::to_string(i);
+ }
+ std::string new_log(LAST_LOG_FILE);
+ new_log += "." + std::to_string(i+1);
+
+ // Ignore errors if old_log doesn't exist.
+ rename(old_log.c_str(), new_log.c_str());
+
+ std::string old_kmsg(LAST_KMSG_FILE);
+ if (i > 0) {
+ old_kmsg += "." + std::to_string(i);
+ }
+ std::string new_kmsg(LAST_KMSG_FILE);
+ new_kmsg += "." + std::to_string(i+1);
+
+ rename(old_kmsg.c_str(), new_kmsg.c_str());
+ }
+}
+
+ssize_t logsave(
+ log_id_t /* logId */,
+ char /* prio */,
+ const char *filename,
+ const char *buf, size_t len,
+ void * /* arg */) {
+
+ std::string destination("/data/misc/");
+ destination += filename;
+
+ std::string buffer(buf, len);
+
+ {
+ std::string content;
+ android::base::ReadFileToString(destination, &content);
+
+ if (buffer.compare(content) == 0) {
+ return len;
+ }
+ }
+
+ // ToDo: Any others that match? Are we pulling in multiple
+ // already-rotated files? Algorithm thus far is KISS: one file,
+ // one rotation allowed.
+
+ rotate_logs(KEEP_LOG_COUNT);
+
+ return android::base::WriteStringToFile(buffer, destination.c_str());
+}
+
+int main(int argc, char **argv) {
+
+ /* Is /cache a mount?, we have been delivered where we are not wanted */
+ /*
+ * Following code halves the size of the executable as compared to:
+ *
+ * load_volume_table();
+ * has_cache = volume_for_path(CACHE_ROOT) != nullptr;
+ */
+ bool has_cache = false;
+ static const char mounts_file[] = "/proc/mounts";
+ FILE *fp = fopen(mounts_file, "r");
+ if (!fp) {
+ SLOGV("%s %s", mounts_file, strerror(errno));
+ } else {
+ char *line = NULL;
+ size_t len = 0;
+ ssize_t read;
+ while ((read = getline(&line, &len, fp)) != -1) {
+ if (strstr(line, " /cache ")) {
+ has_cache = true;
+ break;
+ }
+ }
+ free(line);
+ fclose(fp);
+ }
+
+ if (has_cache) {
+ /*
+ * TBD: Future location to move content from
+ * /cache/recovery to /data/misc/recovery/
+ */
+ /* if --force-persist flag, then transfer pmsg data anyways */
+ if ((argc <= 1) || !argv[1] || strcmp(argv[1], "--force-persist")) {
+ return 0;
+ }
+ }
+
+ /* Is there something in pmsg? */
+ if (access(LAST_PMSG_FILE, R_OK)) {
+ return 0;
+ }
+
+ // Take last pmsg file contents and send it off to the logsave
+ __android_log_pmsg_file_read(
+ LOG_ID_SYSTEM, ANDROID_LOG_INFO, "recovery/", logsave, NULL);
+
+ /* Is there a last console log too? */
+ if (rotated && !access(LAST_CONSOLE_FILE, R_OK)) {
+ copy_file(LAST_CONSOLE_FILE, LAST_KMSG_FILE);
+ }
+
+ return 0;
+}