diff options
Diffstat (limited to 'recovery-persist.cpp')
| -rw-r--r-- | recovery-persist.cpp | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/recovery-persist.cpp b/recovery-persist.cpp new file mode 100644 index 000000000..8587e9a66 --- /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; +} |