From 2efc9d994ce59f9ebfc2290c2adc5d760e8939c2 Mon Sep 17 00:00:00 2001 From: Doug Zongker Date: Mon, 18 Aug 2014 15:55:28 -0700 Subject: clear BCB in misc partition before rebooting Something is leaving behind wipe commands in the BCB area of the /misc partition. We don't know what is doing that. It should always be safe to zero out that area from uncrypt, though (because if uncrypt is running then it's got the command we want in the recovery command file rather than the BCB). Bug: 16715412 Change-Id: Iad01124287f13b80ff71d6371db6371f43c43211 --- uncrypt/uncrypt.c | 46 +++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 43 insertions(+), 3 deletions(-) (limited to 'uncrypt') diff --git a/uncrypt/uncrypt.c b/uncrypt/uncrypt.c index bce53dbb9..77bfdc207 100644 --- a/uncrypt/uncrypt.c +++ b/uncrypt/uncrypt.c @@ -56,6 +56,8 @@ #define RECOVERY_COMMAND_FILE_TMP "/cache/recovery/command.tmp" #define CACHE_BLOCK_MAP "/cache/recovery/block.map" +static struct fstab* fstab = NULL; + static int write_at_offset(unsigned char* buffer, size_t size, int wfd, off64_t offset) { @@ -101,8 +103,10 @@ void add_block_to_ranges(int** ranges, int* range_alloc, int* range_used, int ne } } -const char* find_block_device(const char* path, int* encryptable, int* encrypted) +static struct fstab* read_fstab() { + fstab = NULL; + // The fstab path is always "/fstab.${ro.hardware}". char fstab_path[PATH_MAX+1] = "/fstab."; if (!property_get("ro.hardware", fstab_path+strlen(fstab_path), "")) { @@ -110,12 +114,17 @@ const char* find_block_device(const char* path, int* encryptable, int* encrypted return NULL; } - struct fstab* fstab = fs_mgr_read_fstab(fstab_path); + fstab = fs_mgr_read_fstab(fstab_path); if (!fstab) { fprintf(stderr, "failed to read %s\n", fstab_path); return NULL; } + return fstab; +} + +const char* find_block_device(const char* path, int* encryptable, int* encrypted) +{ // Look for a volume whose mount point is the prefix of path and // return its block device. Set encrypted if it's currently // encrypted. @@ -302,6 +311,33 @@ int produce_block_map(const char* path, const char* map_file, const char* blk_de return 0; } +void wipe_misc() { + int i; + for (i = 0; i < fstab->num_entries; ++i) { + struct fstab_rec* v = &fstab->recs[i]; + if (!v->mount_point) continue; + if (strcmp(v->mount_point, "/misc") == 0) { + int fd = open(v->blk_device, O_RDWR); + uint8_t zeroes[1088]; // sizeof(bootloader_message) from recovery + memset(zeroes, 0, sizeof(zeroes)); + + size_t written = 0; + size_t size = sizeof(zeroes); + while (written < size) { + ssize_t w = write(fd, zeroes, size-written); + if (w < 0 && errno != EINTR) { + fprintf(stderr, "zero write failed: %s\n", strerror(errno)); + return; + } else { + written += w; + } + } + + close(fd); + } + } +} + void reboot_to_recovery() { property_set("sys.powerctl", "reboot,recovery"); sleep(10); @@ -347,6 +383,9 @@ int main(int argc, char** argv) int encryptable; int encrypted; + if (read_fstab() == NULL) { + return 1; + } const char* blk_dev = find_block_device(path, &encryptable, &encrypted); if (blk_dev == NULL) { fprintf(stderr, "failed to find block device for %s\n", path); @@ -376,7 +415,8 @@ int main(int argc, char** argv) } } + wipe_misc(); rename(RECOVERY_COMMAND_FILE_TMP, RECOVERY_COMMAND_FILE); - reboot_to_recovery(); + if (do_reboot) reboot_to_recovery(); return 0; } -- cgit v1.2.3