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-rw-r--r--recovery/recovery_updater.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/recovery/recovery_updater.c b/recovery/recovery_updater.c
index 02963f5..0c49f9a 100644
--- a/recovery/recovery_updater.c
+++ b/recovery/recovery_updater.c
@@ -19,6 +19,11 @@
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <cryptfs.h>
#include "edify/expr.h"
#include "bootloader.h"
@@ -55,8 +60,68 @@ Value* WriteBootloaderFn(const char* name, State* state, int argc, Expr* argv[])
return StringValue(strdup(result == 0 ? "t" : ""));
}
+/*
+ * The size of the userdata partition for HSPA Galaxy Nexus devices is incorrect
+ * in the partition as it comes from the factory. Updating the bootloader fixes
+ * the partition table, and makes the size of the userdata partition 1 sector
+ * smaller. However, if the user had encrypted their device with the original
+ * incorrect size of the partition table, the crypto footer has saved that
+ * size, and tries to map that much data when decrypting. However, with the
+ * new partition table, that size is too big to be mapped, and the kernel
+ * throws an error, and the user can't decrypt and boot the device after the
+ * OTA is installed. Oops!
+ *
+ * The fix here is to recognize a crypto footer that has the wrong size, and
+ * update it to the new correct size. This program should be run as part of
+ * the recovery script for HSPA Galaxy Nexus devices.
+ */
+
+#define BAD_SIZE 0x01b14fdfULL
+#define GOOD_SIZE 0x01b14fdeULL
+
+#define HSPA_PRIME_KEY_PARTITION "/dev/block/platform/omap/omap_hsmmc.0/by-name/metadata"
+
+Value* FsSizeFixFn(const char* name, State* state, int argc, Expr* argv[])
+{
+ struct crypt_mnt_ftr ftr;
+ int fd;
+
+ if (argc != 0) {
+ return ErrorAbort(state, "%s() expects 0 args, got %d", name, argc);
+ }
+
+ if ((fd = open(HSPA_PRIME_KEY_PARTITION, O_RDWR)) == -1) {
+ return ErrorAbort(state, "%s() Cannot open %s\n", name, HSPA_PRIME_KEY_PARTITION);
+ }
+
+ if (read(fd, &ftr, sizeof(ftr)) != sizeof(ftr)) {
+ close(fd);
+ return ErrorAbort(state, "%s() Cannot read crypto footer %s\n", name, HSPA_PRIME_KEY_PARTITION);
+ }
+
+ if ((ftr.magic == CRYPT_MNT_MAGIC) && (ftr.fs_size == BAD_SIZE)) {
+ ftr.fs_size = GOOD_SIZE;
+ if (lseek(fd, 0, SEEK_SET) == 0) {
+ if (write(fd, &ftr, sizeof(ftr)) == sizeof(ftr)) {
+ fsync(fd); /* Make sure it gets to the disk */
+ fprintf(stderr, "Footer updated\n");
+ close(fd);
+ return StringValue(strdup("t"));
+ }
+ }
+ close(fd);
+ return ErrorAbort(state, "%s() Cannot seek or write crypto footer %s\n", name, HSPA_PRIME_KEY_PARTITION);
+ }
+
+ /* Nothing to do */
+ fprintf(stderr, "Footer doesn't need updating\n");
+ close(fd);
+ return StringValue(strdup("t"));
+}
+
void Register_librecovery_updater_tuna() {
fprintf(stderr, "installing samsung updater extensions\n");
RegisterFunction("samsung.write_bootloader", WriteBootloaderFn);
+ RegisterFunction("samsung.fs_size_fix", FsSizeFixFn);
}