From: Rafał Miłecki <ra...@milecki.pl> Reading MTD data with (p)read doesn't return any error when accessing bad block. As the result, with current code, CRC32 covers "data" stored in bad blocks.
That behavior doesn't match CFE's one (bootloader simply skips bad blocks) and may result in: 1) Invalid CRC32 2) CFE refusing to boot firmware with a following error: Boot program checksum is invalid Fix that problem by checking every block before reading its content. Signed-off-by: Rafał Miłecki <ra...@milecki.pl> --- V2: Bump PKG_RELEASE Use min() to make code easier to understand Recalculate data_size to make sure old size value (including bad blocks) isn't used. Drop some unneeded helper variables. --- package/system/mtd/Makefile | 2 +- package/system/mtd/src/trx.c | 40 ++++++++++++++++++++++++++++++++++------ 2 files changed, 35 insertions(+), 7 deletions(-) diff --git a/package/system/mtd/Makefile b/package/system/mtd/Makefile index 9ae03a77a9..969e1c711c 100644 --- a/package/system/mtd/Makefile +++ b/package/system/mtd/Makefile @@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk include $(INCLUDE_DIR)/kernel.mk PKG_NAME:=mtd -PKG_RELEASE:=21 +PKG_RELEASE:=22 PKG_BUILD_DIR := $(KERNEL_BUILD_DIR)/$(PKG_NAME) STAMP_PREPARED := $(STAMP_PREPARED)_$(call confvar,CONFIG_MTD_REDBOOT_PARTS) diff --git a/package/system/mtd/src/trx.c b/package/system/mtd/src/trx.c index 1f5c52914c..d4d486c32b 100644 --- a/package/system/mtd/src/trx.c +++ b/package/system/mtd/src/trx.c @@ -46,6 +46,12 @@ struct trx_header { uint32_t offsets[3]; /* Offsets of partitions from start of header */ }; +#define min(x,y) ({ \ + typeof(x) _x = (x); \ + typeof(y) _y = (y); \ + (void) (&_x == &_y); \ + _x < _y ? _x : _y; }) + #if __BYTE_ORDER == __BIG_ENDIAN #define STORE32_LE(X) ((((X) & 0x000000FF) << 24) | (((X) & 0x0000FF00) << 8) | (((X) & 0x00FF0000) >> 8) | (((X) & 0xFF000000) >> 24)) #elif __BYTE_ORDER == __LITTLE_ENDIAN @@ -156,7 +162,7 @@ mtd_fixtrx(const char *mtd, size_t offset, size_t data_size) int fd; struct trx_header *trx; char *first_block; - char *buf; + char *buf, *to; ssize_t res; size_t block_offset; @@ -214,11 +220,34 @@ mtd_fixtrx(const char *mtd, size_t offset, size_t data_size) exit(1); } - res = pread(fd, buf, data_size, data_offset); - if (res != data_size) { - perror("pread"); - exit(1); + to = buf; + while (data_size) { + size_t read_block_offset = data_offset & ~(erasesize - 1); + size_t read_chunk; + + read_chunk = erasesize - (data_offset & (erasesize - 1)); + read_chunk = min(read_chunk, data_size); + + res = ioctl(fd, MEMGETBADBLOCK, &read_block_offset); + if (res == -1) { + perror("ioctl"); + exit(1); + } + + /* Read from good blocks only to match CFE behavior */ + if (res == 0) { + res = pread(fd, to, read_chunk, data_offset); + if (res != read_chunk) { + perror("pread"); + exit(1); + } + to += read_chunk; + } + + data_offset += read_chunk; + data_size -= read_chunk; } + data_size = to - buf; trx->len = STORE32_LE(data_size + offsetof(struct trx_header, flag_version)); @@ -244,4 +273,3 @@ mtd_fixtrx(const char *mtd, size_t offset, size_t data_size) return 0; } - -- 2.13.7 _______________________________________________ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/mailman/listinfo/openwrt-devel