Edward O'Callaghan has uploaded this change for review. ( https://review.coreboot.org/c/flashrom/+/48974 )
Change subject: realtek_mst_i2c_spi.c: Don't depend on int overflows ......................................................................
realtek_mst_i2c_spi.c: Don't depend on int overflows
Be explicit to mask the first byte after the shifts as highlighted by Angel Pos.
BUG=none BRANCH=none TEST=builds
Change-Id: I7d1215678094d709e79b8f8c96aa3810586cd72e Signed-off-by: Edward O'Callaghan quasisec@google.com Spotted-by: Angel Pons th3fanbus@gmail.com --- M realtek_mst_i2c_spi.c 1 file changed, 6 insertions(+), 6 deletions(-)
git pull ssh://review.coreboot.org:29418/flashrom refs/changes/74/48974/1
diff --git a/realtek_mst_i2c_spi.c b/realtek_mst_i2c_spi.c index dabec70..3e84b23 100644 --- a/realtek_mst_i2c_spi.c +++ b/realtek_mst_i2c_spi.c @@ -330,9 +330,9 @@ start--; ret |= realtek_mst_i2c_spi_write_register(fd, 0x60, 0x46); // ** ret |= realtek_mst_i2c_spi_write_register(fd, 0x61, OPCODE_READ); - uint8_t block_idx = start >> 16; - uint8_t page_idx = start >> 8; - uint8_t byte_idx = start; + uint8_t block_idx = (start >> 16) & 0xff; + uint8_t page_idx = (start >> 8) & 0xff; + uint8_t byte_idx = start & 0xff; ret |= realtek_mst_i2c_spi_map_page(fd, block_idx, page_idx, byte_idx); ret |= realtek_mst_i2c_spi_write_register(fd, 0x6a, 0x03); ret |= realtek_mst_i2c_spi_write_register(fd, 0x60, 0x47); // ** @@ -384,9 +384,9 @@ uint16_t page_len = min(len - i, PAGE_SIZE); if (len - i < PAGE_SIZE) ret |= realtek_mst_i2c_spi_write_register(fd, 0x71, page_len-1); - uint8_t block_idx = (start + i) >> 16; - uint8_t page_idx = (start + i) >> 8; - uint8_t byte_idx = start + i; + uint8_t block_idx = ((start + i) >> 16) & 0xff; + uint8_t page_idx = ((start + i) >> 8) & 0xff; + uint8_t byte_idx = (start + i) & 0xff; ret |= realtek_mst_i2c_spi_map_page(fd, block_idx, page_idx, byte_idx); if (ret) break;