From: Sergey Shtylyov Date: Fri, 13 May 2022 20:50:14 +0000 (+0300) Subject: ata: libata-core: fix sloppy typing in ata_id_n_sectors() X-Git-Tag: block-6.0-2022-08-12~32^2~10 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=79ad6a561958777d6d8ecfa66e51d09d35ec6450;p=linux-block.git ata: libata-core: fix sloppy typing in ata_id_n_sectors() The code multiplying the # of cylinders/heads/sectors in ata_id_n_sectors() to get a disk capacity implicitly uses the *int* type for that calculation and casting the result to 'u64' before returning ensues a sign extension. Explicitly casting the 'u16' typed multipliers to 'u32' results in avoiding a sign extension instruction and so in a more compact code... Found by Linux Verification Center (linuxtesting.org) with the SVACE static analysis tool. Signed-off-by: Sergey Shtylyov Signed-off-by: Damien Le Moal --- diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 9601fa92950a..e3f1c3da5950 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -1107,11 +1107,13 @@ static u64 ata_id_n_sectors(const u16 *id) return ata_id_u32(id, ATA_ID_LBA_CAPACITY); } else { if (ata_id_current_chs_valid(id)) - return id[ATA_ID_CUR_CYLS] * id[ATA_ID_CUR_HEADS] * - id[ATA_ID_CUR_SECTORS]; + return (u32)id[ATA_ID_CUR_CYLS] * + (u32)id[ATA_ID_CUR_HEADS] * + (u32)id[ATA_ID_CUR_SECTORS]; else - return id[ATA_ID_CYLS] * id[ATA_ID_HEADS] * - id[ATA_ID_SECTORS]; + return (u32)id[ATA_ID_CYLS] * + (u32)id[ATA_ID_HEADS] * + (u32)id[ATA_ID_SECTORS]; } }