Commit 79ad6a56 authored May 13, 2022 by Sergey Shtylyov Committed by Damien Le Moal Jun 13, 2022

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 <s.shtylyov@omp.ru>
Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>

parent 6cd379f7

drivers/ata/libata-core.c

+6 −4

Original line number	Diff line number	Diff line
		@@ -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];
		}
		}