From: Sergey Shtylyov <s.shtylyov@omp.ru>
Date: Fri, 13 May 2022 23:50:14 +0300
Subject: ata: libata-core: fix sloppy typing in ata_id_n_sectors()
Git-commit: 79ad6a561958777d6d8ecfa66e51d09d35ec6450
Patch-mainline: v6.0-rc1
References: jsc#PED-1118
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>
Acked-by: Lee Duncan <lduncan@suse.com>
---
drivers/ata/libata-core.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
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];
}
}