scsi: sym53c8xx: Avoid undefined behaviour

On parisc I see this UBSAN warning with a sym53c896:

 UBSAN: Undefined behaviour in ./drivers/scsi/sym53c8xx_2/sym_hipd.c:762:24
 index -1903078336 is out of range for type 'u32 [7]'

Avoid this warning by switching to div64_ul().

[mkp: fix typo]

Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/sym53c8xx_2/sym_hipd.c b/drivers/scsi/sym53c8xx_2/sym_hipd.c
index 6b349e3018692435b3523f8d0cef4e4daaf6f3ef..15ff285a9f8f746ee7946e65f4f6264a5a524f67 100644 (file)
--- a/drivers/scsi/sym53c8xx_2/sym_hipd.c
+++ b/drivers/scsi/sym53c8xx_2/sym_hipd.c
@@ -759,7 +759,7 @@ static int sym_prepare_setting(struct Scsi_Host *shost, struct sym_hcb *np, stru
        /*
         * Maximum synchronous period factor supported by the chip.
         */
-       period = (11 * div_10M[np->clock_divn - 1]) / (4 * np->clock_khz);
+       period = div64_ul(11 * div_10M[np->clock_divn - 1], 4 * np->clock_khz);
        np->maxsync = period > 2540 ? 254 : period / 10;
 
        /*