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* [PATCH] sym53c8xx: Avoid undefined behaviour in drivers/scsi/sym53c8xx_2/sym_hipd.c:762
@ 2017-08-10 19:08 Helge Deller
  2017-08-11  7:24 ` Johannes Thumshirn
  2017-08-15  3:07 ` Martin K. Petersen
  0 siblings, 2 replies; 3+ messages in thread
From: Helge Deller @ 2017-08-10 19:08 UTC (permalink / raw)
  To: linux-scsi, James Bottomley, linux-kernel; +Cc: linux-parisc

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 dev64_ul().

Signed-off-by: Helge Deller <deller@gmx.de>

diff --git a/drivers/scsi/sym53c8xx_2/sym_hipd.c b/drivers/scsi/sym53c8xx_2/sym_hipd.c
index 6b349e3..15ff285a9 100644
--- 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;
 
 	/*

^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH] sym53c8xx: Avoid undefined behaviour in drivers/scsi/sym53c8xx_2/sym_hipd.c:762
  2017-08-10 19:08 [PATCH] sym53c8xx: Avoid undefined behaviour in drivers/scsi/sym53c8xx_2/sym_hipd.c:762 Helge Deller
@ 2017-08-11  7:24 ` Johannes Thumshirn
  2017-08-15  3:07 ` Martin K. Petersen
  1 sibling, 0 replies; 3+ messages in thread
From: Johannes Thumshirn @ 2017-08-11  7:24 UTC (permalink / raw)
  To: Helge Deller; +Cc: linux-scsi, James Bottomley, linux-kernel, linux-parisc

On Thu, Aug 10, 2017 at 09:08:49PM +0200, Helge Deller wrote:
> 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 dev64_ul().
                            div64_ul() ^

Otherwise,
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>


-- 
Johannes Thumshirn                                          Storage
jthumshirn@suse.de                                +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)
Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] sym53c8xx: Avoid undefined behaviour in drivers/scsi/sym53c8xx_2/sym_hipd.c:762
  2017-08-10 19:08 [PATCH] sym53c8xx: Avoid undefined behaviour in drivers/scsi/sym53c8xx_2/sym_hipd.c:762 Helge Deller
  2017-08-11  7:24 ` Johannes Thumshirn
@ 2017-08-15  3:07 ` Martin K. Petersen
  1 sibling, 0 replies; 3+ messages in thread
From: Martin K. Petersen @ 2017-08-15  3:07 UTC (permalink / raw)
  To: Helge Deller; +Cc: linux-scsi, James Bottomley, linux-kernel, linux-parisc


Helge,

> 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 dev64_ul().

Applied to 4.14/scsi-queue. Thank you, Helge!

-- 
Martin K. Petersen	Oracle Linux Engineering

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2017-08-15  3:07 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2017-08-10 19:08 [PATCH] sym53c8xx: Avoid undefined behaviour in drivers/scsi/sym53c8xx_2/sym_hipd.c:762 Helge Deller
2017-08-11  7:24 ` Johannes Thumshirn
2017-08-15  3:07 ` Martin K. Petersen

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