blk-settings.c integer truncation

blk-settings.c integer truncation

[Sergey Senozhatsky]

Hello.

commit e475bba2fdee9c3dbfe25f026f8fb8de69508ad2
introduced 'void blk_set_default_limits(struct queue_limits *lim)'

blkdev.h
...
#endif
#define BLK_BOUNCE_ANY		(-1ULL)
#define BLK_BOUNCE_ISA		(ISA_DMA_THRESHOLD)


struct queue_limits {
	unsigned long		bounce_pfn;
	unsigned long		seg_boundary_mask;
....
};

Assignment at block/blk-settings.c:115 (4 bytes = 8 bytes):
lim->bounce_pfn = BLK_BOUNCE_ANY;

leads to truncation:
block/blk-settings.c: In function ‘blk_set_default_limits’:
block/blk-settings.c:115: warning: large integer implicitly truncated to unsigned type


Should BLK_BOUNCE_ANY be (-1UL)?


Thanks.

	Sergey

p.s.
In case it's already fixed - let me know.

Re: blk-settings.c integer truncation

[Martin K. Petersen]

>>>>> "Sergey" == Sergey Senozhatsky <sergey.senozhatsky@mail.by> writes:

Sergey> Hello.  commit e475bba2fdee9c3dbfe25f026f8fb8de69508ad2
Sergey> introduced 'void blk_set_default_limits(struct queue_limits
Sergey> *lim)'

This was discussed here a couple of days ago.  There is a fix in Jens'
tree but Linus hasn't pulled it yet.

In any case the warning is harmless.

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: blk-settings.c integer truncation

[Sergey Senozhatsky]

On (06/19/09 10:24), Martin K. Petersen wrote:
> >>>>> "Sergey" == Sergey Senozhatsky <sergey.senozhatsky@mail.by> writes:
> 
> Sergey> Hello.  commit e475bba2fdee9c3dbfe25f026f8fb8de69508ad2
> Sergey> introduced 'void blk_set_default_limits(struct queue_limits
> Sergey> *lim)'
> 
> This was discussed here a couple of days ago.  There is a fix in Jens'
> tree but Linus hasn't pulled it yet.
> 
> In any case the warning is harmless.
> 
> -- 
> Martin K. Petersen	Oracle Linux Engineering
> 


OK. Thanks.

	Sergey

blk-settings.c integer truncation

[Sergey Senozhatsky]

Hello.
I was asking
> Should BLK_BOUNCE_ANY be (-1UL)?

No. It should not.

git annotate gives for blkdev.h:
Andi Kleen     2008-04-21 09:51:05 +0200       705)#define BLK_BOUNCE_ANY              (-1ULL)
...

...
(Martin K. Petersen     2009-05-22 17:17:51 -0400       311)    unsigned long           bounce_pfn;
...
(Martin K. Petersen     2009-05-22 17:17:50 -0400       1020)static inline unsigned long queue_bounce_pfn(struct request_queue *q)
(Martin K. Petersen     2009-05-22 17:17:50 -0400       1021){
(Martin K. Petersen     2009-05-22 17:17:51 -0400       1022)   return q->limits.bounce_pfn;
(Martin K. Petersen     2009-05-22 17:17:50 -0400       1023)}
...

I think, commit need to be reworked a bit.

	Sergey