Re: [PATCH v3 05/17] block/io: support int64_t bytes in bdrv_co_do_pwrite_zeroes()

[Eric Blake]

On 5/11/20 12:17 PM, Alberto Garcia wrote:
On Thu 30 Apr 2020 01:10:21 PM CEST, Vladimir Sementsov-Ogievskiy wrote:
     compute 'int tail' via % 'int alignment' - safe

     tail = (offset + bytes) % alignment;

both are int64_t, no chance of overflow here?

Good question - I know several places check that offset+bytes does not 
overflow, but did not specifically audit if this one does.  Adding an 
assert() in this function may be easier than trying to prove all callers 
pass in safe values.

--
Eric Blake, Principal Software Engineer
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