This is the mail archive of the libc-hacker@sources.redhat.com mailing list for the glibc project.

Note that libc-hacker is a closed list. You may look at the archives of this list, but subscription and posting are not open.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH] xdr_array and calloc security fix


Jakub Jelinek <jakub@redhat.com> writes:

|> On Fri, Aug 02, 2002 at 02:50:40AM -0700, Ulrich Drepper wrote:
|> > Ulrich Drepper wrote:
|> > 
|> > > It should be possible to have something like
|> > > 
|> > >   ((a | b) > (a * b))
|> > > 
|> > > for unsigned values.  I'm not 100% sure, though.
|> > 
|> > I mean, this is an approximation which lets us avoid the division in 
|> > many (most?) cases.
|> 
|> Many. a=1 b=2 -> is this overflow?
|> a=0x6000000 b=64 -> this would signal no overflow, while in fact

But (a > a * b || b > a * b) should work, shouldn't it?

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux AG, Deutschherrnstr. 15-19, D-90429 Nürnberg
Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]