two 4GB mallocs => SEGV

Willem Jan Withagen wjw at
Tue Oct 26 07:47:21 PDT 2004

Georgi Guninski wrote:

> On Tue, Oct 26, 2004 at 03:51:22PM +0200, Willem Jan Withagen wrote:
>>And again on a 5.2 i386 box:
>>[/tmp] root at freebee> a.out
> actually on i386 linux i get 0 and i don't crash at all.

facinating, but true...
Willest compiling I get a warning of a overflow that 2G gives a wrap in long, 
but things are interpreted unsigned as far as I see.
And that is because I changed your 4G to 2G, 'cause I only had 2Gb of mem and 
5Gb of swap.

Yours just really overflows to 0, I guess. eg. if the optimizer (or the code) 
calculates the expression from right to left, and *4 is done 'by shiftleft 2'
you're left with an all-zeros...


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