Subject: Re: PROPOSAL: removal of brk()/sbrk().
To: None <email@example.com, firstname.lastname@example.org>
From: der Mouse <mouse@Rodents.Montreal.QC.CA>
Date: 02/28/2002 15:19:43
> Does sbrk() return zero'ed memory. Looking at some code
> (moncontrol()) it appears to assume this.
Then it's broken. :-) When sbrk allocates new pages, they are
demand-zero. But as one person pointed out, negative sbrk()s can cause
old, written-to, memory to be returned by a future sbrk(), and if the
break is not page-aligned it's possible to scribble on the padding
memory, above the break but below the next page boundary, even if there
are no negative sbrk()s happening.
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