DragonFly bugs List (threaded) for 2006-06
Re: another SSP bug? (Re: userland ppp ("No context" errors))
On Mon, Jun 19, 2006 at 01:30:51PM +0200, joerg@xxxxxxxxxxxxxxxxx wrote:
> On Mon, Jun 19, 2006 at 07:06:40PM +0900, YONETANI Tomokazu wrote:
> > This seems like another stack-smash-protector bug and still lives
> > in our compiler, only triggered when you use -O(s|[2-9]) flags AND
> > -march flag (which defaults to pentiumpro) .
> -march or -mcpu? The former is certainly not default and can trigger a
> variety of bugs.
Sorry, the default is -mtune, but both -march=pentiumpro and
-mtune=pentiumpro can trigger the bug(and the compiler complained
that -mcpu is deprecated).
> > If you do one of the following and the problem disappears:
> > - add -fno-stack-smash-protector to CFLAGS
> > - change prefix in function FindExec() shown below to a static array
> > so as there's no char array in the local parameter. char array of
> > size more than 8 bytes on the stack can trigger the bug.
> Well, under 8 byte the stack protection would not be active.
I have almost zero knowledge of how stack protector works, but
does it only care about char array of size greater than 8 bytes
(8 bytes was ok)? I also tried int and double, but none of them