On 6/18/24 3:38 PM, Segher Boessenkool wrote:
> From my viewpoint, -mrop-protect should not change code generation at
> all, except of course it has to emit some hash* insns :-)
Ideally, I agree with that. That said, the hash* insns only accept negative
offsets and the allowed range is rather
On Tue, Jun 18, 2024 at 12:53:09PM -0500, Peter Bergner wrote:
> On 6/18/24 8:20 AM, Segher Boessenkool wrote:
> > On Mon, Jun 17, 2024 at 08:54:46PM -0500, Peter Bergner wrote:
> >> So we should be able to shrink-wrap in the presence of the ROP protection.
> [snip]
> > But do we want to? And,
On 6/18/24 8:20 AM, Segher Boessenkool wrote:
> On Mon, Jun 17, 2024 at 08:54:46PM -0500, Peter Bergner wrote:
>> So we should be able to shrink-wrap in the presence of the ROP protection.
[snip]
> But do we want to? And, how far, in what cases not?
My answer to the above would be "yes", "as far
On Mon, Jun 17, 2024 at 08:54:46PM -0500, Peter Bergner wrote:
> On 6/17/24 7:57 PM, Segher Boessenkool wrote:
> > On Mon, Jun 17, 2024 at 06:49:18PM -0500, Peter Bergner wrote:
> >> On 6/17/24 6:11 PM, Segher Boessenkool wrote:
> >> Yeah, I didn't write that, I only moved it, but I can try to
On 6/17/24 7:57 PM, Segher Boessenkool wrote:
> On Mon, Jun 17, 2024 at 06:49:18PM -0500, Peter Bergner wrote:
>> On 6/17/24 6:11 PM, Segher Boessenkool wrote:
>> Yeah, I didn't write that, I only moved it, but I can try to come up with
>> an explanation of why we need to disable it now. That
Hi!
On Mon, Jun 17, 2024 at 06:49:18PM -0500, Peter Bergner wrote:
> On 6/17/24 6:11 PM, Segher Boessenkool wrote:
> >> - /* If we are inserting ROP-protect instructions, disable shrink wrap.
> >> */
> >> - if (rs6000_rop_protect)
> >> -flag_shrink_wrap = 0;
> >> }
> >
> > (Yes, I know
While auditing our ROP code generation for some test cases I wrote, I noticed
a few issues which I'm tracking in PR114759. The first issue I noticed is we
disable shrink-wrapping when using -mrop-protect, even in the cases where we
never emit the ROP instructions because they're not needed. The
On 6/17/24 6:11 PM, Segher Boessenkool wrote:
> "ROP insns" are the instructions used in such exploits, not what you
> mean here :-)
>
> The instructions are called "hash*"C, so maybe call tbem "hash insns"
> or "ROP protect hash insns"?.
Ok, that bad verbiage was in the extra commentary not
Hi!
On Mon, Jun 17, 2024 at 05:26:39PM -0500, Peter Bergner wrote:
> While auditing our ROP code generation for some test cases I wrote, I noticed
> a few issues which I'm tracking in PR114759. The first issue I noticed is we
> disable shrink-wrapping when using -mrop-protect, even in the cases
