Displaying 5 results from an estimated 5 matches for "x86retpolinethunks".
2020 Mar 09
2
How to make when developing machine function pass ?
Hi
I am modifying X86RetpolineThunks.cpp.
X86RetpolineThunks.cpp 's location is llvm-src/lib/Target/X86.
Which target should I use , next time use clang test.c , I can see the
difference .
I found that "make llc" doesn't work.
And either "make LLVMX86CodeGen" doen't work.
"make clang" w...
2018 Feb 09
2
retpoline mitigation and 6.0
...> using any registers, to pop that too.
>
Yeah, we expect a complicated dance to re-order the stack to get the
correct return address into the correct place.
You can see the sequence in the comments here:
https://github.com/llvm-project/llvm-project-20170507/blob/master/llvm/lib/Target/X86/X86RetpolineThunks.cpp#L179-L194
>
> I expected the emitted code for a *call* using the thunk to look more
> like
>
> jmp 2f
> 1: pushl -0x20(%ebp) # cmp_func
> jmp __x86_thunk_indirect # jmp, not call
> 2: call 1b # set up address for cmp_func to return to
>...
2018 Feb 09
0
retpoline mitigation and 6.0
...s, to pop that too.
>
> Yeah, we expect a complicated dance to re-order the stack to get the
> correct return address into the correct place.
>
> You can see the sequence in the comments here:
> https://github.com/llvm-project/llvm-project-20170507/blob/master/llvm/lib/Target/X86/X86RetpolineThunks.cpp#L179-L194
Great, thanks.
> Anyways, it appears that we have the first case where my suspicions
> were borne out and we have somewhat reasonably different ABIs for
> some of the thunks.
>
> How should we name them to distinguish things?
For now it's only ever going to be...
2018 Feb 09
0
retpoline mitigation and 6.0
On Fri, 2018-02-09 at 02:21 +0000, David Woodhouse wrote:
> On Fri, 2018-02-09 at 01:18 +0000, David Woodhouse wrote:
> >
> >
> > For now I'm just going to attempt to work around it like this in the
> > kernel, so I can concentrate on the retpoline bits:
> > http://david.woodhou.se/clang-percpu-hack.patch
>
> 32-bit doesn't boot. Built without
2018 Feb 09
2
retpoline mitigation and 6.0
On Fri, 2018-02-09 at 01:18 +0000, David Woodhouse wrote:
>
> For now I'm just going to attempt to work around it like this in the
> kernel, so I can concentrate on the retpoline bits:
> http://david.woodhou.se/clang-percpu-hack.patch
32-bit doesn't boot. Built without CONFIG_RETPOLINE and with Clang 5.0
(and the above patch) it does. I'm rebuilding a Release build of