search for: x86retpolinethunks

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