Messages in this thread | | | From | Sedat Dilek <> | Date | Sat, 23 Jan 2021 03:50:21 +0100 | Subject | Re: [PATCH v2 00/20] objtool: vmlinux.o and CLANG LTO support |
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On Sat, Jan 23, 2021 at 3:46 AM Josh Poimboeuf <jpoimboe@redhat.com> wrote: > > On Sat, Jan 23, 2021 at 03:31:20AM +0100, Sedat Dilek wrote: > > On Sat, Jan 23, 2021 at 3:26 AM Josh Poimboeuf <jpoimboe@redhat.com> wrote: > > > > > > On Fri, Jan 22, 2021 at 05:32:43PM -0800, Nick Desaulniers wrote: > > > > > In this specific case, find_func_by_offset returns NULL for > > > > > .text..L.cfi.jumptable.43 at addend 0x8, because Clang doesn't emit > > > > > jump table symbols for static functions: > > > > > > > > > > 0000000000000000 <__typeid__ZTSFjmiE_global_addr>: > > > > > 0: e9 00 00 00 00 jmpq 5 <__typeid__ZTSFjmiE_global_addr+0x5> > > > > > 1: R_X86_64_PLT32 io_serial_in-0x4 > > > > > 5: cc int3 > > > > > 6: cc int3 > > > > > 7: cc int3 > > > > > 8: e9 00 00 00 00 jmpq d <__typeid__ZTSFjmiE_global_addr+0xd> > > > > > 9: R_X86_64_PLT32 mem32_serial_in-0x4 > > > > > d: cc int3 > > > > > e: cc int3 > > > > > f: cc int3 > > > > > > > > > > Nick, do you remember if there were plans to change this? > > > > > > > > Do you have a link to any previous discussion to help jog my mind; I > > > > don't really remember this one. > > > > > > > > Is it that `__typeid__ZTSFjmiE_global_addr` is the synthesized jump > > > > table, and yet there is no `__typeid__ZTSFjmiE_global_addr` entry in > > > > the symbol table? > > > > > > I think he means there's not a 'mem32_serial_in.cfi_jt' symbol at > > > '__typeid__ZTSFjmiE_global_addr+8'. Probably more aggressive symbol > > > pruning from the assembler. > > > > > > It's fine though. I just need to rewrite the CFI support a bit. > > > > > > But that can come later. For now I'll just drop the two CFI-related > > > patches from this set so I can merge the others next week. > > > > > > > Two CFI-related patches? > > > > What's the other than "objtool: Add CONFIG_CFI_CLANG support"? > > I was referring to patches 10 and 11: > > objtool: Move unsuffixed symbol conversion to a helper function > objtool: Add CONFIG_CFI_CLANG support >
OK, thanks.
I will test with a revert of these two patches in another scenario where I have problems with Clang's IAS but not with GNU AS.
- Sedat -
> You can just drop those patches from your testing (and don't test with > CFI). > > > Do you plan (or offer) a v3 of objtool-vmlinux? > > Not unless there are any more comments. > > -- > Josh > > -- > You received this message because you are subscribed to the Google Groups "Clang Built Linux" group. > To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/20210123024634.qu62tyq3nkqusken%40treble.
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