From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Nick Desaulniers <ndesaulniers@google.com>
Cc: Sami Tolvanen <samitolvanen@google.com>,
Sedat Dilek <sedat.dilek@gmail.com>, X86 ML <x86@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Kees Cook <keescook@chromium.org>,
Clang-Built-Linux ML <clang-built-linux@googlegroups.com>,
Miroslav Benes <mbenes@suse.cz>,
Fangrui Song <maskray@google.com>,
Peter Collingbourne <pcc@google.com>
Subject: Re: [PATCH v2 00/20] objtool: vmlinux.o and CLANG LTO support
Date: Fri, 22 Jan 2021 20:26:09 -0600 [thread overview]
Message-ID: <20210123022609.n7xsj2a4potoijz7@treble> (raw)
In-Reply-To: <CAKwvOdkcoCFKD63xtQzRdFikDk-GUUfUG5EEKiCTA3cueEZQNA@mail.gmail.com>
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.
--
Josh
next prev parent reply other threads:[~2021-01-23 2:28 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-21 21:29 [PATCH v2 00/20] objtool: vmlinux.o and CLANG LTO support Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 01/20] objtool: Fix error handling for STD/CLD warnings Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 02/20] objtool: Fix retpoline detection in asm code Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 03/20] objtool: Fix ".cold" section suffix check for newer versions of GCC Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 04/20] objtool: Support retpoline jump detection for vmlinux.o Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 05/20] x86/ftrace: Add UNWIND_HINT_FUNC annotation for ftrace_stub Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 06/20] objtool: Assume only ELF functions do sibling calls Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 07/20] objtool: Add asm version of STACK_FRAME_NON_STANDARD Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 08/20] objtool: Combine UNWIND_HINT_RET_OFFSET and UNWIND_HINT_FUNC Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 09/20] objtool: Add xen_start_kernel() to noreturn list Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 10/20] objtool: Move unsuffixed symbol conversion to a helper function Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 11/20] objtool: Add CONFIG_CFI_CLANG support Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 12/20] x86/xen: Support objtool validation in xen-asm.S Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 13/20] x86/xen: Support objtool vmlinux.o validation in xen-head.S Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 14/20] x86/xen/pvh: Annotate indirect branch as safe Josh Poimboeuf
2021-01-22 5:17 ` Jürgen Groß
2021-01-21 21:29 ` [PATCH v2 15/20] x86/ftrace: Support objtool vmlinux.o validation in ftrace_64.S Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 16/20] x86/acpi: Annotate indirect branch as safe Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 17/20] x86/acpi: Support objtool validation in wakeup_64.S Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 18/20] x86/power: Annotate indirect branches as safe Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 19/20] x86/power: Move restore_registers() to top of the file Josh Poimboeuf
2021-01-21 21:29 ` [PATCH v2 20/20] x86/power: Support objtool validation in hibernate_asm_64.S Josh Poimboeuf
2021-01-21 22:38 ` [PATCH v2 00/20] objtool: vmlinux.o and CLANG LTO support Sedat Dilek
2021-01-22 15:41 ` Josh Poimboeuf
2021-01-22 21:17 ` Sami Tolvanen
2021-01-23 1:32 ` Nick Desaulniers
2021-01-23 2:26 ` Josh Poimboeuf [this message]
2021-01-23 2:31 ` Sedat Dilek
2021-01-23 2:46 ` Josh Poimboeuf
2021-01-23 2:50 ` Sedat Dilek
2021-01-25 22:43 ` Sami Tolvanen
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