Re: [PATCH v6 03/30] objtool: Disassemble code with libopcodes instead of running objdump

[Alexandre Chartre <alexandre.chartre@oracle.com>]

On 12/9/25 07:58, Guenter Roeck wrote:
> Hi,
> 
> On Fri, Nov 21, 2025 at 10:53:13AM +0100, Alexandre Chartre wrote:
>> objtool executes the objdump command to disassemble code. Use libopcodes
>> instead to have more control about the disassembly scope and output.
>> If libopcodes is not present then objtool is built without disassembly
>> support.
>>
>> Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
> 
> With this patch in mainline, I get the following build error when trying
> to build x86_64:defconfig (and other configurations).
> 
> Bisect log is attached. I see the problem with gcc 11.4.0, 13.3.0, and
> 14.3.0. I tried with both Ubuntu 22.04 and 24.04.
> 

This sounds like a configuration issue depending on the binutils version; in
particular the setting of DISASM_INIT_STYLED (although that's supposed to be
automatically configured by tools/objtool/Makefile).

Which binutils-devel version are you using?

Thanks,

alex.

> 
> Building x86_64:defconfig ... failed
> --------------
> Error log:
> In file included from disas.c:17:
> tools/include/tools/dis-asm-compat.h:19:39: error: ‘enum disassembler_style’ declared inside parameter list will not be visible outside of this definition or declaration [-Werror]
>     19 |                                  enum disassembler_style style,
>        |                                       ^~~~~~~~~~~~~~~~~~
> tools/include/tools/dis-asm-compat.h:19:58: error: parameter 2 (‘style’) has incomplete type
>     19 |                                  enum disassembler_style style,
>        |                                  ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
> tools/include/tools/dis-asm-compat.h:42:49: error: unknown type name ‘fprintf_styled_ftype’; did you mean ‘fprintf_ftype’?
>     42 |                                                 fprintf_styled_ftype styled_func)
>        |                                                 ^~~~~~~~~~~~~~~~~~~~
>        |                                                 fprintf_ftype
> disas.c:152:38: error: ‘enum disassembler_style’ declared inside parameter list will not be visible outside of this definition or declaration [-Werror]
>    152 |                                 enum disassembler_style style,
>        |                                      ^~~~~~~~~~~~~~~~~~
> disas.c:152:57: error: parameter 2 (‘style’) has incomplete type
>    152 |                                 enum disassembler_style style,
>        |                                 ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~
> disas.c: In function ‘disas_context_create’:
> disas.c:367:9: error: implicit declaration of function ‘init_disassemble_info_compat’; did you mean ‘init_disassemble_info’? [-Werror=implicit-function-declaration]
>    367 |         init_disassemble_info_compat(dinfo, dctx,
>        |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
>        |         init_disassemble_info
> In file included from tools/include/linux/kernel.h:5,
>                   from tools/include/linux/list.h:7,
>                   from tools/objtool/include/objtool/arch.h:10,
>                   from disas.c:9:
> disas.c: In function ‘disas_fprintf_styled’:
> disas.c:158:9: error: ‘va_start’ used in function with fixed arguments
>    158 |         va_start(arg, fmt);
>        |         ^~~~~~~~
> cc1: all warnings being treated as errors
> 
> ---
> Bisect:
> 
> # bad: [cb015814f8b6eebcbb8e46e111d108892c5e6821] Merge tag 'f2fs-for-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs
> # good: [7d0a66e4bb9081d75c82ec4957c50034cb0ea449] Linux 6.18
> git bisect start 'HEAD' 'v6.18'
> # bad: [6dfafbd0299a60bfb5d5e277fdf100037c7ded07] Merge tag 'drm-next-2025-12-03' of https://gitlab.freedesktop.org/drm/kernel
> git bisect bad 6dfafbd0299a60bfb5d5e277fdf100037c7ded07
> # bad: [8f7aa3d3c7323f4ca2768a9e74ebbe359c4f8f88] Merge tag 'net-next-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
> git bisect bad 8f7aa3d3c7323f4ca2768a9e74ebbe359c4f8f88
> # bad: [4a4e0199378f309fa7259132e1443efe56c1e276] Merge tag 'lkmm.2025.12.01a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
> git bisect bad 4a4e0199378f309fa7259132e1443efe56c1e276
> # bad: [a61288200e8b6f42bff116508dc72ebcc206f10a] Merge tag 'ras_core_for_v6.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
> git bisect bad a61288200e8b6f42bff116508dc72ebcc206f10a
> # good: [1b5dd29869b1e63f7e5c37d7552e2dcf22de3c26] Merge tag 'vfs-6.19-rc1.fd_prepare.fs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
> git bisect good 1b5dd29869b1e63f7e5c37d7552e2dcf22de3c26
> # bad: [dcd8637edb873bd940e6aa82417dfb33ae980778] Merge tag 'x86-core-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
> git bisect bad dcd8637edb873bd940e6aa82417dfb33ae980778
> # bad: [7e017720aae87dc2ca2471ac295e34e2b240e5f5] objtool: Disassemble jump table alternatives
> git bisect bad 7e017720aae87dc2ca2471ac295e34e2b240e5f5
> # good: [164c9201e1dad8d5c0c38f583dba81e4b6da9cc7] objtool: Add base objtool support for livepatch modules
> git bisect good 164c9201e1dad8d5c0c38f583dba81e4b6da9cc7
> # good: [9205a322cf96f16a49e412dfa3f09431f3e02fc5] objtool: Return canonical symbol when aliases exist in symbol finding helpers
> git bisect good 9205a322cf96f16a49e412dfa3f09431f3e02fc5
> # bad: [0bb080ba6469a573bc85122153d931334d10a173] objtool: Disassemble instruction on warning or backtrace
> git bisect bad 0bb080ba6469a573bc85122153d931334d10a173
> # good: [93863f3f859a626347ce2ec18947b11357b4ca14] kbuild: Check for functions with ambiguous -ffunction-sections section names
> git bisect good 93863f3f859a626347ce2ec18947b11357b4ca14
> # bad: [59953303827eceb06d486ba66cc0d71f55ded8ec] objtool: Disassemble code with libopcodes instead of running objdump
> git bisect bad 59953303827eceb06d486ba66cc0d71f55ded8ec
> # good: [55d2a473f317ab028d78a5c5ca69473643657c3d] objtool: Move disassembly functions to a separated file
> git bisect good 55d2a473f317ab028d78a5c5ca69473643657c3d
> # good: [1013f2e37bec39b1df5679e1c1e2572ece87c088] objtool: Create disassembly context
> git bisect good 1013f2e37bec39b1df5679e1c1e2572ece87c088
> # first bad commit: [59953303827eceb06d486ba66cc0d71f55ded8ec] objtool: Disassemble code with libopcodes instead of running objdump