Re: [PATCH v2] objtool: Fix STACK_FRAME_NON_STANDARD reloc type

[Josh Poimboeuf]

On Fri, Apr 29, 2022 at 11:22:35PM +0200, Peter Zijlstra wrote:
> On Fri, Apr 29, 2022 at 01:13:25PM -0700, Josh Poimboeuf wrote:
> > Can use _ASM_PTR here, and objtool.h needs synced to tools.
> 
> Here goes..
> 
> ---
> Subject: objtool: Fix STACK_FRAME_NON_STANDARD reloc type
> From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Date: Tue Apr 26 17:08:53 CEST 2022
> 
> STACK_FRAME_NON_STANDARD results in inconsistent relocation types
> depending on .c or .S usage:
> 
>   Relocation section '.rela.discard.func_stack_frame_non_standard' at offset 0x3c01090 contains 5 entries:
>   Offset             Info             Type               Symbol's Value  Symbol's Name + Addend
>   0000000000000000  00020c2200000002 R_X86_64_PC32          0000000000047b40 do_suspend_lowlevel + 0
>   0000000000000008  0002461e00000001 R_X86_64_64            00000000000480a0 machine_real_restart + 0
>   0000000000000010  0000001400000001 R_X86_64_64            0000000000000000 .rodata + b3d4
>   0000000000000018  0002444600000002 R_X86_64_PC32          00000000000678a0 __efi64_thunk + 0
>   0000000000000020  0002659d00000001 R_X86_64_64            0000000000113160 __crash_kexec + 0
> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
> ---
>  include/linux/objtool.h       |    2 +-
>  tools/include/linux/objtool.h |    2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> --- a/include/linux/objtool.h
> +++ b/include/linux/objtool.h
> @@ -137,7 +137,7 @@ struct unwind_hint {
>  
>  .macro STACK_FRAME_NON_STANDARD func:req
>  	.pushsection .discard.func_stack_frame_non_standard, "aw"
> -		.long \func - .
> +	_ASM_PTR \func
>  	.popsection
>  .endm

This file needs to include <asm/asm.h>, otherwise you get:

arch/x86/kernel/acpi/wakeup_64.S: Assembler messages:
arch/x86/kernel/acpi/wakeup_64.S:132: Error: no such instruction: `_asm_ptr do_suspend_lowlevel'


-- 
Josh