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Date:   Fri, 29 Apr 2022 13:13:25 -0700
From:   Josh Poimboeuf <jpoimboe@redhat.com>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] objtool: Fix STACK_FRAME_NON_STANDARD reloc type
Message-ID: <20220429201325.d5kifdezdru2i3lp@treble>
References: <20220429092024.GT2731@worktop.programming.kicks-ass.net>
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On Fri, Apr 29, 2022 at 11:20:24AM +0200, Peter Zijlstra wrote:
> 
> 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@infradead.org>
> ---
>  include/linux/objtool.h |    6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> --- a/include/linux/objtool.h
> +++ b/include/linux/objtool.h
> @@ -137,7 +137,11 @@ struct unwind_hint {
>  
>  .macro STACK_FRAME_NON_STANDARD func:req
>  	.pushsection .discard.func_stack_frame_non_standard, "aw"
> -		.long \func - .
> +#ifdef CONFIG_64BIT
> +		.quad \func
> +#else
> +		.long \func
> +#endif
>  	.popsection
>  .endm

Can use _ASM_PTR here, and objtool.h needs synced to tools.

-- 
Josh