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From: Miroslav Benes <mbenes@suse.cz>
To: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
	 Peter Zijlstra <peterz@infradead.org>,
	 Brendan Jackman <jackmanb@google.com>,
	 Nathan Chancellor <nathan@kernel.org>
Subject: Re: [PATCH 04/13] objtool: Update documentation
Date: Mon, 17 Mar 2025 11:46:53 +0100 (CET)	[thread overview]
Message-ID: <alpine.LSU.2.21.2503171143290.4236@pobox.suse.cz> (raw)
In-Reply-To: <2552ee8b48631127bf269359647a7389edf5f002.1741975349.git.jpoimboe@kernel.org>

Hi,

>  1. Each callable function must be annotated as such with the ELF
>     function type.  In asm code, this is typically done using the
> -   ENTRY/ENDPROC macros.  If objtool finds a return instruction
> +   SYM_FUNC_{START,END} macros.  If objtool finds a return instruction
>     outside of a function, it flags an error since that usually indicates
>     callable code which should be annotated accordingly.

there is one more occurrence of ENDPROC/END under "1. file.o: warning: 
objtool: func()+0x128: call without frame pointer save/setup" section 
which might be nice to update as well.

> @@ -339,23 +351,21 @@ the objtool maintainers.
>  
>     This is a kernel entry/exit instruction like sysenter or iret.  Such
>     instructions aren't allowed in a callable function, and are most
> -   likely part of the kernel entry code.  They should usually not have
> -   the callable function annotation (ENDPROC) and should always be
> -   annotated with the unwind hint macros in asm/unwind_hints.h.
> +   likely part of the kernel entry code.  Such code should probably be
> +   placed in a SYM_FUNC_CODE block with unwind hints.

SYM_CODE_{START,END} block?

>  7. file: warning: objtool: func()+0x5c: stack state mismatch
> @@ -371,8 +381,8 @@ the objtool maintainers.
>  
>     Another possibility is that the code has some asm or inline asm which
>     does some unusual things to the stack or the frame pointer.  In such
> -   cases it's probably appropriate to use the unwind hint macros in
> -   asm/unwind_hints.h.
> +   cases it's probably appropriate to use SYM_FUNC_CODE with unwind
> +   hints.

dtto

Miroslav

  parent reply	other threads:[~2025-03-17 10:46 UTC|newest]

Thread overview: 68+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-03-14 19:28 [PATCH 00/13] Fail the build on objtool warnings Josh Poimboeuf
2025-03-14 19:28 ` [PATCH 01/13] x86/traps: Make exc_double_fault() consistently noreturn Josh Poimboeuf
2025-03-17  8:26   ` Brendan Jackman
2025-03-17 10:46   ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2025-03-17 10:47   ` [PATCH 01/13] " Miroslav Benes
2025-03-14 19:29 ` [PATCH 02/13] objtool: Fix error handling inconsistencies in check() Josh Poimboeuf
2025-03-17  8:29   ` Brendan Jackman
2025-03-17 10:46   ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2025-03-17 10:47   ` [PATCH 02/13] " Miroslav Benes
2025-03-14 19:29 ` [PATCH 03/13] objtool: Improve __noreturn annotation warning Josh Poimboeuf
2025-03-17  8:31   ` Brendan Jackman
2025-03-17 10:36     ` Miroslav Benes
2025-03-17 10:46   ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2025-03-14 19:29 ` [PATCH 04/13] objtool: Update documentation Josh Poimboeuf
2025-03-17  8:47   ` Brendan Jackman
2025-03-17 10:46   ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2025-03-17 10:46   ` Miroslav Benes [this message]
2025-03-14 19:29 ` [PATCH 05/13] objtool: Increase per-function WARN_FUNC() rate limit Josh Poimboeuf
2025-03-17  9:15   ` Brendan Jackman
2025-03-17 12:29     ` Miroslav Benes
2025-03-18 10:59       ` Brendan Jackman
2025-03-17 10:46   ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2025-03-14 19:29 ` [PATCH 06/13] objtool: Remove --unret dependency on --rethunk Josh Poimboeuf
2025-03-14 19:38   ` Peter Zijlstra
2025-03-14 19:52     ` Josh Poimboeuf
2025-03-14 19:58       ` Peter Zijlstra
2025-03-17 12:33       ` Miroslav Benes
2025-03-17 10:46   ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2025-03-14 19:29 ` [PATCH 07/13] objtool: Consolidate option validation Josh Poimboeuf
2025-03-17  9:19   ` Brendan Jackman
2025-03-17 10:46   ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2025-03-17 12:35   ` [PATCH 07/13] " Miroslav Benes
2025-03-14 19:29 ` [PATCH 08/13] objtool: Upgrade "Linked object detected" warning to error Josh Poimboeuf
2025-03-17  9:21   ` Brendan Jackman
2025-03-17 10:46   ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2025-03-17 12:38   ` [PATCH 08/13] " Miroslav Benes
2025-03-14 19:29 ` [PATCH 09/13] objtool: Add --output option Josh Poimboeuf
2025-03-17  9:40   ` Brendan Jackman
2025-03-17 10:46   ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2025-03-17 12:48   ` [PATCH 09/13] " Miroslav Benes
2025-03-14 19:29 ` [PATCH 10/13] objtool: Add --Werror option Josh Poimboeuf
2025-03-17 10:46   ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2025-03-17 12:53   ` [PATCH 10/13] " Miroslav Benes
2025-03-14 19:29 ` [PATCH 11/13] objtool: Change "warning:" to "error:" for --Werror Josh Poimboeuf
2025-03-17  9:42   ` Brendan Jackman
2025-03-17 10:46   ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2025-03-17 13:04   ` [PATCH 11/13] " Miroslav Benes
2025-03-14 19:29 ` [PATCH 12/13] objtool: Create backup on error and print args Josh Poimboeuf
2025-03-17  9:53   ` Brendan Jackman
2025-03-17 10:46   ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2025-03-17 14:09   ` [PATCH 12/13] " Miroslav Benes
2025-03-14 19:29 ` [PATCH 13/13] objtool: Add CONFIG_OBJTOOL_WERROR Josh Poimboeuf
2025-03-16  0:41   ` Ingo Molnar
2025-03-16  1:49     ` Josh Poimboeuf
2025-03-16 11:56       ` Ingo Molnar
2025-03-18  4:55         ` Josh Poimboeuf
2025-03-17 10:46   ` [tip: objtool/core] " tip-bot2 for Josh Poimboeuf
2025-03-17 11:07   ` tip-bot2 for Josh Poimboeuf
2025-03-17 21:27     ` Ingo Molnar
2025-03-18  0:05       ` Josh Poimboeuf
2025-03-20 17:10         ` Steven Rostedt
2025-03-18 11:51       ` Ingo Molnar
2025-03-18 14:26         ` Josh Poimboeuf
2025-03-20  8:51         ` Ingo Molnar
2025-03-18  0:27     ` Josh Poimboeuf
2025-03-18  4:59       ` Josh Poimboeuf
2025-03-17 14:14   ` [PATCH 13/13] " Miroslav Benes
2025-03-23  7:50     ` Josh Poimboeuf

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