linux-kernel - Re: [PATCH v4 03/10] objtool: Handle different entry size of rodata

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20241126070214.26gj5fnsjx5b5vp3@jpoimboe>
Date: Mon, 25 Nov 2024 23:02:14 -0800
From: Josh Poimboeuf <jpoimboe@...nel.org>
To: Tiezhu Yang <yangtiezhu@...ngson.cn>
Cc: Huacai Chen <chenhuacai@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>, loongarch@...ts.linux.dev,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 03/10] objtool: Handle different entry size of rodata

On Fri, Nov 22, 2024 at 12:49:58PM +0800, Tiezhu Yang wrote:
> @@ -2107,8 +2112,15 @@ static int add_jump_table(struct objtool_file *file, struct instruction *insn,
>  		if (reloc != table && reloc == next_table)
>  			break;
>  
> +		/* Handle the special cases compiled with Clang on LoongArch */

This comment is not helpful at all.  A comment is only needed if the
code is not already obvious.  In that case it should describe what is
being done and why.

> +		if (file->elf->ehdr.e_machine == EM_LOONGARCH &&
> +		    reloc_type(reloc) == R_LARCH_32_PCREL)
> +			rodata_entry_size = 4;
> +		else
> +			rodata_entry_size = 8;

Is this really loongarch-specific or is it only related to the size of
the reloc?  Can this be abstracted out to a reloc_size() function like
so?

  https://git.kernel.org/pub/scm/linux/kernel/git/jpoimboe/linux.git/tree/tools/objtool/klp-diff.c?h=objtool-diff#n834

maybe it could live in elf.h.

-- 
Josh