From: Peter Zijlstra <peterz@infradead.org>
To: Miroslav Benes <mbenes@suse.cz>
Cc: x86@kernel.org, jpoimboe@redhat.com, jgross@suse.com,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 6/9] objtool: Add elf_create_undef_symbol()
Date: Wed, 17 Mar 2021 15:13:43 +0100 [thread overview]
Message-ID: <YFIOl/3NcnnV0jDa@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <alpine.LSU.2.21.2103171444570.23081@pobox.suse.cz>
On Wed, Mar 17, 2021 at 02:52:23PM +0100, Miroslav Benes wrote:
> > + if (!elf_symbol_add(elf, sym, SHN_XINDEX)) {
> > + WARN("elf_symbol_add");
> > + return NULL;
> > + }
>
> SHN_XINDEX means that the extended section index is used. Above you seem
> to use it in the opposite sense too (assigning to shndx when shndx_data is
> NULL). While it makes the code easier to handle, it is a bit confusing
> (and maybe I am just confused now). Could you add a comment about that,
> please? elf_symbol_add() seems like a good place.
Yes, that was a horrible thing to do :/ And you understood it right.
Looking at it again, I'm not sure it is actually correct tho; shouldn't
elf_create_undef_symbol() also look at gelf_getsymshndx() of symtab ?
What toolchain generates these extended sections and how? That is, how
do I test this crud..
next prev parent reply other threads:[~2021-03-17 14:14 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-12 17:16 [PATCH 0/9] x86,objtool: Optimize !RETPOLINE Peter Zijlstra
2021-03-12 17:16 ` [PATCH 1/9] x86/retpoline: Simplify retpolines Peter Zijlstra
2021-03-12 17:16 ` [PATCH 2/9] objtool: Correctly handle retpoline thunk calls Peter Zijlstra
2021-03-16 21:19 ` Josh Poimboeuf
2021-03-12 17:16 ` [PATCH 3/9] objtool: Per arch retpoline naming Peter Zijlstra
2021-03-12 17:16 ` [PATCH 4/9] objtool: Fix static_call list generation Peter Zijlstra
2021-03-17 3:18 ` Josh Poimboeuf
2021-03-12 17:16 ` [PATCH 5/9] objtool: Rework rebuild_reloc logic Peter Zijlstra
2021-03-17 3:34 ` Josh Poimboeuf
2021-03-17 8:12 ` Peter Zijlstra
2021-03-18 0:49 ` Josh Poimboeuf
2021-03-18 12:57 ` Peter Zijlstra
2021-03-18 16:36 ` Josh Poimboeuf
2021-03-18 17:04 ` Peter Zijlstra
2021-03-18 17:38 ` Josh Poimboeuf
2021-03-19 0:19 ` Josh Poimboeuf
2021-03-19 9:22 ` Peter Zijlstra
2021-03-19 15:15 ` Josh Poimboeuf
2021-03-12 17:16 ` [PATCH 6/9] objtool: Add elf_create_undef_symbol() Peter Zijlstra
2021-03-17 13:52 ` Miroslav Benes
2021-03-17 14:13 ` Peter Zijlstra [this message]
2021-03-17 14:39 ` Miroslav Benes
2021-03-17 15:08 ` Sami Tolvanen
2021-03-18 0:46 ` Josh Poimboeuf
2021-03-18 7:56 ` Peter Zijlstra
2021-03-12 17:16 ` [PATCH 7/9] objtool: Allow archs to rewrite retpolines Peter Zijlstra
2021-03-12 17:16 ` [PATCH 8/9] objtool: Skip magical retpoline .altinstr_replacement Peter Zijlstra
2021-03-12 17:16 ` [PATCH 9/9] objtool,x86: Rewrite retpoline thunk calls Peter Zijlstra
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