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From: Peter Zijlstra <peterz@infradead.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
	linux-kbuild@vger.kernel.org, bpf <bpf@vger.kernel.org>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Masahiro Yamada <masahiroy@kernel.org>,
	Nathan Chancellor <nathan@kernel.org>,
	Nicolas Schier <nicolas@fjasle.eu>,
	Zheng Yejian <zhengyejian1@huawei.com>,
	Martin Kelly <martin.kelly@crowdstrike.com>,
	Christophe Leroy <christophe.leroy@csgroup.eu>,
	Josh Poimboeuf <jpoimboe@redhat.com>
Subject: Re: [PATCH 14/14] scripts/sorttable: ftrace: Do not add weak functions to available_filter_functions
Date: Thu, 2 Jan 2025 21:24:04 +0100	[thread overview]
Message-ID: <20250102202404.GD7274@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <20250102145501.3e821c56@gandalf.local.home>

On Thu, Jan 02, 2025 at 02:55:01PM -0500, Steven Rostedt wrote:
> On Thu, 2 Jan 2025 20:48:14 +0100
> Peter Zijlstra <peterz@infradead.org> wrote:
> 
> > *sigh*.. can we please just either add the 'hole' symbols in symtab, or
> > fix symtab to have entry size?
> > 
> > You're just fixing your one problem and leaving everybody else that has
> > extra data inside the dead weak things up a creek :/
> > 
> > Eg. if might make sense to also ignore alternative / static_branch /
> > static_call patching for such 'dead' code. Yes, that's not an immediate
> > problem atm, but just fixing __mcount_loc seems very short sighted.
> 
> Read my reply to the email that I forgot to add to the cover letter (but
> mention in the last patch). Fixing kallsyms does not remove the place
> holders in the available_filter_functions. This has nothing to do with
> kallsyms. I need to remove the fentry/mcount references in the mcount_loc
> section.
> 
> The kallsyms is a completely different issue.

It is not. If kallsyms is fixed, you can use that to tell which
fentry/mcount sites are 'invalid'.

Better yet, other people can then also tell if their things are inside
dead weak code or not.

  parent reply	other threads:[~2025-01-02 20:24 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-01-02 18:58 [PATCH 00/14] scripts/sorttable: ftrace: Remove place holders for weak functions in available_filter_functions Steven Rostedt
2025-01-02 18:58 ` [PATCH 01/14] scripts/sorttable: Remove unused macro defines Steven Rostedt
2025-01-02 18:58 ` [PATCH 02/14] scripts/sorttable: Remove unused write functions Steven Rostedt
2025-01-02 18:58 ` [PATCH 03/14] scripts/sorttable: Remove unneeded Elf_Rel Steven Rostedt
2025-01-02 18:58 ` [PATCH 04/14] scripts/sorttable: Have the ORC code use the _r() functions to read Steven Rostedt
2025-01-02 18:58 ` [PATCH 05/14] scripts/sorttable: Make compare_extable() into two functions Steven Rostedt
2025-01-02 18:58 ` [PATCH 06/14] scripts/sorttable: Convert Elf_Ehdr to union Steven Rostedt
2025-01-02 18:58 ` [PATCH 07/14] scripts/sorttable: Replace Elf_Shdr Macro with a union Steven Rostedt
2025-01-02 18:58 ` [PATCH 08/14] scripts/sorttable: Convert Elf_Sym MACRO over to " Steven Rostedt
2025-01-02 18:58 ` [PATCH 09/14] scripts/sorttable: Add helper functions for Elf_Ehdr Steven Rostedt
2025-01-02 18:58 ` [PATCH 10/14] scripts/sorttable: Add helper functions for Elf_Shdr Steven Rostedt
2025-01-02 18:58 ` [PATCH 11/14] scripts/sorttable: Add helper functions for Elf_Sym Steven Rostedt
2025-01-02 18:58 ` [PATCH 12/14] scripts/sorttable: Use uint64_t for mcount sorting Steven Rostedt
2025-01-02 18:58 ` [PATCH 13/14] scripts/sorttable: Move code from sorttable.h into sorttable.c Steven Rostedt
2025-01-02 18:58 ` [PATCH 14/14] scripts/sorttable: ftrace: Do not add weak functions to available_filter_functions Steven Rostedt
2025-01-02 19:48   ` Peter Zijlstra
2025-01-02 19:55     ` Steven Rostedt
2025-01-02 20:03       ` Steven Rostedt
2025-01-02 20:32         ` Peter Zijlstra
2025-01-02 20:41           ` Steven Rostedt
2025-01-02 20:48             ` Peter Zijlstra
2025-01-02 20:53               ` Steven Rostedt
2025-01-02 20:24       ` Peter Zijlstra [this message]
2025-01-02 20:30         ` Steven Rostedt
2025-01-02 20:36           ` Peter Zijlstra
2025-01-02 20:45             ` Steven Rostedt
2025-01-03 11:10   ` Jiri Olsa
2025-01-03 11:41     ` Peter Zijlstra
2025-01-03 12:14       ` Steven Rostedt
2025-01-03 18:06         ` Jiri Olsa
2025-01-02 19:24 ` [PATCH 00/14] scripts/sorttable: ftrace: Remove place holders for weak functions in available_filter_functions Steven Rostedt
2025-01-02 19:30 ` Linus Torvalds
2025-01-02 19:45   ` Steven Rostedt
2025-01-02 19:47     ` Steven Rostedt
2025-01-02 21:44   ` Steven Rostedt
2025-01-02 22:14     ` Steven Rostedt

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