From: Steven Rostedt <rostedt@goodmis.org>
To: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>,
x86@kernel.org, linux-kernel@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>,
Vince Weaver <vincent.weaver@maine.edu>, Dave Jones <dsj@fb.com>,
Jann Horn <jannh@google.com>, Miroslav Benes <mbenes@suse.cz>,
Andy Lutomirski <luto@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Masami Hiramatsu <mhiramat@kernel.org>,
Nilay Vaish <nilayvaish@google.com>
Subject: Re: [PATCH v2 06/11] x86/unwind/orc: Convert global variables to static
Date: Mon, 18 Mar 2024 11:58:02 -0400 [thread overview]
Message-ID: <20240318115802.39f89b73@gandalf.local.home> (raw)
In-Reply-To: <20240229004252.awmammhp63f5udyy@treble>
On Wed, 28 Feb 2024 16:42:52 -0800
Josh Poimboeuf <jpoimboe@kernel.org> wrote:
> > I'm guessing because we don't have the full dwarf info?
>
> DWARF isn't needed for that. Even the symbol table has it (as does
> System.map). For both globals and statics.
It is in System.map, but I guess the real issue is that the compiler can
optimize it out. That is, the number is never set as it is static and the
compiler doesn't need to do anything to make it valid. To the compiler, the
number is just a local variable. I'm not exactly sure how it does that, as
it sets the value in one function and uses it in another. But clang appears
to not be setting it when it is static.
Either removing static or making it volatile makes it work again.
Thoughts?
-- Steve
next prev parent reply other threads:[~2024-03-18 15:55 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-25 10:02 [PATCH v2 00/11] ORC fixes Josh Poimboeuf
2020-04-25 10:03 ` [PATCH v2 01/11] objtool: Fix stack offset tracking for indirect CFAs Josh Poimboeuf
2020-04-26 6:47 ` [tip: x86/urgent] " tip-bot2 for Josh Poimboeuf
2020-04-25 10:03 ` [PATCH v2 02/11] x86/entry/64: Fix unwind hints in register clearing code Josh Poimboeuf
2020-04-26 6:47 ` [tip: x86/urgent] " tip-bot2 for Josh Poimboeuf
2020-04-25 10:03 ` [PATCH v2 03/11] x86/entry/64: Fix unwind hints in kernel exit path Josh Poimboeuf
2020-04-26 6:47 ` [tip: x86/urgent] " tip-bot2 for Josh Poimboeuf
2020-04-25 10:03 ` [PATCH v2 04/11] x86/entry/64: Fix unwind hints in __switch_to_asm() Josh Poimboeuf
2020-04-26 6:47 ` [tip: x86/urgent] " tip-bot2 for Josh Poimboeuf
2020-04-25 10:03 ` [PATCH v2 05/11] x86/entry/64: Fix unwind hints in rewind_stack_do_exit() Josh Poimboeuf
2020-04-26 6:47 ` [tip: x86/urgent] " tip-bot2 for Jann Horn
2020-04-25 10:03 ` [PATCH v2 06/11] x86/unwind/orc: Convert global variables to static Josh Poimboeuf
2020-04-26 6:47 ` [tip: x86/urgent] " tip-bot2 for Josh Poimboeuf
2024-02-28 23:35 ` [PATCH v2 06/11] " Steven Rostedt
2024-02-29 0:03 ` Josh Poimboeuf
2024-02-29 0:14 ` Steven Rostedt
2024-02-29 0:42 ` Josh Poimboeuf
2024-02-29 23:40 ` Steven Rostedt
2024-03-18 15:58 ` Steven Rostedt [this message]
2020-04-25 10:03 ` [PATCH v2 07/11] x86/unwind: Prevent false warnings for non-current tasks Josh Poimboeuf
2020-04-26 6:47 ` [tip: x86/urgent] " tip-bot2 for Josh Poimboeuf
2020-04-25 10:03 ` [PATCH v2 08/11] x86/unwind/orc: Don't skip the first frame for inactive tasks Josh Poimboeuf
2020-04-26 6:47 ` [tip: x86/urgent] " tip-bot2 for Miroslav Benes
2020-04-25 10:03 ` [PATCH v2 09/11] x86/unwind/orc: Prevent unwinding before ORC initialization Josh Poimboeuf
2020-04-25 10:12 ` Josh Poimboeuf
2020-04-26 6:47 ` [tip: x86/urgent] " tip-bot2 for Josh Poimboeuf
2020-04-25 10:06 ` [PATCH v2 10/11] x86/unwind/orc: Fix error path for bad ORC entry type Josh Poimboeuf
2020-04-26 6:47 ` [tip: x86/urgent] " tip-bot2 for Josh Poimboeuf
2020-04-25 10:06 ` [PATCH v2 11/11] x86/unwind/orc: Fix premature unwind stoppage due to IRET frames Josh Poimboeuf
2020-04-26 6:47 ` [tip: x86/urgent] " tip-bot2 for Josh Poimboeuf
2020-04-25 10:25 ` [PATCH v2 00/11] ORC fixes Ingo Molnar
2020-04-25 10:41 ` Josh Poimboeuf
2020-04-26 7:26 ` Ingo Molnar
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