From: Steven Rostedt <rostedt@goodmis.org>
To: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
"the arch/x86 maintainers" <x86@kernel.org>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Linus Torvalds <torvalds@linux-foundation.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Jason Baron <jbaron@akamai.com>, Jiri Kosina <jkosina@suse.cz>,
David Laight <David.Laight@aculab.com>,
Borislav Petkov <bp@alien8.de>
Subject: Re: [RFC PATCH 1/3] static_call: Add static call infrastructure
Date: Sat, 10 Nov 2018 08:09:17 -0500 [thread overview]
Message-ID: <20181110080917.29af5d66@vmware.local.home> (raw)
In-Reply-To: <CAKv+Gu-y=O6=dSbCXSaMxkj7LxfL9txzJ4r8Bcf1U0G6JQNUng@mail.gmail.com>
On Sat, 10 Nov 2018 12:58:08 +0100
Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:
> > The complaint is on:
> >
> > DEFINE_STATIC_CALL(__tp_func_##name, __tracepoint_iter_##name);
> >
> > And the previous definition is on:
> >
> > DECLARE_STATIC_CALL(__tp_func_##name, __tracepoint_iter_##name); \
> >
>
> Does the DECLARE really need the __ADDRESSABLE? Its purpose is to
> ensure that symbols with static linkage are not optimized away, but
> since the reference is from a header file, the symbol should have
> external linkage anyway.
I applied the following change and it compiled fine:
diff --git a/include/linux/static_call.h b/include/linux/static_call.h
index 90b580b95303..5f8a0f0e77be 100644
--- a/include/linux/static_call.h
+++ b/include/linux/static_call.h
@@ -108,8 +108,6 @@ extern void arch_static_call_poison_tramp(unsigned long insn);
#define DECLARE_STATIC_CALL(key, func) \
extern struct static_call_key key; \
extern typeof(func) STATIC_CALL_TRAMP(key); \
- /* Preserve the ELF symbol so objtool can access it: */ \
- __ADDRESSABLE(key)
#define DEFINE_STATIC_CALL(key, _func) \
DECLARE_STATIC_CALL(key, _func); \
@@ -117,7 +115,9 @@ extern void arch_static_call_poison_tramp(unsigned long insn);
.func = _func, \
.site_mods = LIST_HEAD_INIT(key.site_mods), \
}; \
- ARCH_STATIC_CALL_TEMPORARY_TRAMP(key)
+ ARCH_STATIC_CALL_TEMPORARY_TRAMP(key); \
+ /* Preserve the ELF symbol so objtool can access it: */ \
+ __ADDRESSABLE(key)
#define static_call(key, args...) STATIC_CALL_TRAMP(key)(args)
Thanks!
-- Steve
next prev parent reply other threads:[~2018-11-10 13:09 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-08 21:15 [PATCH RFC 0/3] Static calls Josh Poimboeuf
2018-11-08 21:15 ` [RFC PATCH 1/3] static_call: Add static call infrastructure Josh Poimboeuf
2018-11-09 9:51 ` Ard Biesheuvel
2018-11-09 14:55 ` Josh Poimboeuf
2018-11-09 13:39 ` Ard Biesheuvel
2018-11-09 15:10 ` Josh Poimboeuf
2018-11-09 15:14 ` Ard Biesheuvel
2018-11-09 17:25 ` Ard Biesheuvel
2018-11-09 17:31 ` Josh Poimboeuf
2018-11-09 17:33 ` Ard Biesheuvel
2018-11-09 17:46 ` Josh Poimboeuf
2018-11-09 17:52 ` Ard Biesheuvel
2018-11-09 17:53 ` Ard Biesheuvel
2018-11-09 19:03 ` Josh Poimboeuf
2018-11-09 19:12 ` Ard Biesheuvel
2018-11-09 17:33 ` Josh Poimboeuf
2018-11-09 18:33 ` Steven Rostedt
2018-11-09 19:35 ` Josh Poimboeuf
2018-11-09 19:57 ` Steven Rostedt
2018-11-09 20:34 ` Josh Poimboeuf
2018-11-10 5:10 ` Steven Rostedt
2018-11-10 11:58 ` Ard Biesheuvel
2018-11-10 13:09 ` Steven Rostedt [this message]
2018-11-12 3:07 ` Josh Poimboeuf
2018-11-12 4:39 ` Ard Biesheuvel
2018-11-12 4:56 ` Josh Poimboeuf
2018-11-12 5:02 ` Ard Biesheuvel
2018-11-10 11:56 ` Ard Biesheuvel
2018-11-08 21:15 ` [RFC PATCH 2/3] x86/static_call: Add x86 unoptimized static call implementation Josh Poimboeuf
2018-11-08 21:15 ` [RFC PATCH 3/3] x86/static_call: Add optimized static call implementation for 64-bit Josh Poimboeuf
2018-11-08 21:24 ` [PATCH RFC 0/3] Static calls Josh Poimboeuf
2018-11-09 7:28 ` Ingo Molnar
2018-11-09 7:50 ` Ingo Molnar
2018-11-09 13:50 ` Ard Biesheuvel
2018-11-09 15:20 ` Josh Poimboeuf
2018-11-10 23:20 ` Peter Zijlstra
2018-11-11 13:42 ` Ard Biesheuvel
2018-11-11 14:25 ` Peter Zijlstra
2018-11-09 14:45 ` Josh Poimboeuf
2018-11-12 5:02 ` Ingo Molnar
2018-11-12 5:30 ` Josh Poimboeuf
2018-11-12 9:39 ` Ard Biesheuvel
2018-11-12 22:52 ` Josh Poimboeuf
2018-11-12 17:03 ` Steven Rostedt
2018-11-12 22:56 ` Josh Poimboeuf
2018-11-12 5:34 ` Andy Lutomirski
2018-11-09 15:16 ` Andy Lutomirski
2018-11-09 15:21 ` Josh Poimboeuf
2018-11-09 16:41 ` Josh Poimboeuf
2018-11-09 18:42 ` Steven Rostedt
2018-11-09 19:05 ` Andy Lutomirski
2018-11-09 19:37 ` Steven Rostedt
2018-11-09 19:44 ` Josh Poimboeuf
2018-11-09 19:59 ` Steven Rostedt
2018-11-09 20:36 ` Josh Poimboeuf
2018-11-10 15:13 ` Masami Hiramatsu
2018-11-09 20:53 ` Rasmus Villemoes
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