From: Peter Zijlstra <peterz@infradead.org>
To: Alexandre Chartre <alexandre.chartre@oracle.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>,
x86@kernel.org, linux-kernel@vger.kernel.org,
jthierry@redhat.com, tglx@linutronix.de
Subject: Re: [PATCH V2 9/9] x86/speculation: Remove all ANNOTATE_NOSPEC_ALTERNATIVE directives
Date: Thu, 9 Apr 2020 12:40:08 +0200 [thread overview]
Message-ID: <20200409104008.GO20760@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20200409103424.GC20713@hirez.programming.kicks-ass.net>
On Thu, Apr 09, 2020 at 12:34:24PM +0200, Peter Zijlstra wrote:
> @@ -111,23 +83,21 @@
> */
> .macro JMP_NOSPEC reg:req
> #ifdef CONFIG_RETPOLINE
> - ANNOTATE_NOSPEC_ALTERNATIVE
> - ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; jmp *\reg), \
> - __stringify(RETPOLINE_JMP \reg), X86_FEATURE_RETPOLINE, \
> - __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; jmp *\reg), X86_FEATURE_RETPOLINE_AMD
> + ALTERNATIVE "", "lfence", X86_FEATURE_RETPOLINE_AMD
> + ALTERNATIVE __stringify(ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), \
> + __stringify(jmp __x86_retpoline_\reg), X86_FEATURE_RETPOLINE
Still, I am being an idiot, only the call (below) needs this, this can
stay what it was:
+ ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), \
+ __stringify(jmp __x86_retpoline_\()\reg), X86_FEATURE_RETPOLINE, \
+ __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), X86_FEATURE_RETPOLINE_AMD
> #else
> - jmp *\reg
> + jmp *%\reg
> #endif
> .endm
>
> .macro CALL_NOSPEC reg:req
> #ifdef CONFIG_RETPOLINE
> - ANNOTATE_NOSPEC_ALTERNATIVE
> - ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; call *\reg), \
> - __stringify(RETPOLINE_CALL \reg), X86_FEATURE_RETPOLINE,\
> - __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; call *\reg), X86_FEATURE_RETPOLINE_AMD
And then this needs a comment on why it is not ALTERNATIVE_2 like above.
> + ALTERNATIVE "", "lfence", X86_FEATURE_RETPOLINE_AMD
> + ALTERNATIVE __stringify(ANNOTATE_RETPOLINE_SAFE; call *%\reg), \
> + __stringify(call __x86_retpoline_\reg), X86_FEATURE_RETPOLINE
> #else
> - call *\reg
> + call *%\reg
> #endif
> .endm
next prev parent reply other threads:[~2020-04-09 10:40 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-07 7:31 [PATCH V2 0/9] objtool changes to remove all ANNOTATE_NOSPEC_ALTERNATIVE Alexandre Chartre
2020-04-07 7:31 ` [PATCH V2 1/9] objtool: Introduce HINT_RET_OFFSET Alexandre Chartre
2020-04-07 12:53 ` Peter Zijlstra
2020-04-07 13:17 ` Alexandre Chartre
2020-04-07 7:31 ` [PATCH V2 2/9] objtool: UNWIND_HINT_RET_OFFSET should not check registers Alexandre Chartre
2020-05-01 18:22 ` [tip: objtool/core] " tip-bot2 for Alexandre Chartre
2020-04-07 7:31 ` [PATCH V2 3/9] objtool: is_fentry_call() crashes if call has no destination Alexandre Chartre
2020-04-07 7:31 ` [PATCH V2 4/9] objtool: Allow branches within the same alternative Alexandre Chartre
2020-04-07 7:31 ` [PATCH V2 5/9] objtool: Add support for intra-function calls Alexandre Chartre
2020-04-07 13:07 ` Peter Zijlstra
2020-04-07 13:28 ` Alexandre Chartre
2020-04-08 14:06 ` Alexandre Chartre
2020-04-08 14:19 ` Julien Thierry
2020-04-08 16:03 ` Alexandre Chartre
2020-04-08 16:04 ` Julien Thierry
2020-04-08 17:06 ` Alexandre Chartre
2020-04-08 17:07 ` Julien Thierry
2020-04-07 7:31 ` [PATCH V2 6/9] x86/speculation: Change __FILL_RETURN_BUFFER to work with objtool Alexandre Chartre
2020-04-07 13:27 ` Josh Poimboeuf
2020-04-07 7:31 ` [PATCH V2 7/9] x86/speculation: Annotate intra-function calls Alexandre Chartre
2020-04-07 7:31 ` [PATCH V2 8/9] x86/speculation: Add unwind hint to trampoline return Alexandre Chartre
2020-04-07 7:31 ` [PATCH V2 9/9] x86/speculation: Remove all ANNOTATE_NOSPEC_ALTERNATIVE directives Alexandre Chartre
2020-04-07 13:28 ` Peter Zijlstra
2020-04-07 13:34 ` Josh Poimboeuf
2020-04-07 14:32 ` Alexandre Chartre
2020-04-07 16:18 ` Alexandre Chartre
2020-04-07 16:28 ` Josh Poimboeuf
2020-04-07 17:01 ` Alexandre Chartre
2020-04-07 17:26 ` Peter Zijlstra
2020-04-07 17:27 ` Peter Zijlstra
2020-04-08 21:35 ` Peter Zijlstra
2020-04-09 8:18 ` Alexandre Chartre
2020-04-09 10:34 ` Peter Zijlstra
2020-04-09 10:40 ` Peter Zijlstra [this message]
2020-04-07 16:41 ` Peter Zijlstra
2020-04-07 17:04 ` Alexandre Chartre
2020-04-07 13:52 ` Peter Zijlstra
2020-04-07 13:59 ` Peter Zijlstra
2020-04-07 13:35 ` [PATCH V2 0/9] objtool changes to remove all ANNOTATE_NOSPEC_ALTERNATIVE Josh Poimboeuf
2020-04-07 14:02 ` Alexandre Chartre
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