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From: Peter Zijlstra <peterz@infradead.org>
To: x86@kernel.org, jpoimboe@redhat.com, brgerst@gmail.com,
	jiangshanlai@gmail.com, Andrew.Cooper3@citrix.com
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org
Subject: [PATCH 1/2] x86: Simplify Retpoline thunk
Date: Tue, 19 Apr 2022 22:41:10 +0200	[thread overview]
Message-ID: <20220419205241.280037046@infradead.org> (raw)
In-Reply-To: 20220419204109.520779286@infradead.org

Now that we rewrite all the indirect call sites, per commit:

  750850090081 ("x86/alternative: Implement .retpoline_sites support")

it doesn't make sense to have the retpoline thunks be an ALTERNATIVE_2
that still includes a 'naked' indirect jump.

(this accidentally 'defunnels' i386 by going back to full retpolines)

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/x86/lib/retpoline.S |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/arch/x86/lib/retpoline.S
+++ b/arch/x86/lib/retpoline.S
@@ -32,9 +32,9 @@
 SYM_INNER_LABEL(__x86_indirect_thunk_\reg, SYM_L_GLOBAL)
 	UNWIND_HINT_EMPTY
 
-	ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), \
-		      __stringify(RETPOLINE \reg), X86_FEATURE_RETPOLINE, \
-		      __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; jmp *%\reg; int3), X86_FEATURE_RETPOLINE_LFENCE
+	ALTERNATIVE __stringify(RETPOLINE \reg), \
+		    __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; jmp *%\reg; int3), \
+		    X86_FEATURE_RETPOLINE_LFENCE
 
 .endm
 



  reply	other threads:[~2022-04-19 20:54 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-19 20:41 [PATCH 0/2] x86: A few random cleanups Peter Zijlstra
2022-04-19 20:41 ` Peter Zijlstra [this message]
2022-04-20 15:27   ` [PATCH 1/2] x86: Simplify Retpoline thunk Josh Poimboeuf
2022-04-20 15:51     ` Peter Zijlstra
2022-04-20 16:01       ` Josh Poimboeuf
2022-04-19 20:41 ` [PATCH 2/2] x86,entry: Use PUSH_AND_CLEAR_REGS for compat Peter Zijlstra
2022-04-20  3:21   ` Josh Poimboeuf
2022-04-20  7:07     ` Peter Zijlstra
2022-04-20 14:58       ` Josh Poimboeuf
2022-04-20  4:29   ` Lai Jiangshan
2022-04-20 14:26   ` Andy Lutomirski
2022-04-20 14:51     ` Peter Zijlstra

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