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From: Peter Zijlstra <peterz@infradead.org>
To: x86@kernel.org
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
	David.Kaplan@amd.com, Andrew.Cooper3@citrix.com,
	jpoimboe@kernel.org, gregkh@linuxfoundation.org,
	nik.borisov@suse.com
Subject: [PATCH v2 04/11] x86/alternative: Make custom return thunk unconditional
Date: Mon, 14 Aug 2023 13:44:30 +0200	[thread overview]
Message-ID: <20230814121148.775293785@infradead.org> (raw)
In-Reply-To: 20230814114426.057251214@infradead.org

There is infrastructure to rewrite return thunks to point to any
random thunk one desires, unwrap that from CALL_THUNKS, which up to
now was the sole user of that.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/x86/include/asm/nospec-branch.h |    4 ----
 arch/x86/kernel/alternative.c        |    2 --
 2 files changed, 6 deletions(-)

--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -347,11 +347,7 @@ extern void srso_untrain_ret(void);
 extern void srso_untrain_ret_alias(void);
 extern void entry_ibpb(void);
 
-#ifdef CONFIG_CALL_THUNKS
 extern void (*x86_return_thunk)(void);
-#else
-#define x86_return_thunk	(&__x86_return_thunk)
-#endif
 
 #ifdef CONFIG_CALL_DEPTH_TRACKING
 extern void __x86_return_skl(void);
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -687,9 +687,7 @@ void __init_or_module noinline apply_ret
 
 #ifdef CONFIG_RETHUNK
 
-#ifdef CONFIG_CALL_THUNKS
 void (*x86_return_thunk)(void) __ro_after_init = &__x86_return_thunk;
-#endif
 
 /*
  * Rewrite the compiler generated return thunk tail-calls.



  parent reply	other threads:[~2023-08-14 12:20 UTC|newest]

Thread overview: 74+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-14 11:44 [PATCH v2 00/11] Fix up SRSO stuff Peter Zijlstra
2023-08-14 11:44 ` [PATCH v2 01/11] x86/cpu: Fixup __x86_return_thunk Peter Zijlstra
2023-08-16  7:55   ` [tip: x86/urgent] x86/cpu: Fix __x86_return_thunk symbol type tip-bot2 for Peter Zijlstra
2023-08-14 11:44 ` [PATCH v2 02/11] x86/cpu: Fix up srso_safe_ret() and __x86_return_thunk() Peter Zijlstra
2023-08-16  7:55   ` [tip: x86/urgent] " tip-bot2 for Peter Zijlstra
2023-08-14 11:44 ` [PATCH v2 03/11] objtool/x86: Fix SRSO mess Peter Zijlstra
2023-08-14 12:54   ` Andrew.Cooper3
2023-08-16  7:55   ` [tip: x86/urgent] " tip-bot2 for Peter Zijlstra
2023-08-16 11:59     ` Peter Zijlstra
2023-08-16 20:31       ` Josh Poimboeuf
2023-08-16 22:08         ` [PATCH] objtool/x86: Fixup frame-pointer vs rethunk Peter Zijlstra
2023-08-16 22:22           ` Josh Poimboeuf
2023-08-17  8:39       ` [tip: x86/urgent] " tip-bot2 for Peter Zijlstra
2023-08-14 11:44 ` Peter Zijlstra [this message]
2023-08-16  7:55   ` [tip: x86/urgent] x86/alternative: Make custom return thunk unconditional tip-bot2 for Peter Zijlstra
2023-08-14 11:44 ` [PATCH v2 05/11] x86/cpu: Clean up SRSO return thunk mess Peter Zijlstra
2023-08-14 13:02   ` Borislav Petkov
2023-08-14 17:48   ` Borislav Petkov
2023-08-15 21:29   ` Nathan Chancellor
2023-08-15 22:43     ` Peter Zijlstra
2023-08-16  7:38       ` Borislav Petkov
2023-08-16 14:52         ` Nathan Chancellor
2023-08-16 15:08           ` Borislav Petkov
2023-08-16  7:55   ` [tip: x86/urgent] " tip-bot2 for Peter Zijlstra
2023-08-16 18:58     ` Nathan Chancellor
2023-08-16 19:24       ` Borislav Petkov
2023-08-16 19:30         ` Nathan Chancellor
2023-08-16 19:42           ` Borislav Petkov
2023-08-16 19:57             ` Borislav Petkov
2023-08-16 21:20   ` tip-bot2 for Peter Zijlstra
2023-08-14 11:44 ` [PATCH v2 06/11] x86/cpu: Rename original retbleed methods Peter Zijlstra
2023-08-14 19:41   ` Josh Poimboeuf
2023-08-16  7:55   ` [tip: x86/urgent] " tip-bot2 for Peter Zijlstra
2023-08-16 21:20   ` tip-bot2 for Peter Zijlstra
2023-08-14 11:44 ` [PATCH v2 07/11] x86/cpu: Rename srso_(.*)_alias to srso_alias_\1 Peter Zijlstra
2023-08-16  7:55   ` [tip: x86/urgent] " tip-bot2 for Peter Zijlstra
2023-08-16 21:20   ` tip-bot2 for Peter Zijlstra
2023-08-14 11:44 ` [PATCH v2 08/11] x86/cpu: Cleanup the untrain mess Peter Zijlstra
2023-08-16  7:55   ` [tip: x86/urgent] " tip-bot2 for Peter Zijlstra
2023-08-16 21:20   ` tip-bot2 for Peter Zijlstra
2023-08-14 11:44 ` [PATCH v2 09/11] x86/cpu/kvm: Provide UNTRAIN_RET_VM Peter Zijlstra
2023-08-16  7:55   ` [tip: x86/urgent] " tip-bot2 for Peter Zijlstra
2023-08-16 21:20   ` tip-bot2 for Peter Zijlstra
2023-08-14 11:44 ` [PATCH v2 10/11] x86/alternatives: Simplify ALTERNATIVE_n() Peter Zijlstra
2023-08-15 20:49   ` Nikolay Borisov
2023-08-15 22:44     ` Peter Zijlstra
2023-09-07  8:31   ` Borislav Petkov
2023-09-07 11:09     ` Peter Zijlstra
2023-09-07 11:11       ` Peter Zijlstra
2023-09-07 11:16         ` Peter Zijlstra
2023-09-07 15:06       ` Borislav Petkov
2023-09-07 15:30         ` Borislav Petkov
2023-09-09  7:50           ` Borislav Petkov
2023-09-09  9:25             ` Peter Zijlstra
2023-09-09  9:42               ` Peter Zijlstra
2023-09-10 14:42               ` Borislav Petkov
2023-09-12  9:27                 ` Peter Zijlstra
2023-09-12  9:44                   ` Peter Zijlstra
2023-09-13  4:37                     ` Borislav Petkov
2023-09-13  8:46                       ` Peter Zijlstra
2023-09-13 14:38                         ` Borislav Petkov
2023-09-13 16:14                           ` Peter Zijlstra
2023-09-15  7:46                           ` Peter Zijlstra
2023-09-15  7:51                             ` Peter Zijlstra
2023-09-15 12:05                               ` Borislav Petkov
2023-09-13  4:24                   ` Borislav Petkov
2023-08-14 11:44 ` [PATCH v2 11/11] x86/cpu: Use fancy alternatives to get rid of entry_untrain_ret() Peter Zijlstra
2023-08-14 16:44 ` [PATCH v2 00/11] Fix up SRSO stuff Borislav Petkov
2023-08-14 19:51   ` Josh Poimboeuf
2023-08-14 19:57     ` Borislav Petkov
2023-08-14 20:01     ` Josh Poimboeuf
2023-08-14 20:09       ` Borislav Petkov
2023-08-15 14:26         ` [PATCH] x86/srso: Explain the untraining sequences a bit more Borislav Petkov
2023-08-15 15:41           ` Nikolay Borisov

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