linux-kernel - [tip: x86/urgent] x86/speculation: Remove the extra #ifdef around CALL

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Message-ID: <174288816788.14745.10398589976376988106.tip-bot2@tip-bot2>
Date: Tue, 25 Mar 2025 07:36:07 -0000
From: "tip-bot2 for Pawan Gupta" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>,
 Ingo Molnar <mingo@...nel.org>, Josh Poimboeuf <jpoimboe@...nel.org>,
 x86@...nel.org, linux-kernel@...r.kernel.org
Subject:
 [tip: x86/urgent] x86/speculation: Remove the extra #ifdef around CALL_NOSPEC

The following commit has been merged into the x86/urgent branch of tip:

Commit-ID:     c8c81458863ab686cda4fe1e603fccaae0f12460
Gitweb:        https://git.kernel.org/tip/c8c81458863ab686cda4fe1e603fccaae0f12460
Author:        Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>
AuthorDate:    Thu, 20 Mar 2025 11:13:15 -07:00
Committer:     Ingo Molnar <mingo@...nel.org>
CommitterDate: Sat, 22 Mar 2025 08:41:47 +01:00

x86/speculation: Remove the extra #ifdef around CALL_NOSPEC

Commit:

  010c4a461c1d ("x86/speculation: Simplify and make CALL_NOSPEC consistent")

added an #ifdef CONFIG_MITIGATION_RETPOLINE around the CALL_NOSPEC definition.
This is not required as this code is already under a larger #ifdef.

Remove the extra #ifdef, no functional change.

vmlinux size remains same before and after this change:

 CONFIG_MITIGATION_RETPOLINE=y:
      text       data        bss         dec        hex    filename
  25434752    7342290    2301212    35078254    217406e    vmlinux.before
  25434752    7342290    2301212    35078254    217406e    vmlinux.after

 # CONFIG_MITIGATION_RETPOLINE is not set:
      text       data        bss         dec        hex    filename
  22943094    6214994    1550152    30708240    1d49210    vmlinux.before
  22943094    6214994    1550152    30708240    1d49210    vmlinux.after

Signed-off-by: Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@...nel.org>
Link: https://lore.kernel.org/r/20250320-call-nospec-extra-ifdef-v1-1-d9b084d24820@linux.intel.com
---
 arch/x86/include/asm/nospec-branch.h | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index 804b66a..29ea8fb 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -435,12 +435,8 @@ static inline void call_depth_return_thunk(void) {}
  * Inline asm uses the %V modifier which is only in newer GCC
  * which is ensured when CONFIG_MITIGATION_RETPOLINE is defined.
  */
-#ifdef CONFIG_MITIGATION_RETPOLINE
 #define CALL_NOSPEC	__CS_PREFIX("%V[thunk_target]")	\
 			"call __x86_indirect_thunk_%V[thunk_target]\n"
-#else
-#define CALL_NOSPEC	"call *%[thunk_target]\n"
-#endif
 
 # define THUNK_TARGET(addr) [thunk_target] "r" (addr)