linux-kernel - [PATCH] x86/mm: Inline mm_mangle_tif_spec_bits() and l1d_flush

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250623174355.9421-1-khaliidcaliy@gmail.com>
Date: Mon, 23 Jun 2025 17:43:25 +0000
From: Khalid Ali <khaliidcaliy@...il.com>
To: dave.hansen@...ux.intel.com,
	luto@...nel.org,
	peterz@...radead.org,
	tglx@...utronix.de,
	mingo@...hat.com,
	bp@...en8.de
Cc: x86@...nel.org,
	hpa@...or.com,
	linux-kernel@...r.kernel.org,
	Khalid Ali <khaliidcaliy@...il.com>
Subject: [PATCH] x86/mm: Inline mm_mangle_tif_spec_bits() and l1d_flush_evaluate()

From: Khalid Ali <khaliidcaliy@...il.com>

These two functions are called from performance critical path like context
switch.

So make sure the compiler optimizes out by inlining. This won't result
increase of size because these functions only have one call site.

Signed-off-by: Khalid Ali <khaliidcaliy@...il.com>
---
 arch/x86/mm/tlb.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index 39f80111e6f1..657e8e254b69 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -624,7 +624,7 @@ static void l1d_flush_force_sigbus(struct callback_head *ch)
 	force_sig(SIGBUS);
 }
 
-static void l1d_flush_evaluate(unsigned long prev_mm, unsigned long next_mm,
+static __always_inline void l1d_flush_evaluate(unsigned long prev_mm, unsigned long next_mm,
 				struct task_struct *next)
 {
 	/* Flush L1D if the outgoing task requests it */
@@ -648,7 +648,7 @@ static void l1d_flush_evaluate(unsigned long prev_mm, unsigned long next_mm,
 	}
 }
 
-static unsigned long mm_mangle_tif_spec_bits(struct task_struct *next)
+static __always_inline unsigned long mm_mangle_tif_spec_bits(struct task_struct *next)
 {
 	unsigned long next_tif = read_task_thread_flags(next);
 	unsigned long spec_bits = (next_tif >> TIF_SPEC_IB) & LAST_USER_MM_SPEC_MASK;
-- 
2.49.0