linux-kernel - [PATCH v14 09/13] x86/mm: global ASID process exit helpers

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

Message-ID: <20250226030129.530345-10-riel@surriel.com>
Date: Tue, 25 Feb 2025 22:00:44 -0500
From: Rik van Riel <riel@...riel.com>
To: x86@...nel.org
Cc: linux-kernel@...r.kernel.org,
	bp@...en8.de,
	peterz@...radead.org,
	dave.hansen@...ux.intel.com,
	zhengqi.arch@...edance.com,
	nadav.amit@...il.com,
	thomas.lendacky@....com,
	kernel-team@...a.com,
	linux-mm@...ck.org,
	akpm@...ux-foundation.org,
	jackmanb@...gle.com,
	jannh@...gle.com,
	mhklinux@...look.com,
	andrew.cooper3@...rix.com,
	Manali.Shukla@....com,
	mingo@...nel.org,
	Rik van Riel <riel@...riel.com>
Subject: [PATCH v14 09/13] x86/mm: global ASID process exit helpers

A global ASID is allocated for the lifetime of a process.

Free the global ASID at process exit time.

Signed-off-by: Rik van Riel <riel@...riel.com>
---
 arch/x86/include/asm/mmu_context.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h
index a2c70e495b1b..b47ac6d270e6 100644
--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -163,6 +163,14 @@ static inline int init_new_context(struct task_struct *tsk,
 		mm->context.execute_only_pkey = -1;
 	}
 #endif
+
+#ifdef CONFIG_X86_BROADCAST_TLB_FLUSH
+	if (cpu_feature_enabled(X86_FEATURE_INVLPGB)) {
+		mm->context.global_asid = 0;
+		mm->context.asid_transition = false;
+	}
+#endif
+
 	mm_reset_untag_mask(mm);
 	init_new_context_ldt(mm);
 	return 0;
@@ -172,6 +180,10 @@ static inline int init_new_context(struct task_struct *tsk,
 static inline void destroy_context(struct mm_struct *mm)
 {
 	destroy_context_ldt(mm);
+#ifdef CONFIG_X86_BROADCAST_TLB_FLUSH
+	if (cpu_feature_enabled(X86_FEATURE_INVLPGB))
+		mm_free_global_asid(mm);
+#endif
 }
 
 extern void switch_mm(struct mm_struct *prev, struct mm_struct *next,
-- 
2.47.1