linux-kernel - [PATCH v5 01/13] x86/irqflags: Provide native versions of the local_irq

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: <c4c33c0d07200164a3dd8cfd6da0344f57732648.1717600736.git.thomas.lendacky@amd.com>
Date: Wed, 5 Jun 2024 10:18:44 -0500
From: Tom Lendacky <thomas.lendacky@....com>
To: <linux-kernel@...r.kernel.org>, <x86@...nel.org>,
	<linux-coco@...ts.linux.dev>, <svsm-devel@...onut-svsm.dev>
CC: Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>,
	Borislav Petkov <bp@...en8.de>, Dave Hansen <dave.hansen@...ux.intel.com>,
	"H. Peter Anvin" <hpa@...or.com>, Andy Lutomirski <luto@...nel.org>, "Peter
 Zijlstra" <peterz@...radead.org>, Dan Williams <dan.j.williams@...el.com>,
	Michael Roth <michael.roth@....com>, Ashish Kalra <ashish.kalra@....com>
Subject: [PATCH v5 01/13] x86/irqflags: Provide native versions of the local_irq_save()/restore()

Functions that need to disable IRQs, but are common to both early boot and
post-boot execution, are unable to deal with paravirt support associated
with local_irq_save() and local_irq_restore().

Create native versions of these for use in these situations.

Signed-off-by: Tom Lendacky <thomas.lendacky@....com>
---
 arch/x86/include/asm/irqflags.h | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h
index 8c5ae649d2df..cf7fc2b8e3ce 100644
--- a/arch/x86/include/asm/irqflags.h
+++ b/arch/x86/include/asm/irqflags.h
@@ -54,6 +54,26 @@ static __always_inline void native_halt(void)
 	asm volatile("hlt": : :"memory");
 }
 
+static __always_inline int native_irqs_disabled_flags(unsigned long flags)
+{
+	return !(flags & X86_EFLAGS_IF);
+}
+
+static __always_inline unsigned long native_local_irq_save(void)
+{
+	unsigned long flags = native_save_fl();
+
+	native_irq_disable();
+
+	return flags;
+}
+
+static __always_inline void native_local_irq_restore(unsigned long flags)
+{
+	if (!native_irqs_disabled_flags(flags))
+		native_irq_enable();
+}
+
 #endif
 
 #ifdef CONFIG_PARAVIRT_XXL
-- 
2.43.2