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From: David Long <dave.long@linaro.org>
To: <stable@vger.kernel.org>,
	Russell King - ARM Linux <linux@armlinux.org.uk>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Tony Lindgren <tony@atomide.com>,
	Marc Zyngier <marc.zyngier@arm.com>,
	Mark Rutland <mark.rutland@arm.com>
Cc: Greg KH <gregkh@linuxfoundation.org>, Mark Brown <broonie@kernel.org>
Subject: [PATCH 4.14 17/24] ARM: spectre-v1: add array_index_mask_nospec() implementation
Date: Mon, 15 Oct 2018 11:32:11 -0400	[thread overview]
Message-ID: <1539617538-22328-18-git-send-email-dave.long@linaro.org> (raw)
In-Reply-To: <1539617538-22328-1-git-send-email-dave.long@linaro.org>

From: Russell King <rmk+kernel@armlinux.org.uk>

Commit 1d4238c56f9816ce0f9c8dbe42d7f2ad81cb6613 upstream.

Add an implementation of the array_index_mask_nospec() function for
mitigating Spectre variant 1 throughout the kernel.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
---
 arch/arm/include/asm/barrier.h | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/arch/arm/include/asm/barrier.h b/arch/arm/include/asm/barrier.h
index 3d9c1d4..69772e7 100644
--- a/arch/arm/include/asm/barrier.h
+++ b/arch/arm/include/asm/barrier.h
@@ -76,6 +76,25 @@ extern void arm_heavy_mb(void);
 #define __smp_rmb()	__smp_mb()
 #define __smp_wmb()	dmb(ishst)
 
+#ifdef CONFIG_CPU_SPECTRE
+static inline unsigned long array_index_mask_nospec(unsigned long idx,
+						    unsigned long sz)
+{
+	unsigned long mask;
+
+	asm volatile(
+		"cmp	%1, %2\n"
+	"	sbc	%0, %1, %1\n"
+	CSDB
+	: "=r" (mask)
+	: "r" (idx), "Ir" (sz)
+	: "cc");
+
+	return mask;
+}
+#define array_index_mask_nospec array_index_mask_nospec
+#endif
+
 #include <asm-generic/barrier.h>
 
 #endif /* !__ASSEMBLY__ */
-- 
2.5.0

  parent reply	other threads:[~2018-10-15 23:18 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-15 15:31 [PATCH 4.14 00/24] V4.14 backport of 32-bit arm spectre patches David Long
2018-10-15 15:31 ` [PATCH 4.14 01/24] ARM: add more CPU part numbers for Cortex and Brahma B15 CPUs David Long
2018-10-15 15:31 ` [PATCH 4.14 02/24] ARM: bugs: prepare processor bug infrastructure David Long
2018-10-15 15:31 ` [PATCH 4.14 03/24] ARM: bugs: hook processor bug checking into SMP and suspend paths David Long
2018-10-15 15:31 ` [PATCH 4.14 04/24] ARM: bugs: add support for per-processor bug checking David Long
2018-10-15 15:31 ` [PATCH 4.14 05/24] ARM: spectre: add Kconfig symbol for CPUs vulnerable to Spectre David Long
2018-10-15 15:32 ` [PATCH 4.14 06/24] ARM: spectre-v2: harden branch predictor on context switches David Long
2018-10-15 15:32 ` [PATCH 4.14 07/24] ARM: spectre-v2: add Cortex A8 and A15 validation of the IBE bit David Long
2018-10-15 15:32 ` [PATCH 4.14 08/24] ARM: spectre-v2: harden user aborts in kernel space David Long
2018-10-15 15:32 ` [PATCH 4.14 09/24] ARM: spectre-v2: add firmware based hardening David Long
2018-10-15 15:32 ` [PATCH 4.14 10/24] ARM: spectre-v2: warn about incorrect context switching functions David Long
2018-10-15 15:32 ` [PATCH 4.14 11/24] ARM: KVM: invalidate BTB on guest exit for Cortex-A12/A17 David Long
2018-10-15 15:32 ` [PATCH 4.14 12/24] ARM: KVM: invalidate icache on guest exit for Cortex-A15 David Long
2018-10-15 15:32 ` [PATCH 4.14 13/24] ARM: spectre-v2: KVM: invalidate icache on guest exit for Brahma B15 David Long
2018-10-15 15:32 ` [PATCH 4.14 14/24] ARM: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling David Long
2018-10-15 15:32 ` [PATCH 4.14 15/24] ARM: KVM: report support for SMCCC_ARCH_WORKAROUND_1 David Long
2018-10-15 15:32 ` [PATCH 4.14 16/24] ARM: spectre-v1: add speculation barrier (csdb) macros David Long
2018-10-15 15:32 ` David Long [this message]
2018-10-15 15:32 ` [PATCH 4.14 18/24] ARM: spectre-v1: fix syscall entry David Long
2018-10-15 15:32 ` [PATCH 4.14 19/24] ARM: signal: copy registers using __copy_from_user() David Long
2018-10-15 15:32 ` [PATCH 4.14 20/24] ARM: vfp: use __copy_from_user() when restoring VFP state David Long
2018-10-15 15:32 ` [PATCH 4.14 21/24] ARM: oabi-compat: copy semops using __copy_from_user() David Long
2018-10-15 15:32 ` [PATCH 4.14 22/24] ARM: use __inttype() in get_user() David Long
2018-10-15 15:32 ` [PATCH 4.14 23/24] ARM: spectre-v1: use get_user() for __get_user() David Long
2018-10-15 15:32 ` [PATCH 4.14 24/24] ARM: spectre-v1: mitigate user accesses David Long
2018-10-16 16:10 ` [PATCH 4.14 00/24] V4.14 backport of 32-bit arm spectre patches Greg KH

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