From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 1/9] arm64: barrier: Add CSDB macros to control data-value prediction
Date: Mon, 5 Feb 2018 15:34:16 +0000 [thread overview]
Message-ID: <1517844864-15887-2-git-send-email-will.deacon@arm.com> (raw)
In-Reply-To: <1517844864-15887-1-git-send-email-will.deacon@arm.com>
For CPUs capable of data value prediction, CSDB waits for any outstanding
predictions to architecturally resolve before allowing speculative execution
to continue. Provide macros to expose it to the arch code.
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
arch/arm64/include/asm/assembler.h | 7 +++++++
arch/arm64/include/asm/barrier.h | 1 +
2 files changed, 8 insertions(+)
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index 794fe8122602..709adde9e80f 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -116,6 +116,13 @@
.endm
/*
+ * Value prediction barrier
+ */
+ .macro csdb
+ hint #20
+ .endm
+
+/*
* NOP sequence
*/
.macro nops, num
diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h
index 77651c49ef44..c0a846d2c602 100644
--- a/arch/arm64/include/asm/barrier.h
+++ b/arch/arm64/include/asm/barrier.h
@@ -32,6 +32,7 @@
#define dsb(opt) asm volatile("dsb " #opt : : : "memory")
#define psb_csync() asm volatile("hint #17" : : : "memory")
+#define csdb() asm volatile("hint #20" : : : "memory")
#define mb() dsb(sy)
#define rmb() dsb(ld)
--
2.1.4
next prev parent reply other threads:[~2018-02-05 15:34 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-05 15:34 [PATCH 0/9] Mitigations against spectre-v1 in the arm64 Linux kernel Will Deacon
2018-02-05 15:34 ` Will Deacon [this message]
2018-02-05 15:34 ` [PATCH 2/9] arm64: Implement array_index_mask_nospec() Will Deacon
2018-02-05 15:34 ` [PATCH 3/9] arm64: Make USER_DS an inclusive limit Will Deacon
2018-02-05 15:34 ` [PATCH 4/9] arm64: Use pointer masking to limit uaccess speculation Will Deacon
2018-02-05 15:34 ` [PATCH 5/9] arm64: entry: Ensure branch through syscall table is bounded under speculation Will Deacon
2018-02-05 15:34 ` [PATCH 6/9] arm64: uaccess: Prevent speculative use of the current addr_limit Will Deacon
2018-02-05 15:34 ` [PATCH 7/9] arm64: uaccess: Don't bother eliding access_ok checks in __{get, put}_user Will Deacon
2018-02-05 15:34 ` [PATCH 8/9] arm64: uaccess: Mask __user pointers for __arch_{clear, copy_*}_user Will Deacon
2018-02-05 15:34 ` [PATCH 9/9] arm64: futex: Mask __user pointers prior to dereference Will Deacon
2018-02-06 22:17 ` [PATCH 0/9] Mitigations against spectre-v1 in the arm64 Linux kernel Catalin Marinas
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