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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Sasha Levin <sashal@kernel.org>,
	Jean-Philippe Brucker <jean-philippe@linaro.org>,
	iommu@lists.linux-foundation.org, Will Deacon <will@kernel.org>,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH AUTOSEL 4.19 177/252] iommu/arm-smmu-v3: Use WRITE_ONCE() when changing validity of an STE
Date: Fri, 14 Feb 2020 11:10:32 -0500
Message-ID: <20200214161147.15842-177-sashal@kernel.org> (raw)
In-Reply-To: <20200214161147.15842-1-sashal@kernel.org>

From: Will Deacon <will@kernel.org>

[ Upstream commit d71e01716b3606a6648df7e5646ae12c75babde4 ]

If, for some bizarre reason, the compiler decided to split up the write
of STE DWORD 0, we could end up making a partial structure valid.

Although this probably won't happen, follow the example of the
context-descriptor code and use WRITE_ONCE() to ensure atomicity of the
write.

Reported-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iommu/arm-smmu-v3.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index eff1f3aa5ef43..6b7664052b5be 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -1185,7 +1185,8 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_device *smmu, u32 sid,
 	}
 
 	arm_smmu_sync_ste_for_sid(smmu, sid);
-	dst[0] = cpu_to_le64(val);
+	/* See comment in arm_smmu_write_ctx_desc() */
+	WRITE_ONCE(dst[0], cpu_to_le64(val));
 	arm_smmu_sync_ste_for_sid(smmu, sid);
 
 	/* It's likely that we'll want to use the new STE soon */
-- 
2.20.1


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Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20200214161147.15842-1-sashal@kernel.org>
2020-02-14 16:07 ` [PATCH AUTOSEL 4.19 004/252] soc: fsl: qe: change return type of cpm_muram_alloc() to s32 Sasha Levin
2020-02-14 16:08 ` [PATCH AUTOSEL 4.19 028/252] arm64: cpufeature: Fix the type of no FP/SIMD capability Sasha Levin
2020-02-14 16:08 ` [PATCH AUTOSEL 4.19 032/252] clocksource/drivers/bcm2835_timer: Fix memory leak of timer Sasha Levin
2020-02-14 16:08 ` [PATCH AUTOSEL 4.19 037/252] scsi: ufs: Fix ufshcd_probe_hba() reture value in case ufshcd_scsi_add_wlus() fails Sasha Levin
2020-02-14 16:08 ` [PATCH AUTOSEL 4.19 044/252] ARM: 8952/1: Disable kmemleak on XIP kernels Sasha Levin
2020-02-14 16:08 ` [PATCH AUTOSEL 4.19 081/252] arm64: dts: allwinner: H6: Add PMU mode Sasha Levin
2020-02-14 16:08 ` [PATCH AUTOSEL 4.19 082/252] arm: dts: allwinner: H3: Add PMU node Sasha Levin
2020-02-14 16:08 ` [PATCH AUTOSEL 4.19 083/252] ARM: dts: at91: Reenable UART TX pull-ups Sasha Levin
2020-02-14 16:09 ` [PATCH AUTOSEL 4.19 088/252] ARM: dts: imx6: rdu2: Disable WP for USDHC2 and USDHC3 Sasha Levin
2020-02-14 16:09 ` [PATCH AUTOSEL 4.19 089/252] ARM: dts: imx6: rdu2: Limit USBH1 to Full Speed Sasha Levin
2020-02-14 16:09 ` [PATCH AUTOSEL 4.19 091/252] PCI: iproc: Apply quirk_paxc_bridge() for module as well as built-in Sasha Levin
2020-02-14 16:09 ` [PATCH AUTOSEL 4.19 102/252] Revert "tty/serial: atmel: fix out of range clock divider handling" Sasha Levin
2020-02-14 16:09 ` [PATCH AUTOSEL 4.19 113/252] drm/mediatek: handle events when enabling/disabling crtc Sasha Levin
2020-02-14 16:09 ` [PATCH AUTOSEL 4.19 118/252] dmaengine: imx-sdma: Fix memory leak Sasha Levin
2020-02-14 16:09 ` [PATCH AUTOSEL 4.19 125/252] reset: uniphier: Add SCSSI reset control for each channel Sasha Levin
2020-02-14 16:09 ` [PATCH AUTOSEL 4.19 127/252] clk: sunxi-ng: add mux and pll notifiers for A64 CPU clock Sasha Levin
2020-02-14 16:09 ` [PATCH AUTOSEL 4.19 129/252] clk: uniphier: Add SCSSI clock gate for each channel Sasha Levin
2020-02-14 16:09 ` [PATCH AUTOSEL 4.19 137/252] soc: fsl: qe: remove set but not used variable 'mm_gc' Sasha Levin
2020-02-14 16:09 ` [PATCH AUTOSEL 4.19 139/252] crypto: atmel-sha - fix error handling when setting hmac key Sasha Levin
2020-02-14 16:09 ` [PATCH AUTOSEL 4.19 140/252] ARM: dts: stm32: Add power-supply for DSI panel on stm32f469-disco Sasha Levin
2020-02-14 16:09 ` [PATCH AUTOSEL 4.19 143/252] iommu/arm-smmu-v3: Populate VMID field for CMDQ_OP_TLBI_NH_VA Sasha Levin
2020-02-14 16:10 ` [PATCH AUTOSEL 4.19 148/252] ARM: dts: at91: sama5d3: fix maximum peripheral clock rates Sasha Levin
2020-02-14 16:10 ` [PATCH AUTOSEL 4.19 149/252] ARM: dts: at91: sama5d3: define clock rate range for tcb1 Sasha Levin
2020-02-14 16:10 ` [PATCH AUTOSEL 4.19 155/252] ASoC: atmel: fix build error with CONFIG_SND_ATMEL_SOC_DMA=m Sasha Levin
2020-02-14 16:10 ` [PATCH AUTOSEL 4.19 165/252] arm64: ptrace: nofpsimd: Fail FP/SIMD regset operations Sasha Levin
2020-02-14 16:10 ` Sasha Levin [this message]
2020-02-14 16:10 ` [PATCH AUTOSEL 4.19 181/252] arm64: fix alternatives with LLVM's integrated assembler Sasha Levin
2020-02-14 16:10 ` [PATCH AUTOSEL 4.19 186/252] ACPI/IORT: Fix 'Number of IDs' handling in iort_id_map() Sasha Levin
2020-02-14 16:11 ` [PATCH AUTOSEL 4.19 218/252] ARM: 8951/1: Fix Kexec compilation issue Sasha Levin

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