linux-kernel - [PATCH AUTOSEL 5.2 01/85] ARM: riscpc: fix DMA

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

Message-Id: <20190726133936.11177-1-sashal@kernel.org>
Date:   Fri, 26 Jul 2019 09:38:11 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Russell King <rmk+kernel@...linux.org.uk>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH AUTOSEL 5.2 01/85] ARM: riscpc: fix DMA

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

[ Upstream commit ffd9a1ba9fdb7f2bd1d1ad9b9243d34e96756ba2 ]

DMA got broken a while back in two different ways:
1) a change in the behaviour of disable_irq() to wait for the interrupt
   to finish executing causes us to deadlock at the end of DMA.
2) a change to avoid modifying the scatterlist left the first transfer
   uninitialised.

DMA is only used with expansion cards, so has gone unnoticed.

Fixes: fa4e99899932 ("[ARM] dma: RiscPC: don't modify DMA SG entries")
Signed-off-by: Russell King <rmk+kernel@...linux.org.uk>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 arch/arm/mach-rpc/dma.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-rpc/dma.c b/arch/arm/mach-rpc/dma.c
index 488d5c3b37f4..799e0b016b62 100644
--- a/arch/arm/mach-rpc/dma.c
+++ b/arch/arm/mach-rpc/dma.c
@@ -128,7 +128,7 @@ static irqreturn_t iomd_dma_handle(int irq, void *dev_id)
 	} while (1);
 
 	idma->state = ~DMA_ST_AB;
-	disable_irq(irq);
+	disable_irq_nosync(irq);
 
 	return IRQ_HANDLED;
 }
@@ -177,6 +177,9 @@ static void iomd_enable_dma(unsigned int chan, dma_t *dma)
 				DMA_FROM_DEVICE : DMA_TO_DEVICE);
 		}
 
+		idma->dma_addr = idma->dma.sg->dma_address;
+		idma->dma_len = idma->dma.sg->length;
+
 		iomd_writeb(DMA_CR_C, dma_base + CR);
 		idma->state = DMA_ST_AB;
 	}
-- 
2.20.1