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Message-Id: <1587406568-26592-1-git-send-email-alan.mikhak@sifive.com>
Date: Mon, 20 Apr 2020 11:16:08 -0700
From: Alan Mikhak <alan.mikhak@...ive.com>
To: dmaengine@...r.kernel.org, linux-kernel@...r.kernel.org,
linux-pci@...r.kernel.org, gustavo.pimentel@...opsys.com,
dan.j.williams@...el.com, vkoul@...nel.org, kishon@...com,
maz@...nel.org, paul.walmsley@...ive.com
Cc: Alan Mikhak <alan.mikhak@...ive.com>
Subject: [PATCH] dmaengine: dw-edma: Check MSI descriptor before copying
From: Alan Mikhak <alan.mikhak@...ive.com>
Modify dw_edma_irq_request() to check if a struct msi_desc entry exists
before copying the contents of its struct msi_msg pointer.
Without this sanity check, __get_cached_msi_msg() crashes when invoked by
dw_edma_irq_request() running on a Linux-based PCIe endpoint device. MSI
interrupt are not received by PCIe endpoint devices. If irq_get_msi_desc()
returns null, then there is no cached struct msi_msg to be copied.
This patch depends on the following patch:
[PATCH v2] dmaengine: dw-edma: Decouple dw-edma-core.c from struct pci_dev
https://patchwork.kernel.org/patch/11491757/
Signed-off-by: Alan Mikhak <alan.mikhak@...ive.com>
---
drivers/dma/dw-edma/dw-edma-core.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index db401eb11322..a5d15f6ed5eb 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -773,6 +773,7 @@ static int dw_edma_irq_request(struct dw_edma_chip *chip,
u32 rd_mask = 1;
int i, err = 0;
u32 ch_cnt;
+ int irq;
ch_cnt = dw->wr_ch_cnt + dw->rd_ch_cnt;
@@ -781,16 +782,16 @@ static int dw_edma_irq_request(struct dw_edma_chip *chip,
if (dw->nr_irqs == 1) {
/* Common IRQ shared among all channels */
- err = request_irq(dw->ops->irq_vector(dev, 0),
- dw_edma_interrupt_common,
+ irq = dw->ops->irq_vector(dev, 0);
+ err = request_irq(irq, dw_edma_interrupt_common,
IRQF_SHARED, dw->name, &dw->irq[0]);
if (err) {
dw->nr_irqs = 0;
return err;
}
- get_cached_msi_msg(dw->ops->irq_vector(dev, 0),
- &dw->irq[0].msi);
+ if (irq_get_msi_desc(irq))
+ get_cached_msi_msg(irq, &dw->irq[0].msi);
} else {
/* Distribute IRQs equally among all channels */
int tmp = dw->nr_irqs;
@@ -804,7 +805,8 @@ static int dw_edma_irq_request(struct dw_edma_chip *chip,
dw_edma_add_irq_mask(&rd_mask, *rd_alloc, dw->rd_ch_cnt);
for (i = 0; i < (*wr_alloc + *rd_alloc); i++) {
- err = request_irq(dw->ops->irq_vector(dev, i),
+ irq = dw->ops->irq_vector(dev, i);
+ err = request_irq(irq,
i < *wr_alloc ?
dw_edma_interrupt_write :
dw_edma_interrupt_read,
@@ -815,8 +817,8 @@ static int dw_edma_irq_request(struct dw_edma_chip *chip,
return err;
}
- get_cached_msi_msg(dw->ops->irq_vector(dev, i),
- &dw->irq[i].msi);
+ if (irq_get_msi_desc(irq))
+ get_cached_msi_msg(irq, &dw->irq[i].msi);
}
dw->nr_irqs = i;
--
2.7.4
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