Commit 7edfe3df authored by Alan Mikhak's avatar Alan Mikhak Committed by Vinod Koul
Browse files

dmaengine: dw-edma: Check MSI descriptor before copying 



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.

Reported-by: default avatarkbuild test robot <lkp@intel.com>
Signed-off-by: default avatarAlan Mikhak <alan.mikhak@sifive.com>
Acked-by: default avatarGustavo Pimentel <gustavo.pimentel@synopsys.com>
Link: https://lore.kernel.org/r/1587607101-31914-1-git-send-email-alan.mikhak@sifive.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent db474931

drivers/dma/dw-edma/dw-edma-core.c

+10 −7
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <linux/dmaengine.h>

#include <linux/err.h>

#include <linux/interrupt.h>

#include <linux/irq.h>

#include <linux/dma/edma.h>

#include <linux/dma-mapping.h>
@@ -773,6 +774,7 @@ 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 +783,16 @@ 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 +806,8 @@ 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 +818,8 @@ 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;