2020-04-20 18:17:51

by Alan Mikhak

[permalink] [raw]
Subject: [PATCH] dmaengine: dw-edma: Check MSI descriptor before copying

From: Alan Mikhak <[email protected]>

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 <[email protected]>
---
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


2020-04-22 21:04:08

by kernel test robot

[permalink] [raw]
Subject: Re: [PATCH] dmaengine: dw-edma: Check MSI descriptor before copying

Hi Alan,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on slave-dma/next]
[also build test WARNING on next-20200421]
[cannot apply to linus/master linux/master v5.7-rc2]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url: https://github.com/0day-ci/linux/commits/Alan-Mikhak/dmaengine-dw-edma-Check-MSI-descriptor-before-copying/20200422-131121
base: https://git.kernel.org/pub/scm/linux/kernel/git/vkoul/slave-dma.git next
config: x86_64-randconfig-f003-20200422 (attached as .config)
compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64

If you fix the issue, kindly add following tag as appropriate
Reported-by: kbuild test robot <[email protected]>

All warnings (new ones prefixed by >>):

In file included from include/linux/export.h:43:0,
from include/linux/linkage.h:7,
from include/linux/kernel.h:8,
from include/linux/list.h:9,
from include/linux/module.h:12,
from drivers/dma/dw-edma/dw-edma-core.c:9:
drivers/dma/dw-edma/dw-edma-core.c: In function 'dw_edma_irq_request':
drivers/dma/dw-edma/dw-edma-core.c:793:7: error: implicit declaration of function 'irq_get_msi_desc'; did you mean 'irq_to_desc'? [-Werror=implicit-function-declaration]
if (irq_get_msi_desc(irq))
^
include/linux/compiler.h:58:52: note: in definition of macro '__trace_if_var'
#define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
^~~~
>> drivers/dma/dw-edma/dw-edma-core.c:793:3: note: in expansion of macro 'if'
if (irq_get_msi_desc(irq))
^~
cc1: some warnings being treated as errors

vim +/if +793 drivers/dma/dw-edma/dw-edma-core.c

766
767 static int dw_edma_irq_request(struct dw_edma_chip *chip,
768 u32 *wr_alloc, u32 *rd_alloc)
769 {
770 struct device *dev = chip->dev;
771 struct dw_edma *dw = chip->dw;
772 u32 wr_mask = 1;
773 u32 rd_mask = 1;
774 int i, err = 0;
775 u32 ch_cnt;
776 int irq;
777
778 ch_cnt = dw->wr_ch_cnt + dw->rd_ch_cnt;
779
780 if (dw->nr_irqs < 1)
781 return -EINVAL;
782
783 if (dw->nr_irqs == 1) {
784 /* Common IRQ shared among all channels */
785 irq = dw->ops->irq_vector(dev, 0);
786 err = request_irq(irq, dw_edma_interrupt_common,
787 IRQF_SHARED, dw->name, &dw->irq[0]);
788 if (err) {
789 dw->nr_irqs = 0;
790 return err;
791 }
792
> 793 if (irq_get_msi_desc(irq))
794 get_cached_msi_msg(irq, &dw->irq[0].msi);
795 } else {
796 /* Distribute IRQs equally among all channels */
797 int tmp = dw->nr_irqs;
798
799 while (tmp && (*wr_alloc + *rd_alloc) < ch_cnt) {
800 dw_edma_dec_irq_alloc(&tmp, wr_alloc, dw->wr_ch_cnt);
801 dw_edma_dec_irq_alloc(&tmp, rd_alloc, dw->rd_ch_cnt);
802 }
803
804 dw_edma_add_irq_mask(&wr_mask, *wr_alloc, dw->wr_ch_cnt);
805 dw_edma_add_irq_mask(&rd_mask, *rd_alloc, dw->rd_ch_cnt);
806
807 for (i = 0; i < (*wr_alloc + *rd_alloc); i++) {
808 irq = dw->ops->irq_vector(dev, i);
809 err = request_irq(irq,
810 i < *wr_alloc ?
811 dw_edma_interrupt_write :
812 dw_edma_interrupt_read,
813 IRQF_SHARED, dw->name,
814 &dw->irq[i]);
815 if (err) {
816 dw->nr_irqs = i;
817 return err;
818 }
819
820 if (irq_get_msi_desc(irq))
821 get_cached_msi_msg(irq, &dw->irq[i].msi);
822 }
823
824 dw->nr_irqs = i;
825 }
826
827 return err;
828 }
829

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/[email protected]


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2020-04-22 22:42:11

by kernel test robot

[permalink] [raw]
Subject: Re: [PATCH] dmaengine: dw-edma: Check MSI descriptor before copying

Hi Alan,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on slave-dma/next]
[also build test ERROR on next-20200421]
[cannot apply to linus/master linux/master v5.7-rc2]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url: https://github.com/0day-ci/linux/commits/Alan-Mikhak/dmaengine-dw-edma-Check-MSI-descriptor-before-copying/20200422-131121
base: https://git.kernel.org/pub/scm/linux/kernel/git/vkoul/slave-dma.git next
config: s390-allmodconfig (attached as .config)
compiler: s390-linux-gcc (GCC) 9.3.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day GCC_VERSION=9.3.0 make.cross ARCH=s390

If you fix the issue, kindly add following tag as appropriate
Reported-by: kbuild test robot <[email protected]>

All errors (new ones prefixed by >>):

drivers/dma/dw-edma/dw-edma-core.c: In function 'dw_edma_irq_request':
>> drivers/dma/dw-edma/dw-edma-core.c:793:7: error: implicit declaration of function 'irq_get_msi_desc'; did you mean 'irq_to_desc'? [-Werror=implicit-function-declaration]
793 | if (irq_get_msi_desc(irq))
| ^~~~~~~~~~~~~~~~
| irq_to_desc
cc1: some warnings being treated as errors

vim +793 drivers/dma/dw-edma/dw-edma-core.c

766
767 static int dw_edma_irq_request(struct dw_edma_chip *chip,
768 u32 *wr_alloc, u32 *rd_alloc)
769 {
770 struct device *dev = chip->dev;
771 struct dw_edma *dw = chip->dw;
772 u32 wr_mask = 1;
773 u32 rd_mask = 1;
774 int i, err = 0;
775 u32 ch_cnt;
776 int irq;
777
778 ch_cnt = dw->wr_ch_cnt + dw->rd_ch_cnt;
779
780 if (dw->nr_irqs < 1)
781 return -EINVAL;
782
783 if (dw->nr_irqs == 1) {
784 /* Common IRQ shared among all channels */
785 irq = dw->ops->irq_vector(dev, 0);
786 err = request_irq(irq, dw_edma_interrupt_common,
787 IRQF_SHARED, dw->name, &dw->irq[0]);
788 if (err) {
789 dw->nr_irqs = 0;
790 return err;
791 }
792
> 793 if (irq_get_msi_desc(irq))
794 get_cached_msi_msg(irq, &dw->irq[0].msi);
795 } else {
796 /* Distribute IRQs equally among all channels */
797 int tmp = dw->nr_irqs;
798
799 while (tmp && (*wr_alloc + *rd_alloc) < ch_cnt) {
800 dw_edma_dec_irq_alloc(&tmp, wr_alloc, dw->wr_ch_cnt);
801 dw_edma_dec_irq_alloc(&tmp, rd_alloc, dw->rd_ch_cnt);
802 }
803
804 dw_edma_add_irq_mask(&wr_mask, *wr_alloc, dw->wr_ch_cnt);
805 dw_edma_add_irq_mask(&rd_mask, *rd_alloc, dw->rd_ch_cnt);
806
807 for (i = 0; i < (*wr_alloc + *rd_alloc); i++) {
808 irq = dw->ops->irq_vector(dev, i);
809 err = request_irq(irq,
810 i < *wr_alloc ?
811 dw_edma_interrupt_write :
812 dw_edma_interrupt_read,
813 IRQF_SHARED, dw->name,
814 &dw->irq[i]);
815 if (err) {
816 dw->nr_irqs = i;
817 return err;
818 }
819
820 if (irq_get_msi_desc(irq))
821 get_cached_msi_msg(irq, &dw->irq[i].msi);
822 }
823
824 dw->nr_irqs = i;
825 }
826
827 return err;
828 }
829

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/[email protected]


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