pci: add O_CLOEXEC when open uio device
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Commit Message
In this scenario, the DPDK process invokes a script which
inherits an open file descriptor (FD) for a UIO device.
After the script execution is complete, the UIO device's
close operation is called. However, in a new kernel version
(865a11f987ab5f03:uio/uio_pci_generic: Disable bus-mastering on release),
this close operation causes the PCI bus master bit to be cleared,
rendering the device unusable and leading to unexpected behavior.
This modification was made to prevent the UIO device's FD
from being inherited by the child process.
Cc: stable@dpdk.org
Signed-off-by: Weifeng Su <suweifeng1@huawei.com>
---
drivers/bus/pci/linux/pci_uio.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Comments
On Thu, 25 May 2023 11:00:35 +0800
Weifeng Su <suweifeng1@huawei.com> wrote:
> In this scenario, the DPDK process invokes a script which
> inherits an open file descriptor (FD) for a UIO device.
> After the script execution is complete, the UIO device's
> close operation is called. However, in a new kernel version
> (865a11f987ab5f03:uio/uio_pci_generic: Disable bus-mastering on release),
> this close operation causes the PCI bus master bit to be cleared,
> rendering the device unusable and leading to unexpected behavior.
> This modification was made to prevent the UIO device's FD
> from being inherited by the child process.
> Cc: stable@dpdk.org
>
> Signed-off-by: Weifeng Su <suweifeng1@huawei.com>
Makes sense that UIO fd's would be marked close on exec.
But should the interrupt fd, and all the other fd's which EAL leaves.
DPDK internal code doesn't invoke scripts. If your application is
going to do so then it needs to lots more cleanup. Probably some
variant of closing all fd's.
@@ -246,7 +246,7 @@ pci_uio_alloc_resource(struct rte_pci_device *dev,
snprintf(devname, sizeof(devname), "/dev/uio%u", uio_num);
/* save fd if in primary process */
- fd = open(devname, O_RDWR);
+ fd = open(devname, O_RDWR | O_CLOEXEC);
if (fd < 0) {
RTE_LOG(ERR, EAL, "Cannot open %s: %s\n",
devname, strerror(errno));