[v2] pci: add O_CLOEXEC when open uio device

Message ID 20230629025339.49404-1-suweifeng1@huawei.com (mailing list archive)
State New
Delegated to: Thomas Monjalon
Headers
Series [v2] pci: add O_CLOEXEC when open uio device |

Checks

Context Check Description
ci/checkpatch warning coding style issues
ci/Intel-compilation success Compilation OK
ci/intel-Testing success Testing PASS
ci/github-robot: build success github build: passed
ci/loongarch-compilation success Compilation OK
ci/loongarch-unit-testing success Unit Testing PASS
ci/iol-mellanox-Performance success Performance Testing PASS
ci/iol-abi-testing success Testing PASS
ci/iol-unit-testing success Testing PASS
ci/iol-x86_64-compile-testing success Testing PASS
ci/iol-aarch-unit-testing success Testing PASS
ci/iol-testing success Testing PASS
ci/iol-x86_64-unit-testing success Testing PASS
ci/intel-Functional success Functional PASS
ci/iol-intel-Performance success Performance Testing PASS
ci/iol-broadcom-Functional success Functional Testing PASS
ci/iol-intel-Functional success Functional Testing PASS
ci/iol-broadcom-Performance success Performance Testing PASS
ci/iol-aarch64-compile-testing success Testing PASS

Commit Message

Weifeng Su June 29, 2023, 2:53 a.m. UTC
  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.

Signed-off-by: Weifeng Su <suweifeng1@huawei.com>
---
 drivers/bus/pci/linux/pci_uio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
  

Comments

Stephen Hemminger July 6, 2023, 8:04 p.m. UTC | #1
On Thu, 29 Jun 2023 10:53:39 +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.
> 
> Signed-off-by: Weifeng Su <suweifeng1@huawei.com>

Makes sense, the eventfd used form VFIO is already marked as close on exec.

Acked-by: Stephen Hamminger <stephen@networkplumber.org>
  

Patch

diff --git a/drivers/bus/pci/linux/pci_uio.c b/drivers/bus/pci/linux/pci_uio.c
index d52125e49b..7ac142c36e 100644
--- a/drivers/bus/pci/linux/pci_uio.c
+++ b/drivers/bus/pci/linux/pci_uio.c
@@ -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));