From a62b8f87c770fa4109ce515e4d8a0d4701a4ca5f Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Fri, 7 Apr 2023 13:31:42 -0700 Subject: dmaengine: idxd: add pid to exported sysfs attribute for opened file Provide the pid of the application for the opened file. This allows the monitor daemon to easily correlate which app opened the file and easily kill the app by pid if that is desired action. Tested-by: Tony Zhu Signed-off-by: Dave Jiang Co-developed-by: Fenghua Yu Signed-off-by: Fenghua Yu Link: https://lore.kernel.org/r/20230407203143.2189681-16-fenghua.yu@intel.com Signed-off-by: Vinod Koul --- Documentation/ABI/stable/sysfs-driver-dma-idxd | 8 ++++++++ drivers/dma/idxd/cdev.c | 11 +++++++++++ 2 files changed, 19 insertions(+) diff --git a/Documentation/ABI/stable/sysfs-driver-dma-idxd b/Documentation/ABI/stable/sysfs-driver-dma-idxd index 73ab86196a41..5d0df57f5298 100644 --- a/Documentation/ABI/stable/sysfs-driver-dma-idxd +++ b/Documentation/ABI/stable/sysfs-driver-dma-idxd @@ -335,3 +335,11 @@ Description: Show the number of Completion Record (CR) faults failures that this driver cannot fault in the address for the CR. Typically this is caused by a bad address programmed in the submitted descriptor or a malicious submitter is using bad CR address on purpose. + +What: /sys/bus/dsa/devices/wq./dsa\!wq./file/pid +Date: Sept 14, 2022 +KernelVersion: 6.4.0 +Contact: dmaengine@vger.kernel.org +Description: Show the process id of the application that opened the file. This is + helpful information for a monitor daemon that wants to kill the + application that opened the file. diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c index 2fb905f2545b..ecbf67c2ad2b 100644 --- a/drivers/dma/idxd/cdev.c +++ b/drivers/dma/idxd/cdev.c @@ -49,6 +49,7 @@ struct idxd_user_context { struct idxd_dev idxd_dev; u64 counters[COUNTER_MAX]; int id; + pid_t pid; }; static void idxd_cdev_evl_drain_pasid(struct idxd_wq *wq, u32 pasid); @@ -78,9 +79,18 @@ static ssize_t cr_fault_failures_show(struct device *dev, } static DEVICE_ATTR_RO(cr_fault_failures); +static ssize_t pid_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct idxd_user_context *ctx = dev_to_uctx(dev); + + return sysfs_emit(buf, "%u\n", ctx->pid); +} +static DEVICE_ATTR_RO(pid); + static struct attribute *cdev_file_attributes[] = { &dev_attr_cr_faults.attr, &dev_attr_cr_fault_failures.attr, + &dev_attr_pid.attr, NULL }; @@ -238,6 +248,7 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp) ctx->wq = wq; filp->private_data = ctx; + ctx->pid = current->pid; if (device_user_pasid_enabled(idxd)) { sva = iommu_sva_bind_device(dev, current->mm); -- cgit