Commit 0f899fd4 authored by Felix Kuehling's avatar Felix Kuehling Committed by Alex Deucher
Browse files

drm/amdkfd: Improve kfd_process lookup in kfd_ioctl 



Use filep->private_data to store a pointer to the kfd_process data
structure. Take an extra reference for that, which gets released in
the kfd_release callback. Check that the process calling kfd_ioctl
is the same that opened the file descriptor. Return -EBADF if it's
not, so that this error can be distinguished in user mode.

Signed-off-by: default avatarFelix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: default avatarPhilip Yang <Philip.Yang@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent ea117312

drivers/gpu/drm/amd/amdkfd/kfd_chardev.c

+26 −4
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ 


static long kfd_ioctl(struct file *, unsigned int, unsigned long);

static int kfd_open(struct inode *, struct file *);

static int kfd_release(struct inode *, struct file *);

static int kfd_mmap(struct file *, struct vm_area_struct *);



static const char kfd_dev_name[] = "kfd";
@@ -51,6 +52,7 @@ static const struct file_operations kfd_fops = { 
	.unlocked_ioctl = kfd_ioctl,

	.compat_ioctl = compat_ptr_ioctl,

	.open = kfd_open,

	.release = kfd_release,

	.mmap = kfd_mmap,

};
@@ -124,8 +126,13 @@ static int kfd_open(struct inode *inode, struct file *filep) 
	if (IS_ERR(process))

		return PTR_ERR(process);



	if (kfd_is_locked())

	if (kfd_is_locked()) {

		kfd_unref_process(process);

		return -EAGAIN;

	}



	/* filep now owns the reference returned by kfd_create_process */

	filep->private_data = process;



	dev_dbg(kfd_device, "process %d opened, compat mode (32 bit) - %d\n",

		process->pasid, process->is_32bit_user_mode);
@@ -133,6 +140,16 @@ static int kfd_open(struct inode *inode, struct file *filep) 
	return 0;

}



static int kfd_release(struct inode *inode, struct file *filep)

{

	struct kfd_process *process = filep->private_data;



	if (process)

		kfd_unref_process(process);



	return 0;

}



static int kfd_ioctl_get_version(struct file *filep, struct kfd_process *p,

					void *data)

{
@@ -1801,9 +1818,14 @@ static long kfd_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) 


	dev_dbg(kfd_device, "ioctl cmd 0x%x (#0x%x), arg 0x%lx\n", cmd, nr, arg);



	process = kfd_get_process(current);

	if (IS_ERR(process)) {

		dev_dbg(kfd_device, "no process\n");

	/* Get the process struct from the filep. Only the process

	 * that opened /dev/kfd can use the file descriptor. Child

	 * processes need to create their own KFD device context.

	 */

	process = filep->private_data;

	if (process->lead_thread != current->group_leader) {

		dev_dbg(kfd_device, "Using KFD FD in wrong process\n");

		retcode = -EBADF;

		goto err_i1;

	}

drivers/gpu/drm/amd/amdkfd/kfd_process.c

+2 −0
Original line number Diff line number Diff line
@@ -324,6 +324,8 @@ struct kfd_process *kfd_create_process(struct file *filep) 
					(int)process->lead_thread->pid);

	}

out:

	if (!IS_ERR(process))

		kref_get(&process->ref);

	mutex_unlock(&kfd_processes_mutex);



	return process;

CRA Git | Maintained and supported by SUSTech CRA and CCSE