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: Felix Kuehling <[email protected]> --- drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 30 ++++++++++++++++++++---- drivers/gpu/drm/amd/amdkfd/kfd_process.c | 2 ++ 2 files changed, 28 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c index 2cb51d1e857c..1aebda4bbbe7 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c @@ -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 = kfd_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) { @@ -1840,9 +1857,14 @@ 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; } diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c index 8276601a122f..bb2f26532feb 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c @@ -324,6 +324,8 @@ struct kfd_process *kfd_create_process(struct file *filep) (int)process->lead_thread->pid); } out: + if (process) + kref_get(&process->ref); mutex_unlock(&kfd_processes_mutex); return process; -- 2.24.0 _______________________________________________ amd-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/amd-gfx
