[PATCH 23/24] drm/amdkfd: add pc sampling capability check

[James Zhu]

From: David Yat Sin <david.yat...@amd.com>

Add pc sampling capability check.

Signed-off-by: David Yat Sin <david.yat...@amd.com>
Signed-off-by: James Zhu <james....@amd.com>
---
 drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 10 +++++++++-
 drivers/gpu/drm/amd/amdkfd/kfd_priv.h    | 13 +++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
index b00390e451bf..5e47e374d824 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
@@ -3259,7 +3259,7 @@ static const struct amdkfd_ioctl_desc amdkfd_ioctls[] = {
                        kfd_ioctl_set_debug_trap, 0),
 
        AMDKFD_IOCTL_DEF(AMDKFD_IOC_PC_SAMPLE,
-                       kfd_ioctl_pc_sample, 0),
+                       kfd_ioctl_pc_sample, KFD_IOC_FLAG_PERFMON),
 };
 
 #define AMDKFD_CORE_IOCTL_COUNT        ARRAY_SIZE(amdkfd_ioctls)
@@ -3336,6 +3336,14 @@ static long kfd_ioctl(struct file *filep, unsigned int 
cmd, unsigned long arg)
                }
        }
 
+       /* PC Sampling Monitor */
+       if (unlikely(ioctl->flags & KFD_IOC_FLAG_PERFMON)) {
+               if (!capable(CAP_PERFMON) && !capable(CAP_SYS_ADMIN)) {
+                       retcode = -EACCES;
+                       goto err_i1;
+               }
+       }
+
        if (cmd & (IOC_IN | IOC_OUT)) {
                if (asize <= sizeof(stack_kdata)) {
                        kdata = stack_kdata;
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h 
b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
index b7062033fda4..236d3de85153 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
@@ -144,6 +144,19 @@ enum kfd_ioctl_flags {
         * we also allow ioctls with SYS_ADMIN capability.
         */
        KFD_IOC_FLAG_CHECKPOINT_RESTORE = BIT(0),
+
+       /*
+        * @KFD_IOC_FLAG_PERFMON:
+        * Performance monitoring feature, GPU performance monitoring can allow 
users
+        * to gather some information about other processes. PC sampling can 
allow
+        * users to infer information about wavefronts from other processes 
that are
+        * running on the same CUs, such as which execution units they are 
using. As
+        * such, this type of performance monitoring should be protected and 
only
+        * available to users with sufficient capabilities: either CAP_PERFMON, 
or,
+        * for backwards compatibility, CAP_SYS_ADMIN.
+        */
+
+       KFD_IOC_FLAG_PERFMON = BIT(1),
 };
 /*
  * Kernel module parameter to specify maximum number of supported queues per
-- 
2.25.1