[bug report] drm/amdgpu: add amdgpu_ras.c to support ras (v2)

[Zhou1, Tao]

[AMD Public Use]

Hi Dan:

Please check the following piece of code in amdgpu_ras_debugfs_ctrl_parse_data:

	if (op != -1) {
		if (amdgpu_ras_find_block_id_by_name(block_name, &block_id))
			return -EINVAL;

		data->head.block = block_id;

amdgpu_ras_find_block_id_by_name will return error directly if someone try to provide an invalid block_name intentionally via debugfs.

Regards,
Tao

> -----Original Message-----
> From: amd-gfx <amd-gfx-bounces at lists.freedesktop.org> On Behalf Of Dan
> Carpenter
> Sent: 2020年5月5日 17:13
> To: Pan, Xinhui <Xinhui.Pan at amd.com>
> Cc: amd-gfx at lists.freedesktop.org
> Subject: [bug report] drm/amdgpu: add amdgpu_ras.c to support ras (v2)
> 
> Hello xinhui pan,
> 
> The patch c030f2e4166c: "drm/amdgpu: add amdgpu_ras.c to support ras
> (v2)" from Oct 31, 2018, leads to the following static checker
> warning:
> 
> 	drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c:620
> amdgpu_ras_feature_enable()
> 	warn: uncapped user index 'ras_block_string[head->block]'
> 
> drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
>    587  int amdgpu_ras_feature_enable(struct amdgpu_device *adev,
>    588                  struct ras_common_if *head, bool enable)
>    589  {
>    590          struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
>    591          union ta_ras_cmd_input info;
>    592          int ret;
>    593
>    594          if (!con)
>    595                  return -EINVAL;
>    596
>    597          if (!enable) {
>    598                  info.disable_features = (struct ta_ras_disable_features_input)
> {
>    599                          .block_id =  amdgpu_ras_block_to_ta(head->block),
>    600                          .error_type = amdgpu_ras_error_to_ta(head->type),
>    601                  };
>    602          } else {
>    603                  info.enable_features = (struct ta_ras_enable_features_input)
> {
>    604                          .block_id =  amdgpu_ras_block_to_ta(head->block),
>    605                          .error_type = amdgpu_ras_error_to_ta(head->type),
>    606                  };
>    607          }
>    608
>    609          /* Do not enable if it is not allowed. */
>    610          WARN_ON(enable && !amdgpu_ras_is_feature_allowed(adev,
> head));
>    611          /* Are we alerady in that state we are going to set? */
>    612          if (!(!!enable ^ !!amdgpu_ras_is_feature_enabled(adev, head)))
>    613                  return 0;
>    614
>    615          if (!amdgpu_ras_intr_triggered()) {
>    616                  ret = psp_ras_enable_features(&adev->psp, &info, enable);
>    617                  if (ret) {
>    618                          amdgpu_ras_parse_status_code(adev,
>    619                                                       enable ? "enable":"disable",
>    620                                                       ras_block_str(head->block),
>                                                                            ^^^^^^^^^^^ The head->block
> value can be set to anything using debugfs.  That's a problem because it
> could easily lead to a kernel panic (which is
> annoying) and also because these days we try to restrict what root can do.
> 
>    621                                                      (enum ta_ras_status)ret);
>    622                          if (ret == TA_RAS_STATUS__RESET_NEEDED)
>    623                                  return -EAGAIN;
>    624                          return -EINVAL;
>    625                  }
>    626          }
>    627
>    628          /* setup the obj */
>    629          __amdgpu_ras_feature_enable(adev, head, enable);
>    630
>    631          return 0;
>    632  }
> 
> regards,
> dan carpenter
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