It corrects the issue by checking if 'adev->dm.dmub_srv' is NULL before
accessing its 'meta_info' member. This ensures that we do not
dereference a NULL pointer.
Fixes the below:
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_debugfs.c:917 dmub_tracebuffer_show()
warn: address of 'adev->dm.dmub_srv->meta_info' is non-NULL
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_debugfs.c
901 static int dmub_tracebuffer_show(struct seq_file *m, void *data)
902 {
903 struct amdgpu_device *adev = m->private;
904 struct dmub_srv_fb_info *fb_info = adev->dm.dmub_fb_info;
905 struct dmub_fw_meta_info *fw_meta_info = &adev->dm.dmub_srv->meta_info;
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Even if adev->dm.dmub_srv is NULL, the address of ->meta_info can't be NULL
906 struct dmub_debugfs_trace_entry *entries;
907 uint8_t *tbuf_base;
908 uint32_t tbuf_size, max_entries, num_entries, first_entry, i;
909
910 if (!fb_info)
911 return 0;
912
913 tbuf_base = (uint8_t *)fb_info->fb[DMUB_WINDOW_5_TRACEBUFF].cpu_addr;
914 if (!tbuf_base)
915 return 0;
916
--> 917 tbuf_size = fw_meta_info ? fw_meta_info->trace_buffer_size :
^^^^^^^^^^^^ Always non-NULL
918 DMUB_TRACE_BUFFER_SIZE;
919 max_entries = (tbuf_size - sizeof(struct dmub_debugfs_trace_header)) /
920 sizeof(struct dmub_debugfs_trace_entry);
921
922 num_entries =
Fixes: c506f6e03b18 ("drm/amd/display: Make DMCUB tracebuffer debugfs chronological")
Cc: Leo Li <sunpeng.li@xxxxxxx>
Cc: Tom Chung <chiahsuan.chung@xxxxxxx>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira@xxxxxxx>
Cc: Roman Li <roman.li@xxxxxxx>
Cc: Alex Hung <alex.hung@xxxxxxx>
Cc: Aurabindo Pillai <aurabindo.pillai@xxxxxxx>
Cc: Harry Wentland <harry.wentland@xxxxxxx>
Cc: Hamza Mahfooz <hamza.mahfooz@xxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@xxxxxxx>
---
v2:
- initially initialize struct dmub_fw_meta_info *fw_meta_info to NULL (Dan
Carpenter)
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
index 11a7ac54f91c..2d31836ecb98 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c
@@ -902,7 +902,7 @@ static int dmub_tracebuffer_show(struct seq_file *m, void *data)
{
struct amdgpu_device *adev = m->private;
struct dmub_srv_fb_info *fb_info = adev->dm.dmub_fb_info;
- struct dmub_fw_meta_info *fw_meta_info = &adev->dm.dmub_srv->meta_info;
+ struct dmub_fw_meta_info *fw_meta_info = NULL;
struct dmub_debugfs_trace_entry *entries;
uint8_t *tbuf_base;
uint32_t tbuf_size, max_entries, num_entries, first_entry, i;
@@ -914,6 +914,9 @@ static int dmub_tracebuffer_show(struct seq_file *m, void *data)
if (!tbuf_base)
return 0;
+ if (adev->dm.dmub_srv)
+ fw_meta_info = &adev->dm.dmub_srv->meta_info;
+
tbuf_size = fw_meta_info ? fw_meta_info->trace_buffer_size :
DMUB_TRACE_BUFFER_SIZE;
max_entries = (tbuf_size - sizeof(struct dmub_debugfs_trace_header)) /
--
2.34.1
