In dc_dmub_srv_log_diagnostic_data() and
dc_dmub_srv_enable_dpia_trace().
Both functions check:
if (!dc_dmub_srv || !dc_dmub_srv->dmub)
and then call DC_LOG_ERROR() inside that block.
DC_LOG_ERROR() uses dc_dmub_srv->ctx internally. So if
dc_dmub_srv is NULL, the logging itself can dereference a
NULL pointer and cause a crash.
Fix this by splitting the checks.
First check if dc_dmub_srv is NULL and return immediately.
Then check dc_dmub_srv->dmub and log the error only when
dc_dmub_srv is valid.
Fixes the below:
../display/dc/dc_dmub_srv.c:962 dc_dmub_srv_log_diagnostic_data() error: we
previously assumed 'dc_dmub_srv' could be null (see line 961)
../display/dc/dc_dmub_srv.c:1167 dc_dmub_srv_enable_dpia_trace() error: we
previously assumed 'dc_dmub_srv' could be null (see line 1166)
Fixes: 2631ac1ac328 ("drm/amd/display: add DMUB registers to crash dump
diagnostic data.")
Fixes: 71ba6b577a35 ("drm/amd/display: Add interface to enable DPIA trace")
Cc: Roman Li <[email protected]>
Cc: Alex Hung <[email protected]>
Cc: Tom Chung <[email protected]>
Cc: Dan Carpenter <[email protected]>
Cc: Aurabindo Pillai <[email protected]>
Signed-off-by: Srinivasan Shanmugam <[email protected]>
---
drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c
b/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c
index d6a08064456b..cab8fb4c56d0 100644
--- a/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c
+++ b/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c
@@ -958,7 +958,10 @@ void dc_dmub_srv_log_diagnostic_data(struct dc_dmub_srv
*dc_dmub_srv)
{
uint32_t i;
- if (!dc_dmub_srv || !dc_dmub_srv->dmub) {
+ if (!dc_dmub_srv)
+ return;
+
+ if (!dc_dmub_srv->dmub) {
DC_LOG_ERROR("%s: invalid parameters.", __func__);
return;
}
@@ -1163,7 +1166,10 @@ void dc_dmub_srv_enable_dpia_trace(const struct dc *dc)
{
struct dc_dmub_srv *dc_dmub_srv = dc->ctx->dmub_srv;
- if (!dc_dmub_srv || !dc_dmub_srv->dmub) {
+ if (!dc_dmub_srv)
+ return;
+
+ if (!dc_dmub_srv->dmub) {
DC_LOG_ERROR("%s: invalid parameters.", __func__);
return;
}
--
2.34.1
