[Intel-gfx] [PATCH 3/5] drm/i915/guc: Don't go bang in GuC log if no GuC

John.C.Harrison
2021-12-03T18:34:05Z

From: John Harrison <John.C.Harrison@Intel.com>

If the GuC has failed to load for any reason and then the user pokes
the debugfs GuC log interface, a BUG and/or null pointer deref can
occur. Don't let that happen.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
---
drivers/gpu/drm/i915/gt/uc/intel_guc_log_debugfs.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_log_debugfs.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_log_debugfs.c
index 46026c2c1722..8fd068049376 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_log_debugfs.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_log_debugfs.c
@@ -31,7 +31,7 @@ static int guc_log_level_get(void *data, u64 *val)
{
struct intel_guc_log *log = data;

- if (!intel_guc_is_used(log_to_guc(log)))
+ if (!log->vma)
return -ENODEV;

*val = intel_guc_log_get_level(log);
@@ -43,7 +43,7 @@ static int guc_log_level_set(void *data, u64 val)
{
struct intel_guc_log *log = data;

- if (!intel_guc_is_used(log_to_guc(log)))
+ if (!log->vma)
return -ENODEV;

return intel_guc_log_set_level(log, val);
--
2.25.1