| Message ID | 20180205142916.27092-2-msrb@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c index 8ba932b22f7c..de7ec59433d1 100644 --- a/drivers/gpu/drm/i915/i915_cmd_parser.c +++ b/drivers/gpu/drm/i915/i915_cmd_parser.c @@ -1038,7 +1038,7 @@ find_reg(const struct intel_engine_cs *engine, bool is_master, u32 addr) const struct drm_i915_reg_table *table = engine->reg_tables; int count = engine->reg_table_count; - do { + for (; count > 0; ++table, --count) { if (!table->master || is_master) { const struct drm_i915_reg_descriptor *reg; @@ -1046,7 +1046,7 @@ find_reg(const struct intel_engine_cs *engine, bool is_master, u32 addr) if (reg != NULL) return reg; } - } while (table++, --count); + } return NULL; }
The find_reg function was assuming that there is always at least one table in reg_tables. It is not always true. In case of VCS or VECS, the reg_tables is NULL and reg_table_count is 0, implying that no register-accessing commands are allowed. However, the command tables include commands such as MI_STORE_REGISTER_MEM. When trying to check such command, the find_reg would dereference NULL pointer. Now it will just return NULL meaning that the register was not found and the command will be rejected. Signed-off-by: Michal Srb <msrb@suse.com> --- drivers/gpu/drm/i915/i915_cmd_parser.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)