From 80177980dc46739d9d8b8871a79766d7dce3811d Mon Sep 17 00:00:00 2001
From: Matthew Brost <matthew.brost@intel.com>
Date: Sat, 18 Dec 2021 16:19:09 -0800
Subject: drm/i915: Fix possible uninitialized variable in parallel extension
Git-commit: 0f9d36af8f211d296ffd23bdce61a72cdfbb1a3c
Patch-mainline: v5.16-rc8
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225
Alt-commit: cbffbac9c14220b8716b0a9c29d72243f6b14ef3
'prev_engine' was declared inside the output loop and checked in the
inner after at least 1 pass of either loop. The variable should be
declared outside both loops as it needs to be persistent across the
entire loop structure.
Fixes: e5e32171a2cf ("drm/i915/guc: Connect UAPI to GuC multi-lrc interface")
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211219001909.24348-1-matthew.brost@intel.com
(cherry picked from commit cbffbac9c14220b8716b0a9c29d72243f6b14ef3)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/i915/gem/i915_gem_context.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index fb33d0322960..c37c9f0d8167 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -564,6 +564,7 @@ set_proto_ctx_engines_parallel_submit(struct i915_user_extension __user *base,
container_of_user(base, typeof(*ext), base);
const struct set_proto_ctx_engines *set = data;
struct drm_i915_private *i915 = set->i915;
+ struct i915_engine_class_instance prev_engine;
u64 flags;
int err = 0, n, i, j;
u16 slot, width, num_siblings;
@@ -629,7 +630,6 @@ set_proto_ctx_engines_parallel_submit(struct i915_user_extension __user *base,
/* Create contexts / engines */
for (i = 0; i < width; ++i) {
intel_engine_mask_t current_mask = 0;
- struct i915_engine_class_instance prev_engine;
for (j = 0; j < num_siblings; ++j) {
struct i915_engine_class_instance ci;
--
2.38.1