drm/i915/perf: Avoid polluting the i915_oa_config with error pointers

Use a local variable to track the allocation errors to avoid polluting
the struct and keep the free simple.

Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191013095211.2922-1-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index b4e2332d35cb0587d8263178f2969bfd2f064aba..366580701ba2bef2c6890333aa61da80a94dd12e 100644 (file)
--- a/drivers/gpu/drm/i915/i915_perf.c
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -384,12 +384,9 @@ void i915_oa_config_release(struct kref *ref)
        struct i915_oa_config *oa_config =
                container_of(ref, typeof(*oa_config), ref);
 
-       if (!PTR_ERR(oa_config->flex_regs))
-               kfree(oa_config->flex_regs);
-       if (!PTR_ERR(oa_config->b_counter_regs))
-               kfree(oa_config->b_counter_regs);
-       if (!PTR_ERR(oa_config->mux_regs))
-               kfree(oa_config->mux_regs);
+       kfree(oa_config->flex_regs);
+       kfree(oa_config->b_counter_regs);
+       kfree(oa_config->mux_regs);
 
        kfree_rcu(oa_config, rcu);
 }
@@ -3631,6 +3628,7 @@ int i915_perf_add_config_ioctl(struct drm_device *dev, void *data,
        struct i915_perf *perf = &to_i915(dev)->perf;
        struct drm_i915_perf_oa_config *args = data;
        struct i915_oa_config *oa_config, *tmp;
+       static struct i915_oa_reg *regs;
        int err, id;
 
        if (!perf->i915) {
@@ -3676,30 +3674,30 @@ int i915_perf_add_config_ioctl(struct drm_device *dev, void *data,
        memcpy(oa_config->uuid, args->uuid, sizeof(args->uuid));
 
        oa_config->mux_regs_len = args->n_mux_regs;
-       oa_config->mux_regs =
-               alloc_oa_regs(perf,
-                             perf->ops.is_valid_mux_reg,
-                             u64_to_user_ptr(args->mux_regs_ptr),
-                             args->n_mux_regs);
+       regs = alloc_oa_regs(perf,
+                            perf->ops.is_valid_mux_reg,
+                            u64_to_user_ptr(args->mux_regs_ptr),
+                            args->n_mux_regs);
 
-       if (IS_ERR(oa_config->mux_regs)) {
+       if (IS_ERR(regs)) {
                DRM_DEBUG("Failed to create OA config for mux_regs\n");
-               err = PTR_ERR(oa_config->mux_regs);
+               err = PTR_ERR(regs);
                goto reg_err;
        }
+       oa_config->mux_regs = regs;
 
        oa_config->b_counter_regs_len = args->n_boolean_regs;
-       oa_config->b_counter_regs =
-               alloc_oa_regs(perf,
-                             perf->ops.is_valid_b_counter_reg,
-                             u64_to_user_ptr(args->boolean_regs_ptr),
-                             args->n_boolean_regs);
+       regs = alloc_oa_regs(perf,
+                            perf->ops.is_valid_b_counter_reg,
+                            u64_to_user_ptr(args->boolean_regs_ptr),
+                            args->n_boolean_regs);
 
-       if (IS_ERR(oa_config->b_counter_regs)) {
+       if (IS_ERR(regs)) {
                DRM_DEBUG("Failed to create OA config for b_counter_regs\n");
-               err = PTR_ERR(oa_config->b_counter_regs);
+               err = PTR_ERR(regs);
                goto reg_err;
        }
+       oa_config->b_counter_regs = regs;
 
        if (INTEL_GEN(perf->i915) < 8) {
                if (args->n_flex_regs != 0) {
@@ -3708,17 +3706,17 @@ int i915_perf_add_config_ioctl(struct drm_device *dev, void *data,
                }
        } else {
                oa_config->flex_regs_len = args->n_flex_regs;
-               oa_config->flex_regs =
-                       alloc_oa_regs(perf,
-                                     perf->ops.is_valid_flex_reg,
-                                     u64_to_user_ptr(args->flex_regs_ptr),
-                                     args->n_flex_regs);
+               regs = alloc_oa_regs(perf,
+                                    perf->ops.is_valid_flex_reg,
+                                    u64_to_user_ptr(args->flex_regs_ptr),
+                                    args->n_flex_regs);
 
-               if (IS_ERR(oa_config->flex_regs)) {
+               if (IS_ERR(regs)) {
                        DRM_DEBUG("Failed to create OA config for flex_regs\n");
-                       err = PTR_ERR(oa_config->flex_regs);
+                       err = PTR_ERR(regs);
                        goto reg_err;
                }
+               oa_config->flex_regs = regs;
        }
 
        err = mutex_lock_interruptible(&perf->metrics_lock);