From 1e3197d6ad73ef34b71d96cfb37ddf0b7bddac0e Mon Sep 17 00:00:00 2001
From: fred gao <fred.gao@intel.com>
Date: Fri, 18 Aug 2017 15:41:11 +0800
Subject: [PATCH] drm/i915/gvt: Refine error handling for perform_bb_shadow
Git-commit: 1e3197d6ad73ef34b71d96cfb37ddf0b7bddac0e
Patch-mainline: v4.15-rc1
References: FATE#322643 bsc#1055900

fix the wrong return type and return error once the unknown
command is scanned.

V2: 
- separate this error handle from healthy rating code. (Zhenyu)

Signed-off-by: fred gao <fred.gao@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/i915/gvt/cmd_parser.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/i915/gvt/cmd_parser.c
+++ b/drivers/gpu/drm/i915/gvt/cmd_parser.c
@@ -1576,11 +1576,11 @@ static int batch_buffer_needs_scan(struc
 	return 1;
 }
 
-static uint32_t find_bb_size(struct parser_exec_state *s)
+static int find_bb_size(struct parser_exec_state *s)
 {
 	unsigned long gma = 0;
 	struct cmd_info *info;
-	uint32_t bb_size = 0;
+	int bb_size = 0;
 	uint32_t cmd_len = 0;
 	bool met_bb_end = false;
 	struct intel_vgpu *vgpu = s->vgpu;
@@ -1637,6 +1637,8 @@ static int perform_bb_shadow(struct pars
 
 	/* get the size of the batch buffer */
 	bb_size = find_bb_size(s);
+	if (bb_size < 0)
+		return -EINVAL;
 
 	/* allocate shadow batch buffer */
 	entry_obj = kmalloc(sizeof(*entry_obj), GFP_KERNEL);