From 6bdc692f5c9e2aae8861be9ededcb4a950182568 Mon Sep 17 00:00:00 2001 From: Tina Zhang Date: Thu, 23 May 2019 06:18:36 +0800 Subject: [PATCH] drm/i915/gvt: Initialize intel_gvt_gtt_entry in stack commit 387a4c2b55291b37e245c840813bd8a8bd06ed49 upstream. Stack struct intel_gvt_gtt_entry value needs to be initialized before being used, as the fields may contain garbage values. W/o this patch, set_ggtt_entry prints: ------------------------------------- 274.046840: set_ggtt_entry: vgpu1:set ggtt entry 0x9bed8000ffffe900 274.046846: set_ggtt_entry: vgpu1:set ggtt entry 0xe55df001 274.046852: set_ggtt_entry: vgpu1:set ggtt entry 0x9bed8000ffffe900 0x9bed8000 is the stack grabage. W/ this patch, set_ggtt_entry prints: ------------------------------------ 274.046840: set_ggtt_entry: vgpu1:set ggtt entry 0xffffe900 274.046846: set_ggtt_entry: vgpu1:set ggtt entry 0xe55df001 274.046852: set_ggtt_entry: vgpu1:set ggtt entry 0xffffe900 v2: - Initialize during declaration. (Zhenyu) Fixes: 7598e8700e9a ("drm/i915/gvt: Missed to cancel dma map for ggtt entries") Cc: stable@vger.kernel.org # v4.20+ Cc: Zhenyu Wang Reviewed-by: Zhenyu Wang Signed-off-by: Tina Zhang Signed-off-by: Zhenyu Wang Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/gvt/gtt.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c index 542f31ce108fd..40b32b4d1d98b 100644 --- a/drivers/gpu/drm/i915/gvt/gtt.c +++ b/drivers/gpu/drm/i915/gvt/gtt.c @@ -2161,7 +2161,8 @@ static int emulate_ggtt_mmio_write(struct intel_vgpu *vgpu, unsigned int off, struct intel_gvt_gtt_pte_ops *ops = gvt->gtt.pte_ops; unsigned long g_gtt_index = off >> info->gtt_entry_size_shift; unsigned long gma, gfn; - struct intel_gvt_gtt_entry e, m; + struct intel_gvt_gtt_entry e = {.val64 = 0, .type = GTT_TYPE_GGTT_PTE}; + struct intel_gvt_gtt_entry m = {.val64 = 0, .type = GTT_TYPE_GGTT_PTE}; dma_addr_t dma_addr; int ret; @@ -2237,7 +2238,8 @@ static int emulate_ggtt_mmio_write(struct intel_vgpu *vgpu, unsigned int off, if (ops->test_present(&e)) { gfn = ops->get_pfn(&e); - m = e; + m.val64 = e.val64; + m.type = e.type; /* one PTE update may be issued in multiple writes and the * first write may not construct a valid gfn