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drm/i915/gvt: fix double free bug in split_2MB_gtt_entry

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If intel_gvt_dma_map_guest_page failed, it will call
ppgtt_invalidate_spt, which will finally free the spt.
But the caller function ppgtt_populate_spt_by_guest_entry
does not notice that, it will free spt again in its error
path.

Fix this by canceling the mapping of DMA address and freeing sub_spt.
Besides, leave the handle of spt destroy to caller function instead
of callee function when error occurs.

Fixes: b901b252b6 ("drm/i915/gvt: Add 2M huge gtt support")
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20221229165641.1192455-1-zyytlz.wz@163.com
This commit is contained in:
Zheng Wang 2022-12-30 00:56:41 +08:00 committed by Zhenyu Wang
parent a06d4b9e15
commit 4a61648af6
1 changed files with 13 additions and 4 deletions
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17
drivers/gpu/drm/i915/gvt/gtt.c
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@ -1209,10 +1209,8 @@ static int split_2MB_gtt_entry(struct intel_vgpu *vgpu,
for_each_shadow_entry(sub_spt, &sub_se, sub_index) {
ret = intel_gvt_dma_map_guest_page(vgpu, start_gfn + sub_index,
PAGE_SIZE, &dma_addr);
if (ret) {
ppgtt_invalidate_spt(spt);
return ret;
}
if (ret)
goto err;
sub_se.val64 = se->val64;
/* Copy the PAT field from PDE. */
@ -1231,6 +1229,17 @@ static int split_2MB_gtt_entry(struct intel_vgpu *vgpu,
ops->set_pfn(se, sub_spt->shadow_page.mfn);
ppgtt_set_shadow_entry(spt, se, index);
return 0;
err:
/* Cancel the existing addess mappings of DMA addr. */
for_each_present_shadow_entry(sub_spt, &sub_se, sub_index) {
gvt_vdbg_mm("invalidate 4K entry\n");
ppgtt_invalidate_pte(sub_spt, &sub_se);
}
/* Release the new allocated spt. */
trace_spt_change(sub_spt->vgpu->id, "release", sub_spt,
sub_spt->guest_page.gfn, sub_spt->shadow_page.type);
ppgtt_free_spt(sub_spt);
return ret;
}
static int split_64KB_gtt_entry(struct intel_vgpu *vgpu,