Hello Zhi Wang,
The patch 2707e4446688: "drm/i915/gvt: vGPU graphics memory
virtualization" from Mar 28, 2016, leads to the following static
checker warnings:
drivers/gpu/drm/i915/gvt/gtt.c:1675 intel_vgpu_pin_mm()
warn: 'mm->pincount.counter' not decremented on lines: 1670,1675.
drivers/gpu/drm/i915/gvt/gtt.c:1932 intel_gvt_create_scratch_page()
warn: signedness bug returning '(-12)'
drivers/gpu/drm/i915/gvt/gtt.c
1647 /**
1648 * intel_vgpu_pin_mm - increase the pin count of a vGPU mm object
1649 * @vgpu: a vGPU
1650 *
1651 * This function is called when user wants to use a vGPU mm object. If this
1652 * mm object hasn't been shadowed yet, the shadow will be populated at this
1653 * time.
1654 *
1655 * Returns:
1656 * Zero on success, negative error code if failed.
1657 */
1658 int intel_vgpu_pin_mm(struct intel_vgpu_mm *mm)
1659 {
1660 int ret;
1661
1662 if (WARN_ON(mm->type != INTEL_GVT_MM_PPGTT))
1663 return 0;
Should this be "return -EINVAL;"?
1664
1665 atomic_inc(&mm->pincount);
1666
1667 if (!mm->shadowed) {
1668 ret = shadow_mm(mm);
1669 if (ret)
1670 return ret;
Should we decrement ->pincount before we return? Or perhaps in
invalidate_mm()?
1671 }
1672
1673 list_del_init(&mm->lru_list);
1674 list_add_tail(&mm->lru_list, &mm->vgpu->gvt->gtt.mm_lru_list_head);
1675 return 0;
1676 }
[ snip ]
1922 bool intel_gvt_create_scratch_page(struct intel_vgpu *vgpu)
^^^^
1923 {
1924 struct intel_vgpu_gtt *gtt = &vgpu->gtt;
1925 void *p;
1926 void *vaddr;
1927 unsigned long mfn;
1928
1929 gtt->scratch_page = alloc_page(GFP_KERNEL);
1930 if (!gtt->scratch_page) {
1931 gvt_err("Failed to allocate scratch page.\n");
1932 return -ENOMEM;
^^^^^^^^^^^^^^^
This means return true.
1933 }
1934
1935 /* set to zero */
1936 p = kmap_atomic(gtt->scratch_page);
1937 memset(p, 0, PAGE_SIZE);
1938 kunmap_atomic(p);
1939
1940 /* translate page to mfn */
1941 vaddr = page_address(gtt->scratch_page);
1942 mfn = intel_gvt_hypervisor_virt_to_mfn(vaddr);
1943
1944 if (mfn == INTEL_GVT_INVALID_ADDR) {
1945 gvt_err("fail to translate vaddr:0x%llx\n", (u64)vaddr);
1946 __free_page(gtt->scratch_page);
1947 gtt->scratch_page = NULL;
1948 return -ENXIO;
^^^^^^^^^^^^^
Same. The caller doesn't care. Maybe make this a void function?
1949 }
1950
1951 gtt->scratch_page_mfn = mfn;
1952 gvt_dbg_core("vgpu%d create scratch page: mfn=0x%lx\n", vgpu->id, mfn);
1953 return 0;
1954 }
regards,
dan carpenter
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
