| Message ID | 1587361342-83494-1-git-send-email-xiyuyang19@fudan.edu.cn (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915/selftests: Fix i915_address_space refcnt leak | expand |
Quoting Xiyu Yang (2020-04-20 06:41:54) > igt_ppgtt_pin_update() invokes i915_gem_context_get_vm_rcu(), which > returns a reference of the i915_address_space object to "vm" with > increased refcount. > > When igt_ppgtt_pin_update() returns, "vm" becomes invalid, so the > refcount should be decreased to keep refcount balanced. > > The reference counting issue happens in two exception handling paths of > igt_ppgtt_pin_update(). When i915_gem_object_create_internal() returns > IS_ERR, the refcnt increased by i915_gem_context_get_vm_rcu() is not > decreased, causing a refcnt leak. > > Fix this issue by jumping to "out_vm" label when > i915_gem_object_create_internal() returns IS_ERR. > > Fixes: 4049866f0913 ("drm/i915/selftests: huge page tests") Actually, Fixes: a4e7ccdac38e ("drm/i915: Move context management under GEM") > Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn> > Signed-off-by: Xin Tan <tanxin.ctf@gmail.com> Other than that, Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> -Chris
diff --git a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c index 9311250d7d6f..7a7763be6b2e 100644 --- a/drivers/gpu/drm/i915/gem/selftests/huge_pages.c +++ b/drivers/gpu/drm/i915/gem/selftests/huge_pages.c @@ -1578,8 +1578,10 @@ static int igt_ppgtt_pin_update(void *arg) unsigned int page_size = BIT(first); obj = i915_gem_object_create_internal(dev_priv, page_size); - if (IS_ERR(obj)) - return PTR_ERR(obj); + if (IS_ERR(obj)) { + err = PTR_ERR(obj); + goto out_vm; + } vma = i915_vma_instance(obj, vm, NULL); if (IS_ERR(vma)) { @@ -1632,8 +1634,10 @@ static int igt_ppgtt_pin_update(void *arg) } obj = i915_gem_object_create_internal(dev_priv, PAGE_SIZE); - if (IS_ERR(obj)) - return PTR_ERR(obj); + if (IS_ERR(obj)) { + err = PTR_ERR(obj); + goto out_vm; + } vma = i915_vma_instance(obj, vm, NULL); if (IS_ERR(vma)) {
igt_ppgtt_pin_update() invokes i915_gem_context_get_vm_rcu(), which returns a reference of the i915_address_space object to "vm" with increased refcount. When igt_ppgtt_pin_update() returns, "vm" becomes invalid, so the refcount should be decreased to keep refcount balanced. The reference counting issue happens in two exception handling paths of igt_ppgtt_pin_update(). When i915_gem_object_create_internal() returns IS_ERR, the refcnt increased by i915_gem_context_get_vm_rcu() is not decreased, causing a refcnt leak. Fix this issue by jumping to "out_vm" label when i915_gem_object_create_internal() returns IS_ERR. Fixes: 4049866f0913 ("drm/i915/selftests: huge page tests") Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com> --- drivers/gpu/drm/i915/gem/selftests/huge_pages.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)