drm/i915/selftests: Fix i915_address_space refcnt leak

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: a4e7ccdac3 ("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>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/1587361342-83494-1-git-send-email-xiyuyang19@fudan.edu.cn
(cherry picked from commit e07c7606a0)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
This commit is contained in:
Xiyu Yang 2020-04-20 13:41:54 +08:00 committed by Rodrigo Vivi
parent d082119f42
commit 5d5e100a20

View File

@ -1477,8 +1477,10 @@ 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)) {
@ -1531,8 +1533,10 @@ 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)) {