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msm: kgsl: Remove sysfs entries after releasing memory

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Consider a scenario when device is in OOM situation. Assume a process is
doing sysfs operation, grabs kernfs_mutex and wants to allocate memory.
LMKD tries to kill processes but kgsl processes will be blocked waiting
for kernfs_mutex in sysfs_remove_file.

kgsl_process_private_close > kgsl_process_uninit_sysfs > sysfs_remove_file

KGSL won't free up memory as it is done after sysfs removal leading to a
livelock. Fix it by releasing memory before removing sysfs entries.

Change-Id: I99640d7a653faffa671d5b035abb78e9473da12e
Signed-off-by: Kamal Agrawal <kamaagra@codeaurora.org>
This commit is contained in:
Kamal Agrawal 2021-02-08 10:03:28 +05:30 committed by Hareesh Gundu
parent f9416d6476
commit 6b16d08cad
1 changed files with 4 additions and 8 deletions
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12
drivers/gpu/msm/kgsl.c
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@ -1057,11 +1057,14 @@ static void kgsl_process_private_close(struct kgsl_device_private *dev_priv,
* directories and garbage collect any outstanding resources
*/
kgsl_process_uninit_sysfs(private);
process_release_memory(private);
/* Release all syncsource objects from process private */
kgsl_syncsource_process_release_syncsources(private);
debugfs_remove_recursive(private->debug_root);
kgsl_process_uninit_sysfs(private);
/* When using global pagetables, do not detach global pagetable */
if (private->pagetable->name != KGSL_MMU_GLOBAL_PT)
kgsl_mmu_detach_pagetable(private->pagetable);
@ -1071,15 +1074,8 @@ static void kgsl_process_private_close(struct kgsl_device_private *dev_priv,
list_del(&private->list);
spin_unlock(&kgsl_driver.proclist_lock);
debugfs_remove_recursive(private->debug_root);
/*
* Unlock the mutex before releasing the memory - this prevents a
* deadlock with the IOMMU mutex if a page fault occurs.
*/
mutex_unlock(&kgsl_driver.process_mutex);
process_release_memory(private);
kgsl_process_private_put(private);
}