From 268ebc9cae4c891b79292661c7463c64584353d4 Mon Sep 17 00:00:00 2001 From: Sherry Yang Date: Fri, 8 Sep 2017 02:09:26 -0400 Subject: FROMLIST: android: binder: Drop lru lock in isolate callback MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit (from https://patchwork.kernel.org/patch/9945123/) Drop the global lru lock in isolate callback before calling zap_page_range which calls cond_resched, and re-acquire the global lru lock before returning. Also change return code to LRU_REMOVED_RETRY. Use mmput_async when fail to acquire mmap sem in an atomic context. Fix "BUG: sleeping function called from invalid context" errors when CONFIG_DEBUG_ATOMIC_SLEEP is enabled. Bug: 63926541 Change-Id: I45dbada421b715abed9a66d03d30ae2285671ca1 Fixes: f2517eb76f1f2 ("android: binder: Add global lru shrinker to binder") Reported-by: Kyle Yan Acked-by: Arve Hjønnevåg Signed-off-by: Sherry Yang --- drivers/android/binder_alloc.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'drivers/android') diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c index 1c1a7d9c86ed..9839afa84dfd 100644 --- a/drivers/android/binder_alloc.c +++ b/drivers/android/binder_alloc.c @@ -913,6 +913,7 @@ enum lru_status binder_alloc_free_page(struct list_head *item, struct binder_alloc *alloc; uintptr_t page_addr; size_t index; + struct vm_area_struct *vma; alloc = page->alloc; if (!mutex_trylock(&alloc->mutex)) @@ -923,16 +924,22 @@ enum lru_status binder_alloc_free_page(struct list_head *item, index = page - alloc->pages; page_addr = (uintptr_t)alloc->buffer + index * PAGE_SIZE; - if (alloc->vma) { + vma = alloc->vma; + if (vma) { mm = get_task_mm(alloc->tsk); if (!mm) goto err_get_task_mm_failed; if (!down_write_trylock(&mm->mmap_sem)) goto err_down_write_mmap_sem_failed; + } + + list_lru_isolate(lru, item); + spin_unlock(lock); + if (vma) { trace_binder_unmap_user_start(alloc, index); - zap_page_range(alloc->vma, + zap_page_range(vma, page_addr + alloc->user_buffer_offset, PAGE_SIZE, NULL); @@ -951,13 +958,12 @@ enum lru_status binder_alloc_free_page(struct list_head *item, trace_binder_unmap_kernel_end(alloc, index); - list_lru_isolate(lru, item); - + spin_lock(lock); mutex_unlock(&alloc->mutex); - return LRU_REMOVED; + return LRU_REMOVED_RETRY; err_down_write_mmap_sem_failed: - mmput(mm); + mmput_async(mm); err_get_task_mm_failed: err_page_already_freed: mutex_unlock(&alloc->mutex); -- cgit v1.2.3