diff --git a/drivers/android/binder.c b/drivers/android/binder.c index e4b6055aafc7..ba9e613b42d6 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -5243,6 +5243,8 @@ static int __init binder_init(void) struct binder_device *device; struct hlist_node *tmp; + binder_alloc_shrinker_init(); + atomic_set(&binder_transaction_log.cur, ~0U); atomic_set(&binder_transaction_log_failed.cur, ~0U); diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c index e96659215f25..11a08bf72bcc 100644 --- a/drivers/android/binder_alloc.c +++ b/drivers/android/binder_alloc.c @@ -27,9 +27,12 @@ #include #include #include +#include #include "binder_alloc.h" #include "binder_trace.h" +struct list_lru binder_alloc_lru; + static DEFINE_MUTEX(binder_alloc_mmap_lock); enum { @@ -188,8 +191,9 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate, { void *page_addr; unsigned long user_page_addr; - struct page **page; - struct mm_struct *mm; + struct binder_lru_page *page; + struct mm_struct *mm = NULL; + bool need_mm = false; binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, "%d: %s pages %pK-%pK\n", alloc->pid, @@ -200,9 +204,18 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate, trace_binder_update_page_range(alloc, allocate, start, end); - if (vma) - mm = NULL; - else + if (allocate == 0) + goto free_range; + + for (page_addr = start; page_addr < end; page_addr += PAGE_SIZE) { + page = &alloc->pages[(page_addr - alloc->buffer) / PAGE_SIZE]; + if (!page->page_ptr) { + need_mm = true; + break; + } + } + + if (!vma && need_mm) mm = get_task_mm(alloc->tsk); if (mm) { @@ -215,10 +228,7 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate, } } - if (allocate == 0) - goto free_range; - - if (vma == NULL) { + if (!vma && need_mm) { pr_err("%d: binder_alloc_buf failed to map pages in userspace, no vma\n", alloc->pid); goto err_no_vma; @@ -226,18 +236,33 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate, for (page_addr = start; page_addr < end; page_addr += PAGE_SIZE) { int ret; + bool on_lru; page = &alloc->pages[(page_addr - alloc->buffer) / PAGE_SIZE]; - BUG_ON(*page); - *page = alloc_page(GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO); - if (*page == NULL) { + if (page->page_ptr) { + on_lru = list_lru_del(&binder_alloc_lru, &page->lru); + WARN_ON(!on_lru); + continue; + } + + if (WARN_ON(!vma)) + goto err_page_ptr_cleared; + + page->page_ptr = alloc_page(GFP_KERNEL | + __GFP_HIGHMEM | + __GFP_ZERO); + if (!page->page_ptr) { pr_err("%d: binder_alloc_buf failed for page at %pK\n", alloc->pid, page_addr); goto err_alloc_page_failed; } + page->alloc = alloc; + INIT_LIST_HEAD(&page->lru); + ret = map_kernel_range_noflush((unsigned long)page_addr, - PAGE_SIZE, PAGE_KERNEL, page); + PAGE_SIZE, PAGE_KERNEL, + &page->page_ptr); flush_cache_vmap((unsigned long)page_addr, (unsigned long)page_addr + PAGE_SIZE); if (ret != 1) { @@ -247,7 +272,7 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate, } user_page_addr = (uintptr_t)page_addr + alloc->user_buffer_offset; - ret = vm_insert_page(vma, user_page_addr, page[0]); + ret = vm_insert_page(vma, user_page_addr, page[0].page_ptr); if (ret) { pr_err("%d: binder_alloc_buf failed to map page at %lx in userspace\n", alloc->pid, user_page_addr); @@ -264,16 +289,21 @@ static int binder_update_page_range(struct binder_alloc *alloc, int allocate, free_range: for (page_addr = end - PAGE_SIZE; page_addr >= start; page_addr -= PAGE_SIZE) { + bool ret; + page = &alloc->pages[(page_addr - alloc->buffer) / PAGE_SIZE]; - if (vma) - zap_page_range(vma, (uintptr_t)page_addr + - alloc->user_buffer_offset, PAGE_SIZE); + + ret = list_lru_add(&binder_alloc_lru, &page->lru); + WARN_ON(!ret); + continue; + err_vm_insert_page_failed: unmap_kernel_range((unsigned long)page_addr, PAGE_SIZE); err_map_kernel_failed: - __free_page(*page); - *page = NULL; + __free_page(page->page_ptr); + page->page_ptr = NULL; err_alloc_page_failed: +err_page_ptr_cleared: ; } err_no_vma: @@ -731,16 +761,20 @@ void binder_alloc_deferred_release(struct binder_alloc *alloc) for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) { void *page_addr; + bool on_lru; - if (!alloc->pages[i]) + if (!alloc->pages[i].page_ptr) continue; + on_lru = list_lru_del(&binder_alloc_lru, + &alloc->pages[i].lru); page_addr = alloc->buffer + i * PAGE_SIZE; binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, - "%s: %d: page %d at %pK not freed\n", - __func__, alloc->pid, i, page_addr); + "%s: %d: page %d at %pK %s\n", + __func__, alloc->pid, i, page_addr, + on_lru ? "on lru" : "active"); unmap_kernel_range((unsigned long)page_addr, PAGE_SIZE); - __free_page(alloc->pages[i]); + __free_page(alloc->pages[i].page_ptr); page_count++; } kfree(alloc->pages); @@ -816,6 +850,93 @@ void binder_alloc_vma_close(struct binder_alloc *alloc) WRITE_ONCE(alloc->vma_vm_mm, NULL); } +/** + * binder_alloc_free_page() - shrinker callback to free pages + * @item: item to free + * @lock: lock protecting the item + * @cb_arg: callback argument + * + * Called from list_lru_walk() in binder_shrink_scan() to free + * up pages when the system is under memory pressure. + */ +enum lru_status binder_alloc_free_page(struct list_head *item, + struct list_lru_one *lru, + spinlock_t *lock, + void *cb_arg) +{ + struct mm_struct *mm = NULL; + struct binder_lru_page *page = container_of(item, + struct binder_lru_page, + lru); + struct binder_alloc *alloc; + uintptr_t page_addr; + size_t index; + + alloc = page->alloc; + if (!mutex_trylock(&alloc->mutex)) + goto err_get_alloc_mutex_failed; + + if (!page->page_ptr) + goto err_page_already_freed; + + index = page - alloc->pages; + page_addr = (uintptr_t)alloc->buffer + index * PAGE_SIZE; + if (alloc->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; + + zap_page_range(alloc->vma, + page_addr + alloc->user_buffer_offset, + PAGE_SIZE); + + up_write(&mm->mmap_sem); + mmput(mm); + } + + unmap_kernel_range(page_addr, PAGE_SIZE); + __free_page(page->page_ptr); + page->page_ptr = NULL; + + list_lru_isolate(lru, item); + + mutex_unlock(&alloc->mutex); + return LRU_REMOVED; + +err_down_write_mmap_sem_failed: + mmput(mm); +err_get_task_mm_failed: +err_page_already_freed: + mutex_unlock(&alloc->mutex); +err_get_alloc_mutex_failed: + return LRU_SKIP; +} + +static unsigned long +binder_shrink_count(struct shrinker *shrink, struct shrink_control *sc) +{ + unsigned long ret = list_lru_count(&binder_alloc_lru); + return ret; +} + +static unsigned long +binder_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) +{ + unsigned long ret; + + ret = list_lru_walk(&binder_alloc_lru, binder_alloc_free_page, + NULL, sc->nr_to_scan); + return ret; +} + +struct shrinker binder_shrinker = { + .count_objects = binder_shrink_count, + .scan_objects = binder_shrink_scan, + .seeks = DEFAULT_SEEKS, +}; + /** * binder_alloc_init() - called by binder_open() for per-proc initialization * @alloc: binder_alloc for this proc @@ -830,3 +951,8 @@ void binder_alloc_init(struct binder_alloc *alloc) mutex_init(&alloc->mutex); } +void binder_alloc_shrinker_init(void) +{ + list_lru_init(&binder_alloc_lru); + register_shrinker(&binder_shrinker); +} diff --git a/drivers/android/binder_alloc.h b/drivers/android/binder_alloc.h index dd5649bf6469..fa707cc63393 100644 --- a/drivers/android/binder_alloc.h +++ b/drivers/android/binder_alloc.h @@ -21,7 +21,9 @@ #include #include #include +#include +extern struct list_lru binder_alloc_lru; struct binder_transaction; /** @@ -60,6 +62,18 @@ struct binder_buffer { void *data; }; +/** + * struct binder_lru_page - page object used for binder shrinker + * @page_ptr: pointer to physical page in mmap'd space + * @lru: entry in binder_alloc_lru + * @alloc: binder_alloc for a proc + */ +struct binder_lru_page { + struct list_head lru; + struct page *page_ptr; + struct binder_alloc *alloc; +}; + /** * struct binder_alloc - per-binder proc state for binder allocator * @vma: vm_area_struct passed to mmap_handler @@ -75,8 +89,7 @@ struct binder_buffer { * @allocated_buffers: rb tree of allocated buffers sorted by address * @free_async_space: VA space available for async buffers. This is * initialized at mmap time to 1/2 the full VA space - * @pages: array of physical page addresses for each - * page of mmap'd space + * @pages: array of binder_lru_page * @buffer_size: size of address space specified via mmap * @pid: pid for associated binder_proc (invariant after init) * @@ -96,7 +109,7 @@ struct binder_alloc { struct rb_root free_buffers; struct rb_root allocated_buffers; size_t free_async_space; - struct page **pages; + struct binder_lru_page *pages; size_t buffer_size; uint32_t buffer_free; int pid; @@ -107,12 +120,16 @@ void binder_selftest_alloc(struct binder_alloc *alloc); #else static inline void binder_selftest_alloc(struct binder_alloc *alloc) {} #endif +enum lru_status binder_alloc_free_page(struct list_head *item, + struct list_lru_one *lru, + spinlock_t *lock, void *cb_arg); extern struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc, size_t data_size, size_t offsets_size, size_t extra_buffers_size, int is_async); extern void binder_alloc_init(struct binder_alloc *alloc); +void binder_alloc_shrinker_init(void); extern void binder_alloc_vma_close(struct binder_alloc *alloc); extern struct binder_buffer * binder_alloc_prepare_to_free(struct binder_alloc *alloc, diff --git a/drivers/android/binder_alloc_selftest.c b/drivers/android/binder_alloc_selftest.c index 0bf72079a9da..8bd7bcef967d 100644 --- a/drivers/android/binder_alloc_selftest.c +++ b/drivers/android/binder_alloc_selftest.c @@ -109,9 +109,11 @@ static bool check_buffer_pages_allocated(struct binder_alloc *alloc, page_addr = buffer->data; for (; page_addr < end; page_addr += PAGE_SIZE) { page_index = (page_addr - alloc->buffer) / PAGE_SIZE; - if (!alloc->pages[page_index]) { - pr_err("incorrect alloc state at page index %d\n", - page_index); + if (!alloc->pages[page_index].page_ptr || + !list_empty(&alloc->pages[page_index].lru)) { + pr_err("expect alloc but is %s at page index %d\n", + alloc->pages[page_index].page_ptr ? + "lru" : "free", page_index); return false; } } @@ -137,28 +139,63 @@ static void binder_selftest_alloc_buf(struct binder_alloc *alloc, static void binder_selftest_free_buf(struct binder_alloc *alloc, struct binder_buffer *buffers[], - size_t *sizes, int *seq) + size_t *sizes, int *seq, size_t end) { int i; for (i = 0; i < BUFFER_NUM; i++) binder_alloc_free_buf(alloc, buffers[seq[i]]); + for (i = 0; i < end / PAGE_SIZE; i++) { + /** + * Error message on a free page can be false positive + * if binder shrinker ran during binder_alloc_free_buf + * calls above. + */ + if (list_empty(&alloc->pages[i].lru)) { + pr_err_size_seq(sizes, seq); + pr_err("expect lru but is %s at page index %d\n", + alloc->pages[i].page_ptr ? "alloc" : "free", i); + binder_selftest_failures++; + } + } +} + +static void binder_selftest_free_page(struct binder_alloc *alloc) +{ + int i; + unsigned long count; + + while ((count = list_lru_count(&binder_alloc_lru))) { + list_lru_walk(&binder_alloc_lru, binder_alloc_free_page, + NULL, count); + } + for (i = 0; i < (alloc->buffer_size / PAGE_SIZE); i++) { - if ((!alloc->pages[i]) == (i == 0)) { - pr_err("incorrect free state at page index %d\n", i); + if (alloc->pages[i].page_ptr) { + pr_err("expect free but is %s at page index %d\n", + list_empty(&alloc->pages[i].lru) ? + "alloc" : "lru", i); binder_selftest_failures++; } } } static void binder_selftest_alloc_free(struct binder_alloc *alloc, - size_t *sizes, int *seq) + size_t *sizes, int *seq, size_t end) { struct binder_buffer *buffers[BUFFER_NUM]; binder_selftest_alloc_buf(alloc, buffers, sizes, seq); - binder_selftest_free_buf(alloc, buffers, sizes, seq); + binder_selftest_free_buf(alloc, buffers, sizes, seq, end); + + /* Allocate from lru. */ + binder_selftest_alloc_buf(alloc, buffers, sizes, seq); + if (list_lru_count(&binder_alloc_lru)) + pr_err("lru list should be empty but is not\n"); + + binder_selftest_free_buf(alloc, buffers, sizes, seq, end); + binder_selftest_free_page(alloc); } static bool is_dup(int *seq, int index, int val) @@ -174,19 +211,20 @@ static bool is_dup(int *seq, int index, int val) /* Generate BUFFER_NUM factorial free orders. */ static void binder_selftest_free_seq(struct binder_alloc *alloc, - size_t *sizes, int *seq, int index) + size_t *sizes, int *seq, + int index, size_t end) { int i; if (index == BUFFER_NUM) { - binder_selftest_alloc_free(alloc, sizes, seq); + binder_selftest_alloc_free(alloc, sizes, seq, end); return; } for (i = 0; i < BUFFER_NUM; i++) { if (is_dup(seq, index, i)) continue; seq[index] = i; - binder_selftest_free_seq(alloc, sizes, seq, index + 1); + binder_selftest_free_seq(alloc, sizes, seq, index + 1, end); } } @@ -211,8 +249,9 @@ static void binder_selftest_alloc_size(struct binder_alloc *alloc, * we need one giant buffer before getting to the last page. */ back_sizes[0] += alloc->buffer_size - end_offset[BUFFER_NUM - 1]; - binder_selftest_free_seq(alloc, front_sizes, seq, 0); - binder_selftest_free_seq(alloc, back_sizes, seq, 0); + binder_selftest_free_seq(alloc, front_sizes, seq, 0, + end_offset[BUFFER_NUM - 1]); + binder_selftest_free_seq(alloc, back_sizes, seq, 0, alloc->buffer_size); } static void binder_selftest_alloc_offset(struct binder_alloc *alloc, @@ -246,7 +285,8 @@ static void binder_selftest_alloc_offset(struct binder_alloc *alloc, * * Allocate BUFFER_NUM buffers to cover all page alignment cases, * then free them in all orders possible. Check that pages are - * allocated after buffer alloc and freed after freeing buffer. + * correctly allocated, put onto lru when buffers are freed, and + * are freed when binder_alloc_free_page is called. */ void binder_selftest_alloc(struct binder_alloc *alloc) {