Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Todd Kjos | 3490 | 69.03% | 11 | 28.21% |
Sherry Yang | 1146 | 22.67% | 12 | 30.77% |
Martijn Coenen | 206 | 4.07% | 2 | 5.13% |
MinChan Kim | 97 | 1.92% | 1 | 2.56% |
Jann Horn | 63 | 1.25% | 4 | 10.26% |
Tetsuo Handa | 29 | 0.57% | 2 | 5.13% |
Kees Cook | 11 | 0.22% | 1 | 2.56% |
Michel Lespinasse | 7 | 0.14% | 2 | 5.13% |
Guenter Roeck | 3 | 0.06% | 1 | 2.56% |
Thomas Gleixner | 2 | 0.04% | 1 | 2.56% |
Xiongwei Song | 1 | 0.02% | 1 | 2.56% |
Joel A Fernandes | 1 | 0.02% | 1 | 2.56% |
Total | 5056 | 39 |
// SPDX-License-Identifier: GPL-2.0-only /* binder_alloc.c * * Android IPC Subsystem * * Copyright (C) 2007-2017 Google, Inc. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/list.h> #include <linux/sched/mm.h> #include <linux/module.h> #include <linux/rtmutex.h> #include <linux/rbtree.h> #include <linux/seq_file.h> #include <linux/vmalloc.h> #include <linux/slab.h> #include <linux/sched.h> #include <linux/list_lru.h> #include <linux/ratelimit.h> #include <asm/cacheflush.h> #include <linux/uaccess.h> #include <linux/highmem.h> #include <linux/sizes.h> #include "binder_alloc.h" #include "binder_trace.h" struct list_lru binder_alloc_lru; static DEFINE_MUTEX(binder_alloc_mmap_lock); enum { BINDER_DEBUG_USER_ERROR = 1U << 0, BINDER_DEBUG_OPEN_CLOSE = 1U << 1, BINDER_DEBUG_BUFFER_ALLOC = 1U << 2, BINDER_DEBUG_BUFFER_ALLOC_ASYNC = 1U << 3, }; static uint32_t binder_alloc_debug_mask = BINDER_DEBUG_USER_ERROR; module_param_named(debug_mask, binder_alloc_debug_mask, uint, 0644); #define binder_alloc_debug(mask, x...) \ do { \ if (binder_alloc_debug_mask & mask) \ pr_info_ratelimited(x); \ } while (0) static struct binder_buffer *binder_buffer_next(struct binder_buffer *buffer) { return list_entry(buffer->entry.next, struct binder_buffer, entry); } static struct binder_buffer *binder_buffer_prev(struct binder_buffer *buffer) { return list_entry(buffer->entry.prev, struct binder_buffer, entry); } static size_t binder_alloc_buffer_size(struct binder_alloc *alloc, struct binder_buffer *buffer) { if (list_is_last(&buffer->entry, &alloc->buffers)) return alloc->buffer + alloc->buffer_size - buffer->user_data; return binder_buffer_next(buffer)->user_data - buffer->user_data; } static void binder_insert_free_buffer(struct binder_alloc *alloc, struct binder_buffer *new_buffer) { struct rb_node **p = &alloc->free_buffers.rb_node; struct rb_node *parent = NULL; struct binder_buffer *buffer; size_t buffer_size; size_t new_buffer_size; BUG_ON(!new_buffer->free); new_buffer_size = binder_alloc_buffer_size(alloc, new_buffer); binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, "%d: add free buffer, size %zd, at %pK\n", alloc->pid, new_buffer_size, new_buffer); while (*p) { parent = *p; buffer = rb_entry(parent, struct binder_buffer, rb_node); BUG_ON(!buffer->free); buffer_size = binder_alloc_buffer_size(alloc, buffer); if (new_buffer_size < buffer_size) p = &parent->rb_left; else p = &parent->rb_right; } rb_link_node(&new_buffer->rb_node, parent, p); rb_insert_color(&new_buffer->rb_node, &alloc->free_buffers); } static void binder_insert_allocated_buffer_locked( struct binder_alloc *alloc, struct binder_buffer *new_buffer) { struct rb_node **p = &alloc->allocated_buffers.rb_node; struct rb_node *parent = NULL; struct binder_buffer *buffer; BUG_ON(new_buffer->free); while (*p) { parent = *p; buffer = rb_entry(parent, struct binder_buffer, rb_node); BUG_ON(buffer->free); if (new_buffer->user_data < buffer->user_data) p = &parent->rb_left; else if (new_buffer->user_data > buffer->user_data) p = &parent->rb_right; else BUG(); } rb_link_node(&new_buffer->rb_node, parent, p); rb_insert_color(&new_buffer->rb_node, &alloc->allocated_buffers); } static struct binder_buffer *binder_alloc_prepare_to_free_locked( struct binder_alloc *alloc, uintptr_t user_ptr) { struct rb_node *n = alloc->allocated_buffers.rb_node; struct binder_buffer *buffer; void __user *uptr; uptr = (void __user *)user_ptr; while (n) { buffer = rb_entry(n, struct binder_buffer, rb_node); BUG_ON(buffer->free); if (uptr < buffer->user_data) n = n->rb_left; else if (uptr > buffer->user_data) n = n->rb_right; else { /* * Guard against user threads attempting to * free the buffer when in use by kernel or * after it's already been freed. */ if (!buffer->allow_user_free) return ERR_PTR(-EPERM); buffer->allow_user_free = 0; return buffer; } } return NULL; } /** * binder_alloc_prepare_to_free() - get buffer given user ptr * @alloc: binder_alloc for this proc * @user_ptr: User pointer to buffer data * * Validate userspace pointer to buffer data and return buffer corresponding to * that user pointer. Search the rb tree for buffer that matches user data * pointer. * * Return: Pointer to buffer or NULL */ struct binder_buffer *binder_alloc_prepare_to_free(struct binder_alloc *alloc, uintptr_t user_ptr) { struct binder_buffer *buffer; mutex_lock(&alloc->mutex); buffer = binder_alloc_prepare_to_free_locked(alloc, user_ptr); mutex_unlock(&alloc->mutex); return buffer; } static int binder_update_page_range(struct binder_alloc *alloc, int allocate, void __user *start, void __user *end) { void __user *page_addr; unsigned long user_page_addr; struct binder_lru_page *page; struct vm_area_struct *vma = NULL; struct mm_struct *mm = NULL; bool need_mm = false; binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, "%d: %s pages %pK-%pK\n", alloc->pid, allocate ? "allocate" : "free", start, end); if (end <= start) return 0; trace_binder_update_page_range(alloc, allocate, start, end); 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 (need_mm && mmget_not_zero(alloc->vma_vm_mm)) mm = alloc->vma_vm_mm; if (mm) { mmap_read_lock(mm); vma = alloc->vma; } if (!vma && need_mm) { binder_alloc_debug(BINDER_DEBUG_USER_ERROR, "%d: binder_alloc_buf failed to map pages in userspace, no vma\n", alloc->pid); goto err_no_vma; } for (page_addr = start; page_addr < end; page_addr += PAGE_SIZE) { int ret; bool on_lru; size_t index; index = (page_addr - alloc->buffer) / PAGE_SIZE; page = &alloc->pages[index]; if (page->page_ptr) { trace_binder_alloc_lru_start(alloc, index); on_lru = list_lru_del(&binder_alloc_lru, &page->lru); WARN_ON(!on_lru); trace_binder_alloc_lru_end(alloc, index); continue; } if (WARN_ON(!vma)) goto err_page_ptr_cleared; trace_binder_alloc_page_start(alloc, index); 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); user_page_addr = (uintptr_t)page_addr; 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); goto err_vm_insert_page_failed; } if (index + 1 > alloc->pages_high) alloc->pages_high = index + 1; trace_binder_alloc_page_end(alloc, index); } if (mm) { mmap_read_unlock(mm); mmput(mm); } return 0; free_range: for (page_addr = end - PAGE_SIZE; 1; page_addr -= PAGE_SIZE) { bool ret; size_t index; index = (page_addr - alloc->buffer) / PAGE_SIZE; page = &alloc->pages[index]; trace_binder_free_lru_start(alloc, index); ret = list_lru_add(&binder_alloc_lru, &page->lru); WARN_ON(!ret); trace_binder_free_lru_end(alloc, index); if (page_addr == start) break; continue; err_vm_insert_page_failed: __free_page(page->page_ptr); page->page_ptr = NULL; err_alloc_page_failed: err_page_ptr_cleared: if (page_addr == start) break; } err_no_vma: if (mm) { mmap_read_unlock(mm); mmput(mm); } return vma ? -ENOMEM : -ESRCH; } static inline void binder_alloc_set_vma(struct binder_alloc *alloc, struct vm_area_struct *vma) { if (vma) alloc->vma_vm_mm = vma->vm_mm; /* * If we see alloc->vma is not NULL, buffer data structures set up * completely. Look at smp_rmb side binder_alloc_get_vma. * We also want to guarantee new alloc->vma_vm_mm is always visible * if alloc->vma is set. */ smp_wmb(); alloc->vma = vma; } static inline struct vm_area_struct *binder_alloc_get_vma( struct binder_alloc *alloc) { struct vm_area_struct *vma = NULL; if (alloc->vma) { /* Look at description in binder_alloc_set_vma */ smp_rmb(); vma = alloc->vma; } return vma; } static struct binder_buffer *binder_alloc_new_buf_locked( struct binder_alloc *alloc, size_t data_size, size_t offsets_size, size_t extra_buffers_size, int is_async) { struct rb_node *n = alloc->free_buffers.rb_node; struct binder_buffer *buffer; size_t buffer_size; struct rb_node *best_fit = NULL; void __user *has_page_addr; void __user *end_page_addr; size_t size, data_offsets_size; int ret; if (!binder_alloc_get_vma(alloc)) { binder_alloc_debug(BINDER_DEBUG_USER_ERROR, "%d: binder_alloc_buf, no vma\n", alloc->pid); return ERR_PTR(-ESRCH); } data_offsets_size = ALIGN(data_size, sizeof(void *)) + ALIGN(offsets_size, sizeof(void *)); if (data_offsets_size < data_size || data_offsets_size < offsets_size) { binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, "%d: got transaction with invalid size %zd-%zd\n", alloc->pid, data_size, offsets_size); return ERR_PTR(-EINVAL); } size = data_offsets_size + ALIGN(extra_buffers_size, sizeof(void *)); if (size < data_offsets_size || size < extra_buffers_size) { binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, "%d: got transaction with invalid extra_buffers_size %zd\n", alloc->pid, extra_buffers_size); return ERR_PTR(-EINVAL); } if (is_async && alloc->free_async_space < size + sizeof(struct binder_buffer)) { binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, "%d: binder_alloc_buf size %zd failed, no async space left\n", alloc->pid, size); return ERR_PTR(-ENOSPC); } /* Pad 0-size buffers so they get assigned unique addresses */ size = max(size, sizeof(void *)); while (n) { buffer = rb_entry(n, struct binder_buffer, rb_node); BUG_ON(!buffer->free); buffer_size = binder_alloc_buffer_size(alloc, buffer); if (size < buffer_size) { best_fit = n; n = n->rb_left; } else if (size > buffer_size) n = n->rb_right; else { best_fit = n; break; } } if (best_fit == NULL) { size_t allocated_buffers = 0; size_t largest_alloc_size = 0; size_t total_alloc_size = 0; size_t free_buffers = 0; size_t largest_free_size = 0; size_t total_free_size = 0; for (n = rb_first(&alloc->allocated_buffers); n != NULL; n = rb_next(n)) { buffer = rb_entry(n, struct binder_buffer, rb_node); buffer_size = binder_alloc_buffer_size(alloc, buffer); allocated_buffers++; total_alloc_size += buffer_size; if (buffer_size > largest_alloc_size) largest_alloc_size = buffer_size; } for (n = rb_first(&alloc->free_buffers); n != NULL; n = rb_next(n)) { buffer = rb_entry(n, struct binder_buffer, rb_node); buffer_size = binder_alloc_buffer_size(alloc, buffer); free_buffers++; total_free_size += buffer_size; if (buffer_size > largest_free_size) largest_free_size = buffer_size; } binder_alloc_debug(BINDER_DEBUG_USER_ERROR, "%d: binder_alloc_buf size %zd failed, no address space\n", alloc->pid, size); binder_alloc_debug(BINDER_DEBUG_USER_ERROR, "allocated: %zd (num: %zd largest: %zd), free: %zd (num: %zd largest: %zd)\n", total_alloc_size, allocated_buffers, largest_alloc_size, total_free_size, free_buffers, largest_free_size); return ERR_PTR(-ENOSPC); } if (n == NULL) { buffer = rb_entry(best_fit, struct binder_buffer, rb_node); buffer_size = binder_alloc_buffer_size(alloc, buffer); } binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, "%d: binder_alloc_buf size %zd got buffer %pK size %zd\n", alloc->pid, size, buffer, buffer_size); has_page_addr = (void __user *) (((uintptr_t)buffer->user_data + buffer_size) & PAGE_MASK); WARN_ON(n && buffer_size != size); end_page_addr = (void __user *)PAGE_ALIGN((uintptr_t)buffer->user_data + size); if (end_page_addr > has_page_addr) end_page_addr = has_page_addr; ret = binder_update_page_range(alloc, 1, (void __user *) PAGE_ALIGN((uintptr_t)buffer->user_data), end_page_addr); if (ret) return ERR_PTR(ret); if (buffer_size != size) { struct binder_buffer *new_buffer; new_buffer = kzalloc(sizeof(*buffer), GFP_KERNEL); if (!new_buffer) { pr_err("%s: %d failed to alloc new buffer struct\n", __func__, alloc->pid); goto err_alloc_buf_struct_failed; } new_buffer->user_data = (u8 __user *)buffer->user_data + size; list_add(&new_buffer->entry, &buffer->entry); new_buffer->free = 1; binder_insert_free_buffer(alloc, new_buffer); } rb_erase(best_fit, &alloc->free_buffers); buffer->free = 0; buffer->allow_user_free = 0; binder_insert_allocated_buffer_locked(alloc, buffer); binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, "%d: binder_alloc_buf size %zd got %pK\n", alloc->pid, size, buffer); buffer->data_size = data_size; buffer->offsets_size = offsets_size; buffer->async_transaction = is_async; buffer->extra_buffers_size = extra_buffers_size; if (is_async) { alloc->free_async_space -= size + sizeof(struct binder_buffer); binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC_ASYNC, "%d: binder_alloc_buf size %zd async free %zd\n", alloc->pid, size, alloc->free_async_space); } return buffer; err_alloc_buf_struct_failed: binder_update_page_range(alloc, 0, (void __user *) PAGE_ALIGN((uintptr_t)buffer->user_data), end_page_addr); return ERR_PTR(-ENOMEM); } /** * binder_alloc_new_buf() - Allocate a new binder buffer * @alloc: binder_alloc for this proc * @data_size: size of user data buffer * @offsets_size: user specified buffer offset * @extra_buffers_size: size of extra space for meta-data (eg, security context) * @is_async: buffer for async transaction * * Allocate a new buffer given the requested sizes. Returns * the kernel version of the buffer pointer. The size allocated * is the sum of the three given sizes (each rounded up to * pointer-sized boundary) * * Return: The allocated buffer or %NULL if error */ 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) { struct binder_buffer *buffer; mutex_lock(&alloc->mutex); buffer = binder_alloc_new_buf_locked(alloc, data_size, offsets_size, extra_buffers_size, is_async); mutex_unlock(&alloc->mutex); return buffer; } static void __user *buffer_start_page(struct binder_buffer *buffer) { return (void __user *)((uintptr_t)buffer->user_data & PAGE_MASK); } static void __user *prev_buffer_end_page(struct binder_buffer *buffer) { return (void __user *) (((uintptr_t)(buffer->user_data) - 1) & PAGE_MASK); } static void binder_delete_free_buffer(struct binder_alloc *alloc, struct binder_buffer *buffer) { struct binder_buffer *prev, *next = NULL; bool to_free = true; BUG_ON(alloc->buffers.next == &buffer->entry); prev = binder_buffer_prev(buffer); BUG_ON(!prev->free); if (prev_buffer_end_page(prev) == buffer_start_page(buffer)) { to_free = false; binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, "%d: merge free, buffer %pK share page with %pK\n", alloc->pid, buffer->user_data, prev->user_data); } if (!list_is_last(&buffer->entry, &alloc->buffers)) { next = binder_buffer_next(buffer); if (buffer_start_page(next) == buffer_start_page(buffer)) { to_free = false; binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, "%d: merge free, buffer %pK share page with %pK\n", alloc->pid, buffer->user_data, next->user_data); } } if (PAGE_ALIGNED(buffer->user_data)) { binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, "%d: merge free, buffer start %pK is page aligned\n", alloc->pid, buffer->user_data); to_free = false; } if (to_free) { binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, "%d: merge free, buffer %pK do not share page with %pK or %pK\n", alloc->pid, buffer->user_data, prev->user_data, next ? next->user_data : NULL); binder_update_page_range(alloc, 0, buffer_start_page(buffer), buffer_start_page(buffer) + PAGE_SIZE); } list_del(&buffer->entry); kfree(buffer); } static void binder_free_buf_locked(struct binder_alloc *alloc, struct binder_buffer *buffer) { size_t size, buffer_size; buffer_size = binder_alloc_buffer_size(alloc, buffer); size = ALIGN(buffer->data_size, sizeof(void *)) + ALIGN(buffer->offsets_size, sizeof(void *)) + ALIGN(buffer->extra_buffers_size, sizeof(void *)); binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, "%d: binder_free_buf %pK size %zd buffer_size %zd\n", alloc->pid, buffer, size, buffer_size); BUG_ON(buffer->free); BUG_ON(size > buffer_size); BUG_ON(buffer->transaction != NULL); BUG_ON(buffer->user_data < alloc->buffer); BUG_ON(buffer->user_data > alloc->buffer + alloc->buffer_size); if (buffer->async_transaction) { alloc->free_async_space += size + sizeof(struct binder_buffer); binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC_ASYNC, "%d: binder_free_buf size %zd async free %zd\n", alloc->pid, size, alloc->free_async_space); } binder_update_page_range(alloc, 0, (void __user *)PAGE_ALIGN((uintptr_t)buffer->user_data), (void __user *)(((uintptr_t) buffer->user_data + buffer_size) & PAGE_MASK)); rb_erase(&buffer->rb_node, &alloc->allocated_buffers); buffer->free = 1; if (!list_is_last(&buffer->entry, &alloc->buffers)) { struct binder_buffer *next = binder_buffer_next(buffer); if (next->free) { rb_erase(&next->rb_node, &alloc->free_buffers); binder_delete_free_buffer(alloc, next); } } if (alloc->buffers.next != &buffer->entry) { struct binder_buffer *prev = binder_buffer_prev(buffer); if (prev->free) { binder_delete_free_buffer(alloc, buffer); rb_erase(&prev->rb_node, &alloc->free_buffers); buffer = prev; } } binder_insert_free_buffer(alloc, buffer); } /** * binder_alloc_free_buf() - free a binder buffer * @alloc: binder_alloc for this proc * @buffer: kernel pointer to buffer * * Free the buffer allocated via binder_alloc_new_buffer() */ void binder_alloc_free_buf(struct binder_alloc *alloc, struct binder_buffer *buffer) { mutex_lock(&alloc->mutex); binder_free_buf_locked(alloc, buffer); mutex_unlock(&alloc->mutex); } /** * binder_alloc_mmap_handler() - map virtual address space for proc * @alloc: alloc structure for this proc * @vma: vma passed to mmap() * * Called by binder_mmap() to initialize the space specified in * vma for allocating binder buffers * * Return: * 0 = success * -EBUSY = address space already mapped * -ENOMEM = failed to map memory to given address space */ int binder_alloc_mmap_handler(struct binder_alloc *alloc, struct vm_area_struct *vma) { int ret; const char *failure_string; struct binder_buffer *buffer; mutex_lock(&binder_alloc_mmap_lock); if (alloc->buffer_size) { ret = -EBUSY; failure_string = "already mapped"; goto err_already_mapped; } alloc->buffer_size = min_t(unsigned long, vma->vm_end - vma->vm_start, SZ_4M); mutex_unlock(&binder_alloc_mmap_lock); alloc->buffer = (void __user *)vma->vm_start; alloc->pages = kcalloc(alloc->buffer_size / PAGE_SIZE, sizeof(alloc->pages[0]), GFP_KERNEL); if (alloc->pages == NULL) { ret = -ENOMEM; failure_string = "alloc page array"; goto err_alloc_pages_failed; } buffer = kzalloc(sizeof(*buffer), GFP_KERNEL); if (!buffer) { ret = -ENOMEM; failure_string = "alloc buffer struct"; goto err_alloc_buf_struct_failed; } buffer->user_data = alloc->buffer; list_add(&buffer->entry, &alloc->buffers); buffer->free = 1; binder_insert_free_buffer(alloc, buffer); alloc->free_async_space = alloc->buffer_size / 2; binder_alloc_set_vma(alloc, vma); mmgrab(alloc->vma_vm_mm); return 0; err_alloc_buf_struct_failed: kfree(alloc->pages); alloc->pages = NULL; err_alloc_pages_failed: alloc->buffer = NULL; mutex_lock(&binder_alloc_mmap_lock); alloc->buffer_size = 0; err_already_mapped: mutex_unlock(&binder_alloc_mmap_lock); binder_alloc_debug(BINDER_DEBUG_USER_ERROR, "%s: %d %lx-%lx %s failed %d\n", __func__, alloc->pid, vma->vm_start, vma->vm_end, failure_string, ret); return ret; } void binder_alloc_deferred_release(struct binder_alloc *alloc) { struct rb_node *n; int buffers, page_count; struct binder_buffer *buffer; buffers = 0; mutex_lock(&alloc->mutex); BUG_ON(alloc->vma); while ((n = rb_first(&alloc->allocated_buffers))) { buffer = rb_entry(n, struct binder_buffer, rb_node); /* Transaction should already have been freed */ BUG_ON(buffer->transaction); binder_free_buf_locked(alloc, buffer); buffers++; } while (!list_empty(&alloc->buffers)) { buffer = list_first_entry(&alloc->buffers, struct binder_buffer, entry); WARN_ON(!buffer->free); list_del(&buffer->entry); WARN_ON_ONCE(!list_empty(&alloc->buffers)); kfree(buffer); } page_count = 0; if (alloc->pages) { int i; for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) { void __user *page_addr; bool on_lru; 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 %s\n", __func__, alloc->pid, i, page_addr, on_lru ? "on lru" : "active"); __free_page(alloc->pages[i].page_ptr); page_count++; } kfree(alloc->pages); } mutex_unlock(&alloc->mutex); if (alloc->vma_vm_mm) mmdrop(alloc->vma_vm_mm); binder_alloc_debug(BINDER_DEBUG_OPEN_CLOSE, "%s: %d buffers %d, pages %d\n", __func__, alloc->pid, buffers, page_count); } static void print_binder_buffer(struct seq_file *m, const char *prefix, struct binder_buffer *buffer) { seq_printf(m, "%s %d: %pK size %zd:%zd:%zd %s\n", prefix, buffer->debug_id, buffer->user_data, buffer->data_size, buffer->offsets_size, buffer->extra_buffers_size, buffer->transaction ? "active" : "delivered"); } /** * binder_alloc_print_allocated() - print buffer info * @m: seq_file for output via seq_printf() * @alloc: binder_alloc for this proc * * Prints information about every buffer associated with * the binder_alloc state to the given seq_file */ void binder_alloc_print_allocated(struct seq_file *m, struct binder_alloc *alloc) { struct rb_node *n; mutex_lock(&alloc->mutex); for (n = rb_first(&alloc->allocated_buffers); n != NULL; n = rb_next(n)) print_binder_buffer(m, " buffer", rb_entry(n, struct binder_buffer, rb_node)); mutex_unlock(&alloc->mutex); } /** * binder_alloc_print_pages() - print page usage * @m: seq_file for output via seq_printf() * @alloc: binder_alloc for this proc */ void binder_alloc_print_pages(struct seq_file *m, struct binder_alloc *alloc) { struct binder_lru_page *page; int i; int active = 0; int lru = 0; int free = 0; mutex_lock(&alloc->mutex); /* * Make sure the binder_alloc is fully initialized, otherwise we might * read inconsistent state. */ if (binder_alloc_get_vma(alloc) != NULL) { for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) { page = &alloc->pages[i]; if (!page->page_ptr) free++; else if (list_empty(&page->lru)) active++; else lru++; } } mutex_unlock(&alloc->mutex); seq_printf(m, " pages: %d:%d:%d\n", active, lru, free); seq_printf(m, " pages high watermark: %zu\n", alloc->pages_high); } /** * binder_alloc_get_allocated_count() - return count of buffers * @alloc: binder_alloc for this proc * * Return: count of allocated buffers */ int binder_alloc_get_allocated_count(struct binder_alloc *alloc) { struct rb_node *n; int count = 0; mutex_lock(&alloc->mutex); for (n = rb_first(&alloc->allocated_buffers); n != NULL; n = rb_next(n)) count++; mutex_unlock(&alloc->mutex); return count; } /** * binder_alloc_vma_close() - invalidate address space * @alloc: binder_alloc for this proc * * Called from binder_vma_close() when releasing address space. * Clears alloc->vma to prevent new incoming transactions from * allocating more buffers. */ void binder_alloc_vma_close(struct binder_alloc *alloc) { binder_alloc_set_vma(alloc, 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) __must_hold(lock) { 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; struct vm_area_struct *vma; 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; mm = alloc->vma_vm_mm; if (!mmget_not_zero(mm)) goto err_mmget; if (!mmap_read_trylock(mm)) goto err_mmap_read_lock_failed; vma = binder_alloc_get_vma(alloc); list_lru_isolate(lru, item); spin_unlock(lock); if (vma) { trace_binder_unmap_user_start(alloc, index); zap_page_range(vma, page_addr, PAGE_SIZE); trace_binder_unmap_user_end(alloc, index); } mmap_read_unlock(mm); mmput_async(mm); trace_binder_unmap_kernel_start(alloc, index); __free_page(page->page_ptr); page->page_ptr = NULL; trace_binder_unmap_kernel_end(alloc, index); spin_lock(lock); mutex_unlock(&alloc->mutex); return LRU_REMOVED_RETRY; err_mmap_read_lock_failed: mmput_async(mm); err_mmget: 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; } static 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 * * Called from binder_open() to initialize binder_alloc fields for * new binder proc */ void binder_alloc_init(struct binder_alloc *alloc) { alloc->pid = current->group_leader->pid; mutex_init(&alloc->mutex); INIT_LIST_HEAD(&alloc->buffers); } int binder_alloc_shrinker_init(void) { int ret = list_lru_init(&binder_alloc_lru); if (ret == 0) { ret = register_shrinker(&binder_shrinker); if (ret) list_lru_destroy(&binder_alloc_lru); } return ret; } /** * check_buffer() - verify that buffer/offset is safe to access * @alloc: binder_alloc for this proc * @buffer: binder buffer to be accessed * @offset: offset into @buffer data * @bytes: bytes to access from offset * * Check that the @offset/@bytes are within the size of the given * @buffer and that the buffer is currently active and not freeable. * Offsets must also be multiples of sizeof(u32). The kernel is * allowed to touch the buffer in two cases: * * 1) when the buffer is being created: * (buffer->free == 0 && buffer->allow_user_free == 0) * 2) when the buffer is being torn down: * (buffer->free == 0 && buffer->transaction == NULL). * * Return: true if the buffer is safe to access */ static inline bool check_buffer(struct binder_alloc *alloc, struct binder_buffer *buffer, binder_size_t offset, size_t bytes) { size_t buffer_size = binder_alloc_buffer_size(alloc, buffer); return buffer_size >= bytes && offset <= buffer_size - bytes && IS_ALIGNED(offset, sizeof(u32)) && !buffer->free && (!buffer->allow_user_free || !buffer->transaction); } /** * binder_alloc_get_page() - get kernel pointer for given buffer offset * @alloc: binder_alloc for this proc * @buffer: binder buffer to be accessed * @buffer_offset: offset into @buffer data * @pgoffp: address to copy final page offset to * * Lookup the struct page corresponding to the address * at @buffer_offset into @buffer->user_data. If @pgoffp is not * NULL, the byte-offset into the page is written there. * * The caller is responsible to ensure that the offset points * to a valid address within the @buffer and that @buffer is * not freeable by the user. Since it can't be freed, we are * guaranteed that the corresponding elements of @alloc->pages[] * cannot change. * * Return: struct page */ static struct page *binder_alloc_get_page(struct binder_alloc *alloc, struct binder_buffer *buffer, binder_size_t buffer_offset, pgoff_t *pgoffp) { binder_size_t buffer_space_offset = buffer_offset + (buffer->user_data - alloc->buffer); pgoff_t pgoff = buffer_space_offset & ~PAGE_MASK; size_t index = buffer_space_offset >> PAGE_SHIFT; struct binder_lru_page *lru_page; lru_page = &alloc->pages[index]; *pgoffp = pgoff; return lru_page->page_ptr; } /** * binder_alloc_copy_user_to_buffer() - copy src user to tgt user * @alloc: binder_alloc for this proc * @buffer: binder buffer to be accessed * @buffer_offset: offset into @buffer data * @from: userspace pointer to source buffer * @bytes: bytes to copy * * Copy bytes from source userspace to target buffer. * * Return: bytes remaining to be copied */ unsigned long binder_alloc_copy_user_to_buffer(struct binder_alloc *alloc, struct binder_buffer *buffer, binder_size_t buffer_offset, const void __user *from, size_t bytes) { if (!check_buffer(alloc, buffer, buffer_offset, bytes)) return bytes; while (bytes) { unsigned long size; unsigned long ret; struct page *page; pgoff_t pgoff; void *kptr; page = binder_alloc_get_page(alloc, buffer, buffer_offset, &pgoff); size = min_t(size_t, bytes, PAGE_SIZE - pgoff); kptr = kmap(page) + pgoff; ret = copy_from_user(kptr, from, size); kunmap(page); if (ret) return bytes - size + ret; bytes -= size; from += size; buffer_offset += size; } return 0; } static int binder_alloc_do_buffer_copy(struct binder_alloc *alloc, bool to_buffer, struct binder_buffer *buffer, binder_size_t buffer_offset, void *ptr, size_t bytes) { /* All copies must be 32-bit aligned and 32-bit size */ if (!check_buffer(alloc, buffer, buffer_offset, bytes)) return -EINVAL; while (bytes) { unsigned long size; struct page *page; pgoff_t pgoff; void *tmpptr; void *base_ptr; page = binder_alloc_get_page(alloc, buffer, buffer_offset, &pgoff); size = min_t(size_t, bytes, PAGE_SIZE - pgoff); base_ptr = kmap_atomic(page); tmpptr = base_ptr + pgoff; if (to_buffer) memcpy(tmpptr, ptr, size); else memcpy(ptr, tmpptr, size); /* * kunmap_atomic() takes care of flushing the cache * if this device has VIVT cache arch */ kunmap_atomic(base_ptr); bytes -= size; pgoff = 0; ptr = ptr + size; buffer_offset += size; } return 0; } int binder_alloc_copy_to_buffer(struct binder_alloc *alloc, struct binder_buffer *buffer, binder_size_t buffer_offset, void *src, size_t bytes) { return binder_alloc_do_buffer_copy(alloc, true, buffer, buffer_offset, src, bytes); } int binder_alloc_copy_from_buffer(struct binder_alloc *alloc, void *dest, struct binder_buffer *buffer, binder_size_t buffer_offset, size_t bytes) { return binder_alloc_do_buffer_copy(alloc, false, buffer, buffer_offset, dest, bytes); }
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