From ea2735ce19c1c6ce0f6011f813a1eea0272c231d Mon Sep 17 00:00:00 2001 From: Carlos Llamas Date: Fri, 1 Dec 2023 17:21:45 +0000 Subject: binder: refactor page range allocation Instead of looping through the page range twice to first determine if the mmap lock is required, simply do it per-page as needed. Split out all this logic into a separate binder_install_single_page() function. Reviewed-by: Alice Ryhl Signed-off-by: Carlos Llamas Link: https://lore.kernel.org/r/20231201172212.1813387-17-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman --- drivers/android/binder_alloc.c | 107 ++++++++++++++++++----------------------- 1 file changed, 47 insertions(+), 60 deletions(-) (limited to 'drivers/android') diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c index 99eacd8782b8..1caf0e3d3451 100644 --- a/drivers/android/binder_alloc.c +++ b/drivers/android/binder_alloc.c @@ -199,14 +199,51 @@ static void binder_free_page_range(struct binder_alloc *alloc, } } +static int binder_install_single_page(struct binder_alloc *alloc, + struct binder_lru_page *lru_page, + unsigned long addr) +{ + struct page *page; + int ret = 0; + + if (!mmget_not_zero(alloc->mm)) + return -ESRCH; + + mmap_write_lock(alloc->mm); + if (!alloc->vma) { + pr_err("%d: %s failed, no vma\n", alloc->pid, __func__); + ret = -ESRCH; + goto out; + } + + page = alloc_page(GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO); + if (!page) { + pr_err("%d: failed to allocate page\n", alloc->pid); + ret = -ENOMEM; + goto out; + } + + ret = vm_insert_page(alloc->vma, addr, page); + if (ret) { + pr_err("%d: %s failed to insert page at %lx with %d\n", + alloc->pid, __func__, addr, ret); + __free_page(page); + ret = -ENOMEM; + goto out; + } + + lru_page->page_ptr = page; +out: + mmap_write_unlock(alloc->mm); + mmput_async(alloc->mm); + return ret; +} + static int binder_allocate_page_range(struct binder_alloc *alloc, unsigned long start, unsigned long end) { - struct vm_area_struct *vma = NULL; struct binder_lru_page *page; - struct mm_struct *mm = NULL; unsigned long page_addr; - bool need_mm = false; binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, "%d: allocate pages %lx-%lx\n", @@ -218,32 +255,9 @@ static int binder_allocate_page_range(struct binder_alloc *alloc, trace_binder_update_page_range(alloc, true, start, end); 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->mm)) - mm = alloc->mm; - - if (mm) { - mmap_write_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; + unsigned long index; bool on_lru; - size_t index; + int ret; index = (page_addr - alloc->buffer) / PAGE_SIZE; page = &alloc->pages[index]; @@ -258,26 +272,15 @@ static int binder_allocate_page_range(struct binder_alloc *alloc, 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 %lx\n", - alloc->pid, page_addr); - goto err_alloc_page_failed; - } + page->alloc = alloc; INIT_LIST_HEAD(&page->lru); - ret = vm_insert_page(vma, page_addr, page->page_ptr); + ret = binder_install_single_page(alloc, page, page_addr); if (ret) { - pr_err("%d: binder_alloc_buf failed to map page at %lx in userspace\n", - alloc->pid, page_addr); - goto err_vm_insert_page_failed; + binder_free_page_range(alloc, start, page_addr); + return ret; } if (index + 1 > alloc->pages_high) @@ -285,24 +288,8 @@ static int binder_allocate_page_range(struct binder_alloc *alloc, trace_binder_alloc_page_end(alloc, index); } - if (mm) { - mmap_write_unlock(mm); - mmput_async(mm); - } - return 0; -err_vm_insert_page_failed: - __free_page(page->page_ptr); - page->page_ptr = NULL; -err_alloc_page_failed: -err_page_ptr_cleared: - binder_free_page_range(alloc, start, page_addr); -err_no_vma: - if (mm) { - mmap_write_unlock(mm); - mmput_async(mm); - } - return vma ? -ENOMEM : -ESRCH; + return 0; } static inline void binder_alloc_set_vma(struct binder_alloc *alloc, -- cgit