From: Carlos Llamas Date: Tue, 10 Dec 2024 14:30:57 +0000 (+0000) Subject: Revert "binder: switch alloc->mutex to spinlock_t" X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=8b52c7261e04f1325f47e2b173a9d4b980e8f858;p=users%2Fdwmw2%2Flinux.git Revert "binder: switch alloc->mutex to spinlock_t" This reverts commit 7710e2cca32e7f3958480e8bd44f50e29d0c2509. In preparation for concurrent page installations, restore the original alloc->mutex which will serialize zap_page_range_single() against page installations in subsequent patches (instead of the mmap_sem). Resolved trivial conflicts with commit 2c10a20f5e84a ("binder_alloc: Fix sleeping function called from invalid context") and commit da0c02516c50 ("mm/list_lru: simplify the list_lru walk callback function"). Cc: Mukesh Ojha Reviewed-by: Suren Baghdasaryan Signed-off-by: Carlos Llamas Link: https://lore.kernel.org/r/20241210143114.661252-2-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c index a738e77458658..52f6aa3232e1f 100644 --- a/drivers/android/binder_alloc.c +++ b/drivers/android/binder_alloc.c @@ -169,9 +169,9 @@ struct binder_buffer *binder_alloc_prepare_to_free(struct binder_alloc *alloc, { struct binder_buffer *buffer; - spin_lock(&alloc->lock); + mutex_lock(&alloc->mutex); buffer = binder_alloc_prepare_to_free_locked(alloc, user_ptr); - spin_unlock(&alloc->lock); + mutex_unlock(&alloc->mutex); return buffer; } @@ -597,10 +597,10 @@ struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc, if (!next) return ERR_PTR(-ENOMEM); - spin_lock(&alloc->lock); + mutex_lock(&alloc->mutex); buffer = binder_alloc_new_buf_locked(alloc, next, size, is_async); if (IS_ERR(buffer)) { - spin_unlock(&alloc->lock); + mutex_unlock(&alloc->mutex); goto out; } @@ -608,7 +608,7 @@ struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc, buffer->offsets_size = offsets_size; buffer->extra_buffers_size = extra_buffers_size; buffer->pid = current->tgid; - spin_unlock(&alloc->lock); + mutex_unlock(&alloc->mutex); ret = binder_install_buffer_pages(alloc, buffer, size); if (ret) { @@ -785,17 +785,17 @@ void binder_alloc_free_buf(struct binder_alloc *alloc, * We could eliminate the call to binder_alloc_clear_buf() * from binder_alloc_deferred_release() by moving this to * binder_free_buf_locked(). However, that could - * increase contention for the alloc->lock if clear_on_free - * is used frequently for large buffers. This lock is not + * increase contention for the alloc mutex if clear_on_free + * is used frequently for large buffers. The mutex is not * needed for correctness here. */ if (buffer->clear_on_free) { binder_alloc_clear_buf(alloc, buffer); buffer->clear_on_free = false; } - spin_lock(&alloc->lock); + mutex_lock(&alloc->mutex); binder_free_buf_locked(alloc, buffer); - spin_unlock(&alloc->lock); + mutex_unlock(&alloc->mutex); } /** @@ -893,7 +893,7 @@ void binder_alloc_deferred_release(struct binder_alloc *alloc) struct binder_buffer *buffer; buffers = 0; - spin_lock(&alloc->lock); + mutex_lock(&alloc->mutex); BUG_ON(alloc->vma); while ((n = rb_first(&alloc->allocated_buffers))) { @@ -940,7 +940,7 @@ void binder_alloc_deferred_release(struct binder_alloc *alloc) page_count++; } } - spin_unlock(&alloc->lock); + mutex_unlock(&alloc->mutex); kvfree(alloc->pages); if (alloc->mm) mmdrop(alloc->mm); @@ -964,7 +964,7 @@ void binder_alloc_print_allocated(struct seq_file *m, struct binder_buffer *buffer; struct rb_node *n; - spin_lock(&alloc->lock); + mutex_lock(&alloc->mutex); for (n = rb_first(&alloc->allocated_buffers); n; n = rb_next(n)) { buffer = rb_entry(n, struct binder_buffer, rb_node); seq_printf(m, " buffer %d: %lx size %zd:%zd:%zd %s\n", @@ -974,7 +974,7 @@ void binder_alloc_print_allocated(struct seq_file *m, buffer->extra_buffers_size, buffer->transaction ? "active" : "delivered"); } - spin_unlock(&alloc->lock); + mutex_unlock(&alloc->mutex); } /** @@ -991,7 +991,7 @@ void binder_alloc_print_pages(struct seq_file *m, int lru = 0; int free = 0; - spin_lock(&alloc->lock); + mutex_lock(&alloc->mutex); /* * Make sure the binder_alloc is fully initialized, otherwise we might * read inconsistent state. @@ -1007,7 +1007,7 @@ void binder_alloc_print_pages(struct seq_file *m, lru++; } } - spin_unlock(&alloc->lock); + 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); } @@ -1023,10 +1023,10 @@ int binder_alloc_get_allocated_count(struct binder_alloc *alloc) struct rb_node *n; int count = 0; - spin_lock(&alloc->lock); + mutex_lock(&alloc->mutex); for (n = rb_first(&alloc->allocated_buffers); n != NULL; n = rb_next(n)) count++; - spin_unlock(&alloc->lock); + mutex_unlock(&alloc->mutex); return count; } @@ -1070,8 +1070,8 @@ enum lru_status binder_alloc_free_page(struct list_head *item, goto err_mmget; if (!mmap_read_trylock(mm)) goto err_mmap_read_lock_failed; - if (!spin_trylock(&alloc->lock)) - goto err_get_alloc_lock_failed; + if (!mutex_trylock(&alloc->mutex)) + goto err_get_alloc_mutex_failed; if (!page->page_ptr) goto err_page_already_freed; @@ -1090,7 +1090,7 @@ enum lru_status binder_alloc_free_page(struct list_head *item, trace_binder_unmap_kernel_end(alloc, index); list_lru_isolate(lru, item); - spin_unlock(&alloc->lock); + mutex_unlock(&alloc->mutex); spin_unlock(&lru->lock); if (vma) { @@ -1109,8 +1109,8 @@ enum lru_status binder_alloc_free_page(struct list_head *item, err_invalid_vma: err_page_already_freed: - spin_unlock(&alloc->lock); -err_get_alloc_lock_failed: + mutex_unlock(&alloc->mutex); +err_get_alloc_mutex_failed: mmap_read_unlock(mm); err_mmap_read_lock_failed: mmput_async(mm); @@ -1145,7 +1145,7 @@ void binder_alloc_init(struct binder_alloc *alloc) alloc->pid = current->group_leader->pid; alloc->mm = current->mm; mmgrab(alloc->mm); - spin_lock_init(&alloc->lock); + mutex_init(&alloc->mutex); INIT_LIST_HEAD(&alloc->buffers); } diff --git a/drivers/android/binder_alloc.h b/drivers/android/binder_alloc.h index c02c8ebcb466b..33c5f971c0a55 100644 --- a/drivers/android/binder_alloc.h +++ b/drivers/android/binder_alloc.h @@ -9,7 +9,7 @@ #include #include #include -#include +#include #include #include #include @@ -72,7 +72,7 @@ struct binder_lru_page { /** * struct binder_alloc - per-binder proc state for binder allocator - * @lock: protects binder_alloc fields + * @mutex: protects binder_alloc fields * @vma: vm_area_struct passed to mmap_handler * (invariant after mmap) * @mm: copy of task->mm (invariant after open) @@ -96,7 +96,7 @@ struct binder_lru_page { * struct binder_buffer objects used to track the user buffers */ struct binder_alloc { - spinlock_t lock; + struct mutex mutex; struct vm_area_struct *vma; struct mm_struct *mm; unsigned long buffer; @@ -153,9 +153,9 @@ binder_alloc_get_free_async_space(struct binder_alloc *alloc) { size_t free_async_space; - spin_lock(&alloc->lock); + mutex_lock(&alloc->mutex); free_async_space = alloc->free_async_space; - spin_unlock(&alloc->lock); + mutex_unlock(&alloc->mutex); return free_async_space; }