diff --git a/include/linux/simple_ring_buffer.h b/include/linux/simple_ring_buffer.h index 2c4c0ae336bc..21aec556293e 100644 --- a/include/linux/simple_ring_buffer.h +++ b/include/linux/simple_ring_buffer.h @@ -54,4 +54,12 @@ int simple_ring_buffer_reset(struct simple_rb_per_cpu *cpu_buffer); int simple_ring_buffer_swap_reader_page(struct simple_rb_per_cpu *cpu_buffer); +int simple_ring_buffer_init_mm(struct simple_rb_per_cpu *cpu_buffer, + struct simple_buffer_page *bpages, + const struct ring_buffer_desc *desc, + void *(*load_page)(unsigned long va), + void (*unload_page)(void *va)); + +void simple_ring_buffer_unload_mm(struct simple_rb_per_cpu *cpu_buffer, + void (*unload_page)(void *)); #endif diff --git a/kernel/trace/simple_ring_buffer.c b/kernel/trace/simple_ring_buffer.c index 15df9781411b..02af2297ae5a 100644 --- a/kernel/trace/simple_ring_buffer.c +++ b/kernel/trace/simple_ring_buffer.c @@ -71,7 +71,7 @@ static void simple_bpage_reset(struct simple_buffer_page *bpage) local_set(&bpage->page->commit, 0); } -static void simple_bpage_init(struct simple_buffer_page *bpage, unsigned long page) +static void simple_bpage_init(struct simple_buffer_page *bpage, void *page) { INIT_LIST_HEAD(&bpage->link); bpage->page = (struct buffer_data_page *)page; @@ -372,6 +372,90 @@ int simple_ring_buffer_reset(struct simple_rb_per_cpu *cpu_buffer) } EXPORT_SYMBOL_GPL(simple_ring_buffer_reset); +int simple_ring_buffer_init_mm(struct simple_rb_per_cpu *cpu_buffer, + struct simple_buffer_page *bpages, + const struct ring_buffer_desc *desc, + void *(*load_page)(unsigned long va), + void (*unload_page)(void *va)) +{ + struct simple_buffer_page *bpage = bpages; + int ret = 0; + void *page; + int i; + + /* At least 1 reader page and two pages in the ring-buffer */ + if (desc->nr_page_va < 3) + return -EINVAL; + + memset(cpu_buffer, 0, sizeof(*cpu_buffer)); + + cpu_buffer->meta = load_page(desc->meta_va); + if (!cpu_buffer->meta) + return -EINVAL; + + memset(cpu_buffer->meta, 0, sizeof(*cpu_buffer->meta)); + cpu_buffer->meta->meta_page_size = PAGE_SIZE; + cpu_buffer->meta->nr_subbufs = cpu_buffer->nr_pages; + + /* The reader page is not part of the ring initially */ + page = load_page(desc->page_va[0]); + if (!page) { + unload_page(cpu_buffer->meta); + return -EINVAL; + } + + simple_bpage_init(bpage, page); + bpage->id = 0; + + cpu_buffer->nr_pages = 1; + + cpu_buffer->reader_page = bpage; + cpu_buffer->tail_page = bpage + 1; + cpu_buffer->head_page = bpage + 1; + + for (i = 1; i < desc->nr_page_va; i++) { + page = load_page(desc->page_va[i]); + if (!page) { + ret = -EINVAL; + break; + } + + simple_bpage_init(++bpage, page); + + bpage->link.next = &(bpage + 1)->link; + bpage->link.prev = &(bpage - 1)->link; + bpage->id = i; + + cpu_buffer->nr_pages = i + 1; + } + + if (ret) { + for (i--; i >= 0; i--) + unload_page((void *)desc->page_va[i]); + unload_page(cpu_buffer->meta); + + return ret; + } + + /* Close the ring */ + bpage->link.next = &cpu_buffer->tail_page->link; + cpu_buffer->tail_page->link.prev = &bpage->link; + + /* The last init'ed page points to the head page */ + simple_bpage_set_head_link(bpage); + + cpu_buffer->bpages = bpages; + + return 0; +} + +static void *__load_page(unsigned long page) +{ + return (void *)page; +} + +static void __unload_page(void *page) { } + /** * simple_ring_buffer_init - Init @cpu_buffer based on @desc * @cpu_buffer: A simple_rb_per_cpu buffer to init, allocated by the caller. @@ -383,65 +467,34 @@ EXPORT_SYMBOL_GPL(simple_ring_buffer_reset); int simple_ring_buffer_init(struct simple_rb_per_cpu *cpu_buffer, struct simple_buffer_page *bpages, const struct ring_buffer_desc *desc) { - struct simple_buffer_page *bpage = bpages; - int i; - - /* At least 1 reader page and two pages in the ring-buffer */ - if (desc->nr_page_va < 3) - return -EINVAL; - - memset(cpu_buffer, 0, sizeof(*cpu_buffer)); - - cpu_buffer->bpages = bpages; - - cpu_buffer->meta = (void *)desc->meta_va; - memset(cpu_buffer->meta, 0, sizeof(*cpu_buffer->meta)); - cpu_buffer->meta->meta_page_size = PAGE_SIZE; - cpu_buffer->meta->nr_subbufs = cpu_buffer->nr_pages; - - /* The reader page is not part of the ring initially */ - simple_bpage_init(bpage, desc->page_va[0]); - bpage->id = 0; - - cpu_buffer->nr_pages = 1; - - cpu_buffer->reader_page = bpage; - cpu_buffer->tail_page = bpage + 1; - cpu_buffer->head_page = bpage + 1; - - for (i = 1; i < desc->nr_page_va; i++) { - simple_bpage_init(++bpage, desc->page_va[i]); - - bpage->link.next = &(bpage + 1)->link; - bpage->link.prev = &(bpage - 1)->link; - bpage->id = i; - - cpu_buffer->nr_pages = i + 1; - } - - /* Close the ring */ - bpage->link.next = &cpu_buffer->tail_page->link; - cpu_buffer->tail_page->link.prev = &bpage->link; - - /* The last init'ed page points to the head page */ - simple_bpage_set_head_link(bpage); - - return 0; + return simple_ring_buffer_init_mm(cpu_buffer, bpages, desc, __load_page, __unload_page); } EXPORT_SYMBOL_GPL(simple_ring_buffer_init); +void simple_ring_buffer_unload_mm(struct simple_rb_per_cpu *cpu_buffer, + void (*unload_page)(void *)) +{ + int p; + + if (!simple_rb_loaded(cpu_buffer)) + return; + + simple_rb_enable_tracing(cpu_buffer, false); + + unload_page(cpu_buffer->meta); + for (p = 0; p < cpu_buffer->nr_pages; p++) + unload_page(cpu_buffer->bpages[p].page); + + cpu_buffer->bpages = NULL; +} + /** * simple_ring_buffer_unload - Prepare @cpu_buffer for deletion * @cpu_buffer: A simple_rb_per_cpu that will be deleted. */ void simple_ring_buffer_unload(struct simple_rb_per_cpu *cpu_buffer) { - if (!simple_rb_loaded(cpu_buffer)) - return; - - simple_rb_enable_tracing(cpu_buffer, false); - - cpu_buffer->bpages = NULL; + return simple_ring_buffer_unload_mm(cpu_buffer, __unload_page); } EXPORT_SYMBOL_GPL(simple_ring_buffer_unload);