Messages in this thread Patch in this message | | | Subject | Re: [PATCHv3] perf: Fix vmalloc ring buffer free function | From | Peter Zijlstra <> | Date | Tue, 12 Mar 2013 17:24:50 +0100 |
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Right you are..
How about something like the below; using that 0 << -1 is still 0.
--- kernel/events/ring_buffer.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c index 23cb34f..e72ca70 100644 --- a/kernel/events/ring_buffer.c +++ b/kernel/events/ring_buffer.c @@ -316,7 +316,7 @@ void rb_free(struct ring_buffer *rb) struct page * perf_mmap_to_page(struct ring_buffer *rb, unsigned long pgoff) { - if (pgoff > (1UL << page_order(rb))) + if (pgoff > (rb->nr_pages << page_order(rb))) return NULL; return vmalloc_to_page((void *)rb->user_page + pgoff * PAGE_SIZE); @@ -336,10 +336,10 @@ static void rb_free_work(struct work_struct *work) int i, nr; rb = container_of(work, struct ring_buffer, work); - nr = 1 << page_order(rb); + nr = rb->nr_pages << page_order(rb); base = rb->user_page; - for (i = 0; i < nr + 1; i++) + for (i = 0; i <= nr; i++) perf_mmap_unmark_page(base + (i * PAGE_SIZE)); vfree(base); @@ -373,7 +373,7 @@ struct ring_buffer *rb_alloc(int nr_pages, long watermark, int cpu, int flags) rb->user_page = all_buf; rb->data_pages[0] = all_buf + PAGE_SIZE; rb->page_order = ilog2(nr_pages); - rb->nr_pages = 1; + rb->nr_pages = !!nr_pages; ring_buffer_init(rb, watermark, flags);
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