From: Paul Durrant Date: Tue, 16 Jul 2019 11:29:02 +0000 (+0200) Subject: mm.h: fix BUG_ON() condition in put_page_alloc_ref() X-Git-Tag: archive/raspbian/4.14.0+80-gd101b417b7-1+rpi1^2~63^2~1930 X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=44a887d021d;p=xen.git mm.h: fix BUG_ON() condition in put_page_alloc_ref() The BUG_ON() was misplaced when this function was introduced in commit ec83f825 "mm.h: add helper function to test-and-clear _PGC_allocated". It will fire incorrectly if _PGC_allocated is already clear on entry. Thus it should be moved after the if statement. Signed-off-by: Paul Durrant Reviewed-by: Jan Beulich --- diff --git a/xen/include/xen/mm.h b/xen/include/xen/mm.h index 5d0c19f011..cfea38f801 100644 --- a/xen/include/xen/mm.h +++ b/xen/include/xen/mm.h @@ -667,9 +667,11 @@ static inline void put_page_alloc_ref(struct page_info *page) * the caller holding an additional reference. I.e. the allocation * reference must never be the last reference held. */ - BUG_ON((page->count_info & PGC_count_mask) <= 1); if ( test_and_clear_bit(_PGC_allocated, &page->count_info) ) + { + BUG_ON((page->count_info & PGC_count_mask) <= 1); put_page(page); + } } #endif /* __XEN_MM_H__ */