From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f72.google.com (mail-lf0-f72.google.com [209.85.215.72]) by kanga.kvack.org (Postfix) with ESMTP id D14E76B025E for ; Mon, 2 May 2016 07:34:53 -0400 (EDT) Received: by mail-lf0-f72.google.com with SMTP id m64so35693540lfd.1 for ; Mon, 02 May 2016 04:34:53 -0700 (PDT) Received: from mail-lf0-x229.google.com (mail-lf0-x229.google.com. [2a00:1450:4010:c07::229]) by mx.google.com with ESMTPS id i131si16856487lfd.115.2016.05.02.04.34.52 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 02 May 2016 04:34:52 -0700 (PDT) Received: by mail-lf0-x229.google.com with SMTP id m64so30838145lfd.1 for ; Mon, 02 May 2016 04:34:52 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1462167374-6321-1-git-send-email-chengang@emindsoft.com.cn> References: <1462167374-6321-1-git-send-email-chengang@emindsoft.com.cn> Date: Mon, 2 May 2016 13:34:52 +0200 Message-ID: Subject: Re: [PATCH] mm/kasan/kasan.h: Fix boolean checking issue for kasan_report_enabled() From: Alexander Potapenko Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: To: Chen Gang Cc: Andrew Morton , Andrey Ryabinin , Dmitriy Vyukov , kasan-dev , LKML , Linux Memory Management List , Chen Gang On Mon, May 2, 2016 at 7:36 AM, wrote: > From: Chen Gang > > According to kasan_[dis|en]able_current() comments and the kasan_depth' > s initialization, if kasan_depth is zero, it means disable. The comments for those functions are really poor, but there's nothing there that says kasan_depth=3D=3D0 disables KASAN. Actually, kasan_report_enabled() is currently the only place that denotes the semantics of kasan_depth, so it couldn't be wrong. init_task.kasan_depth is 1 during bootstrap and is then set to zero by kasan_init() For every other thread, current->kasan_depth is zero-initialized. > So need use "!!kasan_depth" instead of "!kasan_depth" for checking > enable. > > Signed-off-by: Chen Gang > --- > mm/kasan/kasan.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h > index 7da78a6..6464b8f 100644 > --- a/mm/kasan/kasan.h > +++ b/mm/kasan/kasan.h > @@ -102,7 +102,7 @@ static inline const void *kasan_shadow_to_mem(const v= oid *shadow_addr) > > static inline bool kasan_report_enabled(void) > { > - return !current->kasan_depth; > + return !!current->kasan_depth; > } > > void kasan_report(unsigned long addr, size_t size, > -- > 1.9.3 > --=20 Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Stra=C3=9Fe, 33 80636 M=C3=BCnchen Gesch=C3=A4ftsf=C3=BChrer: Matthew Scott Sucherman, Paul Terence Manicle Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org