From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefano Stabellini Subject: Re: [PATCH 13/34] xen/arm: gic: Introduce GIC_SGI_MAX Date: Tue, 25 Mar 2014 18:19:40 +0000 Message-ID: References: <1395766541-23979-1-git-send-email-julien.grall@linaro.org> <1395766541-23979-14-git-send-email-julien.grall@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1WSVxO-0003sY-Gr for xen-devel@lists.xenproject.org; Tue, 25 Mar 2014 18:20:14 +0000 In-Reply-To: <1395766541-23979-14-git-send-email-julien.grall@linaro.org> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Julien Grall Cc: xen-devel@lists.xenproject.org, tim@xen.org, ian.campbell@citrix.com, stefano.stabellini@citrix.com List-Id: xen-devel@lists.xenproject.org On Tue, 25 Mar 2014, Julien Grall wrote: > All the functions that send an SGI takes an enum. Therefore checking everytime > if the value is in the range is not correct. > > Introduce GIC_SGI_MAX to check the enum will never reach more than 16 values. > > This is fix the compilation with Clang 3.5: > > gic.c:515:15: error: comparison of constant 16 with expression of type 'enum gic_sgi' is always true [-Werror,-Wtautological-constant-out-of-range-compare] > ASSERT(sgi < 16); /* There are only 16 SGIs */ > ~~~ ^ ~~ > xen/xen/include/xen/lib.h:43:26: note: expanded from macro 'ASSERT' > do { if ( unlikely(!(p)) ) assert_failed(#p); } while (0) > ^ > xen/xen/include/xen/compiler.h:11:41: note: expanded from macro 'unlikely' > #define unlikely(x) __builtin_expect((x),0) > > Signed-off-by: Julien Grall > Cc: Ian Campbell > Cc: Stefano Stabellini > Cc: Tim Deegan > --- > xen/arch/arm/gic.c | 7 ++++--- > xen/include/asm-arm/gic.h | 2 ++ > 2 files changed, 6 insertions(+), 3 deletions(-) > > diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c > index 0095b97..41142a5 100644 > --- a/xen/arch/arm/gic.c > +++ b/xen/arch/arm/gic.c > @@ -481,7 +481,8 @@ void send_SGI_mask(const cpumask_t *cpumask, enum gic_sgi sgi) > unsigned int mask = 0; > cpumask_t online_mask; > > - ASSERT(sgi < 16); /* There are only 16 SGIs */ > + BUILD_BUG_ON(GIC_SGI_MAX >= 16); > + ASSERT(sgi != GIC_SGI_MAX); These new checks wouldn't be able to cover the following case, while the previous check could: enum gic_sgi sgi = (enum gic_sgi) integer_greater_than_16; send_SGI_mask(something, sgi);