From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joe Perches Subject: Re: [PATCH] mm: Fix warning comparing pointer to 0 Date: Wed, 24 Nov 2021 20:00:50 -0800 Message-ID: <5391025983087ae9d1292387bc0b2b37c9c57863.camel@perches.com> References: <1637748818-21730-1-git-send-email-jiapeng.chong@linux.alibaba.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1637748818-21730-1-git-send-email-jiapeng.chong@linux.alibaba.com> List-ID: Content-Type: text/plain; charset="us-ascii" To: Jiapeng Chong , rth@twiddle.net Cc: ink@jurassic.park.msu.ru, mattst88@gmail.com, linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org On Wed, 2021-11-24 at 18:13 +0800, Jiapeng Chong wrote: > Fix the following coccicheck warning: > > ./arch/alpha/mm/fault.c:193:52-53: WARNING comparing pointer to 0. > > Reported-by: Abaci Robot > Signed-off-by: Jiapeng Chong [] > diff --git a/arch/alpha/mm/fault.c b/arch/alpha/mm/fault.c [] > @@ -190,7 +190,7 @@ > > no_context: > /* Are we prepared to handle this fault as an exception? */ > - if ((fixup = search_exception_tables(regs->pc)) != 0) { > + if (!(fixup = search_exception_tables(regs->pc)) { This is now a reversed test. The more typical kernel style is: fixup = search_exception_tables(regs->pc); if (fixup) { > unsigned long newpc; > newpc = fixup_exception(dpf_reg, fixup, regs->pc); > regs->pc = newpc; and it looks as if newpc is unnecessary. Maybe: --- arch/alpha/mm/fault.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/arch/alpha/mm/fault.c b/arch/alpha/mm/fault.c index eee5102c3d889..364b6322629cb 100644 --- a/arch/alpha/mm/fault.c +++ b/arch/alpha/mm/fault.c @@ -192,10 +192,9 @@ do_page_fault(unsigned long address, unsigned long mmcsr, no_context: /* Are we prepared to handle this fault as an exception? */ - if ((fixup = search_exception_tables(regs->pc)) != 0) { - unsigned long newpc; - newpc = fixup_exception(dpf_reg, fixup, regs->pc); - regs->pc = newpc; + fixup = search_exception_tables(regs->pc) + if (fixup) { + regs->pc = fixup_exception(dpf_reg, fixup, regs->pc); return; }