From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guo Ren Subject: Re: [PATCH V6 08/33] csky: Process management and Signal Date: Fri, 28 Sep 2018 21:10:47 +0800 Message-ID: <20180928131047.GC2082@guoren-Inspiron-7460> References: <87h8iaoh2k.fsf@xmission.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <87h8iaoh2k.fsf@xmission.com> Sender: linux-kernel-owner@vger.kernel.org To: "Eric W. Biederman" Cc: akpm@linux-foundation.org, arnd@arndb.de, daniel.lezcano@linaro.org, davem@davemloft.net, gregkh@linuxfoundation.org, jason@lakedaemon.net, marc.zyngier@arm.com, mark.rutland@arm.com, mchehab+samsung@kernel.org, peterz@infradead.org, robh@kernel.org, robh+dt@kernel.org, tglx@linutronix.de, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, devicetree@vger.kernel.org, green.hu@gmail.com List-Id: devicetree@vger.kernel.org On Thu, Sep 27, 2018 at 09:50:43PM +0200, Eric W. Biederman wrote: > Guo Ren writes: > > > --- /dev/null > > +++ b/arch/csky/abiv2/fpu.c > > +void fpu_fpe(struct pt_regs * regs) > > +{ > > + int sig; > > + unsigned int fesr; > > + siginfo_t info; > > + > > + fesr = mfcr("cr<2, 2>"); > > + > > + if(fesr & FPE_ILLE){ > > + info.si_code = ILL_ILLOPC; > > + sig = SIGILL; > > + } > > + else if(fesr & FPE_IDC){ > > + info.si_code = ILL_ILLOPN; > > + sig = SIGILL; > > + } > > + else if(fesr & FPE_FEC){ > > + sig = SIGFPE; > > + if(fesr & FPE_IOC){ > > + info.si_code = FPE_FLTINV; > > + } > > + else if(fesr & FPE_DZC){ > > + info.si_code = FPE_FLTDIV; > > + } > > + else if(fesr & FPE_UFC){ > > + info.si_code = FPE_FLTUND; > > + } > > + else if(fesr & FPE_OFC){ > > + info.si_code = FPE_FLTOVF; > > + } > > + else if(fesr & FPE_IXC){ > > + info.si_code = FPE_FLTRES; > > + } > > + else { > > + info.si_code = NSIGFPE; > > + } > > + } > > + else { > > + info.si_code = NSIGFPE; > > + sig = SIGFPE; > > + } > > + info.si_signo = SIGFPE; > > + info.si_errno = 0; > > + info.si_addr = (void *)regs->pc; > > + force_sig_info(sig, &info, current); > > +} > > > This use of sending a signal is buggy. It results in undefined values > being copied to userspace. > > Userspace should never be sent NSIGXXX as a si_code. You can use > FPE_FLTUNK for this default case. Ok, thx for the tips. I'll fix it up in next patch-set. > In new code please use force_sig_fault instead of force_sig_info in new > code. That saves you the trouble of messing with struct siginfo. Ok, got it. Thx Best Regards Guo Ren