From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: Re: [REVIEW][PATCH 03/26] signal/arm64: Use force_sig not force_sig_fault for SIGKILL Date: Thu, 23 May 2019 11:17:02 +0100 Message-ID: <20190523101702.GG26646@fuggles.cambridge.arm.com> References: <20190523003916.20726-1-ebiederm@xmission.com> <20190523003916.20726-4-ebiederm@xmission.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20190523003916.20726-4-ebiederm@xmission.com> Sender: linux-kernel-owner@vger.kernel.org To: "Eric W. Biederman" Cc: linux-kernel@vger.kernel.org, Linux Containers , Oleg Nesterov , linux-arch@vger.kernel.org, Dave Martin , James Morse List-Id: linux-arch.vger.kernel.org On Wed, May 22, 2019 at 07:38:53PM -0500, Eric W. Biederman wrote: > It really only matters to debuggers but the SIGKILL does not have any > si_codes that use the fault member of the siginfo union. Correct this > the simple way and call force_sig instead of force_sig_fault when the > signal is SIGKILL. > > Cc: stable@vger.kernel.org > Cc: Dave Martin > Cc: James Morse > Cc: Will Deacon > Fixes: af40ff687bc9 ("arm64: signal: Ensure si_code is valid for all fault signals") > Signed-off-by: "Eric W. Biederman" > --- > arch/arm64/kernel/traps.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c > index ade32046f3fe..0feb17bdcaa0 100644 > --- a/arch/arm64/kernel/traps.c > +++ b/arch/arm64/kernel/traps.c > @@ -282,6 +282,11 @@ void arm64_notify_die(const char *str, struct pt_regs *regs, > current->thread.fault_address = 0; > current->thread.fault_code = err; > > + if (signo == SIGKILL) { > + arm64_show_signal(signo, str); > + force_sig(signo, current); > + return; > + } I know it's a bit of a misnomer, but I'd rather do this check inside arm64_force_sig_fault, since I think we have other callers (e.g. do_bad_area()) which also blindly pass in SIGKILL here. We could rename the thing if necessary. Will From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from foss.arm.com ([217.140.101.70]:42332 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726846AbfEWKRG (ORCPT ); Thu, 23 May 2019 06:17:06 -0400 Date: Thu, 23 May 2019 11:17:02 +0100 From: Will Deacon Subject: Re: [REVIEW][PATCH 03/26] signal/arm64: Use force_sig not force_sig_fault for SIGKILL Message-ID: <20190523101702.GG26646@fuggles.cambridge.arm.com> References: <20190523003916.20726-1-ebiederm@xmission.com> <20190523003916.20726-4-ebiederm@xmission.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190523003916.20726-4-ebiederm@xmission.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: "Eric W. Biederman" Cc: linux-kernel@vger.kernel.org, Linux Containers , Oleg Nesterov , linux-arch@vger.kernel.org, Dave Martin , James Morse Message-ID: <20190523101702.02rHsbBtSAw3Q3CBLIYnQVhivlvbD0Ri6iaWEr3pt5o@z> On Wed, May 22, 2019 at 07:38:53PM -0500, Eric W. Biederman wrote: > It really only matters to debuggers but the SIGKILL does not have any > si_codes that use the fault member of the siginfo union. Correct this > the simple way and call force_sig instead of force_sig_fault when the > signal is SIGKILL. > > Cc: stable@vger.kernel.org > Cc: Dave Martin > Cc: James Morse > Cc: Will Deacon > Fixes: af40ff687bc9 ("arm64: signal: Ensure si_code is valid for all fault signals") > Signed-off-by: "Eric W. Biederman" > --- > arch/arm64/kernel/traps.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c > index ade32046f3fe..0feb17bdcaa0 100644 > --- a/arch/arm64/kernel/traps.c > +++ b/arch/arm64/kernel/traps.c > @@ -282,6 +282,11 @@ void arm64_notify_die(const char *str, struct pt_regs *regs, > current->thread.fault_address = 0; > current->thread.fault_code = err; > > + if (signo == SIGKILL) { > + arm64_show_signal(signo, str); > + force_sig(signo, current); > + return; > + } I know it's a bit of a misnomer, but I'd rather do this check inside arm64_force_sig_fault, since I think we have other callers (e.g. do_bad_area()) which also blindly pass in SIGKILL here. We could rename the thing if necessary. Will