Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754741Ab1DDO6K (ORCPT ); Mon, 4 Apr 2011 10:58:10 -0400 Received: from arkanian.console-pimps.org ([212.110.184.194]:39497 "EHLO arkanian.console-pimps.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754601Ab1DDO6J (ORCPT ); Mon, 4 Apr 2011 10:58:09 -0400 From: Matt Fleming To: Hans-Christian Egtvedt Cc: linux-kernel@vger.kernel.org, Oleg Nesterov , Matt Fleming Subject: [PATCH] avr32: init cannot ignore signals sent by force_sig_info() Date: Mon, 4 Apr 2011 15:58:04 +0100 Message-Id: <1301929084-2025-1-git-send-email-matt@console-pimps.org> X-Mailer: git-send-email 1.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2767 Lines: 73 From: Matt Fleming We can delete the code that checks to see if we're sending an ignored signal to init because force_sig_info() already handles this case. force_sig_info() will kill init even if the signal handler is SIG_DFL and the scenario described in the comment where init might "generate the same exception over and over again" cannot occur (force_sig_info() clears SIGNAL_UNKILLABLE to ensure that init will die). Also, the use of is_global_init() is not correct in the multhreaded case, as Oleg Nesterov explains, "is_global_init() is not right in theory, /sbin/init can be multithreaded. And, this doesn't cover the sub-namespace inits... I'd suggest to check SIGNAL_UNKILLABLE, but looking closer I think you can simply remove this code." It seems this code was copied from arch/powerpc in March 2007 in commit 623b0355d5b1 "[AVR32] Clean up exception handling code" but the code was deleted from arch/powerpc in November 2009 in commit a0592d42fe3e "powerpc: kill the obsolete code under is_global_init()" So catch up with powerpc and delete the bogus code. Signed-off-by: Matt Fleming --- arch/avr32/kernel/traps.c | 22 ---------------------- 1 files changed, 0 insertions(+), 22 deletions(-) diff --git a/arch/avr32/kernel/traps.c b/arch/avr32/kernel/traps.c index b91b204..7aa2575 100644 --- a/arch/avr32/kernel/traps.c +++ b/arch/avr32/kernel/traps.c @@ -95,28 +95,6 @@ void _exception(long signr, struct pt_regs *regs, int code, info.si_code = code; info.si_addr = (void __user *)addr; force_sig_info(signr, &info, current); - - /* - * Init gets no signals that it doesn't have a handler for. - * That's all very well, but if it has caused a synchronous - * exception and we ignore the resulting signal, it will just - * generate the same exception over and over again and we get - * nowhere. Better to kill it and let the kernel panic. - */ - if (is_global_init(current)) { - __sighandler_t handler; - - spin_lock_irq(¤t->sighand->siglock); - handler = current->sighand->action[signr-1].sa.sa_handler; - spin_unlock_irq(¤t->sighand->siglock); - if (handler == SIG_DFL) { - /* init has generated a synchronous exception - and it doesn't have a handler for the signal */ - printk(KERN_CRIT "init has generated signal %ld " - "but has no handler for it\n", signr); - do_exit(signr); - } - } } asmlinkage void do_nmi(unsigned long ecr, struct pt_regs *regs) -- 1.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/