Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755790AbYAHNAg (ORCPT ); Tue, 8 Jan 2008 08:00:36 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751122AbYAHNA0 (ORCPT ); Tue, 8 Jan 2008 08:00:26 -0500 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:4467 "EHLO spitz.ucw.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750724AbYAHNAZ (ORCPT ); Tue, 8 Jan 2008 08:00:25 -0500 Date: Mon, 7 Jan 2008 15:03:49 +0000 From: Pavel Machek To: Bodo Eggert <7eggert@gmx.de> Cc: Ingo Oeser , Bernd Schubert , linux-kernel@vger.kernel.org, "H. Peter Anvin" Subject: Re: sleep before boot panic Message-ID: <20080107150349.GA6523@ucw.cz> References: <9II6K-1Pg-9@gated-at.bofh.it> <9IJ2M-3l2-3@gated-at.bofh.it> <9IJme-3Nb-13@gated-at.bofh.it> <9IKrY-5vk-15@gated-at.bofh.it> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6901 Lines: 179 Hi! > Introduce config CONFIG_SOFTPANIC > Enabling this option changes a hard panic on boot errors to a > soft panic, which does not stop the system completely. > You can still scroll the screen and read the messages. > > Signed-Off-By: Bodo Eggert <7eggert@gmx.de> Looks good to me... but should this be configurable? IMO we should just do the right thing. Pavel > diff -pruN linux-2.6.23.base/include/linux/kernel.h > linux-2.6.23.softpanic/include/linux/kernel.h > --- linux-2.6.23.base/include/linux/kernel.h 2007-10-11 14:15:39.000000000 +0200 > +++ linux-2.6.23.softpanic/include/linux/kernel.h 2007-10-11 14:45:15.000000000 > +0200 > @@ -108,6 +108,12 @@ extern struct atomic_notifier_head panic > extern long (*panic_blink)(long time); > NORET_TYPE void panic(const char * fmt, ...) > __attribute__ ((NORET_AND format (printf, 1, 2))) __cold; > +#ifdef SOFTPANIC > +NORET_TYPE void softpanic(const char * fmt, ...) > + __attribute__ ((NORET_AND format (printf, 1, 2))) __cold; > +#else > +# define softpanic(...) do { panic(__VA_ARGS__); } while (0) > +#endif > extern void oops_enter(void); > extern void oops_exit(void); > extern int oops_may_print(void); > diff -pruN linux-2.6.23.base/init/Kconfig linux-2.6.23.softpanic/init/Kconfig > --- linux-2.6.23.base/init/Kconfig 2007-10-11 14:15:42.000000000 +0200 > +++ linux-2.6.23.softpanic/init/Kconfig 2007-10-11 15:19:07.000000000 +0200 > @@ -441,6 +441,14 @@ config BUG > option for embedded systems with no facilities for reporting errors. > Just say Y. > > +config SOFTPANIC > + bool "Enable softpanic for boot errors" if EMBEDDED > + default y > + help > + Enabling this option changes a hard panic on boot errors to a > + soft panic, which does not stop the system completely. > + You can still scroll the screen and read the messages. > + > config ELF_CORE > default y > bool "Enable ELF core dumps" if EMBEDDED > diff -pruN linux-2.6.23.base/init/do_mounts.c > linux-2.6.23.softpanic/init/do_mounts.c > --- linux-2.6.23.base/init/do_mounts.c 2007-10-11 14:15:42.000000000 +0200 > +++ linux-2.6.23.softpanic/init/do_mounts.c 2007-10-11 14:48:51.000000000 +0200 > @@ -330,7 +330,7 @@ retry: > printk("Please append a correct \"root=\" boot option; here are the available > partitions:\n"); > > printk_all_partitions(); > - panic("VFS: Unable to mount root fs on %s", b); > + softpanic("VFS: Unable to mount root fs on %s", b); > } > > printk("List of all partitions:\n"); > @@ -342,7 +342,7 @@ retry: > #ifdef CONFIG_BLOCK > __bdevname(ROOT_DEV, b); > #endif > - panic("VFS: Unable to mount root fs on %s", b); > + softpanic("VFS: Unable to mount root fs on %s", b); > out: > putname(fs_names); > } > diff -pruN linux-2.6.23.base/init/main.c linux-2.6.23.softpanic/init/main.c > --- linux-2.6.23.base/init/main.c 2007-10-11 14:15:42.000000000 +0200 > +++ linux-2.6.23.softpanic/init/main.c 2007-10-11 14:40:06.000000000 +0200 > @@ -590,7 +590,7 @@ asmlinkage void __init start_kernel(void > */ > console_init(); > if (panic_later) > - panic(panic_later, panic_param); > + softpanic(panic_later, panic_param); > > lockdep_info(); > > @@ -807,7 +807,7 @@ static int noinline init_post(void) > run_init_process("/bin/init"); > run_init_process("/bin/sh"); > > - panic("No init found. Try passing init= option to kernel."); > + softpanic("No init found. Try passing init= option to kernel."); > } > > static int __init kernel_init(void * unused) > diff -pruN linux-2.6.23.base/kernel/panic.c > linux-2.6.23.softpanic/kernel/panic.c > --- linux-2.6.23.base/kernel/panic.c 2007-10-11 14:15:42.000000000 +0200 > +++ linux-2.6.23.softpanic/kernel/panic.c 2007-10-11 14:53:42.000000000 +0200 > @@ -139,7 +139,66 @@ NORET_TYPE void panic(const char * fmt, > } > } > > +#ifdef SOFTPANIC > +NORET_TYPE void softpanic(const char * fmt, ...) > +{ > + long i; > + static char buf[1024]; > + va_list args; > +#if defined(CONFIG_S390) > + unsigned long caller = (unsigned long) __builtin_return_address(0); > +#endif > + > + va_start(args, fmt); > + vsnprintf(buf, sizeof(buf), fmt, args); > + va_end(args); > + printk(KERN_EMERG "Kernel panic - not syncing: %s\n",buf); > + > + atomic_notifier_call_chain(&panic_notifier_list, 0, buf); > + > + if (!panic_blink) > + panic_blink = no_blink; > + > + if (panic_timeout > 0) { > + /* > + * Delay timeout seconds before rebooting the machine. > + * We can't use the "normal" timers since we just panicked.. > + */ > + printk(KERN_EMERG "Rebooting in %d seconds..",panic_timeout); > + for (i = 0; i < panic_timeout*1000; ) { > + touch_nmi_watchdog(); > + i += panic_blink(i); > + mdelay(1); > + i++; > + } > + /* This will not be a clean reboot, with everything > + * shutting down. But if there is a chance of > + * rebooting the system it will be rebooted. > + */ > + kernel_restart(NULL); > + } > +#ifdef __sparc__ > + { > + extern int stop_a_enabled; > + /* Make sure the user can actually press Stop-A (L1-A) */ > + stop_a_enabled = 1; > + printk(KERN_EMERG "Press Stop-A (L1-A) to return to the boot prom\n"); > + } > +#endif > +#if defined(CONFIG_S390) > + disabled_wait(caller); > +#endif > + for (i = 0;;) { > + touch_softlockup_watchdog(); > + i += panic_blink(i); > + msleep(1); > + i++; > + } > +} > +#endif > + > EXPORT_SYMBOL(panic); > +EXPORT_SYMBOL(softpanic); > > /** > * print_tainted - return a string to represent the kernel taint state. > > -- > 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/ -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- 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/