/* * SoftDog: A Software Watchdog Device * * (c) Copyright 1996 Alan Cox , * All Rights Reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * * Neither Alan Cox nor CymruNet Ltd. admit liability nor provide * warranty for any of this software. This material is provided * "AS-IS" and at no charge. * * (c) Copyright 1995 Alan Cox * * Software only watchdog driver. Unlike its big brother the WDT501P * driver this won't always recover a failed machine. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #define TIMER_MARGIN 60 /* Default is 60 seconds */ static unsigned int soft_margin = TIMER_MARGIN; /* in seconds */ module_param(soft_margin, uint, 0); MODULE_PARM_DESC(soft_margin, "Watchdog soft_margin in seconds. (0 < soft_margin < 65536, default=" __MODULE_STRING(TIMER_MARGIN) ")"); static bool nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); static int soft_noboot; module_param(soft_noboot, int, 0); MODULE_PARM_DESC(soft_noboot, "Softdog action, set to 1 to ignore reboots, 0 to reboot (default=0)"); static int soft_panic; module_param(soft_panic, int, 0); MODULE_PARM_DESC(soft_panic, "Softdog action, set to 1 to panic, 0 to reboot (default=0)"); static void softdog_fire(unsigned long data) { module_put(THIS_MODULE); if (soft_noboot) { pr_crit("Triggered - Reboot ignored\n"); } else if (soft_panic) { pr_crit("Initiating panic\n"); panic("Software Watchdog Timer expired"); } else { pr_crit("Initiating system reboot\n"); emergency_restart(); pr_crit("Reboot didn't ?????\n"); } } static struct timer_list softdog_ticktock = TIMER_INITIALIZER(softdog_fire, 0, 0); static struct watchdog_device softdog_dev; static void softdog_pretimeout(unsigned long data) { watchdog_notify_pretimeout(&softdog_dev); } static struct timer_list softdog_preticktock = TIMER_INITIALIZER(softdog_pretimeout, 0, 0); static int softdog_ping(struct watchdog_device *w) { if (!mod_timer(&softdog_ticktock, jiffies + (w->timeout * HZ))) __module_get(THIS_MODULE); if (w->pretimeout) mod_timer(&softdog_preticktock, jiffies + (w->timeout - w->pretimeout) * HZ); else del_timer(&softdog_preticktock); return 0; } static int softdog_stop(struct watchdog_device *w) { if (del_timer(&softdog_ticktock)) module_put(THIS_MODULE); del_timer(&softdog_preticktock); return 0; } static struct watchdog_info softdog_info = { .identity = "Software Watchdog", .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE | WDIOF_PRETIMEOUT, }; static const struct watchdog_ops softdog_ops = { .owner = THIS_MODULE, .start = softdog_ping, .stop = softdog_stop, }; static struct watchdog_device softdog_dev = { .info = &softdog_info, .ops = &softdog_ops, .min_timeout = 1, .max_timeout = 65535, .timeout = TIMER_MARGIN, }; static int __init softdog_init(void) { int ret; watchdog_init_timeout(&softdog_dev, soft_margin, NULL); watchdog_set_nowayout(&softdog_dev, nowayout); watchdog_stop_on_reboot(&softdog_dev); ret = watchdog_register_device(&softdog_dev); if (ret) return ret; pr_info("initialized. soft_noboot=%d soft_margin=%d sec soft_panic=%d (nowayout=%d)\n", soft_noboot, softdog_dev.timeout, soft_panic, nowayout); return 0; } module_init(softdog_init); static void __exit softdog_exit(void) { watchdog_unregister_device(&softdog_dev); } module_exit(softdog_exit); MODULE_AUTHOR("Alan Cox"); MODULE_DESCRIPTION("Software Watchdog Device Driver"); MODULE_LICENSE("GPL"); 'ctrl'>
authorArd Biesheuvel <ard.biesheuvel@linaro.org>2017-02-01 17:45:02 +0000
committerIngo Molnar <mingo@kernel.org>2017-02-01 21:17:49 +0100
commitc8f325a59cfc718d13a50fbc746ed9b415c25e92 (patch)
treed53fbdac9d0781e39a13b2ac6b2bd258cf3b4140 /sound/core/hwdep.c
parentbf29bddf0417a4783da3b24e8c9e017ac649326f (diff)
efi/fdt: Avoid FDT manipulation after ExitBootServices()
Some AArch64 UEFI implementations disable the MMU in ExitBootServices(), after which unaligned accesses to RAM are no longer supported. Commit: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel") fixed an issue in the memory map handling of the stub FDT code, but inadvertently created an issue with such firmware, by moving some of the FDT manipulation to after the invocation of ExitBootServices(). Given that the stub's libfdt implementation uses the ordinary, accelerated string functions, which rely on hardware handling of unaligned accesses, manipulating the FDT with the MMU off may result in alignment faults. So fix the situation by moving the update_fdt_memmap() call into the callback function invoked by efi_exit_boot_services() right before it calls the ExitBootServices() UEFI service (which is arguably a better place for it anyway) Note that disabling the MMU in ExitBootServices() is not compliant with the UEFI spec, and carries great risk due to the fact that switching from cached to uncached memory accesses halfway through compiler generated code (i.e., involving a stack) can never be done in a way that is architecturally safe. Fixes: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel") Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Riku Voipio <riku.voipio@linaro.org> Cc: <stable@vger.kernel.org> Cc: mark.rutland@arm.com Cc: linux-efi@vger.kernel.org Cc: matt@codeblueprint.co.uk Cc: leif.lindholm@linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1485971102-23330-2-git-send-email-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'sound/core/hwdep.c')