From bdff78707f3ce47e891f3201c9666122a70556ce Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 24 Jul 2009 15:30:45 -0400 Subject: trace: stop tracer in oops_enter() If trace_printk_on_oops is set we lose interesting trace information when the tracer is enabled across oops handling and printing. We want the trace which might give us information _WHY_ we oopsed. Signed-off-by: Thomas Gleixner Signed-off-by: Steven Rostedt --- kernel/panic.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel/panic.c') diff --git a/kernel/panic.c b/kernel/panic.c index 984b3ecbd72..512ab73b0ca 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -301,6 +301,7 @@ int oops_may_print(void) */ void oops_enter(void) { + tracing_off(); /* can't trust the integrity of the kernel anymore: */ debug_locks_off(); do_oops_enter_exit(); -- cgit v1.2.3-70-g09d2 From fe002a419755f991e1219249c8ffe7dc0b798232 Mon Sep 17 00:00:00 2001 From: "Robert P. J. Day" Date: Sun, 28 Jun 2009 21:10:07 -0400 Subject: trivial: Correct print_tainted routine name in comment Signed-off-by: Robert P. J. Day Signed-off-by: Jiri Kosina --- kernel/panic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/panic.c') diff --git a/kernel/panic.c b/kernel/panic.c index 512ab73b0ca..bcdef26e333 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -177,7 +177,7 @@ static const struct tnt tnts[] = { * 'W' - Taint on warning. * 'C' - modules from drivers/staging are loaded. * - * The string is overwritten by the next call to print_taint(). + * The string is overwritten by the next call to print_tainted(). */ const char *print_tainted(void) { -- cgit v1.2.3-70-g09d2 From d014e8894dfc523dd9d2f2a17b6dcb94facea810 Mon Sep 17 00:00:00 2001 From: Aaro Koskinen Date: Fri, 2 Oct 2009 14:41:20 +0300 Subject: panic: Fix panic message visibility by calling bust_spinlocks(0) before dying Commit ffd71da4e3f ("panic: decrease oops_in_progress only after having done the panic") moved bust_spinlocks(0) to the end of the function, which in practice is never reached. As a result console_unblank() is not called, and on some systems the user may not see the panic message. Move it back up to before the unblanking. Signed-off-by: Aaro Koskinen Reviewed-by: Frederic Weisbecker LKML-Reference: <1254483680-25578-1-git-send-email-aaro.koskinen@nokia.com> Signed-off-by: Ingo Molnar --- kernel/panic.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel/panic.c') diff --git a/kernel/panic.c b/kernel/panic.c index 512ab73b0ca..bc4dcb6a389 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -90,6 +90,8 @@ NORET_TYPE void panic(const char * fmt, ...) atomic_notifier_call_chain(&panic_notifier_list, 0, buf); + bust_spinlocks(0); + if (!panic_blink) panic_blink = no_blink; @@ -136,7 +138,6 @@ NORET_TYPE void panic(const char * fmt, ...) mdelay(1); i++; } - bust_spinlocks(0); } EXPORT_SYMBOL(panic); -- cgit v1.2.3-70-g09d2 From 456b565cc52fbcdaa2e19ffdf40d9dd3b726d603 Mon Sep 17 00:00:00 2001 From: Simon Kagstrom Date: Fri, 16 Oct 2009 14:09:18 +0200 Subject: core: Add kernel message dumper to call on oopses and panics The core functionality is implemented as per Linus suggestion from http://lists.infradead.org/pipermail/linux-mtd/2009-October/027620.html (with the kmsg_dump implementation by Linus). A struct kmsg_dumper has been added which contains a callback to dump the kernel log buffers on crashes. The kmsg_dump function gets called from oops_exit() and panic() and invokes this callbacks with the crash reason. [dwmw2: Fix log_end handling] Signed-off-by: Simon Kagstrom Reviewed-by: Anders Grafstrom Reviewed-by: Linus Torvalds Acked-by: Ingo Molnar Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- include/linux/kmsg_dump.h | 44 +++++++++++++++++ kernel/panic.c | 3 ++ kernel/printk.c | 119 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 166 insertions(+) create mode 100644 include/linux/kmsg_dump.h (limited to 'kernel/panic.c') diff --git a/include/linux/kmsg_dump.h b/include/linux/kmsg_dump.h new file mode 100644 index 00000000000..7f089ec5ef3 --- /dev/null +++ b/include/linux/kmsg_dump.h @@ -0,0 +1,44 @@ +/* + * linux/include/kmsg_dump.h + * + * Copyright (C) 2009 Net Insight AB + * + * Author: Simon Kagstrom + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of this archive + * for more details. + */ +#ifndef _LINUX_KMSG_DUMP_H +#define _LINUX_KMSG_DUMP_H + +#include + +enum kmsg_dump_reason { + KMSG_DUMP_OOPS, + KMSG_DUMP_PANIC, +}; + +/** + * struct kmsg_dumper - kernel crash message dumper structure + * @dump: The callback which gets called on crashes. The buffer is passed + * as two sections, where s1 (length l1) contains the older + * messages and s2 (length l2) contains the newer. + * @list: Entry in the dumper list (private) + * @registered: Flag that specifies if this is already registered + */ +struct kmsg_dumper { + void (*dump)(struct kmsg_dumper *dumper, enum kmsg_dump_reason reason, + const char *s1, unsigned long l1, + const char *s2, unsigned long l2); + struct list_head list; + int registered; +}; + +void kmsg_dump(enum kmsg_dump_reason reason); + +int kmsg_dump_register(struct kmsg_dumper *dumper); + +int kmsg_dump_unregister(struct kmsg_dumper *dumper); + +#endif /* _LINUX_KMSG_DUMP_H */ diff --git a/kernel/panic.c b/kernel/panic.c index bcdef26e333..8c43226a544 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -10,6 +10,7 @@ */ #include #include +#include #include #include #include @@ -74,6 +75,7 @@ NORET_TYPE void panic(const char * fmt, ...) dump_stack(); #endif + kmsg_dump(KMSG_DUMP_PANIC); /* * If we have crashed and we have a crash kernel loaded let it handle * everything else. @@ -338,6 +340,7 @@ void oops_exit(void) { do_oops_enter_exit(); print_oops_end_marker(); + kmsg_dump(KMSG_DUMP_OOPS); } #ifdef WANT_WARN_ON_SLOWPATH diff --git a/kernel/printk.c b/kernel/printk.c index f38b07f78a4..051d1f50648 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -33,6 +33,7 @@ #include #include #include +#include #include @@ -1405,3 +1406,121 @@ bool printk_timed_ratelimit(unsigned long *caller_jiffies, } EXPORT_SYMBOL(printk_timed_ratelimit); #endif + +static DEFINE_SPINLOCK(dump_list_lock); +static LIST_HEAD(dump_list); + +/** + * kmsg_dump_register - register a kernel log dumper. + * @dump: pointer to the kmsg_dumper structure + * + * Adds a kernel log dumper to the system. The dump callback in the + * structure will be called when the kernel oopses or panics and must be + * set. Returns zero on success and %-EINVAL or %-EBUSY otherwise. + */ +int kmsg_dump_register(struct kmsg_dumper *dumper) +{ + unsigned long flags; + int err = -EBUSY; + + /* The dump callback needs to be set */ + if (!dumper->dump) + return -EINVAL; + + spin_lock_irqsave(&dump_list_lock, flags); + /* Don't allow registering multiple times */ + if (!dumper->registered) { + dumper->registered = 1; + list_add_tail(&dumper->list, &dump_list); + err = 0; + } + spin_unlock_irqrestore(&dump_list_lock, flags); + + return err; +} +EXPORT_SYMBOL_GPL(kmsg_dump_register); + +/** + * kmsg_dump_unregister - unregister a kmsg dumper. + * @dump: pointer to the kmsg_dumper structure + * + * Removes a dump device from the system. Returns zero on success and + * %-EINVAL otherwise. + */ +int kmsg_dump_unregister(struct kmsg_dumper *dumper) +{ + unsigned long flags; + int err = -EINVAL; + + spin_lock_irqsave(&dump_list_lock, flags); + if (dumper->registered) { + dumper->registered = 0; + list_del(&dumper->list); + err = 0; + } + spin_unlock_irqrestore(&dump_list_lock, flags); + + return err; +} +EXPORT_SYMBOL_GPL(kmsg_dump_unregister); + +static const char const *kmsg_reasons[] = { + [KMSG_DUMP_OOPS] = "oops", + [KMSG_DUMP_PANIC] = "panic", +}; + +static const char *kmsg_to_str(enum kmsg_dump_reason reason) +{ + if (reason >= ARRAY_SIZE(kmsg_reasons) || reason < 0) + return "unknown"; + + return kmsg_reasons[reason]; +} + +/** + * kmsg_dump - dump kernel log to kernel message dumpers. + * @reason: the reason (oops, panic etc) for dumping + * + * Iterate through each of the dump devices and call the oops/panic + * callbacks with the log buffer. + */ +void kmsg_dump(enum kmsg_dump_reason reason) +{ + unsigned long end; + unsigned chars; + struct kmsg_dumper *dumper; + const char *s1, *s2; + unsigned long l1, l2; + unsigned long flags; + + /* Theoretically, the log could move on after we do this, but + there's not a lot we can do about that. The new messages + will overwrite the start of what we dump. */ + spin_lock_irqsave(&logbuf_lock, flags); + end = log_end & LOG_BUF_MASK; + chars = logged_chars; + spin_unlock_irqrestore(&logbuf_lock, flags); + + if (logged_chars > end) { + s1 = log_buf + log_buf_len - logged_chars + end; + l1 = logged_chars - end; + + s2 = log_buf; + l2 = end; + } else { + s1 = ""; + l1 = 0; + + s2 = log_buf + end - logged_chars; + l2 = logged_chars; + } + + if (!spin_trylock_irqsave(&dump_list_lock, flags)) { + printk(KERN_ERR "dump_kmsg: dump list lock is held during %s, skipping dump\n", + kmsg_to_str(reason)); + return; + } + list_for_each_entry(dumper, &dump_list, list) + dumper->dump(dumper, reason, s1, l1, s2, l2); + spin_unlock_irqrestore(&dump_list_lock, flags); +} -- cgit v1.2.3-70-g09d2 From 0f4bd46ec252887f44f1f065b41867cac8f70dfb Mon Sep 17 00:00:00 2001 From: KOSAKI Motohiro Date: Tue, 22 Dec 2009 03:15:43 +0000 Subject: kmsg_dump: Dump on crash_kexec as well crash_kexec gets called before kmsg_dump(KMSG_DUMP_OOPS) if panic_on_oops is set, so the kernel log buffer is not stored for this case. This patch adds a KMSG_DUMP_KEXEC dump type which gets called when crash_kexec() is invoked. To avoid getting double dumps, the old KMSG_DUMP_PANIC is moved below crash_kexec(). The mtdoops driver is modified to handle KMSG_DUMP_KEXEC in the same way as a panic. Signed-off-by: KOSAKI Motohiro Acked-by: Simon Kagstrom Signed-off-by: David Woodhouse --- drivers/mtd/mtdoops.c | 2 +- include/linux/kmsg_dump.h | 1 + kernel/kexec.c | 4 ++++ kernel/panic.c | 3 ++- kernel/printk.c | 1 + 5 files changed, 9 insertions(+), 2 deletions(-) (limited to 'kernel/panic.c') diff --git a/drivers/mtd/mtdoops.c b/drivers/mtd/mtdoops.c index a714ec48276..92e12df0917 100644 --- a/drivers/mtd/mtdoops.c +++ b/drivers/mtd/mtdoops.c @@ -322,7 +322,7 @@ static void mtdoops_do_dump(struct kmsg_dumper *dumper, memcpy(dst + l1_cpy, s2 + s2_start, l2_cpy); /* Panics must be written immediately */ - if (reason == KMSG_DUMP_PANIC) { + if (reason != KMSG_DUMP_OOPS) { if (!cxt->mtd->panic_write) printk(KERN_ERR "mtdoops: Cannot write from panic without panic_write\n"); else diff --git a/include/linux/kmsg_dump.h b/include/linux/kmsg_dump.h index e32aa268efa..24b44145a88 100644 --- a/include/linux/kmsg_dump.h +++ b/include/linux/kmsg_dump.h @@ -17,6 +17,7 @@ enum kmsg_dump_reason { KMSG_DUMP_OOPS, KMSG_DUMP_PANIC, + KMSG_DUMP_KEXEC, }; /** diff --git a/kernel/kexec.c b/kernel/kexec.c index 433e9fcc1fc..ae217488fef 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include @@ -1074,6 +1075,9 @@ void crash_kexec(struct pt_regs *regs) if (mutex_trylock(&kexec_mutex)) { if (kexec_crash_image) { struct pt_regs fixed_regs; + + kmsg_dump(KMSG_DUMP_KEXEC); + crash_setup_regs(&fixed_regs, regs); crash_save_vmcoreinfo(); machine_crash_shutdown(&fixed_regs); diff --git a/kernel/panic.c b/kernel/panic.c index 5827f7b9725..c787333282b 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -75,7 +75,6 @@ NORET_TYPE void panic(const char * fmt, ...) dump_stack(); #endif - kmsg_dump(KMSG_DUMP_PANIC); /* * If we have crashed and we have a crash kernel loaded let it handle * everything else. @@ -83,6 +82,8 @@ NORET_TYPE void panic(const char * fmt, ...) */ crash_kexec(NULL); + kmsg_dump(KMSG_DUMP_PANIC); + /* * Note smp_send_stop is the usual smp shutdown function, which * unfortunately means it may not be hardened to work in a panic diff --git a/kernel/printk.c b/kernel/printk.c index 1ded8e7dd19..2c9dc0b03a5 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -1467,6 +1467,7 @@ EXPORT_SYMBOL_GPL(kmsg_dump_unregister); static const char const *kmsg_reasons[] = { [KMSG_DUMP_OOPS] = "oops", [KMSG_DUMP_PANIC] = "panic", + [KMSG_DUMP_KEXEC] = "kexec", }; static const char *kmsg_to_str(enum kmsg_dump_reason reason) -- cgit v1.2.3-70-g09d2 From 8aeee85a29e27e043db582bf2ae8e5f42767934f Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Fri, 5 Mar 2010 13:42:55 -0800 Subject: panic: fix panic_timeout accuracy when running on a hypervisor I've had some complaints about panic_timeout being wildly innacurate on shared processor PowerPC partitions (a 3 minute panic_timeout taking 30 minutes). The problem is we loop on mdelay(1) and with a 1ms in 10ms hypervisor timeslice each of these will take 10ms (ie 10x) longer. I expect other platforms with shared processor hypervisors will see the same issue. This patch keeps the old behaviour if we have a panic_blink (only keyboard LEDs right now) and does 1 second mdelays if we don't. Signed-off-by: Anton Blanchard Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/panic.c | 46 ++++++++++++++++++++++++++++++---------------- 1 file changed, 30 insertions(+), 16 deletions(-) (limited to 'kernel/panic.c') diff --git a/kernel/panic.c b/kernel/panic.c index c787333282b..13d966b4c14 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -36,15 +36,36 @@ ATOMIC_NOTIFIER_HEAD(panic_notifier_list); EXPORT_SYMBOL(panic_notifier_list); -static long no_blink(long time) -{ - return 0; -} - /* Returns how long it waited in ms */ long (*panic_blink)(long time); EXPORT_SYMBOL(panic_blink); +static void panic_blink_one_second(void) +{ + static long i = 0, end; + + if (panic_blink) { + end = i + MSEC_PER_SEC; + + while (i < end) { + i += panic_blink(i); + mdelay(1); + i++; + } + } else { + /* + * When running under a hypervisor a small mdelay may get + * rounded up to the hypervisor timeslice. For example, with + * a 1ms in 10ms hypervisor timeslice we might inflate a + * mdelay(1) loop by 10x. + * + * If we have nothing to blink, spin on 1 second calls to + * mdelay to avoid this. + */ + mdelay(MSEC_PER_SEC); + } +} + /** * panic - halt the system * @fmt: The text string to print @@ -95,9 +116,6 @@ NORET_TYPE void panic(const char * fmt, ...) bust_spinlocks(0); - if (!panic_blink) - panic_blink = no_blink; - if (panic_timeout > 0) { /* * Delay timeout seconds before rebooting the machine. @@ -105,11 +123,9 @@ NORET_TYPE void panic(const char * fmt, ...) */ printk(KERN_EMERG "Rebooting in %d seconds..", panic_timeout); - for (i = 0; i < panic_timeout*1000; ) { + for (i = 0; i < panic_timeout; i++) { touch_nmi_watchdog(); - i += panic_blink(i); - mdelay(1); - i++; + panic_blink_one_second(); } /* * This will not be a clean reboot, with everything @@ -135,11 +151,9 @@ NORET_TYPE void panic(const char * fmt, ...) } #endif local_irq_enable(); - for (i = 0; ; ) { + while (1) { touch_softlockup_watchdog(); - i += panic_blink(i); - mdelay(1); - i++; + panic_blink_one_second(); } } -- cgit v1.2.3-70-g09d2 From b2be05273a1744d175bf4b67f6665637bb9ac7a8 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Sat, 3 Apr 2010 19:34:56 +0100 Subject: panic: Allow warnings to set different taint flags WARN() is used in some places to report firmware or hardware bugs that are then worked-around. These bugs do not affect the stability of the kernel and should not set the flag for TAINT_WARN. To allow for this, add WARN_TAINT() and WARN_TAINT_ONCE() macros that take a taint number as argument. Architectures that implement warnings using trap instructions instead of calls to warn_slowpath_*() now implement __WARN_TAINT(taint) instead of __WARN(). Signed-off-by: Ben Hutchings Acked-by: Helge Deller Tested-by: Paul Mundt Signed-off-by: David Woodhouse --- Documentation/oops-tracing.txt | 1 + arch/parisc/include/asm/bug.h | 8 ++++---- arch/powerpc/include/asm/bug.h | 6 +++--- arch/s390/include/asm/bug.h | 8 ++++---- arch/sh/include/asm/bug.h | 4 ++-- include/asm-generic/bug.h | 34 ++++++++++++++++++++++++++++++++-- kernel/panic.c | 24 ++++++++++++++++++++---- lib/bug.c | 2 +- 8 files changed, 67 insertions(+), 20 deletions(-) (limited to 'kernel/panic.c') diff --git a/Documentation/oops-tracing.txt b/Documentation/oops-tracing.txt index c10c022b911..069fab3ea4d 100644 --- a/Documentation/oops-tracing.txt +++ b/Documentation/oops-tracing.txt @@ -256,6 +256,7 @@ characters, each representing a particular tainted value. 9: 'A' if the ACPI table has been overridden. 10: 'W' if a warning has previously been issued by the kernel. + (Though some warnings may set more specific taint flags.) 11: 'C' if a staging driver has been loaded. diff --git a/arch/parisc/include/asm/bug.h b/arch/parisc/include/asm/bug.h index 75e46c557a1..72cfdb0cfdd 100644 --- a/arch/parisc/include/asm/bug.h +++ b/arch/parisc/include/asm/bug.h @@ -44,7 +44,7 @@ #endif #ifdef CONFIG_DEBUG_BUGVERBOSE -#define __WARN() \ +#define __WARN_TAINT(taint) \ do { \ asm volatile("\n" \ "1:\t" PARISC_BUG_BREAK_ASM "\n" \ @@ -54,11 +54,11 @@ "\t.org 2b+%c3\n" \ "\t.popsection" \ : : "i" (__FILE__), "i" (__LINE__), \ - "i" (BUGFLAG_WARNING), \ + "i" (BUGFLAG_TAINT(taint)), \ "i" (sizeof(struct bug_entry)) ); \ } while(0) #else -#define __WARN() \ +#define __WARN_TAINT(taint) \ do { \ asm volatile("\n" \ "1:\t" PARISC_BUG_BREAK_ASM "\n" \ @@ -67,7 +67,7 @@ "\t.short %c0\n" \ "\t.org 2b+%c1\n" \ "\t.popsection" \ - : : "i" (BUGFLAG_WARNING), \ + : : "i" (BUGFLAG_TAINT(taint)), \ "i" (sizeof(struct bug_entry)) ); \ } while(0) #endif diff --git a/arch/powerpc/include/asm/bug.h b/arch/powerpc/include/asm/bug.h index 2c15212e170..065c590c991 100644 --- a/arch/powerpc/include/asm/bug.h +++ b/arch/powerpc/include/asm/bug.h @@ -85,12 +85,12 @@ } \ } while (0) -#define __WARN() do { \ +#define __WARN_TAINT(taint) do { \ __asm__ __volatile__( \ "1: twi 31,0,0\n" \ _EMIT_BUG_ENTRY \ : : "i" (__FILE__), "i" (__LINE__), \ - "i" (BUGFLAG_WARNING), \ + "i" (BUGFLAG_TAINT(taint)), \ "i" (sizeof(struct bug_entry))); \ } while (0) @@ -104,7 +104,7 @@ "1: "PPC_TLNEI" %4,0\n" \ _EMIT_BUG_ENTRY \ : : "i" (__FILE__), "i" (__LINE__), \ - "i" (BUGFLAG_WARNING), \ + "i" (BUGFLAG_TAINT(TAINT_WARN)), \ "i" (sizeof(struct bug_entry)), \ "r" (__ret_warn_on)); \ } \ diff --git a/arch/s390/include/asm/bug.h b/arch/s390/include/asm/bug.h index 9beeb9db9b2..bf90d1fd97a 100644 --- a/arch/s390/include/asm/bug.h +++ b/arch/s390/include/asm/bug.h @@ -46,18 +46,18 @@ unreachable(); \ } while (0) -#define __WARN() do { \ - __EMIT_BUG(BUGFLAG_WARNING); \ +#define __WARN_TAINT(taint) do { \ + __EMIT_BUG(BUGFLAG_TAINT(taint)); \ } while (0) #define WARN_ON(x) ({ \ int __ret_warn_on = !!(x); \ if (__builtin_constant_p(__ret_warn_on)) { \ if (__ret_warn_on) \ - __EMIT_BUG(BUGFLAG_WARNING); \ + __WARN(); \ } else { \ if (unlikely(__ret_warn_on)) \ - __EMIT_BUG(BUGFLAG_WARNING); \ + __WARN(); \ } \ unlikely(__ret_warn_on); \ }) diff --git a/arch/sh/include/asm/bug.h b/arch/sh/include/asm/bug.h index d02c01b3e6b..6323f864d11 100644 --- a/arch/sh/include/asm/bug.h +++ b/arch/sh/include/asm/bug.h @@ -48,7 +48,7 @@ do { \ "i" (sizeof(struct bug_entry))); \ } while (0) -#define __WARN() \ +#define __WARN_TAINT(taint) \ do { \ __asm__ __volatile__ ( \ "1:\t.short %O0\n" \ @@ -57,7 +57,7 @@ do { \ : "n" (TRAPA_BUG_OPCODE), \ "i" (__FILE__), \ "i" (__LINE__), \ - "i" (BUGFLAG_WARNING), \ + "i" (BUGFLAG_TAINT(taint)), \ "i" (sizeof(struct bug_entry))); \ } while (0) diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h index 18c435d7c08..c2c9ba032d4 100644 --- a/include/asm-generic/bug.h +++ b/include/asm-generic/bug.h @@ -25,7 +25,10 @@ struct bug_entry { }; #endif /* __ASSEMBLY__ */ -#define BUGFLAG_WARNING (1<<0) +#define BUGFLAG_WARNING (1 << 0) +#define BUGFLAG_TAINT(taint) (BUGFLAG_WARNING | ((taint) << 8)) +#define BUG_GET_TAINT(bug) ((bug)->flags >> 8) + #endif /* CONFIG_GENERIC_BUG */ /* @@ -56,17 +59,25 @@ struct bug_entry { * appear at runtime. Use the versions with printk format strings * to provide better diagnostics. */ -#ifndef __WARN +#ifndef __WARN_TAINT #ifndef __ASSEMBLY__ extern void warn_slowpath_fmt(const char *file, const int line, const char *fmt, ...) __attribute__((format(printf, 3, 4))); +extern void warn_slowpath_fmt_taint(const char *file, const int line, + unsigned taint, const char *fmt, ...) + __attribute__((format(printf, 4, 5))); extern void warn_slowpath_null(const char *file, const int line); #define WANT_WARN_ON_SLOWPATH #endif #define __WARN() warn_slowpath_null(__FILE__, __LINE__) #define __WARN_printf(arg...) warn_slowpath_fmt(__FILE__, __LINE__, arg) +#define __WARN_printf_taint(taint, arg...) \ + warn_slowpath_fmt_taint(__FILE__, __LINE__, taint, arg) #else +#define __WARN() __WARN_TAINT(TAINT_WARN) #define __WARN_printf(arg...) do { printk(arg); __WARN(); } while (0) +#define __WARN_printf_taint(taint, arg...) \ + do { printk(arg); __WARN_TAINT(taint); } while (0) #endif #ifndef WARN_ON @@ -87,6 +98,13 @@ extern void warn_slowpath_null(const char *file, const int line); }) #endif +#define WARN_TAINT(condition, taint, format...) ({ \ + int __ret_warn_on = !!(condition); \ + if (unlikely(__ret_warn_on)) \ + __WARN_printf_taint(taint, format); \ + unlikely(__ret_warn_on); \ +}) + #else /* !CONFIG_BUG */ #ifndef HAVE_ARCH_BUG #define BUG() do {} while(0) @@ -110,6 +128,8 @@ extern void warn_slowpath_null(const char *file, const int line); }) #endif +#define WARN_TAINT(condition, taint, format...) WARN_ON(condition) + #endif #define WARN_ON_ONCE(condition) ({ \ @@ -132,6 +152,16 @@ extern void warn_slowpath_null(const char *file, const int line); unlikely(__ret_warn_once); \ }) +#define WARN_TAINT_ONCE(condition, taint, format...) ({ \ + static bool __warned; \ + int __ret_warn_once = !!(condition); \ + \ + if (unlikely(__ret_warn_once)) \ + if (WARN_TAINT(!__warned, taint, format)) \ + __warned = true; \ + unlikely(__ret_warn_once); \ +}) + #define WARN_ON_RATELIMIT(condition, state) \ WARN_ON((condition) && __ratelimit(state)) diff --git a/kernel/panic.c b/kernel/panic.c index 13d966b4c14..8b821bce66e 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -365,7 +365,8 @@ struct slowpath_args { va_list args; }; -static void warn_slowpath_common(const char *file, int line, void *caller, struct slowpath_args *args) +static void warn_slowpath_common(const char *file, int line, void *caller, + unsigned taint, struct slowpath_args *args) { const char *board; @@ -381,7 +382,7 @@ static void warn_slowpath_common(const char *file, int line, void *caller, struc print_modules(); dump_stack(); print_oops_end_marker(); - add_taint(TAINT_WARN); + add_taint(taint); } void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...) @@ -390,14 +391,29 @@ void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...) args.fmt = fmt; va_start(args.args, fmt); - warn_slowpath_common(file, line, __builtin_return_address(0), &args); + warn_slowpath_common(file, line, __builtin_return_address(0), + TAINT_WARN, &args); va_end(args.args); } EXPORT_SYMBOL(warn_slowpath_fmt); +void warn_slowpath_fmt_taint(const char *file, int line, + unsigned taint, const char *fmt, ...) +{ + struct slowpath_args args; + + args.fmt = fmt; + va_start(args.args, fmt); + warn_slowpath_common(file, line, __builtin_return_address(0), + taint, &args); + va_end(args.args); +} +EXPORT_SYMBOL(warn_slowpath_fmt_taint); + void warn_slowpath_null(const char *file, int line) { - warn_slowpath_common(file, line, __builtin_return_address(0), NULL); + warn_slowpath_common(file, line, __builtin_return_address(0), + TAINT_WARN, NULL); } EXPORT_SYMBOL(warn_slowpath_null); #endif diff --git a/lib/bug.c b/lib/bug.c index 300e41afbf9..f13daf43521 100644 --- a/lib/bug.c +++ b/lib/bug.c @@ -165,7 +165,7 @@ enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs) (void *)bugaddr); show_regs(regs); - add_taint(TAINT_WARN); + add_taint(BUG_GET_TAINT(bug)); return BUG_TRAP_TYPE_WARN; } -- cgit v1.2.3-70-g09d2 From 92946bc72f2e74c3281b7fc12be9704d455fb3ed Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Sat, 3 Apr 2010 19:36:42 +0100 Subject: panic: Add taint flag TAINT_FIRMWARE_WORKAROUND ('I') This taint flag will initially be used when warning about invalid ACPI DMAR tables. Signed-off-by: Ben Hutchings Signed-off-by: David Woodhouse --- Documentation/oops-tracing.txt | 3 +++ include/linux/kernel.h | 1 + kernel/panic.c | 2 ++ 3 files changed, 6 insertions(+) (limited to 'kernel/panic.c') diff --git a/Documentation/oops-tracing.txt b/Documentation/oops-tracing.txt index 069fab3ea4d..6fe9001b926 100644 --- a/Documentation/oops-tracing.txt +++ b/Documentation/oops-tracing.txt @@ -260,6 +260,9 @@ characters, each representing a particular tainted value. 11: 'C' if a staging driver has been loaded. + 12: 'I' if the kernel is working around a severe bug in the platform + firmware (BIOS or similar). + The primary reason for the 'Tainted: ' string is to tell kernel debuggers if this is a clean kernel or if anything unusual has occurred. Tainting is permanent: even if an offending module is diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 7f070746336..7f2f7b34dd0 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -344,6 +344,7 @@ extern enum system_states { #define TAINT_OVERRIDDEN_ACPI_TABLE 8 #define TAINT_WARN 9 #define TAINT_CRAP 10 +#define TAINT_FIRMWARE_WORKAROUND 11 extern void dump_stack(void) __cold; diff --git a/kernel/panic.c b/kernel/panic.c index 8b821bce66e..dbe13dbb057 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -178,6 +178,7 @@ static const struct tnt tnts[] = { { TAINT_OVERRIDDEN_ACPI_TABLE, 'A', ' ' }, { TAINT_WARN, 'W', ' ' }, { TAINT_CRAP, 'C', ' ' }, + { TAINT_FIRMWARE_WORKAROUND, 'I', ' ' }, }; /** @@ -194,6 +195,7 @@ static const struct tnt tnts[] = { * 'A' - ACPI table overridden. * 'W' - Taint on warning. * 'C' - modules from drivers/staging are loaded. + * 'I' - Working around severe firmware bug. * * The string is overwritten by the next call to print_tainted(). */ -- cgit v1.2.3-70-g09d2 From 5b530fc18324602e1ecb70cd280c2194b2656a5e Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Wed, 26 May 2010 14:44:24 -0700 Subject: panic: call console_verbose() in panic Most distros turn the console verbosity down and that means a backtrace after a panic never makes it to the console. I assume we haven't seen this because a panic is often preceeded by an oops which will have called console_verbose. There are however a lot of places we call panic directly, and they are broken. Use console_verbose like we do in the oops path to ensure a directly called panic will print a backtrace. Signed-off-by: Anton Blanchard Acked-by: Greg Kroah-Hartman Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/panic.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel/panic.c') diff --git a/kernel/panic.c b/kernel/panic.c index dbe13dbb057..3b16cd93fa7 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -87,6 +87,7 @@ NORET_TYPE void panic(const char * fmt, ...) */ preempt_disable(); + console_verbose(); bust_spinlocks(1); va_start(args, fmt); vsnprintf(buf, sizeof(buf), fmt, args); -- cgit v1.2.3-70-g09d2 From c7ff0d9c92435e836e13aaa8d0e56d4000424bcc Mon Sep 17 00:00:00 2001 From: TAMUKI Shoichi Date: Tue, 10 Aug 2010 18:03:28 -0700 Subject: panic: keep blinking in spite of long spin timer mode To keep panic_timeout accuracy when running under a hypervisor, the current implementation only spins on long time (1 second) calls to mdelay. That brings a good effect, but the problem is the keyboard LEDs don't blink at all on that situation. This patch changes to call to panic_blink_enter() between every mdelay and keeps blinking in spite of long spin timer mode. The time to call to mdelay is now 100ms. Even this change will keep panic_timeout accuracy enough when running under a hypervisor. Signed-off-by: TAMUKI Shoichi Cc: Ben Dooks Cc: Russell King Acked-by: Dmitry Torokhov Cc: Anton Blanchard Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/kernel-parameters.txt | 3 -- arch/arm/mach-s3c2440/mach-gta02.c | 17 ++++------- drivers/input/serio/i8042.c | 25 ++++------------ include/linux/kernel.h | 2 +- kernel/panic.c | 58 +++++++++++++++++-------------------- 5 files changed, 37 insertions(+), 68 deletions(-) (limited to 'kernel/panic.c') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index d529b1363e9..873b6809009 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -915,9 +915,6 @@ and is between 256 and 4096 characters. It is defined in the file controller i8042.nopnp [HW] Don't use ACPIPnP / PnPBIOS to discover KBD/AUX controllers - i8042.panicblink= - [HW] Frequency with which keyboard LEDs should blink - when kernel panics (default is 0.5 sec) i8042.reset [HW] Reset the controller during init and cleanup i8042.unlock [HW] Unlock (ignore) the keylock diff --git a/arch/arm/mach-s3c2440/mach-gta02.c b/arch/arm/mach-s3c2440/mach-gta02.c index 9e39faa283b..deaabe86741 100644 --- a/arch/arm/mach-s3c2440/mach-gta02.c +++ b/arch/arm/mach-s3c2440/mach-gta02.c @@ -90,24 +90,17 @@ static struct pcf50633 *gta02_pcf; /* - * This gets called every 1ms when we paniced. + * This gets called frequently when we paniced. */ -static long gta02_panic_blink(long count) +static long gta02_panic_blink(int state) { long delay = 0; - static long last_blink; - static char led; + char led; - /* Fast blink: 200ms period. */ - if (count - last_blink < 100) - return 0; - - led ^= 1; + led = (state) ? 1 : 0; gpio_direction_output(GTA02_GPIO_AUX_LED, led); - last_blink = count; - return delay; } @@ -556,7 +549,7 @@ static void gta02_poweroff(void) static void __init gta02_machine_init(void) { - /* Set the panic callback to make AUX LED blink at ~5Hz. */ + /* Set the panic callback to turn AUX LED on or off. */ panic_blink = gta02_panic_blink; s3c_pm_init(); diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c index 258b98b9d7c..46e4ba0b924 100644 --- a/drivers/input/serio/i8042.c +++ b/drivers/input/serio/i8042.c @@ -61,10 +61,6 @@ static bool i8042_noloop; module_param_named(noloop, i8042_noloop, bool, 0); MODULE_PARM_DESC(noloop, "Disable the AUX Loopback command while probing for the AUX port"); -static unsigned int i8042_blink_frequency = 500; -module_param_named(panicblink, i8042_blink_frequency, uint, 0600); -MODULE_PARM_DESC(panicblink, "Frequency with which keyboard LEDs should blink when kernel panics"); - #ifdef CONFIG_X86 static bool i8042_dritek; module_param_named(dritek, i8042_dritek, bool, 0); @@ -1030,8 +1026,8 @@ static void i8042_controller_reset(void) /* - * i8042_panic_blink() will flash the keyboard LEDs and is called when - * kernel panics. Flashing LEDs is useful for users running X who may + * i8042_panic_blink() will turn the keyboard LEDs on or off and is called + * when kernel panics. Flashing LEDs is useful for users running X who may * not see the console and will help distingushing panics from "real" * lockups. * @@ -1041,22 +1037,12 @@ static void i8042_controller_reset(void) #define DELAY do { mdelay(1); if (++delay > 10) return delay; } while(0) -static long i8042_panic_blink(long count) +static long i8042_panic_blink(int state) { long delay = 0; - static long last_blink; - static char led; - - /* - * We expect frequency to be about 1/2s. KDB uses about 1s. - * Make sure they are different. - */ - if (!i8042_blink_frequency) - return 0; - if (count - last_blink < i8042_blink_frequency) - return 0; + char led; - led ^= 0x01 | 0x04; + led = (state) ? 0x01 | 0x04 : 0; while (i8042_read_status() & I8042_STR_IBF) DELAY; dbg("%02x -> i8042 (panic blink)", 0xed); @@ -1069,7 +1055,6 @@ static long i8042_panic_blink(long count) dbg("%02x -> i8042 (panic blink)", led); i8042_write_data(led); DELAY; - last_blink = count; return delay; } diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 5b57236dfbd..452833d67b2 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -177,7 +177,7 @@ struct va_format { }; extern struct atomic_notifier_head panic_notifier_list; -extern long (*panic_blink)(long time); +extern long (*panic_blink)(int state); NORET_TYPE void panic(const char * fmt, ...) __attribute__ ((NORET_AND format (printf, 1, 2))) __cold; extern void oops_enter(void); diff --git a/kernel/panic.c b/kernel/panic.c index 3b16cd93fa7..3e9037ae10e 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -24,6 +24,9 @@ #include #include +#define PANIC_TIMER_STEP 100 +#define PANIC_BLINK_SPD 18 + int panic_on_oops; static unsigned long tainted_mask; static int pause_on_oops; @@ -36,36 +39,15 @@ ATOMIC_NOTIFIER_HEAD(panic_notifier_list); EXPORT_SYMBOL(panic_notifier_list); -/* Returns how long it waited in ms */ -long (*panic_blink)(long time); -EXPORT_SYMBOL(panic_blink); - -static void panic_blink_one_second(void) +static long no_blink(int state) { - static long i = 0, end; - - if (panic_blink) { - end = i + MSEC_PER_SEC; - - while (i < end) { - i += panic_blink(i); - mdelay(1); - i++; - } - } else { - /* - * When running under a hypervisor a small mdelay may get - * rounded up to the hypervisor timeslice. For example, with - * a 1ms in 10ms hypervisor timeslice we might inflate a - * mdelay(1) loop by 10x. - * - * If we have nothing to blink, spin on 1 second calls to - * mdelay to avoid this. - */ - mdelay(MSEC_PER_SEC); - } + return 0; } +/* Returns how long it waited in ms */ +long (*panic_blink)(int state); +EXPORT_SYMBOL(panic_blink); + /** * panic - halt the system * @fmt: The text string to print @@ -78,7 +60,8 @@ NORET_TYPE void panic(const char * fmt, ...) { static char buf[1024]; va_list args; - long i; + long i, i_next = 0; + int state = 0; /* * It's possible to come here directly from a panic-assertion and @@ -117,6 +100,9 @@ NORET_TYPE void panic(const char * fmt, ...) bust_spinlocks(0); + if (!panic_blink) + panic_blink = no_blink; + if (panic_timeout > 0) { /* * Delay timeout seconds before rebooting the machine. @@ -124,9 +110,13 @@ NORET_TYPE void panic(const char * fmt, ...) */ printk(KERN_EMERG "Rebooting in %d seconds..", panic_timeout); - for (i = 0; i < panic_timeout; i++) { + for (i = 0; i < panic_timeout * 1000; i += PANIC_TIMER_STEP) { touch_nmi_watchdog(); - panic_blink_one_second(); + if (i >= i_next) { + i += panic_blink(state ^= 1); + i_next = i + 3600 / PANIC_BLINK_SPD; + } + mdelay(PANIC_TIMER_STEP); } /* * This will not be a clean reboot, with everything @@ -152,9 +142,13 @@ NORET_TYPE void panic(const char * fmt, ...) } #endif local_irq_enable(); - while (1) { + for (i = 0; ; i += PANIC_TIMER_STEP) { touch_softlockup_watchdog(); - panic_blink_one_second(); + if (i >= i_next) { + i += panic_blink(state ^= 1); + i_next = i + 3600 / PANIC_BLINK_SPD; + } + mdelay(PANIC_TIMER_STEP); } } -- cgit v1.2.3-70-g09d2 From 863a6049202412a6d655d052eb1c45ca7dd74a83 Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Tue, 10 Aug 2010 18:03:30 -0700 Subject: lib/bug.c: add oops end marker to WARN implementation We are missing the oops end marker for the exception based WARN implementation in lib/bug.c. This is useful for logfile analysis tools. Signed-off-by: Anton Blanchard Cc: Ingo Molnar Cc: Arjan van de Ven Cc: "Kirill A. Shutemov" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kernel.h | 1 + kernel/panic.c | 2 +- lib/bug.c | 1 + 3 files changed, 3 insertions(+), 1 deletion(-) (limited to 'kernel/panic.c') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 452833d67b2..d848cb85465 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -182,6 +182,7 @@ NORET_TYPE void panic(const char * fmt, ...) __attribute__ ((NORET_AND format (printf, 1, 2))) __cold; extern void oops_enter(void); extern void oops_exit(void); +void print_oops_end_marker(void); extern int oops_may_print(void); NORET_TYPE void do_exit(long error_code) ATTRIB_NORET; diff --git a/kernel/panic.c b/kernel/panic.c index 3e9037ae10e..4c13b1a88eb 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -338,7 +338,7 @@ static int init_oops_id(void) } late_initcall(init_oops_id); -static void print_oops_end_marker(void) +void print_oops_end_marker(void) { init_oops_id(); printk(KERN_WARNING "---[ end trace %016llx ]---\n", diff --git a/lib/bug.c b/lib/bug.c index 6c5b30cf3f0..7cdfad88128 100644 --- a/lib/bug.c +++ b/lib/bug.c @@ -166,6 +166,7 @@ enum bug_trap_type report_bug(unsigned long bugaddr, struct pt_regs *regs) print_modules(); show_regs(regs); + print_oops_end_marker(); add_taint(BUG_GET_TAINT(bug)); return BUG_TRAP_TYPE_WARN; } -- cgit v1.2.3-70-g09d2