user/sven/linux.git/kernel/panic.c, branch v3.10.44

dump_stack: implement arch-specific hardware description in task dumps

2013-05-01T00:04:02Z

x86 and ia64 can acquire extra hardware identification information from DMI and print it along with task dumps; however, the usage isn't consistent. * x86 show_regs() collects vendor, product and board strings and print them out with PID, comm and utsname. Some of the information is printed again later in the same dump. * warn_slowpath_common() explicitly accesses the DMI board and prints it out with "Hardware name:" label. This applies to both x86 and ia64 but is irrelevant on all other archs. * ia64 doesn't show DMI information on other non-WARN dumps. This patch introduces arch-specific hardware description used by dump_stack(). It can be set by calling dump_stack_set_arch_desc() during boot and, if exists, printed out in a separate line with "Hardware name:" label. dmi_set_dump_stack_arch_desc() is added which sets arch-specific description from DMI data. It uses dmi_ids_string[] which is set from dmi_present() used for DMI debug message. It is superset of the information x86 show_regs() is using. The function is called from x86 and ia64 boot code right after dmi_scan_machine(). This makes the explicit DMI handling in warn_slowpath_common() unnecessary. Removed. show_regs() isn't yet converted to use generic debug information printing and this patch doesn't remove the duplicate DMI handling in x86 show_regs(). The next patch will unify show_regs() handling and remove the duplication. An example WARN dump follows. WARNING: at kernel/workqueue.c:4841 init_workqueues+0x35/0x505() Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #3 Hardware name: empty empty/S3992, BIOS 080011 10/26/2007 0000000000000009 ffff88007c861e08 ffffffff81c614dc ffff88007c861e48 ffffffff8108f500 ffffffff82228240 0000000000000040 ffffffff8234a08e 0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58 Call Trace: [] dump_stack+0x19/0x1b [] warn_slowpath_common+0x70/0xa0 [] warn_slowpath_null+0x1a/0x20 [] init_workqueues+0x35/0x505 ... v2: Use the same string as the debug message from dmi_present() which also contains BIOS information. Move hardware name into its own line as warn_slowpath_common() did. This change was suggested by Bjorn Helgaas. Signed-off-by: Tejun Heo Cc: Bjorn Helgaas Cc: David S. Miller Cc: Fengguang Wu Cc: Heiko Carstens Cc: Jesper Nilsson Cc: Martin Schwidefsky Cc: Mike Frysinger Cc: Vineet Gupta Cc: Sam Ravnborg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

taint: add explicit flag to show whether lock dep is still OK.

2013-01-21T06:47:57Z

Fix up all callers as they were before, with make one change: an unsigned module taints the kernel, but doesn't turn off lockdep. Signed-off-by: Rusty Russell

panic: fix a possible deadlock in panic()

2012-07-31T00:25:13Z

panic_lock is meant to ensure that panic processing takes place only on one cpu; if any of the other cpus encounter a panic, they will spin waiting to be shut down. However, this causes a regression in this scenario: 1. Cpu 0 encounters a panic and acquires the panic_lock and proceeds with the panic processing. 2. There is an interrupt on cpu 0 that also encounters an error condition and invokes panic. 3. This second invocation fails to acquire the panic_lock and enters the infinite while loop in panic_smp_self_stop. Thus all panic processing is stopped, and the cpu is stuck for eternity in the while(1) inside panic_smp_self_stop. To address this, disable local interrupts with local_irq_disable before acquiring the panic_lock. This will prevent interrupt handlers from executing during the panic processing, thus avoiding this particular problem. Signed-off-by: Vikram Mulukutla Reviewed-by: Stephen Boyd Cc: Michael Holzheu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kdump: Execute kmsg_dump(KMSG_DUMP_PANIC) after smp_send_stop()

2012-05-18T12:02:10Z

This patch moves kmsg_dump(KMSG_DUMP_PANIC) below smp_send_stop(), to serialize the crash-logging process via smp_send_stop() and to thus retrieve a more stable crash image of all CPUs stopped. Signed-off-by: Seiji Aguchi Acked-by: Don Zickus Cc: dle-develop@lists.sourceforge.net Cc: Satoru Moriya Cc: Tony Luck Cc: a.p.zijlstra@chello.nl Link: http://lkml.kernel.org/r/5C4C569E8A4B9B42A84A977CF070A35B2E4D7A5CE2@USINDEVS01.corp.hds.com Signed-off-by: Ingo Molnar

panic: Make panic_on_oops configurable

2012-05-07T12:45:29Z

Several distros set this by default by patching panic_on_oops. It seems to fit with the BOOTPARAM_{HARD,SOFT}_PANIC options though, so let's add a Kconfig entry and reduce some more upstream delta. Signed-off-by: Kyle McMartin Cc: Andrew Morton Cc: Linus Torvalds Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20120411121529.GH26688@redacted.bos.redhat.com Signed-off-by: Ingo Molnar

panic: fix stack dump print on direct call to panic()

2012-04-12T20:12:12Z

Commit 6e6f0a1f0fa6 ("panic: don't print redundant backtraces on oops") causes a regression where no stack trace will be printed at all for the case where kernel code calls panic() directly while not processing an oops, and of course there are 100's of instances of this type of call. The original commit executed the check (!oops_in_progress), but this will always be false because just before the dump_stack() there is a call to bust_spinlocks(1), which does the following: void __attribute__((weak)) bust_spinlocks(int yes) { if (yes) { ++oops_in_progress; The proper way to resolve the problem that original commit tried to solve is to avoid printing a stack dump from panic() when the either of the following conditions is true: 1) TAINT_DIE has been set (this is done by oops_end()) This indicates and oops has already been printed. 2) oops_in_progress > 1 This guards against the rare case where panic() is invoked a second time, or in between oops_begin() and oops_end() Signed-off-by: Jason Wessel Cc: Andi Kleen Cc: [3.3+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

panic: don't print redundant backtraces on oops

2012-01-13T04:13:11Z

When an oops causes a panic and panic prints another backtrace it's pretty common to have the original oops data be scrolled away on a 80x50 screen. The second backtrace is quite redundant and not needed anyways. So don't print the panic backtrace when oops_in_progress is true. [akpm@linux-foundation.org: add comment] Signed-off-by: Andi Kleen Cc: Michael Holzheu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kdump: fix crash_kexec()/smp_send_stop() race in panic()

2012-01-13T04:13:11Z

When two CPUs call panic at the same time there is a possible race condition that can stop kdump. The first CPU calls crash_kexec() and the second CPU calls smp_send_stop() in panic() before crash_kexec() finished on the first CPU. So the second CPU stops the first CPU and therefore kdump fails: 1st CPU: panic()->crash_kexec()->mutex_trylock(&kexec_mutex)-> do kdump 2nd CPU: panic()->crash_kexec()->kexec_mutex already held by 1st CPU ->smp_send_stop()-> stop 1st CPU (stop kdump) This patch fixes the problem by introducing a spinlock in panic that allows only one CPU to process crash_kexec() and the subsequent panic code. All other CPUs call the weak function panic_smp_self_stop() that stops the CPU itself. This function can be overloaded by architecture code. For example "tile" can use their lower-power "nap" instruction for that. Signed-off-by: Michael Holzheu Acked-by: Chris Metcalf Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

treewide: remove useless NORET_TYPE macro and uses

2012-01-13T04:13:03Z

It's a very old and now unused prototype marking so just delete it. Neaten panic pointer argument style to keep checkpatch quiet. Signed-off-by: Joe Perches Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Haavard Skinnemoen Cc: Hans-Christian Egtvedt Cc: Tony Luck Cc: Fenghua Yu Acked-by: Geert Uytterhoeven Acked-by: Ralf Baechle Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Martin Schwidefsky Cc: Heiko Carstens Cc: Chris Metcalf Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

lockdep, bug: Exclude TAINT_OOT_MODULE from disabling lock debugging

2011-12-07T22:32:10Z

We do want to allow lock debugging for GPL-compatible modules that are not (yet) built in-tree. This was disabled as a side-effect of commit 2449b8ba0745327c5fa49a8d9acffe03b2eded69 ('module,bug: Add TAINT_OOT_MODULE flag for modules not built in-tree'). Lock debug warnings now include taint flags, so kernel developers should still be able to deflect warnings caused by out-of-tree modules. The TAINT_PROPRIETARY_MODULE flag for non-GPL-compatible modules will still disable lock debugging. Signed-off-by: Ben Hutchings Cc: Nick Bowler Cc: Greg KH Cc: Dave Jones Cc: Rusty Russell Cc: Randy Dunlap Cc: Debian kernel maintainers Cc: Peter Zijlstra Cc: Alan Cox Link: http://lkml.kernel.org/r/1323268258.18450.11.camel@deadeye Signed-off-by: Ingo Molnar