user/sven/linux.git/kernel/panic.c, branch v3.12.33

panic: call panic handlers before kmsg_dump

2013-09-11T22:59:30Z

Since the panic handlers may produce additional information (via printk) for the kernel log, it should be reported as part of the panic output saved by kmsg_dump(). Without this re-ordering, nothing that adds information to a panic will show up in pstore's view when kmsg_dump runs, and is therefore not visible to crash reporting tools that examine pstore output. Signed-off-by: Kees Cook Cc: Anton Vorontsov Cc: Colin Cross Acked-by: Tony Luck Cc: Stephen Boyd Cc: Vikram Mulukutla Cc: Peter Zijlstra Cc: Rusty Russell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge tag 'trace-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2013-07-11T16:02:09Z

Pull tracing changes from Steven Rostedt: "The majority of the changes here are cleanups for the large changes that were added to 3.10, which includes several bug fixes that have been marked for stable. As for new features, there were a few, but nothing to write to LWN about. These include: New function trigger called "dump" and "cpudump" that will cause ftrace to dump its buffer to the console when the function is called. The difference between "dump" and "cpudump" is that "dump" will dump the entire contents of the ftrace buffer, where as "cpudump" will only dump the contents of the ftrace buffer for the CPU that called the function. Another small enhancement is a new sysctl switch called "traceoff_on_warning" which, when enabled, will disable tracing if any WARN_ON() is triggered. This is useful if you want to debug what caused a warning and do not want to risk losing your trace data by the ring buffer overwriting the data before you can disable it. There's also a kernel command line option that will make this enabled at boot up called the same thing" * tag 'trace-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (34 commits) tracing: Make tracing_open_generic_{tr,tc}() static tracing: Remove ftrace() function tracing: Remove TRACE_EVENT_TYPE enum definition tracing: Make tracer_tracing_{off,on,is_on}() static tracing: Fix irqs-off tag display in syscall tracing uprobes: Fix return value in error handling path tracing: Fix race between deleting buffer and setting events tracing: Add trace_array_get/put() to event handling tracing: Get trace_array ref counts when accessing trace files tracing: Add trace_array_get/put() to handle instance refs better tracing: Protect ftrace_trace_arrays list in trace_events.c tracing: Make trace_marker use the correct per-instance buffer ftrace: Do not run selftest if command line parameter is set tracing/kprobes: Don't pass addr=ip to perf_trace_buf_submit() tracing: Use flag buffer_disabled for irqsoff tracer tracing/kprobes: Turn trace_probe->files into list_head tracing: Fix disabling of soft disable tracing: Add missing syscall_metadata comment tracing: Simplify code for showing of soft disabled flag tracing/kprobes: Kill probe_enable_lock ...

panic: add cpu/pid to warn_slowpath_common in WARNING printk()s

2013-07-09T17:33:25Z

Add the cpu/pid that called WARN() so that the stack traces can be matched up with the WARNING messages. [akpm@linux-foundation.org: remove stray quote] Signed-off-by: Alex Thorlton Reviewed-by: Robin Holt Cc: Stephen Boyd Cc: Vikram Mulukutla Cc: Rusty Russell Cc: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

tracing: Disable tracing on warning

2013-06-20T03:32:07Z

Add a traceoff_on_warning option in both the kernel command line as well as a sysctl option. When set, any WARN*() function that is hit will cause the tracing_on variable to be cleared, which disables writing to the ring buffer. This is useful especially when tracing a bug with function tracing. When a warning is hit, the print caused by the warning can flood the trace with the functions that producing the output for the warning. This can make the resulting trace useless by either hiding where the bug happened, or worse, by overflowing the buffer and losing the trace of the bug totally. Acked-by: Peter Zijlstra Signed-off-by: Steven Rostedt

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