From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/lib/dump_stack.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 kernel/lib/dump_stack.c (limited to 'kernel/lib/dump_stack.c') diff --git a/kernel/lib/dump_stack.c b/kernel/lib/dump_stack.c new file mode 100644 index 000000000..6745c6230 --- /dev/null +++ b/kernel/lib/dump_stack.c @@ -0,0 +1,63 @@ +/* + * Provide a default dump_stack() function for architectures + * which don't implement their own. + */ + +#include +#include +#include +#include +#include + +static void __dump_stack(void) +{ + dump_stack_print_info(KERN_DEFAULT); + show_stack(NULL, NULL); +} + +/** + * dump_stack - dump the current task information and its stack trace + * + * Architectures can override this implementation by implementing its own. + */ +#ifdef CONFIG_SMP +static atomic_t dump_lock = ATOMIC_INIT(-1); + +asmlinkage __visible void dump_stack(void) +{ + int was_locked; + int old; + int cpu; + + /* + * Permit this cpu to perform nested stack dumps while serialising + * against other CPUs + */ + preempt_disable(); + +retry: + cpu = smp_processor_id(); + old = atomic_cmpxchg(&dump_lock, -1, cpu); + if (old == -1) { + was_locked = 0; + } else if (old == cpu) { + was_locked = 1; + } else { + cpu_relax(); + goto retry; + } + + __dump_stack(); + + if (!was_locked) + atomic_set(&dump_lock, -1); + + preempt_enable(); +} +#else +asmlinkage __visible void dump_stack(void) +{ + __dump_stack(); +} +#endif +EXPORT_SYMBOL(dump_stack); -- cgit 1.2.3-korg