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authorLinus Torvalds <torvalds@linux-foundation.org>2016-10-07 21:38:00 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-10-07 21:38:00 -0700
commitb66484cd74706fa8681d051840fe4b18a3da40ff (patch)
treee8215e7c25661d25f84abc4b98140c2062d6d5de /lib
parentc913fc4146ba7c280e074558d0a461e5c6f07c8a (diff)
parent05fd007e46296afb24d15c7d589d535e5a5b9d5c (diff)
Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton: - fsnotify updates - ocfs2 updates - all of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (127 commits) console: don't prefer first registered if DT specifies stdout-path cred: simpler, 1D supplementary groups CREDITS: update Pavel's information, add GPG key, remove snail mail address mailmap: add Johan Hovold .gitattributes: set git diff driver for C source code files uprobes: remove function declarations from arch/{mips,s390} spelling.txt: "modeled" is spelt correctly nmi_backtrace: generate one-line reports for idle cpus arch/tile: adopt the new nmi_backtrace framework nmi_backtrace: do a local dump_stack() instead of a self-NMI nmi_backtrace: add more trigger_*_cpu_backtrace() methods min/max: remove sparse warnings when they're nested Documentation/filesystems/proc.txt: add more description for maps/smaps mm, proc: fix region lost in /proc/self/smaps proc: fix timerslack_ns CAP_SYS_NICE check when adjusting self proc: add LSM hook checks to /proc/<tid>/timerslack_ns proc: relax /proc/<tid>/timerslack_ns capability requirements meminfo: break apart a very long seq_printf with #ifdefs seq/proc: modify seq_put_decimal_[u]ll to take a const char *, not char proc: faster /proc/*/status ...
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig3
-rw-r--r--lib/atomic64_test.c4
-rw-r--r--lib/nmi_backtrace.c42
3 files changed, 29 insertions, 20 deletions
diff --git a/lib/Kconfig b/lib/Kconfig
index 942fb8091a86..260a80e313b9 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -457,9 +457,6 @@ config NLATTR
config GENERIC_ATOMIC64
bool
-config ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
- def_bool y if GENERIC_ATOMIC64
-
config LRU_CACHE
tristate
diff --git a/lib/atomic64_test.c b/lib/atomic64_test.c
index dbb369145dda..46042901130f 100644
--- a/lib/atomic64_test.c
+++ b/lib/atomic64_test.c
@@ -213,7 +213,6 @@ static __init void test_atomic64(void)
r += one;
BUG_ON(v.counter != r);
-#ifdef CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
INIT(onestwos);
BUG_ON(atomic64_dec_if_positive(&v) != (onestwos - 1));
r -= one;
@@ -226,9 +225,6 @@ static __init void test_atomic64(void)
INIT(-one);
BUG_ON(atomic64_dec_if_positive(&v) != (-one - one));
BUG_ON(v.counter != r);
-#else
-#warning Please implement atomic64_dec_if_positive for your architecture and select the above Kconfig symbol
-#endif
INIT(onestwos);
BUG_ON(!atomic64_inc_not_zero(&v));
diff --git a/lib/nmi_backtrace.c b/lib/nmi_backtrace.c
index 26caf51cc238..75554754eadf 100644
--- a/lib/nmi_backtrace.c
+++ b/lib/nmi_backtrace.c
@@ -16,21 +16,23 @@
#include <linux/delay.h>
#include <linux/kprobes.h>
#include <linux/nmi.h>
+#include <linux/cpu.h>
-#ifdef arch_trigger_all_cpu_backtrace
+#ifdef arch_trigger_cpumask_backtrace
/* For reliability, we're prepared to waste bits here. */
static DECLARE_BITMAP(backtrace_mask, NR_CPUS) __read_mostly;
-/* "in progress" flag of arch_trigger_all_cpu_backtrace */
+/* "in progress" flag of arch_trigger_cpumask_backtrace */
static unsigned long backtrace_flag;
/*
- * When raise() is called it will be is passed a pointer to the
+ * When raise() is called it will be passed a pointer to the
* backtrace_mask. Architectures that call nmi_cpu_backtrace()
* directly from their raise() functions may rely on the mask
* they are passed being updated as a side effect of this call.
*/
-void nmi_trigger_all_cpu_backtrace(bool include_self,
+void nmi_trigger_cpumask_backtrace(const cpumask_t *mask,
+ bool exclude_self,
void (*raise)(cpumask_t *mask))
{
int i, this_cpu = get_cpu();
@@ -44,13 +46,22 @@ void nmi_trigger_all_cpu_backtrace(bool include_self,
return;
}
- cpumask_copy(to_cpumask(backtrace_mask), cpu_online_mask);
- if (!include_self)
+ cpumask_copy(to_cpumask(backtrace_mask), mask);
+ if (exclude_self)
cpumask_clear_cpu(this_cpu, to_cpumask(backtrace_mask));
+ /*
+ * Don't try to send an NMI to this cpu; it may work on some
+ * architectures, but on others it may not, and we'll get
+ * information at least as useful just by doing a dump_stack() here.
+ * Note that nmi_cpu_backtrace(NULL) will clear the cpu bit.
+ */
+ if (cpumask_test_cpu(this_cpu, to_cpumask(backtrace_mask)))
+ nmi_cpu_backtrace(NULL);
+
if (!cpumask_empty(to_cpumask(backtrace_mask))) {
- pr_info("Sending NMI to %s CPUs:\n",
- (include_self ? "all" : "other"));
+ pr_info("Sending NMI from CPU %d to CPUs %*pbl:\n",
+ this_cpu, nr_cpumask_bits, to_cpumask(backtrace_mask));
raise(to_cpumask(backtrace_mask));
}
@@ -77,11 +88,16 @@ bool nmi_cpu_backtrace(struct pt_regs *regs)
int cpu = smp_processor_id();
if (cpumask_test_cpu(cpu, to_cpumask(backtrace_mask))) {
- pr_warn("NMI backtrace for cpu %d\n", cpu);
- if (regs)
- show_regs(regs);
- else
- dump_stack();
+ if (regs && cpu_in_idle(instruction_pointer(regs))) {
+ pr_warn("NMI backtrace for cpu %d skipped: idling at pc %#lx\n",
+ cpu, instruction_pointer(regs));
+ } else {
+ pr_warn("NMI backtrace for cpu %d\n", cpu);
+ if (regs)
+ show_regs(regs);
+ else
+ dump_stack();
+ }
cpumask_clear_cpu(cpu, to_cpumask(backtrace_mask));
return true;
}