10 files changed, 72 insertions, 39 deletions

diff --git a/arch/arm/include/asm/irq.h b/arch/arm/include/asm/irq.h
index 1bd9510de1b9..e53638c8ed8a 100644
--- a/arch/arm/include/asm/irq.h
+++ b/arch/arm/include/asm/irq.h
@@ -36,8 +36,9 @@ extern void set_handle_irq(void (*handle_irq)(struct pt_regs *));
 #endif
 
 #ifdef CONFIG_SMP
-extern void arch_trigger_all_cpu_backtrace(bool);
-#define arch_trigger_all_cpu_backtrace(x) arch_trigger_all_cpu_backtrace(x)
+extern void arch_trigger_cpumask_backtrace(const cpumask_t *mask,
+                                           bool exclude_self);
+#define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace
 #endif
 
 static inline int nr_legacy_irqs(void)
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 937c8920d741..5abc5697e4e5 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -760,7 +760,7 @@ static void raise_nmi(cpumask_t *mask)
         smp_cross_call(mask, IPI_CPU_BACKTRACE);
 }
 
-void arch_trigger_all_cpu_backtrace(bool include_self)
+void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
 {
-        nmi_trigger_all_cpu_backtrace(include_self, raise_nmi);
+        nmi_trigger_cpumask_backtrace(mask, exclude_self, raise_nmi);
 }
diff --git a/arch/mips/include/asm/irq.h b/arch/mips/include/asm/irq.h
index 15e0fecbc300..6bf10e796553 100644
--- a/arch/mips/include/asm/irq.h
+++ b/arch/mips/include/asm/irq.h
@@ -51,7 +51,8 @@ extern int cp0_fdc_irq;
 
 extern int get_c0_fdc_int(void);
 
-void arch_trigger_all_cpu_backtrace(bool);
-#define arch_trigger_all_cpu_backtrace arch_trigger_all_cpu_backtrace
+void arch_trigger_cpumask_backtrace(const struct cpumask *mask,
+                                    bool exclude_self);
+#define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace
 
 #endif /* _ASM_IRQ_H */
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index d2d061520a23..9514e5f2209f 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -569,9 +569,16 @@ static void arch_dump_stack(void *info)
         dump_stack();
 }
 
-void arch_trigger_all_cpu_backtrace(bool include_self)
+void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
 {
-        smp_call_function(arch_dump_stack, NULL, 1);
+        long this_cpu = get_cpu();
+
+        if (cpumask_test_cpu(this_cpu, mask) && !exclude_self)
+                dump_stack();
+
+        smp_call_function_many(mask, arch_dump_stack, NULL, 1);
+
+        put_cpu();
 }
 
 int mips_get_process_fp_mode(struct task_struct *task)
diff --git a/arch/sparc/include/asm/irq_64.h b/arch/sparc/include/asm/irq_64.h
index 3f70f900e834..1d51a11fb261 100644
--- a/arch/sparc/include/asm/irq_64.h
+++ b/arch/sparc/include/asm/irq_64.h
@@ -86,8 +86,9 @@ static inline unsigned long get_softint(void)
         return retval;
 }
 
-void arch_trigger_all_cpu_backtrace(bool);
-#define arch_trigger_all_cpu_backtrace arch_trigger_all_cpu_backtrace
+void arch_trigger_cpumask_backtrace(const struct cpumask *mask,
+                                    bool exclude_self);
+#define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace
 
 extern void *hardirq_stack[NR_CPUS];
 extern void *softirq_stack[NR_CPUS];
diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c
index fa14402b33f9..47ff5588e521 100644
--- a/arch/sparc/kernel/process_64.c
+++ b/arch/sparc/kernel/process_64.c
@@ -239,7 +239,7 @@ static void __global_reg_poll(struct global_reg_snapshot *gp)
         }
 }
 
-void arch_trigger_all_cpu_backtrace(bool include_self)
+void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
 {
         struct thread_info *tp = current_thread_info();
         struct pt_regs *regs = get_irq_regs();
@@ -255,15 +255,15 @@ void arch_trigger_all_cpu_backtrace(bool include_self)
 
         memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
 
-        if (include_self)
+        if (cpumask_test_cpu(this_cpu, mask) && !exclude_self)
                 __global_reg_self(tp, regs, this_cpu);
 
         smp_fetch_global_regs();
 
-        for_each_online_cpu(cpu) {
+        for_each_cpu(cpu, mask) {
                 struct global_reg_snapshot *gp;
 
-                if (!include_self && cpu == this_cpu)
+                if (exclude_self && cpu == this_cpu)
                         continue;
 
                 gp = &global_cpu_snapshot[cpu].reg;
@@ -300,7 +300,7 @@ void arch_trigger_all_cpu_backtrace(bool include_self)
 
 static void sysrq_handle_globreg(int key)
 {
-        arch_trigger_all_cpu_backtrace(true);
+        trigger_all_cpu_backtrace();
 }
 
 static struct sysrq_key_op sparc_globalreg_op = {
diff --git a/arch/x86/include/asm/irq.h b/arch/x86/include/asm/irq.h
index e7de5c9a4fbd..16d3fa211962 100644
--- a/arch/x86/include/asm/irq.h
+++ b/arch/x86/include/asm/irq.h
@@ -50,8 +50,9 @@ extern int vector_used_by_percpu_irq(unsigned int vector);
 extern void init_ISA_irqs(void);
 
 #ifdef CONFIG_X86_LOCAL_APIC
-void arch_trigger_all_cpu_backtrace(bool);
-#define arch_trigger_all_cpu_backtrace arch_trigger_all_cpu_backtrace
+void arch_trigger_cpumask_backtrace(const struct cpumask *mask,
+                                    bool exclude_self);
+#define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace
 #endif
 
 #endif /* _ASM_X86_IRQ_H */
diff --git a/arch/x86/kernel/apic/hw_nmi.c b/arch/x86/kernel/apic/hw_nmi.c
index f29501e1a5c1..c73c9fb281e1 100644
--- a/arch/x86/kernel/apic/hw_nmi.c
+++ b/arch/x86/kernel/apic/hw_nmi.c
@@ -26,32 +26,32 @@ u64 hw_nmi_get_sample_period(int watchdog_thresh)
 }
 #endif
 
-#ifdef arch_trigger_all_cpu_backtrace
+#ifdef arch_trigger_cpumask_backtrace
 static void nmi_raise_cpu_backtrace(cpumask_t *mask)
 {
         apic->send_IPI_mask(mask, NMI_VECTOR);
 }
 
-void arch_trigger_all_cpu_backtrace(bool include_self)
+void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
 {
-        nmi_trigger_all_cpu_backtrace(include_self, nmi_raise_cpu_backtrace);
+        nmi_trigger_cpumask_backtrace(mask, exclude_self,
+                                      nmi_raise_cpu_backtrace);
 }
 
-static int
-arch_trigger_all_cpu_backtrace_handler(unsigned int cmd, struct pt_regs *regs)
+static int nmi_cpu_backtrace_handler(unsigned int cmd, struct pt_regs *regs)
 {
         if (nmi_cpu_backtrace(regs))
                 return NMI_HANDLED;
 
         return NMI_DONE;
 }
-NOKPROBE_SYMBOL(arch_trigger_all_cpu_backtrace_handler);
+NOKPROBE_SYMBOL(nmi_cpu_backtrace_handler);
 
-static int __init register_trigger_all_cpu_backtrace(void)
+static int __init register_nmi_cpu_backtrace_handler(void)
 {
-        register_nmi_handler(NMI_LOCAL, arch_trigger_all_cpu_backtrace_handler,
+        register_nmi_handler(NMI_LOCAL, nmi_cpu_backtrace_handler,
                                 0, "arch_bt");
         return 0;
 }
-early_initcall(register_trigger_all_cpu_backtrace);
+early_initcall(register_nmi_cpu_backtrace_handler);
 #endif
diff --git a/include/linux/nmi.h b/include/linux/nmi.h
index 4630eeae18e0..a78c35cff1ae 100644
--- a/include/linux/nmi.h
+++ b/include/linux/nmi.h
@@ -35,21 +35,34 @@ static inline void hardlockup_detector_disable(void) {}
  * base function. Return whether such support was available,
  * to allow calling code to fall back to some other mechanism:
  */
-#ifdef arch_trigger_all_cpu_backtrace
+#ifdef arch_trigger_cpumask_backtrace
 static inline bool trigger_all_cpu_backtrace(void)
 {
-        arch_trigger_all_cpu_backtrace(true);
-
+        arch_trigger_cpumask_backtrace(cpu_online_mask, false);
         return true;
 }
+
 static inline bool trigger_allbutself_cpu_backtrace(void)
 {
-        arch_trigger_all_cpu_backtrace(false);
+        arch_trigger_cpumask_backtrace(cpu_online_mask, true);
+        return true;
+}
+
+static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
+{
+        arch_trigger_cpumask_backtrace(mask, false);
+        return true;
+}
+
+static inline bool trigger_single_cpu_backtrace(int cpu)
+{
+        arch_trigger_cpumask_backtrace(cpumask_of(cpu), false);
         return true;
 }
 
 /* generic implementation */
-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));
 bool nmi_cpu_backtrace(struct pt_regs *regs);
 
@@ -62,6 +75,14 @@ static inline bool trigger_allbutself_cpu_backtrace(void)
 {
         return false;
 }
+static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
+{
+        return false;
+}
+static inline bool trigger_single_cpu_backtrace(int cpu)
+{
+        return false;
+}
 #endif
 
 #ifdef CONFIG_LOCKUP_DETECTOR
diff --git a/lib/nmi_backtrace.c b/lib/nmi_backtrace.c
index 26caf51cc238..df347e355267 100644
--- a/lib/nmi_backtrace.c
+++ b/lib/nmi_backtrace.c
@@ -17,20 +17,21 @@
 #include <linux/kprobes.h>
 #include <linux/nmi.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 +45,13 @@ 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));
 
         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));
         }