From: "Steven Rostedt (Red Hat)" <[email protected]> Some callbacks of the function tracer use rcu_read_lock(). This means that there's places that can not be traced because RCU is not tracking the CPU for various reasons (like NO_HZ_FULL and coming back from userspace).
Thes functions need to be marked so that callbacks that use RCU do not trace them. Cc: H. Peter Anvin <[email protected]> Cc: Thomas Gleixner <[email protected]> Signed-off-by: Steven Rostedt <[email protected]> --- arch/x86/kernel/apic/apic.c | 2 ++ arch/x86/kernel/irq.c | 1 + arch/x86/kernel/irq_work.c | 3 +++ arch/x86/kernel/smp.c | 8 ++++++++ kernel/softirq.c | 2 ++ 5 files changed, 16 insertions(+) diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index eca89c5..91af16b 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -931,6 +931,7 @@ void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs) set_irq_regs(old_regs); } +FTRACE_UNSAFE_RCU(smp_apic_timer_interrupt); void __irq_entry smp_trace_apic_timer_interrupt(struct pt_regs *regs) { @@ -952,6 +953,7 @@ void __irq_entry smp_trace_apic_timer_interrupt(struct pt_regs *regs) set_irq_regs(old_regs); } +FTRACE_UNSAFE_RCU(smp_trace_apic_timer_interrupt); int setup_profiling_timer(unsigned int multiplier) { diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c index 3a8185c..fccd0d1 100644 --- a/arch/x86/kernel/irq.c +++ b/arch/x86/kernel/irq.c @@ -203,6 +203,7 @@ unsigned int __irq_entry do_IRQ(struct pt_regs *regs) set_irq_regs(old_regs); return 1; } +FTRACE_UNSAFE_RCU(do_IRQ); /* * Handler for X86_PLATFORM_IPI_VECTOR. diff --git a/arch/x86/kernel/irq_work.c b/arch/x86/kernel/irq_work.c index 636a55e..a2199c2 100644 --- a/arch/x86/kernel/irq_work.c +++ b/arch/x86/kernel/irq_work.c @@ -7,6 +7,7 @@ #include <linux/kernel.h> #include <linux/irq_work.h> #include <linux/hardirq.h> +#include <linux/ftrace.h> #include <asm/apic.h> #include <asm/trace/irq_vectors.h> @@ -28,6 +29,7 @@ void smp_irq_work_interrupt(struct pt_regs *regs) __smp_irq_work_interrupt(); exiting_irq(); } +FTRACE_UNSAFE_RCU(smp_irq_work_interrupt); void smp_trace_irq_work_interrupt(struct pt_regs *regs) { @@ -37,6 +39,7 @@ void smp_trace_irq_work_interrupt(struct pt_regs *regs) trace_irq_work_exit(IRQ_WORK_VECTOR); exiting_irq(); } +FTRACE_UNSAFE_RCU(smp_trace_irq_work_interrupt); void arch_irq_work_raise(void) { diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c index cdaa347..3d702ef 100644 --- a/arch/x86/kernel/smp.c +++ b/arch/x86/kernel/smp.c @@ -23,6 +23,7 @@ #include <linux/interrupt.h> #include <linux/cpu.h> #include <linux/gfp.h> +#include <linux/ftrace.h> #include <asm/mtrr.h> #include <asm/tlbflush.h> @@ -175,6 +176,7 @@ asmlinkage void smp_reboot_interrupt(void) stop_this_cpu(NULL); irq_exit(); } +FTRACE_UNSAFE_RCU(smp_reboot_interrupt); static void native_stop_other_cpus(int wait) { @@ -264,6 +266,7 @@ void smp_reschedule_interrupt(struct pt_regs *regs) * KVM uses this interrupt to force a cpu out of guest mode */ } +FTRACE_UNSAFE_RCU(smp_reschedule_interrupt); static inline void smp_entering_irq(void) { @@ -288,6 +291,7 @@ void smp_trace_reschedule_interrupt(struct pt_regs *regs) * KVM uses this interrupt to force a cpu out of guest mode */ } +FTRACE_UNSAFE_RCU(smp_trace_reschedule_interrupt); static inline void __smp_call_function_interrupt(void) { @@ -301,6 +305,7 @@ void smp_call_function_interrupt(struct pt_regs *regs) __smp_call_function_interrupt(); exiting_irq(); } +FTRACE_UNSAFE_RCU(smp_call_function_interrupt); void smp_trace_call_function_interrupt(struct pt_regs *regs) { @@ -310,6 +315,7 @@ void smp_trace_call_function_interrupt(struct pt_regs *regs) trace_call_function_exit(CALL_FUNCTION_VECTOR); exiting_irq(); } +FTRACE_UNSAFE_RCU(smp_trace_call_function_interrupt); static inline void __smp_call_function_single_interrupt(void) { @@ -323,6 +329,7 @@ void smp_call_function_single_interrupt(struct pt_regs *regs) __smp_call_function_single_interrupt(); exiting_irq(); } +FTRACE_UNSAFE_RCU(smp_call_function_single_interrupt); void smp_trace_call_function_single_interrupt(struct pt_regs *regs) { @@ -332,6 +339,7 @@ void smp_trace_call_function_single_interrupt(struct pt_regs *regs) trace_call_function_single_exit(CALL_FUNCTION_SINGLE_VECTOR); exiting_irq(); } +FTRACE_UNSAFE_RCU(smp_trace_call_function_single_interrupt); static int __init nonmi_ipi_setup(char *str) { diff --git a/kernel/softirq.c b/kernel/softirq.c index be3d351..7960e70 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -325,6 +325,7 @@ void irq_enter(void) __irq_enter(); } +FTRACE_UNSAFE_RCU(irq_enter); static inline void invoke_softirq(void) { @@ -367,6 +368,7 @@ void irq_exit(void) tick_irq_exit(); rcu_irq_exit(); } +FTRACE_UNSAFE_RCU(irq_exit); /* * This function must run with irqs disabled! -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
