From: sahara <keun-o.p...@windriver.com> This is a reminder that we still need to fix the return_address function to work correctly with the unwinder. Keun-O Park has made this attempt in the past, which is still under discussion[1], and Dave Martin has also mentioned that he would provide a solution for this problem.
Right now, this patch makes the warning go away and provides an implementation of return_address for the arm unwinder, but causes other problems, so we should *not* apply it. I will keep sending this patch until we have a better solution. [1] http://lkml.org/lkml/2013/1/11/493 Original changelog: This fixes a warning saying: warning: #warning "TODO: return_address should use unwind tables" And, this enables return_address using unwind information. If ARM_UNWIND is selected, unwind_frame in unwind.c will be called in walk_stackframe. Signed-off-by: sahara <keun-o.p...@windriver.com> Signed-off-by: Arnd Bergmann <a...@arndb.de> Cc: Dave Martin <dave.mar...@linaro.org> Cc: Steven Rostedt <rost...@goodmis.org> Cc: Russell King <li...@arm.linux.org.uk> --- arch/arm/include/asm/ftrace.h | 6 ++---- arch/arm/kernel/Makefile | 12 +++++------- arch/arm/kernel/return_address.c | 10 +++------- arch/arm/kernel/stacktrace.c | 3 +++ kernel/trace/trace_irqsoff.c | 26 ++++++++++++-------------- 5 files changed, 25 insertions(+), 32 deletions(-) diff --git a/arch/arm/include/asm/ftrace.h b/arch/arm/include/asm/ftrace.h index f89515a..3552ad9 100644 --- a/arch/arm/include/asm/ftrace.h +++ b/arch/arm/include/asm/ftrace.h @@ -32,13 +32,11 @@ extern void ftrace_call_old(void); #ifndef __ASSEMBLY__ -#if defined(CONFIG_FRAME_POINTER) && !defined(CONFIG_ARM_UNWIND) +#if defined(CONFIG_FRAME_POINTER) || defined(CONFIG_ARM_UNWIND) /* * return_address uses walk_stackframe to do it's work. If both * CONFIG_FRAME_POINTER=y and CONFIG_ARM_UNWIND=y walk_stackframe uses unwind - * information. For this to work in the function tracer many functions would - * have to be marked with __notrace. So for now just depend on - * !CONFIG_ARM_UNWIND. + * information. */ void *return_address(unsigned int); diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index 5bbec7b..09a0d64 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -5,13 +5,11 @@ CPPFLAGS_vmlinux.lds := -DTEXT_OFFSET=$(TEXT_OFFSET) AFLAGS_head.o := -DTEXT_OFFSET=$(TEXT_OFFSET) -ifdef CONFIG_FUNCTION_TRACER -CFLAGS_REMOVE_ftrace.o = -pg -CFLAGS_REMOVE_insn.o = -pg -CFLAGS_REMOVE_patch.o = -pg -endif - -CFLAGS_REMOVE_return_address.o = -pg +CFLAGS_REMOVE_ftrace.o = -pg +CFLAGS_REMOVE_insn.o = -pg +CFLAGS_REMOVE_patch.o = -pg +CFLAGS_REMOVE_unwind.o = -pg +CFLAGS_REMOVE_return_address.o = -pg # Object file lists. diff --git a/arch/arm/kernel/return_address.c b/arch/arm/kernel/return_address.c index 8085417..ccb5e37 100644 --- a/arch/arm/kernel/return_address.c +++ b/arch/arm/kernel/return_address.c @@ -11,7 +11,7 @@ #include <linux/export.h> #include <linux/ftrace.h> -#if defined(CONFIG_FRAME_POINTER) && !defined(CONFIG_ARM_UNWIND) +#if defined(CONFIG_FRAME_POINTER) || defined(CONFIG_ARM_UNWIND) #include <linux/sched.h> #include <asm/stacktrace.h> @@ -56,17 +56,13 @@ void *return_address(unsigned int level) return NULL; } -#else /* if defined(CONFIG_FRAME_POINTER) && !defined(CONFIG_ARM_UNWIND) */ - -#if defined(CONFIG_ARM_UNWIND) -#warning "TODO: return_address should use unwind tables" -#endif +#else /* CONFIG_FRAME_POINTER || CONFIG_ARM_UNWIND */ void *return_address(unsigned int level) { return NULL; } -#endif /* if defined(CONFIG_FRAME_POINTER) && !defined(CONFIG_ARM_UNWIND) / else */ +#endif /* CONFIG_FRAME_POINTER || CONFIG_ARM_UNWIND */ EXPORT_SYMBOL_GPL(return_address); diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c index 00f79e5..aab144b 100644 --- a/arch/arm/kernel/stacktrace.c +++ b/arch/arm/kernel/stacktrace.c @@ -6,6 +6,9 @@ #if defined(CONFIG_FRAME_POINTER) && !defined(CONFIG_ARM_UNWIND) /* + * If both CONFIG_FRAME_POINTER=y and CONFIG_ARM_UNWIND=y walk_stackframe uses + * unwind information. So for now just depend on !CONFIG_ARM_UNWIND. + * * Unwind the current stack frame and store the new register values in the * structure passed as argument. Unwinding is equivalent to a function return, * hence the new PC value rather than LR should be used for backtrace. diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index 713a2ca..6f207ed 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -483,20 +483,6 @@ inline void print_irqtrace_events(struct task_struct *curr) /* * We are only interested in hardirq on/off events: */ -void trace_hardirqs_on(void) -{ - if (!preempt_trace() && irq_trace()) - stop_critical_timing(CALLER_ADDR0, CALLER_ADDR1); -} -EXPORT_SYMBOL(trace_hardirqs_on); - -void trace_hardirqs_off(void) -{ - if (!preempt_trace() && irq_trace()) - start_critical_timing(CALLER_ADDR0, CALLER_ADDR1); -} -EXPORT_SYMBOL(trace_hardirqs_off); - void trace_hardirqs_on_caller(unsigned long caller_addr) { if (!preempt_trace() && irq_trace()) @@ -504,6 +490,12 @@ void trace_hardirqs_on_caller(unsigned long caller_addr) } EXPORT_SYMBOL(trace_hardirqs_on_caller); +void trace_hardirqs_on(void) +{ + trace_hardirqs_on_caller(CALLER_ADDR0); +} +EXPORT_SYMBOL(trace_hardirqs_on); + void trace_hardirqs_off_caller(unsigned long caller_addr) { if (!preempt_trace() && irq_trace()) @@ -511,6 +503,12 @@ void trace_hardirqs_off_caller(unsigned long caller_addr) } EXPORT_SYMBOL(trace_hardirqs_off_caller); +void trace_hardirqs_off(void) +{ + trace_hardirqs_off_caller(CALLER_ADDR0); +} +EXPORT_SYMBOL(trace_hardirqs_off); + #endif /* CONFIG_PROVE_LOCKING */ #endif /* CONFIG_IRQSOFF_TRACER */ -- 1.8.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
