| Message ID | 1364076649-16841-1-git-send-email-rabin@rab.in (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, 2013-03-23 at 23:10 +0100, Rabin Vincent wrote: > Add unwind annotations to the ftrace assembly code so that the function > tracer's stacktracing options (func_stack_trace, etc.) work when > CONFIG_ARM_UNWIND is enabled. > > Signed-off-by: Rabin Vincent <rabin@rab.in> In my test this fixes func_stack_trace: == without patch == # tracer: function # # entries-in-buffer/entries-written: 318/318 #P:1 # # _-------=> irqs-off # / _------=> need-resched # |/ _-----=> need-resched_lazy # ||/ _----=> hardirq/softirq # |||/ _---=> preempt-depth # ||||/ _--=> preempt-lazy-depth # ||||| / _-=> migrate-disable # |||||| / delay # TASK-PID CPU# ||||||| TIMESTAMP FUNCTION # | | | ||||||| | | sh-829 [000] d..h1.. 838.966903: ktime_get <-tick_sched_timer sh-829 [000] d..h1.. 838.966933: <stack trace> => ftrace_ops_no_ops => ftrace_graph_call sh-829 [000] d..h1.. 838.966979: ktime_get <-clockevents_program_event sh-829 [000] d..h1.. 838.966990: <stack trace> == with patch == # tracer: function # # entries-in-buffer/entries-written: 678/678 #P:1 # # _-------=> irqs-off # / _------=> need-resched # |/ _-----=> need-resched_lazy # ||/ _----=> hardirq/softirq # |||/ _---=> preempt-depth # ||||/ _--=> preempt-lazy-depth # ||||| / _-=> migrate-disable # |||||| / delay # TASK-PID CPU# ||||||| TIMESTAMP FUNCTION # | | | ||||||| | | sh-828 [000] d..h2.. 108.367156: ktime_get <-tick_sched_timer sh-828 [000] d..h2.. 108.367224: <stack trace> => ftrace_ops_no_ops => ftrace_graph_call => ktime_get => tick_sched_timer => __run_hrtimer => hrtimer_interrupt => omap2_gp_timer_interrupt => handle_irq_event_percpu => handle_irq_event => handle_level_irq => generic_handle_irq => handle_IRQ => omap3_intc_handle_irq => __irq_svc => sub_preempt_count => cap_vm_enough_memory => security_vm_enough_memory_mm => mmap_region => do_mmap_pgoff => vm_mmap_pgoff => sys_mmap_pgoff => ret_fast_syscall Thanks for this fix! Regards, Jan
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S index 3248cde..fefd7f9 100644 --- a/arch/arm/kernel/entry-common.S +++ b/arch/arm/kernel/entry-common.S @@ -276,7 +276,13 @@ ENDPROC(ftrace_graph_caller_old) */ .macro mcount_enter +/* + * This pad compensates for the push {lr} at the call site. Note that we are + * unable to unwind through a function which does not otherwise save its lr. + */ + UNWIND(.pad #4) stmdb sp!, {r0-r3, lr} + UNWIND(.save {r0-r3, lr}) .endm .macro mcount_get_lr reg @@ -289,6 +295,7 @@ ENDPROC(ftrace_graph_caller_old) .endm ENTRY(__gnu_mcount_nc) +UNWIND(.fnstart) #ifdef CONFIG_DYNAMIC_FTRACE mov ip, lr ldmia sp!, {lr} @@ -296,17 +303,22 @@ ENTRY(__gnu_mcount_nc) #else __mcount #endif +UNWIND(.fnend) ENDPROC(__gnu_mcount_nc) #ifdef CONFIG_DYNAMIC_FTRACE ENTRY(ftrace_caller) +UNWIND(.fnstart) __ftrace_caller +UNWIND(.fnend) ENDPROC(ftrace_caller) #endif #ifdef CONFIG_FUNCTION_GRAPH_TRACER ENTRY(ftrace_graph_caller) +UNWIND(.fnstart) __ftrace_graph_caller +UNWIND(.fnend) ENDPROC(ftrace_graph_caller) #endif
Add unwind annotations to the ftrace assembly code so that the function tracer's stacktracing options (func_stack_trace, etc.) work when CONFIG_ARM_UNWIND is enabled. Signed-off-by: Rabin Vincent <rabin@rab.in> --- arch/arm/kernel/entry-common.S | 12 ++++++++++++ 1 file changed, 12 insertions(+)