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authorPratyush Anand <panand@redhat.com>2016-09-05 08:03:16 +0530
committerWill Deacon <will.deacon@arm.com>2016-09-05 13:41:52 +0100
commit98ab10e9770e3ce9fbd263689644be9d81a06885 (patch)
tree0b046ba330c0f58967bceab34e71be174b5b551d /drivers/perf
parentdc00247576fdb97211e1959b4dfd2a7893cf9d0b (diff)
arm64: ftrace: add save_stack_trace_regs()
Currently, enabling stacktrace of a kprobe events generates warning: echo stacktrace > /sys/kernel/debug/tracing/trace_options echo "p xhci_irq" > /sys/kernel/debug/tracing/kprobe_events echo 1 > /sys/kernel/debug/tracing/events/kprobes/enable save_stack_trace_regs() not implemented yet. ------------[ cut here ]------------ WARNING: CPU: 1 PID: 0 at ../kernel/stacktrace.c:74 save_stack_trace_regs+0x3c/0x48 Modules linked in: CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.8.0-rc4-dirty #5128 Hardware name: ARM Juno development board (r1) (DT) task: ffff800975dd1900 task.stack: ffff800975ddc000 PC is at save_stack_trace_regs+0x3c/0x48 LR is at save_stack_trace_regs+0x3c/0x48 pc : [<ffff000008126c64>] lr : [<ffff000008126c64>] pstate: 600003c5 sp : ffff80097ef52c00 Call trace: save_stack_trace_regs+0x3c/0x48 __ftrace_trace_stack+0x168/0x208 trace_buffer_unlock_commit_regs+0x5c/0x7c kprobe_trace_func+0x308/0x3d8 kprobe_dispatcher+0x58/0x60 kprobe_breakpoint_handler+0xbc/0x18c brk_handler+0x50/0x90 do_debug_exception+0x50/0xbc This patch implements save_stack_trace_regs(), so that stacktrace of a kprobe events can be obtained. After this patch, there is no warning and we can see the stacktrace for kprobe events in trace buffer. more /sys/kernel/debug/tracing/trace <idle>-0 [004] d.h. 1356.000496: p_xhci_irq_0:(xhci_irq+0x0/0x9ac) <idle>-0 [004] d.h. 1356.000497: <stack trace> => xhci_irq => __handle_irq_event_percpu => handle_irq_event_percpu => handle_irq_event => handle_fasteoi_irq => generic_handle_irq => __handle_domain_irq => gic_handle_irq => el1_irq => arch_cpu_idle => default_idle_call => cpu_startup_entry => secondary_start_kernel => Tested-by: David A. Long <dave.long@linaro.org> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Pratyush Anand <panand@redhat.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'drivers/perf')
0 files changed, 0 insertions, 0 deletions