linux/kernel/trace
Thiago Jung Bauermann 7132e2d669 ftrace: Match dot symbols when searching functions on ppc64
In the ppc64 big endian ABI, function symbols point to function
descriptors. The symbols which point to the function entry points
have a dot in front of the function name. Consequently, when the
ftrace filter mechanism searches for the symbol corresponding to
an entry point address, it gets the dot symbol.

As a result, ftrace filter users have to be aware of this ABI detail on
ppc64 and prepend a dot to the function name when setting the filter.

The perf probe command insulates the user from this by ignoring the dot
in front of the symbol name when matching function names to symbols,
but the sysfs interface does not. This patch makes the ftrace filter
mechanism do the same when searching symbols.

Fixes the following failure in ftracetest's kprobe_ftrace.tc:

  .../kprobe_ftrace.tc: line 9: echo: write error: Invalid argument

That failure is on this line of kprobe_ftrace.tc:

  echo _do_fork > set_ftrace_filter

This is because there's no _do_fork entry in the functions list:

  # cat available_filter_functions | grep _do_fork
  ._do_fork

This change introduces no regressions on the perf and ftracetest
testsuite results.

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-04-27 09:47:29 +10:00
..
blktrace.c kernel/...: convert pr_warning to pr_warn 2016-03-22 15:36:02 -07:00
bpf_trace.c
ftrace.c ftrace: Match dot symbols when searching functions on ppc64 2016-04-27 09:47:29 +10:00
Kconfig
Makefile
power-traces.c
ring_buffer.c
ring_buffer_benchmark.c
rpm-traces.c
trace.c Nothing major this round. Mostly small clean ups and fixes. 2016-03-24 10:52:25 -07:00
trace.h tracing: Record and show NMI state 2016-03-22 18:04:10 -04:00
trace_benchmark.c
trace_benchmark.h
trace_branch.c
trace_clock.c
trace_entries.h
trace_event_perf.c
trace_events.c
trace_events_filter.c
trace_events_filter_test.h
trace_events_trigger.c
trace_export.c
trace_functions.c
trace_functions_graph.c arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections 2016-03-25 16:37:42 -07:00
trace_irqsoff.c tracing: Remove redundant reset per-CPU buff in irqsoff tracer 2016-03-18 16:39:11 -04:00
trace_kdb.c
trace_kprobe.c kernel/...: convert pr_warning to pr_warn 2016-03-22 15:36:02 -07:00
trace_mmiotrace.c kernel/...: convert pr_warning to pr_warn 2016-03-22 15:36:02 -07:00
trace_nop.c
trace_output.c tracing: Record and show NMI state 2016-03-22 18:04:10 -04:00
trace_output.h
trace_printk.c tracing: Fix trace_printk() to print when not using bprintk() 2016-03-22 18:02:40 -04:00
trace_probe.c kernel/...: convert pr_warning to pr_warn 2016-03-22 15:36:02 -07:00
trace_probe.h
trace_sched_switch.c
trace_sched_wakeup.c
trace_selftest.c
trace_selftest_dynamic.c
trace_seq.c
trace_stack.c
trace_stat.c kernel/...: convert pr_warning to pr_warn 2016-03-22 15:36:02 -07:00
trace_stat.h
trace_syscalls.c Nothing major this round. Mostly small clean ups and fixes. 2016-03-24 10:52:25 -07:00
trace_uprobe.c kernel/...: convert pr_warning to pr_warn 2016-03-22 15:36:02 -07:00