On Mon, 25 Apr 2016 18:56:14 -0300 Thiago Jung Bauermann <bauer...@linux.vnet.ibm.com> wrote:
> 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 <rost...@goodmis.org> > Cc: Ingo Molnar <mi...@redhat.com> > Cc: Michael Ellerman <m...@ellerman.id.au> > Cc: linuxppc-...@lists.ozlabs.org > Signed-off-by: Thiago Jung Bauermann <bauer...@linux.vnet.ibm.com> > --- Acked-by: Steven Rostedt <rost...@goodmis.org> This can go through the ppc tree. -- Steve
