Re: [PATCH v2] perf machine: Fix load kernel symbol with '-k' option

From: Jiri Olsa
Date: Sun Mar 11 2018 - 15:49:25 EST


On Sat, Mar 10, 2018 at 05:50:56PM +0800, Leo Yan wrote:

SNIP

> > > diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
> > > index 12b7427..3125871 100644
> > > --- a/tools/perf/util/machine.c
> > > +++ b/tools/perf/util/machine.c
> > > @@ -1299,9 +1299,18 @@ static int machine__process_kernel_mmap_event(struct machine *machine,
> > > else
> > > kernel_type = DSO_TYPE_GUEST_KERNEL;
> > >
> > > - is_kernel_mmap = memcmp(event->mmap.filename,
> > > - machine->mmap_name,
> > > - strlen(machine->mmap_name) - 1) == 0;
> > > + /*
> > > + * When symbol_conf.vmlinux_name is not NULL, it includes the specified
> > > + * kernel vmlinux path with option '-k'. So set 'is_kernel_mmap' to
> > > + * true for creating machine symbol map.
> > > + */
> > > + if (symbol_conf.vmlinux_name)
> > > + is_kernel_mmap = true;
> > > + else
> > > + is_kernel_mmap = memcmp(event->mmap.filename,
> > > + machine->mmap_name,
> > > + strlen(machine->mmap_name) - 1) == 0;
> > > +
> > > if (event->mmap.filename[0] == '/' ||
> > > (!is_kernel_mmap && event->mmap.filename[0] == '[')) {
> > > map = machine__findnew_module_map(machine, event->mmap.start,
> >
> > right, the mmap gets confused with the vmlinux path, but I wonder
> > the fix should be not to include symbol_conf.vmlinux_name in the
> > mmap_name like below.. untested
>
> I tested below fixing at my side, and confirm your fixing also can
> resolve this issue. After reviewing the change, it's more neat than my
> own change . So you could add my test tag :)
>
> Tested-by: Leo Yan <leo.yan@xxxxxxxxxx>

thanks

SNIP

> static int machine__set_mmap_name(struct machine *machine)
> {
> - if (machine__is_host(machine)) {
> - if (symbol_conf.vmlinux_name)
> - machine->mmap_name = strdup(symbol_conf.vmlinux_name);
> - else
> - machine->mmap_name = strdup("[kernel.kallsyms]");
> - } else if (machine__is_default_guest(machine)) {
> - if (symbol_conf.default_guest_vmlinux_name)
> - machine->mmap_name = strdup(symbol_conf.default_guest_vmlinux_name);
> - else
> - machine->mmap_name = strdup("[guest.kernel.kallsyms]");
> - } else {
> - if (asprintf(&machine->mmap_name, "[guest.kernel.kallsyms.%d]",
> - machine->pid) < 0)
> - machine->mmap_name = NULL;
> - }
> + if (machine__is_host(machine))
> + machine->mmap_name = strdup("[kernel.kallsyms]");
> + else if (machine__is_default_guest(machine))
> + machine->mmap_name = strdup("[guest.kernel.kallsyms]");
> + else if (asprintf(&machine->mmap_name, "[guest.kernel.kallsyms.%d]",
> + machine->pid) < 0)
> + machine->mmap_name = NULL;

yea, that looks better.. will change

jirka