On Fri, 6 Jan 2017 15:17:11 -0300 Arnaldo Carvalho de Melo <a...@kernel.org> wrote:
> Em Sat, Jan 07, 2017 at 01:22:23AM +0900, Masami Hiramatsu escreveu: > > On Thu, 5 Jan 2017 15:47:43 -0300 > > Arnaldo Carvalho de Melo <a...@kernel.org> wrote: > > > Em Thu, Jan 05, 2017 at 12:30:37PM -0300, Arnaldo Carvalho de Melo > > > escreveu: > > > > Em Thu, Jan 05, 2017 at 08:20:19PM +0900, Masami Hiramatsu escreveu: > > > > > On Wed, 4 Jan 2017 11:48:56 -0300 > > > > > Arnaldo Carvalho de Melo <a...@kernel.org> wrote: > > > > > > [acme@jouet linux]$ grep e1000_xmit_frame /proc/kallsyms > > > > > > ffffffffc046fc10 t e1000_xmit_frame [e1000e] > > > > > > [acme@jouet linux]$ > > > > > > > > OK, it sounds reasonable to me too. BTW, how can I get the map for > > > > > kallsyms? > > > > > May machine__findnew_module_map(host_machine, ,"[kernel.kallsyms]") > > > > > include module symbols too? > > > > > > > Probably what you want is: > > > > > > > symbol = machine__find_kernel_function_by_name(machine, name, &map); > > > > > > > Then, if symbol is not NULL, map->dso->name will have your module name, > > > > map->dso->long_name will have the .ko path, etc. > > > > > > Take a look at 'perf kallsyms' a simple toy cmd that exercises the APIs > > > you need: > > > > > > https://git.kernel.org/cgit/linux/kernel/git/acme/linux.git/commit/?h=perf/core&id=25c92235676d2655e3f31ffe02bd4355d838e5e9 > > > > > > Basically: > > > > > > struct machine *machine = machine__new_kallsyms(); > > > struct map *map; > > > struct symbol *symbol = machine__find_kernel_function_by_name(machine, > > > symbol_name, &map); > > > > > > Then you have symbol->{addr,end,name,etc} and > > > map->dso->{long,short}_name > > > > > > $ perf kallsyms e1000_xmit_frame usb_stor_set_xfer_buf > > > e1000_xmit_frame: [e1000e] > > > /lib/modules/4.9.0+/kernel/drivers/net/ethernet/intel/e1000e/e1000e.ko > > > 0xffffffffc046fc10-0xffffffffc0470bb0 (0x19c80-0x1ac20) > > > usb_stor_set_xfer_buf: [usb_storage] > > > /lib/modules/4.9.0+/kernel/drivers/usb/storage/usb-storage.ko > > > 0xffffffffc057aea0-0xffffffffc057af19 (0xf10-0xf89) > > > > I've found an issue on perf kallsyms. Please see below. > > > > When I run kallsyms without root privilege, it works well. > > > > $ ./perf kallsyms -vv drm_malloc_ab > > Failed to open /proc/kcore. Note /proc/kcore requires CAP_SYS_RAWIO > > capability to access. > > drm_malloc_ab: [i915] > > /lib/modules/4.8.15-300.fc25.x86_64/kernel/drivers/gpu/drm/i915/i915.ko.xz > > 0xffffffffc0211950-0xffffffffc02119a6 (0x309c0-0x30a16) > > > > However, with root privilege it failed to get correct module name... > > > > $ sudo ./perf kallsyms -vv drm_malloc_ab > > Using /proc/kcore for kernel object code > > drm_malloc_ab: [kernel] /proc/kcore 0xffffffffc0211950-0xffffffffc02119b0 > > (0x7fffc0214950-0x7fffc02149b0) > > Right, that is something that needs fixing, please try with the patch > below. > > The problem is that when using /proc/kcore it messes up the creation of > one map per module :-\ OK, it works now :) $ sudo ./perf kallsyms drm_malloc_ab drm_malloc_ab: [i915] /lib/modules/4.8.15-300.fc25.x86_64/kernel/drivers/gpu/drm/i915/i915.ko.xz 0xffffffffc0188950-0xffffffffc01889a6 (0x309c0-0x30a16) Tested-by: Masami Hiramatsu <mhira...@kernel.org> Thanks! > > diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c > index 4aef30ec8bc3..43d533b075df 100644 > --- a/tools/perf/util/machine.c > +++ b/tools/perf/util/machine.c > @@ -91,7 +91,7 @@ struct machine *machine__new_kallsyms(void) > { > struct machine *machine = machine__new_host(); > > - if (machine && machine__load_kallsyms(machine, "/proc/kallsyms", > MAP__FUNCTION) <= 0) { > + if (machine && __machine__load_kallsyms(machine, "/proc/kallsyms", > MAP__FUNCTION, true) <= 0) { > machine__delete(machine); > machine = NULL; > } -- Masami Hiramatsu <mhira...@kernel.org>
