On Tue, Jul 19, 2016 at 07:31:58PM +0800, Song Shan Gong wrote: > At preset, when creating module's map, perf gets 'start' address by parsing > '/proc/modules', but it's module base address, isn't the start address of > '.text' section. In most archs, it's OK. But for s390, it places 'GOT' and > 'PLT' relocations before '.text' section. So there exists an offset between > module base address and '.text' section, which will incur wrong symbol > resolution for modules. > > Fix this bug by getting 'start' address of module's map from parsing > '/sys/module/[module name]/sections/.text', not from '/proc/modules'. > > Signed-off-by: Song Shan Gong <[email protected]> > --- > tools/perf/arch/s390/util/Build | 2 ++ > tools/perf/arch/s390/util/sym-handling.c | 19 +++++++++++++++++++ > tools/perf/util/machine.c | 8 ++++++++ > tools/perf/util/machine.h | 1 + > 4 files changed, 30 insertions(+) > create mode 100644 tools/perf/arch/s390/util/sym-handling.c > > diff --git a/tools/perf/arch/s390/util/Build b/tools/perf/arch/s390/util/Build > index 8a61372..5e322ed 100644 > --- a/tools/perf/arch/s390/util/Build > +++ b/tools/perf/arch/s390/util/Build > @@ -2,3 +2,5 @@ libperf-y += header.o > libperf-y += kvm-stat.o > > libperf-$(CONFIG_DWARF) += dwarf-regs.o > + > +libperf-y += sym-handling.o > diff --git a/tools/perf/arch/s390/util/sym-handling.c > b/tools/perf/arch/s390/util/sym-handling.c > new file mode 100644 > index 0000000..ebfc55d > --- /dev/null > +++ b/tools/perf/arch/s390/util/sym-handling.c
I wonder we should rather put this into arch/s390/util/machine.c other than that: Acked-by: Jiri Olsa <[email protected]> thanks, jirka > @@ -0,0 +1,19 @@ > +#include <stdio.h> > +#include <stdlib.h> > +#include <unistd.h> > +#include "util.h" > +#include "machine.h" > +#include "api/fs/fs.h" > + > +int arch__fix_module_text_start(u64 *start, const char *name) > +{ > + char path[PATH_MAX]; > + > + snprintf(path, PATH_MAX, "module/%.*s/sections/.text", > + (int)strlen(name) - 2, name + 1); > + > + if (sysfs__read_ull(path, (unsigned long long *)start) < 0) > + return -1; > + > + return 0; > +} > diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c > index b177218..97cc9f0 100644 > --- a/tools/perf/util/machine.c > +++ b/tools/perf/util/machine.c > @@ -1091,12 +1091,20 @@ static int machine__set_modules_path(struct machine > *machine) > > return map_groups__set_modules_path_dir(&machine->kmaps, modules_path, > 0); > } > +int __weak arch__fix_module_text_start(u64 *start __maybe_unused, > + const char *name __maybe_unused) > +{ > + return 0; > +} > > static int machine__create_module(void *arg, const char *name, u64 start) > { > struct machine *machine = arg; > struct map *map; > > + if (arch__fix_module_text_start(&start, name) < 0) > + return -1; > + > map = machine__findnew_module_map(machine, start, name); > if (map == NULL) > return -1; > diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h > index 41ac9cf..20739f7 100644 > --- a/tools/perf/util/machine.h > +++ b/tools/perf/util/machine.h > @@ -216,6 +216,7 @@ struct symbol > *machine__find_kernel_function_by_name(struct machine *machine, > > struct map *machine__findnew_module_map(struct machine *machine, u64 start, > const char *filename); > +int arch__fix_module_text_start(u64 *start, const char *name); > > int __machine__load_kallsyms(struct machine *machine, const char *filename, > enum map_type type, bool no_kcore, symbol_filter_t > filter); > -- > 2.3.0 >
