linux/tools/perf/util/map.h
Kirill Smelkov 7a2b620986 perf annotate: Fix it for non-prelinked *.so
The problem was we were incorrectly calculating objdump
addresses for sym->start and sym->end, look:

For simple ET_DYN type DSO (*.so) with one function, objdump -dS
output is something like this:

    000004ac <my_strlen>:
    int my_strlen(const char *s)
     4ac:   55                      push   %ebp
     4ad:   89 e5                   mov    %esp,%ebp
     4af:   83 ec 10                sub    $0x10,%esp
    {

i.e. we have relative-to-dso-mapping IPs (=RIP) there.

For ET_EXEC type and probably for prelinked libs as well (sorry
can't test - I don't use prelink) objdump outputs absolute IPs,
e.g.

    08048604 <zz_strlen>:
    extern "C"
    int zz_strlen(const char *s)
     8048604:       55                      push   %ebp
     8048605:       89 e5                   mov    %esp,%ebp
     8048607:       83 ec 10                sub    $0x10,%esp
    {

So, if sym->start is always relative to dso mapping(*), we'll
have to unmap it for ET_EXEC like cases, and leave as is for
ET_DYN cases.

(*) and it is - we've explicitely made it relative. Look for
    adjust_symbols handling in dso__load_sym()

Previously we were always unmapping sym->start and for ET_DYN
dsos resulting addresses were wrong, and so objdump output was
empty.

The end result was that perf annotate output for symbols from
non-prelinked *.so had always 0.00% percents only, which is
wrong.

To fix it, let's introduce a helper for converting rip to
objdump address, and also let's document what map_ip() and
unmap_ip() do -- I had to study sources for several hours to
understand it.

Signed-off-by: Kirill Smelkov <kirr@landau.phys.spbu.ru>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1265223128-11786-8-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-04 09:33:27 +01:00

93 lines
2.0 KiB
C

#ifndef __PERF_MAP_H
#define __PERF_MAP_H
#include <linux/compiler.h>
#include <linux/list.h>
#include <linux/rbtree.h>
#include <linux/types.h>
enum map_type {
MAP__FUNCTION = 0,
MAP__VARIABLE,
};
#define MAP__NR_TYPES (MAP__VARIABLE + 1)
struct dso;
struct ref_reloc_sym;
struct map_groups;
struct map {
union {
struct rb_node rb_node;
struct list_head node;
};
u64 start;
u64 end;
enum map_type type;
u64 pgoff;
/* ip -> dso rip */
u64 (*map_ip)(struct map *, u64);
/* dso rip -> ip */
u64 (*unmap_ip)(struct map *, u64);
struct dso *dso;
};
struct kmap {
struct ref_reloc_sym *ref_reloc_sym;
struct map_groups *kmaps;
};
static inline struct kmap *map__kmap(struct map *self)
{
return (struct kmap *)(self + 1);
}
static inline u64 map__map_ip(struct map *map, u64 ip)
{
return ip - map->start + map->pgoff;
}
static inline u64 map__unmap_ip(struct map *map, u64 ip)
{
return ip + map->start - map->pgoff;
}
static inline u64 identity__map_ip(struct map *map __used, u64 ip)
{
return ip;
}
/* rip -> addr suitable for passing to `objdump --start-address=` */
u64 map__rip_2objdump(struct map *map, u64 rip);
struct symbol;
struct mmap_event;
typedef int (*symbol_filter_t)(struct map *map, struct symbol *sym);
void map__init(struct map *self, enum map_type type,
u64 start, u64 end, u64 pgoff, struct dso *dso);
struct map *map__new(struct mmap_event *event, enum map_type,
char *cwd, int cwdlen);
void map__delete(struct map *self);
struct map *map__clone(struct map *self);
int map__overlap(struct map *l, struct map *r);
size_t map__fprintf(struct map *self, FILE *fp);
int map__load(struct map *self, symbol_filter_t filter);
struct symbol *map__find_symbol(struct map *self,
u64 addr, symbol_filter_t filter);
struct symbol *map__find_symbol_by_name(struct map *self, const char *name,
symbol_filter_t filter);
void map__fixup_start(struct map *self);
void map__fixup_end(struct map *self);
void map__reloc_vmlinux(struct map *self);
#endif /* __PERF_MAP_H */