linux/tools/perf/util/map.c
Arnaldo Carvalho de Melo 9bac1bd6e6 Revert "perf map: Fix dso->nsinfo refcounting"
This makes 'perf top' abort in some cases, and the right fix will
involve surgery that is too much to do at this stage, so revert for now
and fix it in the next merge window.

This reverts commit 2d6b74baa7.

Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Krister Johansen <kjlx@templeofstupid.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-07-30 18:26:22 -03:00

964 lines
21 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include "symbol.h"
#include <assert.h>
#include <errno.h>
#include <inttypes.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <uapi/linux/mman.h> /* To get things like MAP_HUGETLB even on older libc headers */
#include "dso.h"
#include "map.h"
#include "map_symbol.h"
#include "thread.h"
#include "vdso.h"
#include "build-id.h"
#include "debug.h"
#include "machine.h"
#include <linux/string.h>
#include <linux/zalloc.h>
#include "srcline.h"
#include "namespaces.h"
#include "unwind.h"
#include "srccode.h"
#include "ui/ui.h"
static void __maps__insert(struct maps *maps, struct map *map);
static inline int is_android_lib(const char *filename)
{
return strstarts(filename, "/data/app-lib/") ||
strstarts(filename, "/system/lib/");
}
static inline bool replace_android_lib(const char *filename, char *newfilename)
{
const char *libname;
char *app_abi;
size_t app_abi_length, new_length;
size_t lib_length = 0;
libname = strrchr(filename, '/');
if (libname)
lib_length = strlen(libname);
app_abi = getenv("APP_ABI");
if (!app_abi)
return false;
app_abi_length = strlen(app_abi);
if (strstarts(filename, "/data/app-lib/")) {
char *apk_path;
if (!app_abi_length)
return false;
new_length = 7 + app_abi_length + lib_length;
apk_path = getenv("APK_PATH");
if (apk_path) {
new_length += strlen(apk_path) + 1;
if (new_length > PATH_MAX)
return false;
snprintf(newfilename, new_length,
"%s/libs/%s/%s", apk_path, app_abi, libname);
} else {
if (new_length > PATH_MAX)
return false;
snprintf(newfilename, new_length,
"libs/%s/%s", app_abi, libname);
}
return true;
}
if (strstarts(filename, "/system/lib/")) {
char *ndk, *app;
const char *arch;
int ndk_length, app_length;
ndk = getenv("NDK_ROOT");
app = getenv("APP_PLATFORM");
if (!(ndk && app))
return false;
ndk_length = strlen(ndk);
app_length = strlen(app);
if (!(ndk_length && app_length && app_abi_length))
return false;
arch = !strncmp(app_abi, "arm", 3) ? "arm" :
!strncmp(app_abi, "mips", 4) ? "mips" :
!strncmp(app_abi, "x86", 3) ? "x86" : NULL;
if (!arch)
return false;
new_length = 27 + ndk_length +
app_length + lib_length
+ strlen(arch);
if (new_length > PATH_MAX)
return false;
snprintf(newfilename, new_length,
"%.*s/platforms/%.*s/arch-%s/usr/lib/%s",
ndk_length, ndk, app_length, app, arch, libname);
return true;
}
return false;
}
void map__init(struct map *map, u64 start, u64 end, u64 pgoff, struct dso *dso)
{
map->start = start;
map->end = end;
map->pgoff = pgoff;
map->reloc = 0;
map->dso = dso__get(dso);
map->map_ip = map__map_ip;
map->unmap_ip = map__unmap_ip;
RB_CLEAR_NODE(&map->rb_node);
map->erange_warned = false;
refcount_set(&map->refcnt, 1);
}
struct map *map__new(struct machine *machine, u64 start, u64 len,
u64 pgoff, struct dso_id *id,
u32 prot, u32 flags, struct build_id *bid,
char *filename, struct thread *thread)
{
struct map *map = malloc(sizeof(*map));
struct nsinfo *nsi = NULL;
struct nsinfo *nnsi;
if (map != NULL) {
char newfilename[PATH_MAX];
struct dso *dso;
int anon, no_dso, vdso, android;
android = is_android_lib(filename);
anon = is_anon_memory(filename) || flags & MAP_HUGETLB;
vdso = is_vdso_map(filename);
no_dso = is_no_dso_memory(filename);
map->prot = prot;
map->flags = flags;
nsi = nsinfo__get(thread->nsinfo);
if ((anon || no_dso) && nsi && (prot & PROT_EXEC)) {
snprintf(newfilename, sizeof(newfilename),
"/tmp/perf-%d.map", nsi->pid);
filename = newfilename;
}
if (android) {
if (replace_android_lib(filename, newfilename))
filename = newfilename;
}
if (vdso) {
/* The vdso maps are always on the host and not the
* container. Ensure that we don't use setns to look
* them up.
*/
nnsi = nsinfo__copy(nsi);
if (nnsi) {
nsinfo__put(nsi);
nnsi->need_setns = false;
nsi = nnsi;
}
pgoff = 0;
dso = machine__findnew_vdso(machine, thread);
} else
dso = machine__findnew_dso_id(machine, filename, id);
if (dso == NULL)
goto out_delete;
map__init(map, start, start + len, pgoff, dso);
if (anon || no_dso) {
map->map_ip = map->unmap_ip = identity__map_ip;
/*
* Set memory without DSO as loaded. All map__find_*
* functions still return NULL, and we avoid the
* unnecessary map__load warning.
*/
if (!(prot & PROT_EXEC))
dso__set_loaded(dso);
}
dso->nsinfo = nsi;
if (build_id__is_defined(bid))
dso__set_build_id(dso, bid);
dso__put(dso);
}
return map;
out_delete:
nsinfo__put(nsi);
free(map);
return NULL;
}
/*
* Constructor variant for modules (where we know from /proc/modules where
* they are loaded) and for vmlinux, where only after we load all the
* symbols we'll know where it starts and ends.
*/
struct map *map__new2(u64 start, struct dso *dso)
{
struct map *map = calloc(1, (sizeof(*map) +
(dso->kernel ? sizeof(struct kmap) : 0)));
if (map != NULL) {
/*
* ->end will be filled after we load all the symbols
*/
map__init(map, start, 0, 0, dso);
}
return map;
}
bool __map__is_kernel(const struct map *map)
{
if (!map->dso->kernel)
return false;
return machine__kernel_map(map__kmaps((struct map *)map)->machine) == map;
}
bool __map__is_extra_kernel_map(const struct map *map)
{
struct kmap *kmap = __map__kmap((struct map *)map);
return kmap && kmap->name[0];
}
bool __map__is_bpf_prog(const struct map *map)
{
const char *name;
if (map->dso->binary_type == DSO_BINARY_TYPE__BPF_PROG_INFO)
return true;
/*
* If PERF_RECORD_BPF_EVENT is not included, the dso will not have
* type of DSO_BINARY_TYPE__BPF_PROG_INFO. In such cases, we can
* guess the type based on name.
*/
name = map->dso->short_name;
return name && (strstr(name, "bpf_prog_") == name);
}
bool __map__is_bpf_image(const struct map *map)
{
const char *name;
if (map->dso->binary_type == DSO_BINARY_TYPE__BPF_IMAGE)
return true;
/*
* If PERF_RECORD_KSYMBOL is not included, the dso will not have
* type of DSO_BINARY_TYPE__BPF_IMAGE. In such cases, we can
* guess the type based on name.
*/
name = map->dso->short_name;
return name && is_bpf_image(name);
}
bool __map__is_ool(const struct map *map)
{
return map->dso && map->dso->binary_type == DSO_BINARY_TYPE__OOL;
}
bool map__has_symbols(const struct map *map)
{
return dso__has_symbols(map->dso);
}
static void map__exit(struct map *map)
{
BUG_ON(refcount_read(&map->refcnt) != 0);
dso__zput(map->dso);
}
void map__delete(struct map *map)
{
map__exit(map);
free(map);
}
void map__put(struct map *map)
{
if (map && refcount_dec_and_test(&map->refcnt))
map__delete(map);
}
void map__fixup_start(struct map *map)
{
struct rb_root_cached *symbols = &map->dso->symbols;
struct rb_node *nd = rb_first_cached(symbols);
if (nd != NULL) {
struct symbol *sym = rb_entry(nd, struct symbol, rb_node);
map->start = sym->start;
}
}
void map__fixup_end(struct map *map)
{
struct rb_root_cached *symbols = &map->dso->symbols;
struct rb_node *nd = rb_last(&symbols->rb_root);
if (nd != NULL) {
struct symbol *sym = rb_entry(nd, struct symbol, rb_node);
map->end = sym->end;
}
}
#define DSO__DELETED "(deleted)"
int map__load(struct map *map)
{
const char *name = map->dso->long_name;
int nr;
if (dso__loaded(map->dso))
return 0;
nr = dso__load(map->dso, map);
if (nr < 0) {
if (map->dso->has_build_id) {
char sbuild_id[SBUILD_ID_SIZE];
build_id__sprintf(&map->dso->bid, sbuild_id);
pr_debug("%s with build id %s not found", name, sbuild_id);
} else
pr_debug("Failed to open %s", name);
pr_debug(", continuing without symbols\n");
return -1;
} else if (nr == 0) {
#ifdef HAVE_LIBELF_SUPPORT
const size_t len = strlen(name);
const size_t real_len = len - sizeof(DSO__DELETED);
if (len > sizeof(DSO__DELETED) &&
strcmp(name + real_len + 1, DSO__DELETED) == 0) {
pr_debug("%.*s was updated (is prelink enabled?). "
"Restart the long running apps that use it!\n",
(int)real_len, name);
} else {
pr_debug("no symbols found in %s, maybe install a debug package?\n", name);
}
#endif
return -1;
}
return 0;
}
struct symbol *map__find_symbol(struct map *map, u64 addr)
{
if (map__load(map) < 0)
return NULL;
return dso__find_symbol(map->dso, addr);
}
struct symbol *map__find_symbol_by_name(struct map *map, const char *name)
{
if (map__load(map) < 0)
return NULL;
if (!dso__sorted_by_name(map->dso))
dso__sort_by_name(map->dso);
return dso__find_symbol_by_name(map->dso, name);
}
struct map *map__clone(struct map *from)
{
size_t size = sizeof(struct map);
struct map *map;
if (from->dso && from->dso->kernel)
size += sizeof(struct kmap);
map = memdup(from, size);
if (map != NULL) {
refcount_set(&map->refcnt, 1);
RB_CLEAR_NODE(&map->rb_node);
dso__get(map->dso);
}
return map;
}
size_t map__fprintf(struct map *map, FILE *fp)
{
return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %" PRIx64 " %s\n",
map->start, map->end, map->pgoff, map->dso->name);
}
size_t map__fprintf_dsoname(struct map *map, FILE *fp)
{
char buf[symbol_conf.pad_output_len_dso + 1];
const char *dsoname = "[unknown]";
if (map && map->dso) {
if (symbol_conf.show_kernel_path && map->dso->long_name)
dsoname = map->dso->long_name;
else
dsoname = map->dso->name;
}
if (symbol_conf.pad_output_len_dso) {
scnprintf_pad(buf, symbol_conf.pad_output_len_dso, "%s", dsoname);
dsoname = buf;
}
return fprintf(fp, "%s", dsoname);
}
char *map__srcline(struct map *map, u64 addr, struct symbol *sym)
{
if (map == NULL)
return SRCLINE_UNKNOWN;
return get_srcline(map->dso, map__rip_2objdump(map, addr), sym, true, true, addr);
}
int map__fprintf_srcline(struct map *map, u64 addr, const char *prefix,
FILE *fp)
{
int ret = 0;
if (map && map->dso) {
char *srcline = map__srcline(map, addr, NULL);
if (strncmp(srcline, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0)
ret = fprintf(fp, "%s%s", prefix, srcline);
free_srcline(srcline);
}
return ret;
}
void srccode_state_free(struct srccode_state *state)
{
zfree(&state->srcfile);
state->line = 0;
}
/**
* map__rip_2objdump - convert symbol start address to objdump address.
* @map: memory map
* @rip: symbol start address
*
* objdump wants/reports absolute IPs for ET_EXEC, and RIPs for ET_DYN.
* map->dso->adjust_symbols==1 for ET_EXEC-like cases except ET_REL which is
* relative to section start.
*
* Return: Address suitable for passing to "objdump --start-address="
*/
u64 map__rip_2objdump(struct map *map, u64 rip)
{
struct kmap *kmap = __map__kmap(map);
/*
* vmlinux does not have program headers for PTI entry trampolines and
* kcore may not either. However the trampoline object code is on the
* main kernel map, so just use that instead.
*/
if (kmap && is_entry_trampoline(kmap->name) && kmap->kmaps && kmap->kmaps->machine) {
struct map *kernel_map = machine__kernel_map(kmap->kmaps->machine);
if (kernel_map)
map = kernel_map;
}
if (!map->dso->adjust_symbols)
return rip;
if (map->dso->rel)
return rip - map->pgoff;
/*
* kernel modules also have DSO_TYPE_USER in dso->kernel,
* but all kernel modules are ET_REL, so won't get here.
*/
if (map->dso->kernel == DSO_SPACE__USER)
return rip + map->dso->text_offset;
return map->unmap_ip(map, rip) - map->reloc;
}
/**
* map__objdump_2mem - convert objdump address to a memory address.
* @map: memory map
* @ip: objdump address
*
* Closely related to map__rip_2objdump(), this function takes an address from
* objdump and converts it to a memory address. Note this assumes that @map
* contains the address. To be sure the result is valid, check it forwards
* e.g. map__rip_2objdump(map->map_ip(map, map__objdump_2mem(map, ip))) == ip
*
* Return: Memory address.
*/
u64 map__objdump_2mem(struct map *map, u64 ip)
{
if (!map->dso->adjust_symbols)
return map->unmap_ip(map, ip);
if (map->dso->rel)
return map->unmap_ip(map, ip + map->pgoff);
/*
* kernel modules also have DSO_TYPE_USER in dso->kernel,
* but all kernel modules are ET_REL, so won't get here.
*/
if (map->dso->kernel == DSO_SPACE__USER)
return map->unmap_ip(map, ip - map->dso->text_offset);
return ip + map->reloc;
}
void maps__init(struct maps *maps, struct machine *machine)
{
maps->entries = RB_ROOT;
init_rwsem(&maps->lock);
maps->machine = machine;
maps->last_search_by_name = NULL;
maps->nr_maps = 0;
maps->maps_by_name = NULL;
refcount_set(&maps->refcnt, 1);
}
static void __maps__free_maps_by_name(struct maps *maps)
{
/*
* Free everything to try to do it from the rbtree in the next search
*/
zfree(&maps->maps_by_name);
maps->nr_maps_allocated = 0;
}
void maps__insert(struct maps *maps, struct map *map)
{
down_write(&maps->lock);
__maps__insert(maps, map);
++maps->nr_maps;
if (map->dso && map->dso->kernel) {
struct kmap *kmap = map__kmap(map);
if (kmap)
kmap->kmaps = maps;
else
pr_err("Internal error: kernel dso with non kernel map\n");
}
/*
* If we already performed some search by name, then we need to add the just
* inserted map and resort.
*/
if (maps->maps_by_name) {
if (maps->nr_maps > maps->nr_maps_allocated) {
int nr_allocate = maps->nr_maps * 2;
struct map **maps_by_name = realloc(maps->maps_by_name, nr_allocate * sizeof(map));
if (maps_by_name == NULL) {
__maps__free_maps_by_name(maps);
up_write(&maps->lock);
return;
}
maps->maps_by_name = maps_by_name;
maps->nr_maps_allocated = nr_allocate;
}
maps->maps_by_name[maps->nr_maps - 1] = map;
__maps__sort_by_name(maps);
}
up_write(&maps->lock);
}
static void __maps__remove(struct maps *maps, struct map *map)
{
rb_erase_init(&map->rb_node, &maps->entries);
map__put(map);
}
void maps__remove(struct maps *maps, struct map *map)
{
down_write(&maps->lock);
if (maps->last_search_by_name == map)
maps->last_search_by_name = NULL;
__maps__remove(maps, map);
--maps->nr_maps;
if (maps->maps_by_name)
__maps__free_maps_by_name(maps);
up_write(&maps->lock);
}
static void __maps__purge(struct maps *maps)
{
struct map *pos, *next;
maps__for_each_entry_safe(maps, pos, next) {
rb_erase_init(&pos->rb_node, &maps->entries);
map__put(pos);
}
}
void maps__exit(struct maps *maps)
{
down_write(&maps->lock);
__maps__purge(maps);
up_write(&maps->lock);
}
bool maps__empty(struct maps *maps)
{
return !maps__first(maps);
}
struct maps *maps__new(struct machine *machine)
{
struct maps *maps = zalloc(sizeof(*maps));
if (maps != NULL)
maps__init(maps, machine);
return maps;
}
void maps__delete(struct maps *maps)
{
maps__exit(maps);
unwind__finish_access(maps);
free(maps);
}
void maps__put(struct maps *maps)
{
if (maps && refcount_dec_and_test(&maps->refcnt))
maps__delete(maps);
}
struct symbol *maps__find_symbol(struct maps *maps, u64 addr, struct map **mapp)
{
struct map *map = maps__find(maps, addr);
/* Ensure map is loaded before using map->map_ip */
if (map != NULL && map__load(map) >= 0) {
if (mapp != NULL)
*mapp = map;
return map__find_symbol(map, map->map_ip(map, addr));
}
return NULL;
}
static bool map__contains_symbol(struct map *map, struct symbol *sym)
{
u64 ip = map->unmap_ip(map, sym->start);
return ip >= map->start && ip < map->end;
}
struct symbol *maps__find_symbol_by_name(struct maps *maps, const char *name, struct map **mapp)
{
struct symbol *sym;
struct map *pos;
down_read(&maps->lock);
maps__for_each_entry(maps, pos) {
sym = map__find_symbol_by_name(pos, name);
if (sym == NULL)
continue;
if (!map__contains_symbol(pos, sym)) {
sym = NULL;
continue;
}
if (mapp != NULL)
*mapp = pos;
goto out;
}
sym = NULL;
out:
up_read(&maps->lock);
return sym;
}
int maps__find_ams(struct maps *maps, struct addr_map_symbol *ams)
{
if (ams->addr < ams->ms.map->start || ams->addr >= ams->ms.map->end) {
if (maps == NULL)
return -1;
ams->ms.map = maps__find(maps, ams->addr);
if (ams->ms.map == NULL)
return -1;
}
ams->al_addr = ams->ms.map->map_ip(ams->ms.map, ams->addr);
ams->ms.sym = map__find_symbol(ams->ms.map, ams->al_addr);
return ams->ms.sym ? 0 : -1;
}
size_t maps__fprintf(struct maps *maps, FILE *fp)
{
size_t printed = 0;
struct map *pos;
down_read(&maps->lock);
maps__for_each_entry(maps, pos) {
printed += fprintf(fp, "Map:");
printed += map__fprintf(pos, fp);
if (verbose > 2) {
printed += dso__fprintf(pos->dso, fp);
printed += fprintf(fp, "--\n");
}
}
up_read(&maps->lock);
return printed;
}
int maps__fixup_overlappings(struct maps *maps, struct map *map, FILE *fp)
{
struct rb_root *root;
struct rb_node *next, *first;
int err = 0;
down_write(&maps->lock);
root = &maps->entries;
/*
* Find first map where end > map->start.
* Same as find_vma() in kernel.
*/
next = root->rb_node;
first = NULL;
while (next) {
struct map *pos = rb_entry(next, struct map, rb_node);
if (pos->end > map->start) {
first = next;
if (pos->start <= map->start)
break;
next = next->rb_left;
} else
next = next->rb_right;
}
next = first;
while (next) {
struct map *pos = rb_entry(next, struct map, rb_node);
next = rb_next(&pos->rb_node);
/*
* Stop if current map starts after map->end.
* Maps are ordered by start: next will not overlap for sure.
*/
if (pos->start >= map->end)
break;
if (verbose >= 2) {
if (use_browser) {
pr_debug("overlapping maps in %s (disable tui for more info)\n",
map->dso->name);
} else {
fputs("overlapping maps:\n", fp);
map__fprintf(map, fp);
map__fprintf(pos, fp);
}
}
rb_erase_init(&pos->rb_node, root);
/*
* Now check if we need to create new maps for areas not
* overlapped by the new map:
*/
if (map->start > pos->start) {
struct map *before = map__clone(pos);
if (before == NULL) {
err = -ENOMEM;
goto put_map;
}
before->end = map->start;
__maps__insert(maps, before);
if (verbose >= 2 && !use_browser)
map__fprintf(before, fp);
map__put(before);
}
if (map->end < pos->end) {
struct map *after = map__clone(pos);
if (after == NULL) {
err = -ENOMEM;
goto put_map;
}
after->start = map->end;
after->pgoff += map->end - pos->start;
assert(pos->map_ip(pos, map->end) == after->map_ip(after, map->end));
__maps__insert(maps, after);
if (verbose >= 2 && !use_browser)
map__fprintf(after, fp);
map__put(after);
}
put_map:
map__put(pos);
if (err)
goto out;
}
err = 0;
out:
up_write(&maps->lock);
return err;
}
/*
* XXX This should not really _copy_ te maps, but refcount them.
*/
int maps__clone(struct thread *thread, struct maps *parent)
{
struct maps *maps = thread->maps;
int err;
struct map *map;
down_read(&parent->lock);
maps__for_each_entry(parent, map) {
struct map *new = map__clone(map);
if (new == NULL) {
err = -ENOMEM;
goto out_unlock;
}
err = unwind__prepare_access(maps, new, NULL);
if (err)
goto out_unlock;
maps__insert(maps, new);
map__put(new);
}
err = 0;
out_unlock:
up_read(&parent->lock);
return err;
}
static void __maps__insert(struct maps *maps, struct map *map)
{
struct rb_node **p = &maps->entries.rb_node;
struct rb_node *parent = NULL;
const u64 ip = map->start;
struct map *m;
while (*p != NULL) {
parent = *p;
m = rb_entry(parent, struct map, rb_node);
if (ip < m->start)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
rb_link_node(&map->rb_node, parent, p);
rb_insert_color(&map->rb_node, &maps->entries);
map__get(map);
}
struct map *maps__find(struct maps *maps, u64 ip)
{
struct rb_node *p;
struct map *m;
down_read(&maps->lock);
p = maps->entries.rb_node;
while (p != NULL) {
m = rb_entry(p, struct map, rb_node);
if (ip < m->start)
p = p->rb_left;
else if (ip >= m->end)
p = p->rb_right;
else
goto out;
}
m = NULL;
out:
up_read(&maps->lock);
return m;
}
struct map *maps__first(struct maps *maps)
{
struct rb_node *first = rb_first(&maps->entries);
if (first)
return rb_entry(first, struct map, rb_node);
return NULL;
}
static struct map *__map__next(struct map *map)
{
struct rb_node *next = rb_next(&map->rb_node);
if (next)
return rb_entry(next, struct map, rb_node);
return NULL;
}
struct map *map__next(struct map *map)
{
return map ? __map__next(map) : NULL;
}
struct kmap *__map__kmap(struct map *map)
{
if (!map->dso || !map->dso->kernel)
return NULL;
return (struct kmap *)(map + 1);
}
struct kmap *map__kmap(struct map *map)
{
struct kmap *kmap = __map__kmap(map);
if (!kmap)
pr_err("Internal error: map__kmap with a non-kernel map\n");
return kmap;
}
struct maps *map__kmaps(struct map *map)
{
struct kmap *kmap = map__kmap(map);
if (!kmap || !kmap->kmaps) {
pr_err("Internal error: map__kmaps with a non-kernel map\n");
return NULL;
}
return kmap->kmaps;
}