Commit 8e0cf965 authored by Adrian Hunter's avatar Adrian Hunter Committed by Arnaldo Carvalho de Melo

perf symbols: Add support for reading from /proc/kcore

In the absence of vmlinux, perf tools uses kallsyms for symbols.  If the
user has access, now also map to /proc/kcore.

The dso data_type is now set to either DSO_BINARY_TYPE__KCORE or
DSO_BINARY_TYPE__GUEST_KCORE as approprite.

This patch breaks the "vmlinux symtab matches kallsyms" test.  That is
fixed in a following patch.
Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1375875537-4509-8-git-send-email-adrian.hunter@intel.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 0131c4ec
......@@ -95,6 +95,11 @@ int dso__binary_type_file(struct dso *dso, enum dso_binary_type type,
dso->long_name);
break;
case DSO_BINARY_TYPE__KCORE:
case DSO_BINARY_TYPE__GUEST_KCORE:
snprintf(file, size, "%s", dso->long_name);
break;
default:
case DSO_BINARY_TYPE__KALLSYMS:
case DSO_BINARY_TYPE__GUEST_KALLSYMS:
......
......@@ -21,6 +21,8 @@ enum dso_binary_type {
DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
DSO_BINARY_TYPE__GUEST_KMODULE,
DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
DSO_BINARY_TYPE__KCORE,
DSO_BINARY_TYPE__GUEST_KCORE,
DSO_BINARY_TYPE__NOT_FOUND,
};
......@@ -155,4 +157,10 @@ static inline bool dso__is_vmlinux(struct dso *dso)
dso->data_type == DSO_BINARY_TYPE__GUEST_VMLINUX;
}
static inline bool dso__is_kcore(struct dso *dso)
{
return dso->data_type == DSO_BINARY_TYPE__KCORE ||
dso->data_type == DSO_BINARY_TYPE__GUEST_KCORE;
}
#endif /* __PERF_DSO */
......@@ -856,6 +856,18 @@ static void machine__set_kernel_mmap_len(struct machine *machine,
}
}
static bool machine__uses_kcore(struct machine *machine)
{
struct dso *dso;
list_for_each_entry(dso, &machine->kernel_dsos, node) {
if (dso__is_kcore(dso))
return true;
}
return false;
}
static int machine__process_kernel_mmap_event(struct machine *machine,
union perf_event *event)
{
......@@ -864,6 +876,10 @@ static int machine__process_kernel_mmap_event(struct machine *machine,
enum dso_kernel_type kernel_type;
bool is_kernel_mmap;
/* If we have maps from kcore then we do not need or want any others */
if (machine__uses_kcore(machine))
return 0;
machine__mmap_name(machine, kmmap_prefix, sizeof(kmmap_prefix));
if (machine__is_host(machine))
kernel_type = DSO_TYPE_KERNEL;
......
......@@ -555,3 +555,21 @@ struct map *maps__find(struct rb_root *maps, u64 ip)
return NULL;
}
struct map *maps__first(struct rb_root *maps)
{
struct rb_node *first = rb_first(maps);
if (first)
return rb_entry(first, struct map, rb_node);
return NULL;
}
struct map *maps__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;
}
......@@ -112,6 +112,8 @@ size_t __map_groups__fprintf_maps(struct map_groups *mg,
void maps__insert(struct rb_root *maps, struct map *map);
void maps__remove(struct rb_root *maps, struct map *map);
struct map *maps__find(struct rb_root *maps, u64 addr);
struct map *maps__first(struct rb_root *maps);
struct map *maps__next(struct map *map);
void map_groups__init(struct map_groups *mg);
void map_groups__exit(struct map_groups *mg);
int map_groups__clone(struct map_groups *mg,
......@@ -139,6 +141,17 @@ static inline struct map *map_groups__find(struct map_groups *mg,
return maps__find(&mg->maps[type], addr);
}
static inline struct map *map_groups__first(struct map_groups *mg,
enum map_type type)
{
return maps__first(&mg->maps[type]);
}
static inline struct map *map_groups__next(struct map *map)
{
return maps__next(map);
}
struct symbol *map_groups__find_symbol(struct map_groups *mg,
enum map_type type, u64 addr,
struct map **mapp,
......
......@@ -951,6 +951,57 @@ int dso__load_sym(struct dso *dso, struct map *map,
return err;
}
static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data)
{
GElf_Phdr phdr;
size_t i, phdrnum;
int err;
u64 sz;
if (elf_getphdrnum(elf, &phdrnum))
return -1;
for (i = 0; i < phdrnum; i++) {
if (gelf_getphdr(elf, i, &phdr) == NULL)
return -1;
if (phdr.p_type != PT_LOAD)
continue;
if (exe) {
if (!(phdr.p_flags & PF_X))
continue;
} else {
if (!(phdr.p_flags & PF_R))
continue;
}
sz = min(phdr.p_memsz, phdr.p_filesz);
if (!sz)
continue;
err = mapfn(phdr.p_vaddr, sz, phdr.p_offset, data);
if (err)
return err;
}
return 0;
}
int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data,
bool *is_64_bit)
{
int err;
Elf *elf;
elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
if (elf == NULL)
return -1;
if (is_64_bit)
*is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
err = elf_read_maps(elf, exe, mapfn, data);
elf_end(elf);
return err;
}
void symbol__elf_init(void)
{
elf_version(EV_CURRENT);
......
......@@ -301,6 +301,13 @@ int dso__load_sym(struct dso *dso, struct map *map __maybe_unused,
return 0;
}
int file__read_maps(int fd __maybe_unused, bool exe __maybe_unused,
mapfn_t mapfn __maybe_unused, void *data __maybe_unused,
bool *is_64_bit __maybe_unused)
{
return -1;
}
void symbol__elf_init(void)
{
}
......@@ -327,6 +327,16 @@ static struct symbol *symbols__find(struct rb_root *symbols, u64 ip)
return NULL;
}
static struct symbol *symbols__first(struct rb_root *symbols)
{
struct rb_node *n = rb_first(symbols);
if (n)
return rb_entry(n, struct symbol, rb_node);
return NULL;
}
struct symbol_name_rb_node {
struct rb_node rb_node;
struct symbol sym;
......@@ -397,6 +407,11 @@ struct symbol *dso__find_symbol(struct dso *dso,
return symbols__find(&dso->symbols[type], addr);
}
struct symbol *dso__first_symbol(struct dso *dso, enum map_type type)
{
return symbols__first(&dso->symbols[type]);
}
struct symbol *dso__find_symbol_by_name(struct dso *dso, enum map_type type,
const char *name)
{
......@@ -533,6 +548,53 @@ static int dso__load_all_kallsyms(struct dso *dso, const char *filename,
return kallsyms__parse(filename, &args, map__process_kallsym_symbol);
}
static int dso__split_kallsyms_for_kcore(struct dso *dso, struct map *map,
symbol_filter_t filter)
{
struct map_groups *kmaps = map__kmap(map)->kmaps;
struct map *curr_map;
struct symbol *pos;
int count = 0, moved = 0;
struct rb_root *root = &dso->symbols[map->type];
struct rb_node *next = rb_first(root);
while (next) {
char *module;
pos = rb_entry(next, struct symbol, rb_node);
next = rb_next(&pos->rb_node);
module = strchr(pos->name, '\t');
if (module)
*module = '\0';
curr_map = map_groups__find(kmaps, map->type, pos->start);
if (!curr_map || (filter && filter(curr_map, pos))) {
rb_erase(&pos->rb_node, root);
symbol__delete(pos);
} else {
pos->start -= curr_map->start - curr_map->pgoff;
if (pos->end)
pos->end -= curr_map->start - curr_map->pgoff;
if (curr_map != map) {
rb_erase(&pos->rb_node, root);
symbols__insert(
&curr_map->dso->symbols[curr_map->type],
pos);
++moved;
} else {
++count;
}
}
}
/* Symbols have been adjusted */
dso->adjust_symbols = 1;
return count + moved;
}
/*
* Split the symbols into maps, making sure there are no overlaps, i.e. the
* kernel range is broken in several maps, named [kernel].N, as we don't have
......@@ -674,6 +736,161 @@ bool symbol__restricted_filename(const char *filename,
return restricted;
}
struct kcore_mapfn_data {
struct dso *dso;
enum map_type type;
struct list_head maps;
};
static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
{
struct kcore_mapfn_data *md = data;
struct map *map;
map = map__new2(start, md->dso, md->type);
if (map == NULL)
return -ENOMEM;
map->end = map->start + len;
map->pgoff = pgoff;
list_add(&map->node, &md->maps);
return 0;
}
/*
* If kallsyms is referenced by name then we look for kcore in the same
* directory.
*/
static bool kcore_filename_from_kallsyms_filename(char *kcore_filename,
const char *kallsyms_filename)
{
char *name;
strcpy(kcore_filename, kallsyms_filename);
name = strrchr(kcore_filename, '/');
if (!name)
return false;
if (!strcmp(name, "/kallsyms")) {
strcpy(name, "/kcore");
return true;
}
return false;
}
static int dso__load_kcore(struct dso *dso, struct map *map,
const char *kallsyms_filename)
{
struct map_groups *kmaps = map__kmap(map)->kmaps;
struct machine *machine = kmaps->machine;
struct kcore_mapfn_data md;
struct map *old_map, *new_map, *replacement_map = NULL;
bool is_64_bit;
int err, fd;
char kcore_filename[PATH_MAX];
struct symbol *sym;
/* This function requires that the map is the kernel map */
if (map != machine->vmlinux_maps[map->type])
return -EINVAL;
if (!kcore_filename_from_kallsyms_filename(kcore_filename,
kallsyms_filename))
return -EINVAL;
md.dso = dso;
md.type = map->type;
INIT_LIST_HEAD(&md.maps);
fd = open(kcore_filename, O_RDONLY);
if (fd < 0)
return -EINVAL;
/* Read new maps into temporary lists */
err = file__read_maps(fd, md.type == MAP__FUNCTION, kcore_mapfn, &md,
&is_64_bit);
if (err)
goto out_err;
if (list_empty(&md.maps)) {
err = -EINVAL;
goto out_err;
}
/* Remove old maps */
old_map = map_groups__first(kmaps, map->type);
while (old_map) {
struct map *next = map_groups__next(old_map);
if (old_map != map)
map_groups__remove(kmaps, old_map);
old_map = next;
}
/* Find the kernel map using the first symbol */
sym = dso__first_symbol(dso, map->type);
list_for_each_entry(new_map, &md.maps, node) {
if (sym && sym->start >= new_map->start &&
sym->start < new_map->end) {
replacement_map = new_map;
break;
}
}
if (!replacement_map)
replacement_map = list_entry(md.maps.next, struct map, node);
/* Add new maps */
while (!list_empty(&md.maps)) {
new_map = list_entry(md.maps.next, struct map, node);
list_del(&new_map->node);
if (new_map == replacement_map) {
map->start = new_map->start;
map->end = new_map->end;
map->pgoff = new_map->pgoff;
map->map_ip = new_map->map_ip;
map->unmap_ip = new_map->unmap_ip;
map__delete(new_map);
/* Ensure maps are correctly ordered */
map_groups__remove(kmaps, map);
map_groups__insert(kmaps, map);
} else {
map_groups__insert(kmaps, new_map);
}
}
/*
* Set the data type and long name so that kcore can be read via
* dso__data_read_addr().
*/
if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
dso->data_type = DSO_BINARY_TYPE__GUEST_KCORE;
else
dso->data_type = DSO_BINARY_TYPE__KCORE;
dso__set_long_name(dso, strdup(kcore_filename));
close(fd);
if (map->type == MAP__FUNCTION)
pr_debug("Using %s for kernel object code\n", kcore_filename);
else
pr_debug("Using %s for kernel data\n", kcore_filename);
return 0;
out_err:
while (!list_empty(&md.maps)) {
map = list_entry(md.maps.next, struct map, node);
list_del(&map->node);
map__delete(map);
}
close(fd);
return -EINVAL;
}
int dso__load_kallsyms(struct dso *dso, const char *filename,
struct map *map, symbol_filter_t filter)
{
......@@ -691,6 +908,9 @@ int dso__load_kallsyms(struct dso *dso, const char *filename,
else
dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
if (!dso__load_kcore(dso, map, filename))
return dso__split_kallsyms_for_kcore(dso, map, filter);
else
return dso__split_kallsyms(dso, map, filter);
}
......@@ -1065,7 +1285,7 @@ static int dso__load_kernel_sym(struct dso *dso, struct map *map,
pr_debug("Using %s for symbols\n", kallsyms_filename);
free(kallsyms_allocated_filename);
if (err > 0) {
if (err > 0 && !dso__is_kcore(dso)) {
dso__set_long_name(dso, strdup("[kernel.kallsyms]"));
map__fixup_start(map);
map__fixup_end(map);
......@@ -1109,8 +1329,9 @@ static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
}
err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
if (err > 0) {
if (err > 0)
pr_debug("Using %s for symbols\n", kallsyms_filename);
if (err > 0 && !dso__is_kcore(dso)) {
machine__mmap_name(machine, path, sizeof(path));
dso__set_long_name(dso, strdup(path));
map__fixup_start(map);
......
......@@ -215,6 +215,7 @@ struct symbol *dso__find_symbol(struct dso *dso, enum map_type type,
u64 addr);
struct symbol *dso__find_symbol_by_name(struct dso *dso, enum map_type type,
const char *name);
struct symbol *dso__first_symbol(struct dso *dso, enum map_type type);
int filename__read_build_id(const char *filename, void *bf, size_t size);
int sysfs__read_build_id(const char *filename, void *bf, size_t size);
......@@ -247,4 +248,8 @@ void symbols__fixup_duplicate(struct rb_root *symbols);
void symbols__fixup_end(struct rb_root *symbols);
void __map_groups__fixup_end(struct map_groups *mg, enum map_type type);
typedef int (*mapfn_t)(u64 start, u64 len, u64 pgoff, void *data);
int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data,
bool *is_64_bit);
#endif /* __PERF_SYMBOL */
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