linux/tools/perf/util/symbol.c
Thomas Richter 9ad4652b66 perf record: Fix wrong size in perf_record_mmap for last kernel module
During work on perf report for s390 I ran into the following issue:

0 0x318 [0x78]: PERF_RECORD_MMAP -1/0:
        [0x3ff804d6990(0xfffffc007fb2966f) @ 0]:
        x /lib/modules/4.12.0perf1+/kernel/drivers/s390/net/qeth_l2.ko

This is a PERF_RECORD_MMAP entry of the perf.data file with an invalid
module size for qeth_l2.ko (the s390 ethernet device driver).

Even a mainframe does not have 0xfffffc007fb2966f bytes of main memory.

It turned out that this wrong size is created by the perf record
command.  What happens is this function call sequence from
__cmd_record():

  perf_session__new():
    perf_session__create_kernel_maps():
      machine__create_kernel_maps():
        machine__create_modules():   Creates map for all loaded kernel modules.
          modules__parse():   Reads /proc/modules and extracts module name and
                              load address (1st and last column)
            machine__create_module():   Called for every module found in /proc/modules.
                              Creates a new map for every module found and enters
                              module name and start address into the map. Since the
                              module end address is unknown it is set to zero.

This ends up with a kernel module map list sorted by module start
addresses.  All module end addresses are zero.

Last machine__create_kernel_maps() calls function map_groups__fixup_end().
This function iterates through the maps and assigns each map entry's
end address the successor map entry start address. The last entry of the
map group has no successor, so ~0 is used as end to consume the remaining
memory.

Later __cmd_record calls function record__synthesize() which in turn calls
perf_event__synthesize_kernel_mmap() and perf_event__synthesize_modules()
to create PERF_REPORT_MMAP entries into the perf.data file.

On s390 this results in the last module qeth_l2.ko
(which has highest start address, see module table:
        [root@s8360047 perf]# cat /proc/modules
        qeth_l2 86016 1 - Live 0x000003ff804d6000
        qeth 266240 1 qeth_l2, Live 0x000003ff80296000
        ccwgroup 24576 1 qeth, Live 0x000003ff80218000
        vmur 36864 0 - Live 0x000003ff80182000
        qdio 143360 2 qeth_l2,qeth, Live 0x000003ff80002000
        [root@s8360047 perf]# )
to be the last entry and its map has an end address of ~0.

When the PERF_RECORD_MMAP entry is created for kernel module qeth_l2.ko
its start address and length is written. The length is calculated in line:
    event->mmap.len   = pos->end - pos->start;
and results in 0xffffffffffffffff - 0x3ff804d6990(*) = 0xfffffc007fb2966f

(*) On s390 the module start address is actually determined by a __weak function
named arch__fix_module_text_start() in machine__create_module().

I think this improvable. We can use the module size (2nd column of /proc/modules)
to get each loaded kernel module size and calculate its end address.
Only for map entries which do not have a valid end address (end is still zero)
we can use the heuristic we have now, that is use successor start address or ~0.

Signed-off-by: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Reviewed-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Cc: Zvonko Kosic <zvonko.kosic@de.ibm.com>
LPU-Reference: 20170803134902.47207-2-tmricht@linux.vnet.ibm.com
Link: http://lkml.kernel.org/n/tip-nmoqij5b5vxx7rq2ckwu8iaj@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-08-11 16:06:32 -03:00

2220 lines
50 KiB
C

#include <dirent.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <linux/kernel.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <fcntl.h>
#include <unistd.h>
#include <inttypes.h>
#include "annotate.h"
#include "build-id.h"
#include "util.h"
#include "debug.h"
#include "machine.h"
#include "symbol.h"
#include "strlist.h"
#include "intlist.h"
#include "namespaces.h"
#include "header.h"
#include "path.h"
#include "sane_ctype.h"
#include <elf.h>
#include <limits.h>
#include <symbol/kallsyms.h>
#include <sys/utsname.h>
static int dso__load_kernel_sym(struct dso *dso, struct map *map);
static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map);
static bool symbol__is_idle(const char *name);
int vmlinux_path__nr_entries;
char **vmlinux_path;
struct symbol_conf symbol_conf = {
.use_modules = true,
.try_vmlinux_path = true,
.annotate_src = true,
.demangle = true,
.demangle_kernel = false,
.cumulate_callchain = true,
.show_hist_headers = true,
.symfs = "",
.event_group = true,
};
static enum dso_binary_type binary_type_symtab[] = {
DSO_BINARY_TYPE__KALLSYMS,
DSO_BINARY_TYPE__GUEST_KALLSYMS,
DSO_BINARY_TYPE__JAVA_JIT,
DSO_BINARY_TYPE__DEBUGLINK,
DSO_BINARY_TYPE__BUILD_ID_CACHE,
DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO,
DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
DSO_BINARY_TYPE__GUEST_KMODULE,
DSO_BINARY_TYPE__GUEST_KMODULE_COMP,
DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP,
DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
DSO_BINARY_TYPE__NOT_FOUND,
};
#define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab)
bool symbol_type__is_a(char symbol_type, enum map_type map_type)
{
symbol_type = toupper(symbol_type);
switch (map_type) {
case MAP__FUNCTION:
return symbol_type == 'T' || symbol_type == 'W';
case MAP__VARIABLE:
return symbol_type == 'D';
default:
return false;
}
}
static int prefix_underscores_count(const char *str)
{
const char *tail = str;
while (*tail == '_')
tail++;
return tail - str;
}
int __weak arch__compare_symbol_names(const char *namea, const char *nameb)
{
return strcmp(namea, nameb);
}
int __weak arch__compare_symbol_names_n(const char *namea, const char *nameb,
unsigned int n)
{
return strncmp(namea, nameb, n);
}
int __weak arch__choose_best_symbol(struct symbol *syma,
struct symbol *symb __maybe_unused)
{
/* Avoid "SyS" kernel syscall aliases */
if (strlen(syma->name) >= 3 && !strncmp(syma->name, "SyS", 3))
return SYMBOL_B;
if (strlen(syma->name) >= 10 && !strncmp(syma->name, "compat_SyS", 10))
return SYMBOL_B;
return SYMBOL_A;
}
static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
{
s64 a;
s64 b;
size_t na, nb;
/* Prefer a symbol with non zero length */
a = syma->end - syma->start;
b = symb->end - symb->start;
if ((b == 0) && (a > 0))
return SYMBOL_A;
else if ((a == 0) && (b > 0))
return SYMBOL_B;
/* Prefer a non weak symbol over a weak one */
a = syma->binding == STB_WEAK;
b = symb->binding == STB_WEAK;
if (b && !a)
return SYMBOL_A;
if (a && !b)
return SYMBOL_B;
/* Prefer a global symbol over a non global one */
a = syma->binding == STB_GLOBAL;
b = symb->binding == STB_GLOBAL;
if (a && !b)
return SYMBOL_A;
if (b && !a)
return SYMBOL_B;
/* Prefer a symbol with less underscores */
a = prefix_underscores_count(syma->name);
b = prefix_underscores_count(symb->name);
if (b > a)
return SYMBOL_A;
else if (a > b)
return SYMBOL_B;
/* Choose the symbol with the longest name */
na = strlen(syma->name);
nb = strlen(symb->name);
if (na > nb)
return SYMBOL_A;
else if (na < nb)
return SYMBOL_B;
return arch__choose_best_symbol(syma, symb);
}
void symbols__fixup_duplicate(struct rb_root *symbols)
{
struct rb_node *nd;
struct symbol *curr, *next;
if (symbol_conf.allow_aliases)
return;
nd = rb_first(symbols);
while (nd) {
curr = rb_entry(nd, struct symbol, rb_node);
again:
nd = rb_next(&curr->rb_node);
next = rb_entry(nd, struct symbol, rb_node);
if (!nd)
break;
if (curr->start != next->start)
continue;
if (choose_best_symbol(curr, next) == SYMBOL_A) {
rb_erase(&next->rb_node, symbols);
symbol__delete(next);
goto again;
} else {
nd = rb_next(&curr->rb_node);
rb_erase(&curr->rb_node, symbols);
symbol__delete(curr);
}
}
}
void symbols__fixup_end(struct rb_root *symbols)
{
struct rb_node *nd, *prevnd = rb_first(symbols);
struct symbol *curr, *prev;
if (prevnd == NULL)
return;
curr = rb_entry(prevnd, struct symbol, rb_node);
for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
prev = curr;
curr = rb_entry(nd, struct symbol, rb_node);
if (prev->end == prev->start && prev->end != curr->start)
prev->end = curr->start;
}
/* Last entry */
if (curr->end == curr->start)
curr->end = roundup(curr->start, 4096) + 4096;
}
void __map_groups__fixup_end(struct map_groups *mg, enum map_type type)
{
struct maps *maps = &mg->maps[type];
struct map *next, *curr;
pthread_rwlock_wrlock(&maps->lock);
curr = maps__first(maps);
if (curr == NULL)
goto out_unlock;
for (next = map__next(curr); next; next = map__next(curr)) {
if (!curr->end)
curr->end = next->start;
curr = next;
}
/*
* We still haven't the actual symbols, so guess the
* last map final address.
*/
if (!curr->end)
curr->end = ~0ULL;
out_unlock:
pthread_rwlock_unlock(&maps->lock);
}
struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name)
{
size_t namelen = strlen(name) + 1;
struct symbol *sym = calloc(1, (symbol_conf.priv_size +
sizeof(*sym) + namelen));
if (sym == NULL)
return NULL;
if (symbol_conf.priv_size) {
if (symbol_conf.init_annotation) {
struct annotation *notes = (void *)sym;
pthread_mutex_init(&notes->lock, NULL);
}
sym = ((void *)sym) + symbol_conf.priv_size;
}
sym->start = start;
sym->end = len ? start + len : start;
sym->binding = binding;
sym->namelen = namelen - 1;
pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
__func__, name, start, sym->end);
memcpy(sym->name, name, namelen);
return sym;
}
void symbol__delete(struct symbol *sym)
{
free(((void *)sym) - symbol_conf.priv_size);
}
void symbols__delete(struct rb_root *symbols)
{
struct symbol *pos;
struct rb_node *next = rb_first(symbols);
while (next) {
pos = rb_entry(next, struct symbol, rb_node);
next = rb_next(&pos->rb_node);
rb_erase(&pos->rb_node, symbols);
symbol__delete(pos);
}
}
void __symbols__insert(struct rb_root *symbols, struct symbol *sym, bool kernel)
{
struct rb_node **p = &symbols->rb_node;
struct rb_node *parent = NULL;
const u64 ip = sym->start;
struct symbol *s;
if (kernel) {
const char *name = sym->name;
/*
* ppc64 uses function descriptors and appends a '.' to the
* start of every instruction address. Remove it.
*/
if (name[0] == '.')
name++;
sym->idle = symbol__is_idle(name);
}
while (*p != NULL) {
parent = *p;
s = rb_entry(parent, struct symbol, rb_node);
if (ip < s->start)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
rb_link_node(&sym->rb_node, parent, p);
rb_insert_color(&sym->rb_node, symbols);
}
void symbols__insert(struct rb_root *symbols, struct symbol *sym)
{
__symbols__insert(symbols, sym, false);
}
static struct symbol *symbols__find(struct rb_root *symbols, u64 ip)
{
struct rb_node *n;
if (symbols == NULL)
return NULL;
n = symbols->rb_node;
while (n) {
struct symbol *s = rb_entry(n, struct symbol, rb_node);
if (ip < s->start)
n = n->rb_left;
else if (ip > s->end || (ip == s->end && ip != s->start))
n = n->rb_right;
else
return s;
}
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;
}
static struct symbol *symbols__last(struct rb_root *symbols)
{
struct rb_node *n = rb_last(symbols);
if (n)
return rb_entry(n, struct symbol, rb_node);
return NULL;
}
static struct symbol *symbols__next(struct symbol *sym)
{
struct rb_node *n = rb_next(&sym->rb_node);
if (n)
return rb_entry(n, struct symbol, rb_node);
return NULL;
}
static void symbols__insert_by_name(struct rb_root *symbols, struct symbol *sym)
{
struct rb_node **p = &symbols->rb_node;
struct rb_node *parent = NULL;
struct symbol_name_rb_node *symn, *s;
symn = container_of(sym, struct symbol_name_rb_node, sym);
while (*p != NULL) {
parent = *p;
s = rb_entry(parent, struct symbol_name_rb_node, rb_node);
if (strcmp(sym->name, s->sym.name) < 0)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
rb_link_node(&symn->rb_node, parent, p);
rb_insert_color(&symn->rb_node, symbols);
}
static void symbols__sort_by_name(struct rb_root *symbols,
struct rb_root *source)
{
struct rb_node *nd;
for (nd = rb_first(source); nd; nd = rb_next(nd)) {
struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
symbols__insert_by_name(symbols, pos);
}
}
int symbol__match_symbol_name(const char *name, const char *str,
enum symbol_tag_include includes)
{
const char *versioning;
if (includes == SYMBOL_TAG_INCLUDE__DEFAULT_ONLY &&
(versioning = strstr(name, "@@"))) {
int len = strlen(str);
if (len < versioning - name)
len = versioning - name;
return arch__compare_symbol_names_n(name, str, len);
} else
return arch__compare_symbol_names(name, str);
}
static struct symbol *symbols__find_by_name(struct rb_root *symbols,
const char *name,
enum symbol_tag_include includes)
{
struct rb_node *n;
struct symbol_name_rb_node *s = NULL;
if (symbols == NULL)
return NULL;
n = symbols->rb_node;
while (n) {
int cmp;
s = rb_entry(n, struct symbol_name_rb_node, rb_node);
cmp = symbol__match_symbol_name(s->sym.name, name, includes);
if (cmp > 0)
n = n->rb_left;
else if (cmp < 0)
n = n->rb_right;
else
break;
}
if (n == NULL)
return NULL;
if (includes != SYMBOL_TAG_INCLUDE__DEFAULT_ONLY)
/* return first symbol that has same name (if any) */
for (n = rb_prev(n); n; n = rb_prev(n)) {
struct symbol_name_rb_node *tmp;
tmp = rb_entry(n, struct symbol_name_rb_node, rb_node);
if (arch__compare_symbol_names(tmp->sym.name, s->sym.name))
break;
s = tmp;
}
return &s->sym;
}
void dso__reset_find_symbol_cache(struct dso *dso)
{
enum map_type type;
for (type = MAP__FUNCTION; type <= MAP__VARIABLE; ++type) {
dso->last_find_result[type].addr = 0;
dso->last_find_result[type].symbol = NULL;
}
}
void dso__insert_symbol(struct dso *dso, enum map_type type, struct symbol *sym)
{
__symbols__insert(&dso->symbols[type], sym, dso->kernel);
/* update the symbol cache if necessary */
if (dso->last_find_result[type].addr >= sym->start &&
(dso->last_find_result[type].addr < sym->end ||
sym->start == sym->end)) {
dso->last_find_result[type].symbol = sym;
}
}
struct symbol *dso__find_symbol(struct dso *dso,
enum map_type type, u64 addr)
{
if (dso->last_find_result[type].addr != addr || dso->last_find_result[type].symbol == NULL) {
dso->last_find_result[type].addr = addr;
dso->last_find_result[type].symbol = symbols__find(&dso->symbols[type], addr);
}
return dso->last_find_result[type].symbol;
}
struct symbol *dso__first_symbol(struct dso *dso, enum map_type type)
{
return symbols__first(&dso->symbols[type]);
}
struct symbol *dso__last_symbol(struct dso *dso, enum map_type type)
{
return symbols__last(&dso->symbols[type]);
}
struct symbol *dso__next_symbol(struct symbol *sym)
{
return symbols__next(sym);
}
struct symbol *symbol__next_by_name(struct symbol *sym)
{
struct symbol_name_rb_node *s = container_of(sym, struct symbol_name_rb_node, sym);
struct rb_node *n = rb_next(&s->rb_node);
return n ? &rb_entry(n, struct symbol_name_rb_node, rb_node)->sym : NULL;
}
/*
* Teturns first symbol that matched with @name.
*/
struct symbol *dso__find_symbol_by_name(struct dso *dso, enum map_type type,
const char *name)
{
struct symbol *s = symbols__find_by_name(&dso->symbol_names[type], name,
SYMBOL_TAG_INCLUDE__NONE);
if (!s)
s = symbols__find_by_name(&dso->symbol_names[type], name,
SYMBOL_TAG_INCLUDE__DEFAULT_ONLY);
return s;
}
void dso__sort_by_name(struct dso *dso, enum map_type type)
{
dso__set_sorted_by_name(dso, type);
return symbols__sort_by_name(&dso->symbol_names[type],
&dso->symbols[type]);
}
int modules__parse(const char *filename, void *arg,
int (*process_module)(void *arg, const char *name,
u64 start, u64 size))
{
char *line = NULL;
size_t n;
FILE *file;
int err = 0;
file = fopen(filename, "r");
if (file == NULL)
return -1;
while (1) {
char name[PATH_MAX];
u64 start, size;
char *sep, *endptr;
ssize_t line_len;
line_len = getline(&line, &n, file);
if (line_len < 0) {
if (feof(file))
break;
err = -1;
goto out;
}
if (!line) {
err = -1;
goto out;
}
line[--line_len] = '\0'; /* \n */
sep = strrchr(line, 'x');
if (sep == NULL)
continue;
hex2u64(sep + 1, &start);
sep = strchr(line, ' ');
if (sep == NULL)
continue;
*sep = '\0';
scnprintf(name, sizeof(name), "[%s]", line);
size = strtoul(sep + 1, &endptr, 0);
if (*endptr != ' ' && *endptr != '\t')
continue;
err = process_module(arg, name, start, size);
if (err)
break;
}
out:
free(line);
fclose(file);
return err;
}
struct process_kallsyms_args {
struct map *map;
struct dso *dso;
};
/*
* These are symbols in the kernel image, so make sure that
* sym is from a kernel DSO.
*/
static bool symbol__is_idle(const char *name)
{
const char * const idle_symbols[] = {
"cpu_idle",
"cpu_startup_entry",
"intel_idle",
"default_idle",
"native_safe_halt",
"enter_idle",
"exit_idle",
"mwait_idle",
"mwait_idle_with_hints",
"poll_idle",
"ppc64_runlatch_off",
"pseries_dedicated_idle_sleep",
NULL
};
int i;
for (i = 0; idle_symbols[i]; i++) {
if (!strcmp(idle_symbols[i], name))
return true;
}
return false;
}
static int map__process_kallsym_symbol(void *arg, const char *name,
char type, u64 start)
{
struct symbol *sym;
struct process_kallsyms_args *a = arg;
struct rb_root *root = &a->dso->symbols[a->map->type];
if (!symbol_type__is_a(type, a->map->type))
return 0;
/*
* module symbols are not sorted so we add all
* symbols, setting length to 0, and rely on
* symbols__fixup_end() to fix it up.
*/
sym = symbol__new(start, 0, kallsyms2elf_binding(type), name);
if (sym == NULL)
return -ENOMEM;
/*
* We will pass the symbols to the filter later, in
* map__split_kallsyms, when we have split the maps per module
*/
__symbols__insert(root, sym, !strchr(name, '['));
return 0;
}
/*
* Loads the function entries in /proc/kallsyms into kernel_map->dso,
* so that we can in the next step set the symbol ->end address and then
* call kernel_maps__split_kallsyms.
*/
static int dso__load_all_kallsyms(struct dso *dso, const char *filename,
struct map *map)
{
struct process_kallsyms_args args = { .map = map, .dso = dso, };
return kallsyms__parse(filename, &args, map__process_kallsym_symbol);
}
static int dso__split_kallsyms_for_kcore(struct dso *dso, struct map *map)
{
struct map_groups *kmaps = map__kmaps(map);
struct map *curr_map;
struct symbol *pos;
int count = 0;
struct rb_root old_root = dso->symbols[map->type];
struct rb_root *root = &dso->symbols[map->type];
struct rb_node *next = rb_first(root);
if (!kmaps)
return -1;
*root = RB_ROOT;
while (next) {
char *module;
pos = rb_entry(next, struct symbol, rb_node);
next = rb_next(&pos->rb_node);
rb_erase_init(&pos->rb_node, &old_root);
module = strchr(pos->name, '\t');
if (module)
*module = '\0';
curr_map = map_groups__find(kmaps, map->type, pos->start);
if (!curr_map) {
symbol__delete(pos);
continue;
}
pos->start -= curr_map->start - curr_map->pgoff;
if (pos->end)
pos->end -= curr_map->start - curr_map->pgoff;
symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
++count;
}
/* Symbols have been adjusted */
dso->adjust_symbols = 1;
return count;
}
/*
* 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
* the original ELF section names vmlinux have.
*/
static int dso__split_kallsyms(struct dso *dso, struct map *map, u64 delta)
{
struct map_groups *kmaps = map__kmaps(map);
struct machine *machine;
struct map *curr_map = map;
struct symbol *pos;
int count = 0, moved = 0;
struct rb_root *root = &dso->symbols[map->type];
struct rb_node *next = rb_first(root);
int kernel_range = 0;
if (!kmaps)
return -1;
machine = kmaps->machine;
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) {
if (!symbol_conf.use_modules)
goto discard_symbol;
*module++ = '\0';
if (strcmp(curr_map->dso->short_name, module)) {
if (curr_map != map &&
dso->kernel == DSO_TYPE_GUEST_KERNEL &&
machine__is_default_guest(machine)) {
/*
* We assume all symbols of a module are
* continuous in * kallsyms, so curr_map
* points to a module and all its
* symbols are in its kmap. Mark it as
* loaded.
*/
dso__set_loaded(curr_map->dso,
curr_map->type);
}
curr_map = map_groups__find_by_name(kmaps,
map->type, module);
if (curr_map == NULL) {
pr_debug("%s/proc/{kallsyms,modules} "
"inconsistency while looking "
"for \"%s\" module!\n",
machine->root_dir, module);
curr_map = map;
goto discard_symbol;
}
if (curr_map->dso->loaded &&
!machine__is_default_guest(machine))
goto discard_symbol;
}
/*
* So that we look just like we get from .ko files,
* i.e. not prelinked, relative to map->start.
*/
pos->start = curr_map->map_ip(curr_map, pos->start);
pos->end = curr_map->map_ip(curr_map, pos->end);
} else if (curr_map != map) {
char dso_name[PATH_MAX];
struct dso *ndso;
if (delta) {
/* Kernel was relocated at boot time */
pos->start -= delta;
pos->end -= delta;
}
if (count == 0) {
curr_map = map;
goto add_symbol;
}
if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
snprintf(dso_name, sizeof(dso_name),
"[guest.kernel].%d",
kernel_range++);
else
snprintf(dso_name, sizeof(dso_name),
"[kernel].%d",
kernel_range++);
ndso = dso__new(dso_name);
if (ndso == NULL)
return -1;
ndso->kernel = dso->kernel;
curr_map = map__new2(pos->start, ndso, map->type);
if (curr_map == NULL) {
dso__put(ndso);
return -1;
}
curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
map_groups__insert(kmaps, curr_map);
++kernel_range;
} else if (delta) {
/* Kernel was relocated at boot time */
pos->start -= delta;
pos->end -= delta;
}
add_symbol:
if (curr_map != map) {
rb_erase(&pos->rb_node, root);
symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
++moved;
} else
++count;
continue;
discard_symbol:
rb_erase(&pos->rb_node, root);
symbol__delete(pos);
}
if (curr_map != map &&
dso->kernel == DSO_TYPE_GUEST_KERNEL &&
machine__is_default_guest(kmaps->machine)) {
dso__set_loaded(curr_map->dso, curr_map->type);
}
return count + moved;
}
bool symbol__restricted_filename(const char *filename,
const char *restricted_filename)
{
bool restricted = false;
if (symbol_conf.kptr_restrict) {
char *r = realpath(filename, NULL);
if (r != NULL) {
restricted = strcmp(r, restricted_filename) == 0;
free(r);
return restricted;
}
}
return restricted;
}
struct module_info {
struct rb_node rb_node;
char *name;
u64 start;
};
static void add_module(struct module_info *mi, struct rb_root *modules)
{
struct rb_node **p = &modules->rb_node;
struct rb_node *parent = NULL;
struct module_info *m;
while (*p != NULL) {
parent = *p;
m = rb_entry(parent, struct module_info, rb_node);
if (strcmp(mi->name, m->name) < 0)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
rb_link_node(&mi->rb_node, parent, p);
rb_insert_color(&mi->rb_node, modules);
}
static void delete_modules(struct rb_root *modules)
{
struct module_info *mi;
struct rb_node *next = rb_first(modules);
while (next) {
mi = rb_entry(next, struct module_info, rb_node);
next = rb_next(&mi->rb_node);
rb_erase(&mi->rb_node, modules);
zfree(&mi->name);
free(mi);
}
}
static struct module_info *find_module(const char *name,
struct rb_root *modules)
{
struct rb_node *n = modules->rb_node;
while (n) {
struct module_info *m;
int cmp;
m = rb_entry(n, struct module_info, rb_node);
cmp = strcmp(name, m->name);
if (cmp < 0)
n = n->rb_left;
else if (cmp > 0)
n = n->rb_right;
else
return m;
}
return NULL;
}
static int __read_proc_modules(void *arg, const char *name, u64 start,
u64 size __maybe_unused)
{
struct rb_root *modules = arg;
struct module_info *mi;
mi = zalloc(sizeof(struct module_info));
if (!mi)
return -ENOMEM;
mi->name = strdup(name);
mi->start = start;
if (!mi->name) {
free(mi);
return -ENOMEM;
}
add_module(mi, modules);
return 0;
}
static int read_proc_modules(const char *filename, struct rb_root *modules)
{
if (symbol__restricted_filename(filename, "/proc/modules"))
return -1;
if (modules__parse(filename, modules, __read_proc_modules)) {
delete_modules(modules);
return -1;
}
return 0;
}
int compare_proc_modules(const char *from, const char *to)
{
struct rb_root from_modules = RB_ROOT;
struct rb_root to_modules = RB_ROOT;
struct rb_node *from_node, *to_node;
struct module_info *from_m, *to_m;
int ret = -1;
if (read_proc_modules(from, &from_modules))
return -1;
if (read_proc_modules(to, &to_modules))
goto out_delete_from;
from_node = rb_first(&from_modules);
to_node = rb_first(&to_modules);
while (from_node) {
if (!to_node)
break;
from_m = rb_entry(from_node, struct module_info, rb_node);
to_m = rb_entry(to_node, struct module_info, rb_node);
if (from_m->start != to_m->start ||
strcmp(from_m->name, to_m->name))
break;
from_node = rb_next(from_node);
to_node = rb_next(to_node);
}
if (!from_node && !to_node)
ret = 0;
delete_modules(&to_modules);
out_delete_from:
delete_modules(&from_modules);
return ret;
}
static int do_validate_kcore_modules(const char *filename, struct map *map,
struct map_groups *kmaps)
{
struct rb_root modules = RB_ROOT;
struct map *old_map;
int err;
err = read_proc_modules(filename, &modules);
if (err)
return err;
old_map = map_groups__first(kmaps, map->type);
while (old_map) {
struct map *next = map_groups__next(old_map);
struct module_info *mi;
if (old_map == map || old_map->start == map->start) {
/* The kernel map */
old_map = next;
continue;
}
/* Module must be in memory at the same address */
mi = find_module(old_map->dso->short_name, &modules);
if (!mi || mi->start != old_map->start) {
err = -EINVAL;
goto out;
}
old_map = next;
}
out:
delete_modules(&modules);
return err;
}
/*
* If kallsyms is referenced by name then we look for filename in the same
* directory.
*/
static bool filename_from_kallsyms_filename(char *filename,
const char *base_name,
const char *kallsyms_filename)
{
char *name;
strcpy(filename, kallsyms_filename);
name = strrchr(filename, '/');
if (!name)
return false;
name += 1;
if (!strcmp(name, "kallsyms")) {
strcpy(name, base_name);
return true;
}
return false;
}
static int validate_kcore_modules(const char *kallsyms_filename,
struct map *map)
{
struct map_groups *kmaps = map__kmaps(map);
char modules_filename[PATH_MAX];
if (!kmaps)
return -EINVAL;
if (!filename_from_kallsyms_filename(modules_filename, "modules",
kallsyms_filename))
return -EINVAL;
if (do_validate_kcore_modules(modules_filename, map, kmaps))
return -EINVAL;
return 0;
}
static int validate_kcore_addresses(const char *kallsyms_filename,
struct map *map)
{
struct kmap *kmap = map__kmap(map);
if (!kmap)
return -EINVAL;
if (kmap->ref_reloc_sym && kmap->ref_reloc_sym->name) {
u64 start;
if (kallsyms__get_function_start(kallsyms_filename,
kmap->ref_reloc_sym->name, &start))
return -ENOENT;
if (start != kmap->ref_reloc_sym->addr)
return -EINVAL;
}
return validate_kcore_modules(kallsyms_filename, map);
}
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;
}
static int dso__load_kcore(struct dso *dso, struct map *map,
const char *kallsyms_filename)
{
struct map_groups *kmaps = map__kmaps(map);
struct machine *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;
if (!kmaps)
return -EINVAL;
machine = kmaps->machine;
/* This function requires that the map is the kernel map */
if (map != machine->vmlinux_maps[map->type])
return -EINVAL;
if (!filename_from_kallsyms_filename(kcore_filename, "kcore",
kallsyms_filename))
return -EINVAL;
/* Modules and kernel must be present at their original addresses */
if (validate_kcore_addresses(kallsyms_filename, map))
return -EINVAL;
md.dso = dso;
md.type = map->type;
INIT_LIST_HEAD(&md.maps);
fd = open(kcore_filename, O_RDONLY);
if (fd < 0) {
pr_debug("Failed to open %s. Note /proc/kcore requires CAP_SYS_RAWIO capability to access.\n",
kcore_filename);
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;
dso->is_64_bit = is_64_bit;
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_init(&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;
/* Ensure maps are correctly ordered */
map__get(map);
map_groups__remove(kmaps, map);
map_groups__insert(kmaps, map);
map__put(map);
} else {
map_groups__insert(kmaps, new_map);
}
map__put(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->binary_type = DSO_BINARY_TYPE__GUEST_KCORE;
else
dso->binary_type = DSO_BINARY_TYPE__KCORE;
dso__set_long_name(dso, strdup(kcore_filename), true);
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_init(&map->node);
map__put(map);
}
close(fd);
return -EINVAL;
}
/*
* If the kernel is relocated at boot time, kallsyms won't match. Compute the
* delta based on the relocation reference symbol.
*/
static int kallsyms__delta(struct map *map, const char *filename, u64 *delta)
{
struct kmap *kmap = map__kmap(map);
u64 addr;
if (!kmap)
return -1;
if (!kmap->ref_reloc_sym || !kmap->ref_reloc_sym->name)
return 0;
if (kallsyms__get_function_start(filename, kmap->ref_reloc_sym->name, &addr))
return -1;
*delta = addr - kmap->ref_reloc_sym->addr;
return 0;
}
int __dso__load_kallsyms(struct dso *dso, const char *filename,
struct map *map, bool no_kcore)
{
u64 delta = 0;
if (symbol__restricted_filename(filename, "/proc/kallsyms"))
return -1;
if (dso__load_all_kallsyms(dso, filename, map) < 0)
return -1;
if (kallsyms__delta(map, filename, &delta))
return -1;
symbols__fixup_end(&dso->symbols[map->type]);
symbols__fixup_duplicate(&dso->symbols[map->type]);
if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
dso->symtab_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
else
dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
if (!no_kcore && !dso__load_kcore(dso, map, filename))
return dso__split_kallsyms_for_kcore(dso, map);
else
return dso__split_kallsyms(dso, map, delta);
}
int dso__load_kallsyms(struct dso *dso, const char *filename,
struct map *map)
{
return __dso__load_kallsyms(dso, filename, map, false);
}
static int dso__load_perf_map(const char *map_path, struct dso *dso,
struct map *map)
{
char *line = NULL;
size_t n;
FILE *file;
int nr_syms = 0;
file = fopen(map_path, "r");
if (file == NULL)
goto out_failure;
while (!feof(file)) {
u64 start, size;
struct symbol *sym;
int line_len, len;
line_len = getline(&line, &n, file);
if (line_len < 0)
break;
if (!line)
goto out_failure;
line[--line_len] = '\0'; /* \n */
len = hex2u64(line, &start);
len++;
if (len + 2 >= line_len)
continue;
len += hex2u64(line + len, &size);
len++;
if (len + 2 >= line_len)
continue;
sym = symbol__new(start, size, STB_GLOBAL, line + len);
if (sym == NULL)
goto out_delete_line;
symbols__insert(&dso->symbols[map->type], sym);
nr_syms++;
}
free(line);
fclose(file);
return nr_syms;
out_delete_line:
free(line);
out_failure:
return -1;
}
static bool dso__is_compatible_symtab_type(struct dso *dso, bool kmod,
enum dso_binary_type type)
{
switch (type) {
case DSO_BINARY_TYPE__JAVA_JIT:
case DSO_BINARY_TYPE__DEBUGLINK:
case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
return !kmod && dso->kernel == DSO_TYPE_USER;
case DSO_BINARY_TYPE__KALLSYMS:
case DSO_BINARY_TYPE__VMLINUX:
case DSO_BINARY_TYPE__KCORE:
return dso->kernel == DSO_TYPE_KERNEL;
case DSO_BINARY_TYPE__GUEST_KALLSYMS:
case DSO_BINARY_TYPE__GUEST_VMLINUX:
case DSO_BINARY_TYPE__GUEST_KCORE:
return dso->kernel == DSO_TYPE_GUEST_KERNEL;
case DSO_BINARY_TYPE__GUEST_KMODULE:
case DSO_BINARY_TYPE__GUEST_KMODULE_COMP:
case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
/*
* kernel modules know their symtab type - it's set when
* creating a module dso in machine__findnew_module_map().
*/
return kmod && dso->symtab_type == type;
case DSO_BINARY_TYPE__BUILD_ID_CACHE:
case DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO:
return true;
case DSO_BINARY_TYPE__NOT_FOUND:
default:
return false;
}
}
/* Checks for the existence of the perf-<pid>.map file in two different
* locations. First, if the process is a separate mount namespace, check in
* that namespace using the pid of the innermost pid namespace. If's not in a
* namespace, or the file can't be found there, try in the mount namespace of
* the tracing process using our view of its pid.
*/
static int dso__find_perf_map(char *filebuf, size_t bufsz,
struct nsinfo **nsip)
{
struct nscookie nsc;
struct nsinfo *nsi;
struct nsinfo *nnsi;
int rc = -1;
nsi = *nsip;
if (nsi->need_setns) {
snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nsi->nstgid);
nsinfo__mountns_enter(nsi, &nsc);
rc = access(filebuf, R_OK);
nsinfo__mountns_exit(&nsc);
if (rc == 0)
return rc;
}
nnsi = nsinfo__copy(nsi);
if (nnsi) {
nsinfo__put(nsi);
nnsi->need_setns = false;
snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nnsi->tgid);
*nsip = nnsi;
rc = 0;
}
return rc;
}
int dso__load(struct dso *dso, struct map *map)
{
char *name;
int ret = -1;
u_int i;
struct machine *machine;
char *root_dir = (char *) "";
int ss_pos = 0;
struct symsrc ss_[2];
struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
bool kmod;
bool perfmap;
unsigned char build_id[BUILD_ID_SIZE];
struct nscookie nsc;
char newmapname[PATH_MAX];
const char *map_path = dso->long_name;
perfmap = strncmp(dso->name, "/tmp/perf-", 10) == 0;
if (perfmap) {
if (dso->nsinfo && (dso__find_perf_map(newmapname,
sizeof(newmapname), &dso->nsinfo) == 0)) {
map_path = newmapname;
}
}
nsinfo__mountns_enter(dso->nsinfo, &nsc);
pthread_mutex_lock(&dso->lock);
/* check again under the dso->lock */
if (dso__loaded(dso, map->type)) {
ret = 1;
goto out;
}
if (dso->kernel) {
if (dso->kernel == DSO_TYPE_KERNEL)
ret = dso__load_kernel_sym(dso, map);
else if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
ret = dso__load_guest_kernel_sym(dso, map);
goto out;
}
if (map->groups && map->groups->machine)
machine = map->groups->machine;
else
machine = NULL;
dso->adjust_symbols = 0;
if (perfmap) {
struct stat st;
if (lstat(map_path, &st) < 0)
goto out;
if (!symbol_conf.force && st.st_uid && (st.st_uid != geteuid())) {
pr_warning("File %s not owned by current user or root, "
"ignoring it (use -f to override).\n", map_path);
goto out;
}
ret = dso__load_perf_map(map_path, dso, map);
dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
DSO_BINARY_TYPE__NOT_FOUND;
goto out;
}
if (machine)
root_dir = machine->root_dir;
name = malloc(PATH_MAX);
if (!name)
goto out;
kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE ||
dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
/*
* Read the build id if possible. This is required for
* DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
*/
if (!dso->has_build_id &&
is_regular_file(dso->long_name)) {
__symbol__join_symfs(name, PATH_MAX, dso->long_name);
if (filename__read_build_id(name, build_id, BUILD_ID_SIZE) > 0)
dso__set_build_id(dso, build_id);
}
/*
* Iterate over candidate debug images.
* Keep track of "interesting" ones (those which have a symtab, dynsym,
* and/or opd section) for processing.
*/
for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
struct symsrc *ss = &ss_[ss_pos];
bool next_slot = false;
bool is_reg;
bool nsexit;
int sirc;
enum dso_binary_type symtab_type = binary_type_symtab[i];
nsexit = (symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE ||
symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO);
if (!dso__is_compatible_symtab_type(dso, kmod, symtab_type))
continue;
if (dso__read_binary_type_filename(dso, symtab_type,
root_dir, name, PATH_MAX))
continue;
if (nsexit)
nsinfo__mountns_exit(&nsc);
is_reg = is_regular_file(name);
sirc = symsrc__init(ss, dso, name, symtab_type);
if (nsexit)
nsinfo__mountns_enter(dso->nsinfo, &nsc);
if (!is_reg || sirc < 0) {
if (sirc >= 0)
symsrc__destroy(ss);
continue;
}
if (!syms_ss && symsrc__has_symtab(ss)) {
syms_ss = ss;
next_slot = true;
if (!dso->symsrc_filename)
dso->symsrc_filename = strdup(name);
}
if (!runtime_ss && symsrc__possibly_runtime(ss)) {
runtime_ss = ss;
next_slot = true;
}
if (next_slot) {
ss_pos++;
if (syms_ss && runtime_ss)
break;
} else {
symsrc__destroy(ss);
}
}
if (!runtime_ss && !syms_ss)
goto out_free;
if (runtime_ss && !syms_ss) {
syms_ss = runtime_ss;
}
/* We'll have to hope for the best */
if (!runtime_ss && syms_ss)
runtime_ss = syms_ss;
if (syms_ss)
ret = dso__load_sym(dso, map, syms_ss, runtime_ss, kmod);
else
ret = -1;
if (ret > 0) {
int nr_plt;
nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss, map);
if (nr_plt > 0)
ret += nr_plt;
}
for (; ss_pos > 0; ss_pos--)
symsrc__destroy(&ss_[ss_pos - 1]);
out_free:
free(name);
if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
ret = 0;
out:
dso__set_loaded(dso, map->type);
pthread_mutex_unlock(&dso->lock);
nsinfo__mountns_exit(&nsc);
return ret;
}
struct map *map_groups__find_by_name(struct map_groups *mg,
enum map_type type, const char *name)
{
struct maps *maps = &mg->maps[type];
struct map *map;
pthread_rwlock_rdlock(&maps->lock);
for (map = maps__first(maps); map; map = map__next(map)) {
if (map->dso && strcmp(map->dso->short_name, name) == 0)
goto out_unlock;
}
map = NULL;
out_unlock:
pthread_rwlock_unlock(&maps->lock);
return map;
}
int dso__load_vmlinux(struct dso *dso, struct map *map,
const char *vmlinux, bool vmlinux_allocated)
{
int err = -1;
struct symsrc ss;
char symfs_vmlinux[PATH_MAX];
enum dso_binary_type symtab_type;
if (vmlinux[0] == '/')
snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
else
symbol__join_symfs(symfs_vmlinux, vmlinux);
if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
else
symtab_type = DSO_BINARY_TYPE__VMLINUX;
if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
return -1;
err = dso__load_sym(dso, map, &ss, &ss, 0);
symsrc__destroy(&ss);
if (err > 0) {
if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
else
dso->binary_type = DSO_BINARY_TYPE__VMLINUX;
dso__set_long_name(dso, vmlinux, vmlinux_allocated);
dso__set_loaded(dso, map->type);
pr_debug("Using %s for symbols\n", symfs_vmlinux);
}
return err;
}
int dso__load_vmlinux_path(struct dso *dso, struct map *map)
{
int i, err = 0;
char *filename = NULL;
pr_debug("Looking at the vmlinux_path (%d entries long)\n",
vmlinux_path__nr_entries + 1);
for (i = 0; i < vmlinux_path__nr_entries; ++i) {
err = dso__load_vmlinux(dso, map, vmlinux_path[i], false);
if (err > 0)
goto out;
}
if (!symbol_conf.ignore_vmlinux_buildid)
filename = dso__build_id_filename(dso, NULL, 0, false);
if (filename != NULL) {
err = dso__load_vmlinux(dso, map, filename, true);
if (err > 0)
goto out;
free(filename);
}
out:
return err;
}
static bool visible_dir_filter(const char *name, struct dirent *d)
{
if (d->d_type != DT_DIR)
return false;
return lsdir_no_dot_filter(name, d);
}
static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
{
char kallsyms_filename[PATH_MAX];
int ret = -1;
struct strlist *dirs;
struct str_node *nd;
dirs = lsdir(dir, visible_dir_filter);
if (!dirs)
return -1;
strlist__for_each_entry(nd, dirs) {
scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
"%s/%s/kallsyms", dir, nd->s);
if (!validate_kcore_addresses(kallsyms_filename, map)) {
strlcpy(dir, kallsyms_filename, dir_sz);
ret = 0;
break;
}
}
strlist__delete(dirs);
return ret;
}
/*
* Use open(O_RDONLY) to check readability directly instead of access(R_OK)
* since access(R_OK) only checks with real UID/GID but open() use effective
* UID/GID and actual capabilities (e.g. /proc/kcore requires CAP_SYS_RAWIO).
*/
static bool filename__readable(const char *file)
{
int fd = open(file, O_RDONLY);
if (fd < 0)
return false;
close(fd);
return true;
}
static char *dso__find_kallsyms(struct dso *dso, struct map *map)
{
u8 host_build_id[BUILD_ID_SIZE];
char sbuild_id[SBUILD_ID_SIZE];
bool is_host = false;
char path[PATH_MAX];
if (!dso->has_build_id) {
/*
* Last resort, if we don't have a build-id and couldn't find
* any vmlinux file, try the running kernel kallsyms table.
*/
goto proc_kallsyms;
}
if (sysfs__read_build_id("/sys/kernel/notes", host_build_id,
sizeof(host_build_id)) == 0)
is_host = dso__build_id_equal(dso, host_build_id);
/* Try a fast path for /proc/kallsyms if possible */
if (is_host) {
/*
* Do not check the build-id cache, unless we know we cannot use
* /proc/kcore or module maps don't match to /proc/kallsyms.
* To check readability of /proc/kcore, do not use access(R_OK)
* since /proc/kcore requires CAP_SYS_RAWIO to read and access
* can't check it.
*/
if (filename__readable("/proc/kcore") &&
!validate_kcore_addresses("/proc/kallsyms", map))
goto proc_kallsyms;
}
build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
/* Find kallsyms in build-id cache with kcore */
scnprintf(path, sizeof(path), "%s/%s/%s",
buildid_dir, DSO__NAME_KCORE, sbuild_id);
if (!find_matching_kcore(map, path, sizeof(path)))
return strdup(path);
/* Use current /proc/kallsyms if possible */
if (is_host) {
proc_kallsyms:
return strdup("/proc/kallsyms");
}
/* Finally, find a cache of kallsyms */
if (!build_id_cache__kallsyms_path(sbuild_id, path, sizeof(path))) {
pr_err("No kallsyms or vmlinux with build-id %s was found\n",
sbuild_id);
return NULL;
}
return strdup(path);
}
static int dso__load_kernel_sym(struct dso *dso, struct map *map)
{
int err;
const char *kallsyms_filename = NULL;
char *kallsyms_allocated_filename = NULL;
/*
* Step 1: if the user specified a kallsyms or vmlinux filename, use
* it and only it, reporting errors to the user if it cannot be used.
*
* For instance, try to analyse an ARM perf.data file _without_ a
* build-id, or if the user specifies the wrong path to the right
* vmlinux file, obviously we can't fallback to another vmlinux (a
* x86_86 one, on the machine where analysis is being performed, say),
* or worse, /proc/kallsyms.
*
* If the specified file _has_ a build-id and there is a build-id
* section in the perf.data file, we will still do the expected
* validation in dso__load_vmlinux and will bail out if they don't
* match.
*/
if (symbol_conf.kallsyms_name != NULL) {
kallsyms_filename = symbol_conf.kallsyms_name;
goto do_kallsyms;
}
if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
return dso__load_vmlinux(dso, map, symbol_conf.vmlinux_name, false);
}
if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
err = dso__load_vmlinux_path(dso, map);
if (err > 0)
return err;
}
/* do not try local files if a symfs was given */
if (symbol_conf.symfs[0] != 0)
return -1;
kallsyms_allocated_filename = dso__find_kallsyms(dso, map);
if (!kallsyms_allocated_filename)
return -1;
kallsyms_filename = kallsyms_allocated_filename;
do_kallsyms:
err = dso__load_kallsyms(dso, kallsyms_filename, map);
if (err > 0)
pr_debug("Using %s for symbols\n", kallsyms_filename);
free(kallsyms_allocated_filename);
if (err > 0 && !dso__is_kcore(dso)) {
dso->binary_type = DSO_BINARY_TYPE__KALLSYMS;
dso__set_long_name(dso, DSO__NAME_KALLSYMS, false);
map__fixup_start(map);
map__fixup_end(map);
}
return err;
}
static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map)
{
int err;
const char *kallsyms_filename = NULL;
struct machine *machine;
char path[PATH_MAX];
if (!map->groups) {
pr_debug("Guest kernel map hasn't the point to groups\n");
return -1;
}
machine = map->groups->machine;
if (machine__is_default_guest(machine)) {
/*
* if the user specified a vmlinux filename, use it and only
* it, reporting errors to the user if it cannot be used.
* Or use file guest_kallsyms inputted by user on commandline
*/
if (symbol_conf.default_guest_vmlinux_name != NULL) {
err = dso__load_vmlinux(dso, map,
symbol_conf.default_guest_vmlinux_name,
false);
return err;
}
kallsyms_filename = symbol_conf.default_guest_kallsyms;
if (!kallsyms_filename)
return -1;
} else {
sprintf(path, "%s/proc/kallsyms", machine->root_dir);
kallsyms_filename = path;
}
err = dso__load_kallsyms(dso, kallsyms_filename, map);
if (err > 0)
pr_debug("Using %s for symbols\n", kallsyms_filename);
if (err > 0 && !dso__is_kcore(dso)) {
dso->binary_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
machine__mmap_name(machine, path, sizeof(path));
dso__set_long_name(dso, strdup(path), true);
map__fixup_start(map);
map__fixup_end(map);
}
return err;
}
static void vmlinux_path__exit(void)
{
while (--vmlinux_path__nr_entries >= 0)
zfree(&vmlinux_path[vmlinux_path__nr_entries]);
vmlinux_path__nr_entries = 0;
zfree(&vmlinux_path);
}
static const char * const vmlinux_paths[] = {
"vmlinux",
"/boot/vmlinux"
};
static const char * const vmlinux_paths_upd[] = {
"/boot/vmlinux-%s",
"/usr/lib/debug/boot/vmlinux-%s",
"/lib/modules/%s/build/vmlinux",
"/usr/lib/debug/lib/modules/%s/vmlinux",
"/usr/lib/debug/boot/vmlinux-%s.debug"
};
static int vmlinux_path__add(const char *new_entry)
{
vmlinux_path[vmlinux_path__nr_entries] = strdup(new_entry);
if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
return -1;
++vmlinux_path__nr_entries;
return 0;
}
static int vmlinux_path__init(struct perf_env *env)
{
struct utsname uts;
char bf[PATH_MAX];
char *kernel_version;
unsigned int i;
vmlinux_path = malloc(sizeof(char *) * (ARRAY_SIZE(vmlinux_paths) +
ARRAY_SIZE(vmlinux_paths_upd)));
if (vmlinux_path == NULL)
return -1;
for (i = 0; i < ARRAY_SIZE(vmlinux_paths); i++)
if (vmlinux_path__add(vmlinux_paths[i]) < 0)
goto out_fail;
/* only try kernel version if no symfs was given */
if (symbol_conf.symfs[0] != 0)
return 0;
if (env) {
kernel_version = env->os_release;
} else {
if (uname(&uts) < 0)
goto out_fail;
kernel_version = uts.release;
}
for (i = 0; i < ARRAY_SIZE(vmlinux_paths_upd); i++) {
snprintf(bf, sizeof(bf), vmlinux_paths_upd[i], kernel_version);
if (vmlinux_path__add(bf) < 0)
goto out_fail;
}
return 0;
out_fail:
vmlinux_path__exit();
return -1;
}
int setup_list(struct strlist **list, const char *list_str,
const char *list_name)
{
if (list_str == NULL)
return 0;
*list = strlist__new(list_str, NULL);
if (!*list) {
pr_err("problems parsing %s list\n", list_name);
return -1;
}
symbol_conf.has_filter = true;
return 0;
}
int setup_intlist(struct intlist **list, const char *list_str,
const char *list_name)
{
if (list_str == NULL)
return 0;
*list = intlist__new(list_str);
if (!*list) {
pr_err("problems parsing %s list\n", list_name);
return -1;
}
return 0;
}
static bool symbol__read_kptr_restrict(void)
{
bool value = false;
FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
if (fp != NULL) {
char line[8];
if (fgets(line, sizeof(line), fp) != NULL)
value = ((geteuid() != 0) || (getuid() != 0)) ?
(atoi(line) != 0) :
(atoi(line) == 2);
fclose(fp);
}
return value;
}
int symbol__annotation_init(void)
{
if (symbol_conf.initialized) {
pr_err("Annotation needs to be init before symbol__init()\n");
return -1;
}
if (symbol_conf.init_annotation) {
pr_warning("Annotation being initialized multiple times\n");
return 0;
}
symbol_conf.priv_size += sizeof(struct annotation);
symbol_conf.init_annotation = true;
return 0;
}
int symbol__init(struct perf_env *env)
{
const char *symfs;
if (symbol_conf.initialized)
return 0;
symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
symbol__elf_init();
if (symbol_conf.sort_by_name)
symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
sizeof(struct symbol));
if (symbol_conf.try_vmlinux_path && vmlinux_path__init(env) < 0)
return -1;
if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
pr_err("'.' is the only non valid --field-separator argument\n");
return -1;
}
if (setup_list(&symbol_conf.dso_list,
symbol_conf.dso_list_str, "dso") < 0)
return -1;
if (setup_list(&symbol_conf.comm_list,
symbol_conf.comm_list_str, "comm") < 0)
goto out_free_dso_list;
if (setup_intlist(&symbol_conf.pid_list,
symbol_conf.pid_list_str, "pid") < 0)
goto out_free_comm_list;
if (setup_intlist(&symbol_conf.tid_list,
symbol_conf.tid_list_str, "tid") < 0)
goto out_free_pid_list;
if (setup_list(&symbol_conf.sym_list,
symbol_conf.sym_list_str, "symbol") < 0)
goto out_free_tid_list;
if (setup_list(&symbol_conf.bt_stop_list,
symbol_conf.bt_stop_list_str, "symbol") < 0)
goto out_free_sym_list;
/*
* A path to symbols of "/" is identical to ""
* reset here for simplicity.
*/
symfs = realpath(symbol_conf.symfs, NULL);
if (symfs == NULL)
symfs = symbol_conf.symfs;
if (strcmp(symfs, "/") == 0)
symbol_conf.symfs = "";
if (symfs != symbol_conf.symfs)
free((void *)symfs);
symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
symbol_conf.initialized = true;
return 0;
out_free_sym_list:
strlist__delete(symbol_conf.sym_list);
out_free_tid_list:
intlist__delete(symbol_conf.tid_list);
out_free_pid_list:
intlist__delete(symbol_conf.pid_list);
out_free_comm_list:
strlist__delete(symbol_conf.comm_list);
out_free_dso_list:
strlist__delete(symbol_conf.dso_list);
return -1;
}
void symbol__exit(void)
{
if (!symbol_conf.initialized)
return;
strlist__delete(symbol_conf.bt_stop_list);
strlist__delete(symbol_conf.sym_list);
strlist__delete(symbol_conf.dso_list);
strlist__delete(symbol_conf.comm_list);
intlist__delete(symbol_conf.tid_list);
intlist__delete(symbol_conf.pid_list);
vmlinux_path__exit();
symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
symbol_conf.bt_stop_list = NULL;
symbol_conf.initialized = false;
}
int symbol__config_symfs(const struct option *opt __maybe_unused,
const char *dir, int unset __maybe_unused)
{
char *bf = NULL;
int ret;
symbol_conf.symfs = strdup(dir);
if (symbol_conf.symfs == NULL)
return -ENOMEM;
/* skip the locally configured cache if a symfs is given, and
* config buildid dir to symfs/.debug
*/
ret = asprintf(&bf, "%s/%s", dir, ".debug");
if (ret < 0)
return -ENOMEM;
set_buildid_dir(bf);
free(bf);
return 0;
}