linux/tools/perf/util/symbol.h
Paul Clarke d80406453a perf symbols: Allow user probes on versioned symbols
Symbol versioning, as in glibc, results in symbols being defined as:

  <real symbol>@[@]<version>

(Note that "@@" identifies a default symbol, if the symbol name is
repeated.)

perf is currently unable to deal with this, and is unable to create user
probes at such symbols:

  --
  $ nm /lib/powerpc64le-linux-gnu/libpthread.so.0 | grep pthread_create
  0000000000008d30 t __pthread_create_2_1
  0000000000008d30 T pthread_create@@GLIBC_2.17
  $ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 pthread_create
  probe-definition(0): pthread_create
  symbol:pthread_create file:(null) line:0 offset:0 return:0 lazy:(null)
  0 arguments
  Open Debuginfo file: /usr/lib/debug/lib/powerpc64le-linux-gnu/libpthread-2.19.so
  Try to find probe point from debuginfo.
  Probe point 'pthread_create' not found.
     Error: Failed to add events. Reason: No such file or directory (Code: -2)
  --

One is not able to specify the fully versioned symbol, either, due to
syntactic conflicts with other uses of "@" by perf:

  --
  $ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 pthread_create@@GLIBC_2.17
  probe-definition(0): pthread_create@@GLIBC_2.17
  Semantic error :SRC@SRC is not allowed.
  0 arguments
     Error: Command Parse Error. Reason: Invalid argument (Code: -22)
  --

This patch ignores versioning for default symbols, thus allowing probes to be
created for these symbols:

  --
  $ /usr/bin/sudo ./perf probe -x /lib/powerpc64le-linux-gnu/libpthread.so.0 pthread_create
  Added new event:
     probe_libpthread:pthread_create (on pthread_create in /lib/powerpc64le-linux-gnu/libpthread-2.19.so)

  You can now use it in all perf tools, such as:

           perf record -e probe_libpthread:pthread_create -aR sleep 1

  $ /usr/bin/sudo ./perf record -e probe_libpthread:pthread_create -aR ./test 2
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.052 MB perf.data (2 samples) ]
  $ /usr/bin/sudo ./perf script
               test  2915 [000] 19124.260729: probe_libpthread:pthread_create: (3fff99248d38)
               test  2916 [000] 19124.260962: probe_libpthread:pthread_create: (3fff99248d38)
  $ /usr/bin/sudo ./perf probe --del=probe_libpthread:pthread_create
  Removed event: probe_libpthread:pthread_create
  --

Committer note:

Change the variable storing the result of strlen() to 'int', to fix the build
on debian:experimental-x-mipsel, fedora:24-x-ARC-uClibc, ubuntu:16.04-x-arm,
etc:

  util/symbol.c: In function 'symbol__match_symbol_name':
  util/symbol.c:422:11: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
     if (len < versioning - name)
             ^

Signed-off-by: Paul A. Clarke <pc@us.ibm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Link: http://lkml.kernel.org/r/c2b18d9c-17f8-9285-4868-f58b6359ccac@us.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-05-02 18:23:11 -03:00

388 lines
10 KiB
C

#ifndef __PERF_SYMBOL
#define __PERF_SYMBOL 1
#include <linux/types.h>
#include <stdbool.h>
#include <stdint.h>
#include "map.h"
#include "../perf.h"
#include <linux/list.h>
#include <linux/rbtree.h>
#include <stdio.h>
#include <byteswap.h>
#include <libgen.h>
#include "build-id.h"
#include "event.h"
#include "path.h"
#ifdef HAVE_LIBELF_SUPPORT
#include <libelf.h>
#include <gelf.h>
#endif
#include <elf.h>
#include "dso.h"
/*
* libelf 0.8.x and earlier do not support ELF_C_READ_MMAP;
* for newer versions we can use mmap to reduce memory usage:
*/
#ifdef HAVE_LIBELF_MMAP_SUPPORT
# define PERF_ELF_C_READ_MMAP ELF_C_READ_MMAP
#else
# define PERF_ELF_C_READ_MMAP ELF_C_READ
#endif
#ifdef HAVE_LIBELF_SUPPORT
Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
GElf_Shdr *shp, const char *name, size_t *idx);
#endif
#ifndef DMGL_PARAMS
#define DMGL_NO_OPTS 0 /* For readability... */
#define DMGL_PARAMS (1 << 0) /* Include function args */
#define DMGL_ANSI (1 << 1) /* Include const, volatile, etc */
#endif
#define DSO__NAME_KALLSYMS "[kernel.kallsyms]"
#define DSO__NAME_KCORE "[kernel.kcore]"
/** struct symbol - symtab entry
*
* @ignore - resolvable but tools ignore it (e.g. idle routines)
*/
struct symbol {
struct rb_node rb_node;
u64 start;
u64 end;
u16 namelen;
u8 binding;
u8 idle:1;
u8 ignore:1;
u8 arch_sym;
char name[0];
};
void symbol__delete(struct symbol *sym);
void symbols__delete(struct rb_root *symbols);
/* symbols__for_each_entry - iterate over symbols (rb_root)
*
* @symbols: the rb_root of symbols
* @pos: the 'struct symbol *' to use as a loop cursor
* @nd: the 'struct rb_node *' to use as a temporary storage
*/
#define symbols__for_each_entry(symbols, pos, nd) \
for (nd = rb_first(symbols); \
nd && (pos = rb_entry(nd, struct symbol, rb_node)); \
nd = rb_next(nd))
static inline size_t symbol__size(const struct symbol *sym)
{
return sym->end - sym->start;
}
struct strlist;
struct intlist;
struct symbol_conf {
unsigned short priv_size;
unsigned short nr_events;
bool try_vmlinux_path,
init_annotation,
force,
ignore_vmlinux,
ignore_vmlinux_buildid,
show_kernel_path,
use_modules,
allow_aliases,
sort_by_name,
show_nr_samples,
show_total_period,
use_callchain,
cumulate_callchain,
show_branchflag_count,
exclude_other,
show_cpu_utilization,
initialized,
kptr_restrict,
annotate_asm_raw,
annotate_src,
event_group,
demangle,
demangle_kernel,
filter_relative,
show_hist_headers,
branch_callstack,
has_filter,
show_ref_callgraph,
hide_unresolved,
raw_trace,
report_hierarchy,
inline_name;
const char *vmlinux_name,
*kallsyms_name,
*source_prefix,
*field_sep;
const char *default_guest_vmlinux_name,
*default_guest_kallsyms,
*default_guest_modules;
const char *guestmount;
const char *dso_list_str,
*comm_list_str,
*pid_list_str,
*tid_list_str,
*sym_list_str,
*col_width_list_str,
*bt_stop_list_str;
struct strlist *dso_list,
*comm_list,
*sym_list,
*dso_from_list,
*dso_to_list,
*sym_from_list,
*sym_to_list,
*bt_stop_list;
struct intlist *pid_list,
*tid_list;
const char *symfs;
};
extern struct symbol_conf symbol_conf;
struct symbol_name_rb_node {
struct rb_node rb_node;
struct symbol sym;
};
static inline int __symbol__join_symfs(char *bf, size_t size, const char *path)
{
return path__join(bf, size, symbol_conf.symfs, path);
}
#define symbol__join_symfs(bf, path) __symbol__join_symfs(bf, sizeof(bf), path)
extern int vmlinux_path__nr_entries;
extern char **vmlinux_path;
static inline void *symbol__priv(struct symbol *sym)
{
return ((void *)sym) - symbol_conf.priv_size;
}
struct ref_reloc_sym {
const char *name;
u64 addr;
u64 unrelocated_addr;
};
struct map_symbol {
struct map *map;
struct symbol *sym;
};
struct addr_map_symbol {
struct map *map;
struct symbol *sym;
u64 addr;
u64 al_addr;
};
struct branch_info {
struct addr_map_symbol from;
struct addr_map_symbol to;
struct branch_flags flags;
char *srcline_from;
char *srcline_to;
};
struct mem_info {
struct addr_map_symbol iaddr;
struct addr_map_symbol daddr;
union perf_mem_data_src data_src;
};
struct addr_location {
struct machine *machine;
struct thread *thread;
struct map *map;
struct symbol *sym;
u64 addr;
char level;
u8 filtered;
u8 cpumode;
s32 cpu;
s32 socket;
};
struct symsrc {
char *name;
int fd;
enum dso_binary_type type;
#ifdef HAVE_LIBELF_SUPPORT
Elf *elf;
GElf_Ehdr ehdr;
Elf_Scn *opdsec;
size_t opdidx;
GElf_Shdr opdshdr;
Elf_Scn *symtab;
GElf_Shdr symshdr;
Elf_Scn *dynsym;
size_t dynsym_idx;
GElf_Shdr dynshdr;
bool adjust_symbols;
bool is_64_bit;
#endif
};
void symsrc__destroy(struct symsrc *ss);
int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
enum dso_binary_type type);
bool symsrc__has_symtab(struct symsrc *ss);
bool symsrc__possibly_runtime(struct symsrc *ss);
int dso__load(struct dso *dso, struct map *map);
int dso__load_vmlinux(struct dso *dso, struct map *map,
const char *vmlinux, bool vmlinux_allocated);
int dso__load_vmlinux_path(struct dso *dso, struct map *map);
int __dso__load_kallsyms(struct dso *dso, const char *filename, struct map *map,
bool no_kcore);
int dso__load_kallsyms(struct dso *dso, const char *filename, struct map *map);
void dso__insert_symbol(struct dso *dso, enum map_type type,
struct symbol *sym);
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 *symbol__next_by_name(struct symbol *sym);
struct symbol *dso__first_symbol(struct dso *dso, enum map_type type);
struct symbol *dso__last_symbol(struct dso *dso, enum map_type type);
struct symbol *dso__next_symbol(struct symbol *sym);
enum dso_type dso__type_fd(int fd);
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);
int modules__parse(const char *filename, void *arg,
int (*process_module)(void *arg, const char *name,
u64 start));
int filename__read_debuglink(const char *filename, char *debuglink,
size_t size);
struct perf_env;
int symbol__init(struct perf_env *env);
void symbol__exit(void);
void symbol__elf_init(void);
int symbol__annotation_init(void);
struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name);
size_t __symbol__fprintf_symname_offs(const struct symbol *sym,
const struct addr_location *al,
bool unknown_as_addr,
bool print_offsets, FILE *fp);
size_t symbol__fprintf_symname_offs(const struct symbol *sym,
const struct addr_location *al, FILE *fp);
size_t __symbol__fprintf_symname(const struct symbol *sym,
const struct addr_location *al,
bool unknown_as_addr, FILE *fp);
size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp);
size_t symbol__fprintf(struct symbol *sym, FILE *fp);
bool symbol_type__is_a(char symbol_type, enum map_type map_type);
bool symbol__restricted_filename(const char *filename,
const char *restricted_filename);
int symbol__config_symfs(const struct option *opt __maybe_unused,
const char *dir, int unset __maybe_unused);
int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss,
struct symsrc *runtime_ss, int kmodule);
int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss,
struct map *map);
char *dso__demangle_sym(struct dso *dso, int kmodule, char *elf_name);
void __symbols__insert(struct rb_root *symbols, struct symbol *sym, bool kernel);
void symbols__insert(struct rb_root *symbols, struct symbol *sym);
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);
#define PERF_KCORE_EXTRACT "/tmp/perf-kcore-XXXXXX"
struct kcore_extract {
char *kcore_filename;
u64 addr;
u64 offs;
u64 len;
char extract_filename[sizeof(PERF_KCORE_EXTRACT)];
int fd;
};
int kcore_extract__create(struct kcore_extract *kce);
void kcore_extract__delete(struct kcore_extract *kce);
int kcore_copy(const char *from_dir, const char *to_dir);
int compare_proc_modules(const char *from, const char *to);
int setup_list(struct strlist **list, const char *list_str,
const char *list_name);
int setup_intlist(struct intlist **list, const char *list_str,
const char *list_name);
#ifdef HAVE_LIBELF_SUPPORT
bool elf__needs_adjust_symbols(GElf_Ehdr ehdr);
void arch__sym_update(struct symbol *s, GElf_Sym *sym);
#endif
#define SYMBOL_A 0
#define SYMBOL_B 1
int arch__compare_symbol_names(const char *namea, const char *nameb);
int arch__compare_symbol_names_n(const char *namea, const char *nameb,
unsigned int n);
int arch__choose_best_symbol(struct symbol *syma, struct symbol *symb);
enum symbol_tag_include {
SYMBOL_TAG_INCLUDE__NONE = 0,
SYMBOL_TAG_INCLUDE__DEFAULT_ONLY
};
int symbol__match_symbol_name(const char *namea, const char *nameb,
enum symbol_tag_include includes);
/* structure containing an SDT note's info */
struct sdt_note {
char *name; /* name of the note*/
char *provider; /* provider name */
char *args;
bool bit32; /* whether the location is 32 bits? */
union { /* location, base and semaphore addrs */
Elf64_Addr a64[3];
Elf32_Addr a32[3];
} addr;
struct list_head note_list; /* SDT notes' list */
};
int get_sdt_note_list(struct list_head *head, const char *target);
int cleanup_sdt_note_list(struct list_head *sdt_notes);
int sdt_notes__get_count(struct list_head *start);
#define SDT_BASE_SCN ".stapsdt.base"
#define SDT_NOTE_SCN ".note.stapsdt"
#define SDT_NOTE_TYPE 3
#define SDT_NOTE_NAME "stapsdt"
#define NR_ADDR 3
#endif /* __PERF_SYMBOL */