linux/tools/perf/util/symbol.h
Tommi Rantala ab8bf5f2e0 perf tools: Fix crash with non-jited bpf progs
The addr in PERF_RECORD_KSYMBOL events for non-jited bpf progs points to
the bpf interpreter, ie. within kernel text section. When processing the
unregister event, this causes unexpected removal of vmlinux_map,
crashing perf later in cleanup:

  # perf record -- timeout --signal=INT 2s /usr/share/bcc/tools/execsnoop
  PCOMM            PID    PPID   RET ARGS
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.208 MB perf.data (5155 samples) ]
  perf: tools/include/linux/refcount.h:131: refcount_sub_and_test: Assertion `!(new > val)' failed.
  Aborted (core dumped)

  # perf script -D|grep KSYM
  0 0xa40 [0x48]: PERF_RECORD_KSYMBOL addr ffffffffa9b6b530 len 0 type 1 flags 0x0 name bpf_prog_f958f6eb72ef5af6
  0 0xab0 [0x48]: PERF_RECORD_KSYMBOL addr ffffffffa9b6b530 len 0 type 1 flags 0x0 name bpf_prog_8c42dee26e8cd4c2
  0 0xb20 [0x48]: PERF_RECORD_KSYMBOL addr ffffffffa9b6b530 len 0 type 1 flags 0x0 name bpf_prog_f958f6eb72ef5af6
  108563691893 0x33d98 [0x58]: PERF_RECORD_KSYMBOL addr ffffffffa9b6b3b0 len 0 type 1 flags 0x0 name bpf_prog_bc5697a410556fc2_syscall__execve
  108568518458 0x34098 [0x58]: PERF_RECORD_KSYMBOL addr ffffffffa9b6b3f0 len 0 type 1 flags 0x0 name bpf_prog_45e2203c2928704d_do_ret_sys_execve
  109301967895 0x34830 [0x58]: PERF_RECORD_KSYMBOL addr ffffffffa9b6b3b0 len 0 type 1 flags 0x1 name bpf_prog_bc5697a410556fc2_syscall__execve
  109302007356 0x348b0 [0x58]: PERF_RECORD_KSYMBOL addr ffffffffa9b6b3f0 len 0 type 1 flags 0x1 name bpf_prog_45e2203c2928704d_do_ret_sys_execve
  perf: tools/include/linux/refcount.h:131: refcount_sub_and_test: Assertion `!(new > val)' failed.

Here the addresses match the bpf interpreter:

  # grep -e ffffffffa9b6b530 -e ffffffffa9b6b3b0 -e ffffffffa9b6b3f0 /proc/kallsyms
  ffffffffa9b6b3b0 t __bpf_prog_run224
  ffffffffa9b6b3f0 t __bpf_prog_run192
  ffffffffa9b6b530 t __bpf_prog_run32

Fix by not allowing vmlinux_map to be removed by PERF_RECORD_KSYMBOL
unregister event.

Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/r/20201016114718.54332-1-tommi.t.rantala@nokia.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-11-03 08:30:34 -03:00

290 lines
8.0 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __PERF_SYMBOL
#define __PERF_SYMBOL 1
#include <linux/types.h>
#include <linux/refcount.h>
#include <stdbool.h>
#include <stdint.h>
#include <linux/list.h>
#include <linux/rbtree.h>
#include <stdio.h>
#include "path.h"
#include "symbol_conf.h"
#include "spark.h"
#ifdef HAVE_LIBELF_SUPPORT
#include <libelf.h>
#include <gelf.h>
#endif
#include <elf.h>
struct dso;
struct map;
struct maps;
struct option;
struct build_id;
/*
* 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 ELF_C_READ_MMAP
# 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
/** 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 type:4;
u8 binding:4;
u8 idle:1;
u8 ignore:1;
u8 inlined:1;
u8 arch_sym;
bool annotate2;
char name[];
};
void symbol__delete(struct symbol *sym);
void symbols__delete(struct rb_root_cached *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_cached(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_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 addr_location {
struct thread *thread;
struct maps *maps;
struct map *map;
struct symbol *sym;
const char *srcline;
u64 addr;
char level;
u8 filtered;
u8 cpumode;
s32 cpu;
s32 socket;
};
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,
struct symbol *sym);
void dso__delete_symbol(struct dso *dso,
struct symbol *sym);
struct symbol *dso__find_symbol(struct dso *dso, u64 addr);
struct symbol *dso__find_symbol_by_name(struct dso *dso, const char *name);
struct symbol *symbol__next_by_name(struct symbol *sym);
struct symbol *dso__first_symbol(struct dso *dso);
struct symbol *dso__last_symbol(struct dso *dso);
struct symbol *dso__next_symbol(struct symbol *sym);
enum dso_type dso__type_fd(int fd);
int filename__read_build_id(const char *filename, struct build_id *id);
int sysfs__read_build_id(const char *filename, struct build_id *bid);
int modules__parse(const char *filename, void *arg,
int (*process_module)(void *arg, const char *name,
u64 start, u64 size));
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, u8 type, 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__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);
struct symsrc;
#ifdef HAVE_LIBBFD_SUPPORT
int dso__load_bfd_symbols(struct dso *dso, const char *debugfile);
#endif
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);
char *dso__demangle_sym(struct dso *dso, int kmodule, const char *elf_name);
void __symbols__insert(struct rb_root_cached *symbols, struct symbol *sym,
bool kernel);
void symbols__insert(struct rb_root_cached *symbols, struct symbol *sym);
void symbols__fixup_duplicate(struct rb_root_cached *symbols);
void symbols__fixup_end(struct rb_root_cached *symbols);
void maps__fixup_end(struct maps *maps);
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
const char *arch__normalize_symbol_name(const char *name);
#define SYMBOL_A 0
#define SYMBOL_B 1
void arch__symbols__fixup_end(struct symbol *p, struct symbol *c);
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_PROBES_SCN ".probes"
#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
enum {
SDT_NOTE_IDX_LOC = 0,
SDT_NOTE_IDX_BASE,
SDT_NOTE_IDX_REFCTR,
};
struct mem_info *mem_info__new(void);
struct mem_info *mem_info__get(struct mem_info *mi);
void mem_info__put(struct mem_info *mi);
static inline void __mem_info__zput(struct mem_info **mi)
{
mem_info__put(*mi);
*mi = NULL;
}
#define mem_info__zput(mi) __mem_info__zput(&mi)
#endif /* __PERF_SYMBOL */