mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-25 00:52:02 +00:00
106 lines
2.7 KiB
C
106 lines
2.7 KiB
C
#include <elf.h>
|
|
#include <link.h>
|
|
#include <limits.h>
|
|
#include <stdint.h>
|
|
#include <string.h>
|
|
#include <sys/auxv.h>
|
|
#include "syscall.h"
|
|
|
|
#ifdef VDSO_USEFUL
|
|
|
|
#if ULONG_MAX == 0xffffffff
|
|
typedef Elf32_Ehdr Ehdr;
|
|
typedef Elf32_Phdr Phdr;
|
|
typedef Elf32_Sym Sym;
|
|
typedef Elf32_Verdef Verdef;
|
|
typedef Elf32_Verdaux Verdaux;
|
|
#else
|
|
typedef Elf64_Ehdr Ehdr;
|
|
typedef Elf64_Phdr Phdr;
|
|
typedef Elf64_Sym Sym;
|
|
typedef Elf64_Verdef Verdef;
|
|
typedef Elf64_Verdaux Verdaux;
|
|
#endif
|
|
|
|
static int checkver(Verdef *def, int vsym, const char *vername, char *strings)
|
|
{
|
|
vsym &= 0x7fff;
|
|
for (;;) {
|
|
if (!(def->vd_flags & VER_FLG_BASE)
|
|
&& (def->vd_ndx & 0x7fff) == vsym)
|
|
break;
|
|
if (def->vd_next == 0)
|
|
return 0;
|
|
def = (Verdef *)((char *)def + def->vd_next);
|
|
}
|
|
Verdaux *aux = (Verdaux *)((char *)def + def->vd_aux);
|
|
return !strcmp(vername, strings + aux->vda_name);
|
|
}
|
|
|
|
#define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON)
|
|
#define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
|
|
|
|
extern char** environ;
|
|
static Ehdr *eh = NULL;
|
|
void *__vdsosym(const char *vername, const char *name);
|
|
// We don't have libc struct available here. Compute aux vector manually.
|
|
__attribute__((constructor)) static void auxv_init()
|
|
{
|
|
size_t i, *auxv;
|
|
for (i=0; environ[i]; i++);
|
|
auxv = (void *)(environ+i+1);
|
|
for (i=0; auxv[i] != AT_SYSINFO_EHDR; i+=2)
|
|
if (!auxv[i]) return;
|
|
if (!auxv[i+1]) return;
|
|
eh = (void *)auxv[i+1];
|
|
}
|
|
|
|
void *__vdsosym(const char *vername, const char *name)
|
|
{
|
|
size_t i;
|
|
if (!eh) return 0;
|
|
Phdr *ph = (void *)((char *)eh + eh->e_phoff);
|
|
size_t *dynv=0, base=-1;
|
|
for (i=0; i<eh->e_phnum; i++, ph=(void *)((char *)ph+eh->e_phentsize)) {
|
|
if (ph->p_type == PT_LOAD)
|
|
base = (size_t)eh + ph->p_offset - ph->p_vaddr;
|
|
else if (ph->p_type == PT_DYNAMIC)
|
|
dynv = (void *)((char *)eh + ph->p_offset);
|
|
}
|
|
if (!dynv || base==(size_t)-1) return 0;
|
|
|
|
char *strings = 0;
|
|
Sym *syms = 0;
|
|
Elf_Symndx *hashtab = 0;
|
|
uint16_t *versym = 0;
|
|
Verdef *verdef = 0;
|
|
|
|
for (i=0; dynv[i]; i+=2) {
|
|
void *p = (void *)(base + dynv[i+1]);
|
|
switch(dynv[i]) {
|
|
case DT_STRTAB: strings = p; break;
|
|
case DT_SYMTAB: syms = p; break;
|
|
case DT_HASH: hashtab = p; break;
|
|
case DT_VERSYM: versym = p; break;
|
|
case DT_VERDEF: verdef = p; break;
|
|
}
|
|
}
|
|
|
|
if (!strings || !syms || !hashtab) return 0;
|
|
if (!verdef) versym = 0;
|
|
|
|
for (i=0; i<hashtab[1]; i++) {
|
|
if (!(1<<(syms[i].st_info&0xf) & OK_TYPES)) continue;
|
|
if (!(1<<(syms[i].st_info>>4) & OK_BINDS)) continue;
|
|
if (!syms[i].st_shndx) continue;
|
|
if (strcmp(name, strings+syms[i].st_name)) continue;
|
|
if (versym && !checkver(verdef, versym[i], vername, strings))
|
|
continue;
|
|
return (void *)(base + syms[i].st_value);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
#endif
|