freebsd-dev/lib/libproc/proc_sym.c

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/*-
* Copyright (c) 2010 The FreeBSD Foundation
* Copyright (c) 2008 John Birrell (jb@freebsd.org)
* All rights reserved.
*
* Portions of this software were developed by Rui Paulo under sponsorship
* from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <sys/types.h>
#include <sys/user.h>
#include <assert.h>
#include <err.h>
#include <stdio.h>
#include <libgen.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
#include <libutil.h>
#include "_libproc.h"
static void proc_rdl2prmap(rd_loadobj_t *, prmap_t *);
static void
proc_rdl2prmap(rd_loadobj_t *rdl, prmap_t *map)
{
map->pr_vaddr = rdl->rdl_saddr;
map->pr_size = rdl->rdl_eaddr - rdl->rdl_saddr;
map->pr_offset = rdl->rdl_offset;
map->pr_mflags = 0;
if (rdl->rdl_prot & RD_RDL_R)
map->pr_mflags |= MA_READ;
if (rdl->rdl_prot & RD_RDL_W)
map->pr_mflags |= MA_WRITE;
if (rdl->rdl_prot & RD_RDL_X)
map->pr_mflags |= MA_EXEC;
strlcpy(map->pr_mapname, rdl->rdl_path,
sizeof(map->pr_mapname));
}
char *
proc_objname(struct proc_handle *p, uintptr_t addr, char *objname,
size_t objnamesz)
{
size_t i;
rd_loadobj_t *rdl;
for (i = 0; i < p->nobjs; i++) {
rdl = &p->rdobjs[i];
if (addr >= rdl->rdl_saddr && addr <= rdl->rdl_eaddr) {
strlcpy(objname, rdl->rdl_path, objnamesz);
return (objname);
}
}
return (NULL);
}
prmap_t *
proc_obj2map(struct proc_handle *p, const char *objname)
{
size_t i;
prmap_t *map;
rd_loadobj_t *rdl;
char path[MAXPATHLEN];
for (i = 0; i < p->nobjs; i++) {
rdl = &p->rdobjs[i];
basename_r(rdl->rdl_path, path);
if (strcmp(path, objname) == 0) {
if ((map = malloc(sizeof(*map))) == NULL)
return (NULL);
proc_rdl2prmap(rdl, map);
return (map);
}
}
return (NULL);
}
int
proc_iter_objs(struct proc_handle *p, proc_map_f *func, void *cd)
{
size_t i;
rd_loadobj_t *rdl;
prmap_t map;
char path[MAXPATHLEN];
char last[MAXPATHLEN];
if (p->nobjs == 0)
return (-1);
memset(last, 0, sizeof(last));
for (i = 0; i < p->nobjs; i++) {
rdl = &p->rdobjs[i];
proc_rdl2prmap(rdl, &map);
basename_r(rdl->rdl_path, path);
/*
* We shouldn't call the callback twice with the same object.
* To do that we are assuming the fact that if there are
* repeated object names (i.e. different mappings for the
* same object) they occur next to each other.
*/
if (strcmp(path, last) == 0)
continue;
(*func)(cd, &map, path);
strlcpy(last, path, sizeof(last));
}
return (0);
}
prmap_t *
proc_addr2map(struct proc_handle *p, uintptr_t addr)
{
size_t i;
int cnt, lastvn = 0;
prmap_t *map;
rd_loadobj_t *rdl;
struct kinfo_vmentry *kves, *kve;
/*
* If we don't have a cache of listed objects, we need to query
* it ourselves.
*/
if (p->nobjs == 0) {
if ((kves = kinfo_getvmmap(p->pid, &cnt)) == NULL)
return (NULL);
for (i = 0; i < (size_t)cnt; i++) {
kve = kves + i;
if (kve->kve_type == KVME_TYPE_VNODE)
lastvn = i;
if (addr >= kve->kve_start && addr <= kve->kve_end) {
if ((map = malloc(sizeof(*map))) == NULL) {
free(kves);
return (NULL);
}
map->pr_vaddr = kve->kve_start;
map->pr_size = kve->kve_end - kve->kve_start;
map->pr_offset = kve->kve_offset;
map->pr_mflags = 0;
if (kve->kve_protection & KVME_PROT_READ)
map->pr_mflags |= MA_READ;
if (kve->kve_protection & KVME_PROT_WRITE)
map->pr_mflags |= MA_WRITE;
if (kve->kve_protection & KVME_PROT_EXEC)
map->pr_mflags |= MA_EXEC;
if (kve->kve_flags & KVME_FLAG_COW)
map->pr_mflags |= MA_COW;
if (kve->kve_flags & KVME_FLAG_NEEDS_COPY)
map->pr_mflags |= MA_NEEDS_COPY;
if (kve->kve_flags & KVME_FLAG_NOCOREDUMP)
map->pr_mflags |= MA_NOCOREDUMP;
strlcpy(map->pr_mapname, kves[lastvn].kve_path,
sizeof(map->pr_mapname));
free(kves);
return (map);
}
}
free(kves);
return (NULL);
}
for (i = 0; i < p->nobjs; i++) {
rdl = &p->rdobjs[i];
if (addr >= rdl->rdl_saddr && addr <= rdl->rdl_eaddr) {
if ((map = malloc(sizeof(*map))) == NULL)
return (NULL);
proc_rdl2prmap(rdl, map);
return (map);
}
}
return (NULL);
}
int
proc_addr2sym(struct proc_handle *p, uintptr_t addr, char *name,
size_t namesz, GElf_Sym *symcopy)
{
Elf *e;
Elf_Scn *scn, *dynsymscn = NULL, *symtabscn = NULL;
Elf_Data *data;
GElf_Shdr shdr;
GElf_Sym sym;
GElf_Ehdr ehdr;
int fd, error = -1;
size_t i;
uint64_t rsym;
prmap_t *map;
char *s;
unsigned long symtabstridx = 0, dynsymstridx = 0;
if ((map = proc_addr2map(p, addr)) == NULL)
return (-1);
if (!map->pr_mapname || (fd = open(map->pr_mapname, O_RDONLY, 0)) < 0) {
warn("ERROR: open %s failed", map->pr_mapname);
goto err0;
}
if ((e = elf_begin(fd, ELF_C_READ, NULL)) == NULL) {
warn("ERROR: elf_begin() failed");
goto err1;
}
if (gelf_getehdr(e, &ehdr) == NULL) {
warn("ERROR: gelf_getehdr() failed");
goto err2;
}
/*
* Find the index of the STRTAB and SYMTAB sections to locate
* symbol names.
*/
scn = NULL;
while ((scn = elf_nextscn(e, scn)) != NULL) {
gelf_getshdr(scn, &shdr);
switch (shdr.sh_type) {
case SHT_SYMTAB:
symtabscn = scn;
symtabstridx = shdr.sh_link;
break;
case SHT_DYNSYM:
dynsymscn = scn;
dynsymstridx = shdr.sh_link;
break;
default:
break;
}
}
/*
* Iterate over the Dynamic Symbols table to find the symbol.
* Then look up the string name in STRTAB (.dynstr)
*/
if ((data = elf_getdata(dynsymscn, NULL)) == NULL) {
DPRINTF("ERROR: elf_getdata() failed");
goto err2;
}
i = 0;
while (gelf_getsym(data, i++, &sym) != NULL) {
/*
* Calculate the address mapped to the virtual memory
* by rtld.
*/
rsym = map->pr_vaddr + sym.st_value;
if (addr >= rsym && addr <= (rsym + sym.st_size)) {
s = elf_strptr(e, dynsymstridx, sym.st_name);
if (s) {
strlcpy(name, s, namesz);
memcpy(symcopy, &sym, sizeof(sym));
/*
* DTrace expects the st_value to contain
* only the address relative to the start of
* the function.
*/
symcopy->st_value = rsym;
error = 0;
goto out;
}
}
}
/*
* Iterate over the Symbols Table to find the symbol.
* Then look up the string name in STRTAB (.dynstr)
*/
if (symtabscn == NULL)
goto err2;
if ((data = elf_getdata(symtabscn, NULL)) == NULL) {
DPRINTF("ERROR: elf_getdata() failed");
goto err2;
}
i = 0;
while (gelf_getsym(data, i++, &sym) != NULL) {
/*
* Calculate the address mapped to the virtual memory
* by rtld.
*/
if (ehdr.e_type != ET_EXEC)
rsym = map->pr_vaddr + sym.st_value;
else
rsym = sym.st_value;
if (addr >= rsym && addr <= (rsym + sym.st_size)) {
s = elf_strptr(e, symtabstridx, sym.st_name);
if (s) {
strlcpy(name, s, namesz);
memcpy(symcopy, &sym, sizeof(sym));
/*
* DTrace expects the st_value to contain
* only the address relative to the start of
* the function.
*/
symcopy->st_value = rsym;
error = 0;
goto out;
}
}
}
out:
err2:
elf_end(e);
err1:
close(fd);
err0:
free(map);
return (error);
}
prmap_t *
proc_name2map(struct proc_handle *p, const char *name)
{
size_t i;
int cnt;
prmap_t *map;
char tmppath[MAXPATHLEN];
struct kinfo_vmentry *kves, *kve;
rd_loadobj_t *rdl;
/*
* If we haven't iterated over the list of loaded objects,
* librtld_db isn't yet initialized and it's very likely
* that librtld_db called us. We need to do the heavy
* lifting here to find the symbol librtld_db is looking for.
*/
if (p->nobjs == 0) {
if ((kves = kinfo_getvmmap(proc_getpid(p), &cnt)) == NULL)
return (NULL);
for (i = 0; i < (size_t)cnt; i++) {
kve = kves + i;
basename_r(kve->kve_path, tmppath);
if (strcmp(tmppath, name) == 0) {
map = proc_addr2map(p, kve->kve_start);
free(kves);
return (map);
}
}
free(kves);
return (NULL);
}
if (name == NULL || strcmp(name, "a.out") == 0) {
map = proc_addr2map(p, p->rdobjs[0].rdl_saddr);
return (map);
}
for (i = 0; i < p->nobjs; i++) {
rdl = &p->rdobjs[i];
basename_r(rdl->rdl_path, tmppath);
if (strcmp(tmppath, name) == 0) {
if ((map = malloc(sizeof(*map))) == NULL)
return (NULL);
proc_rdl2prmap(rdl, map);
return (map);
}
}
return (NULL);
}
int
proc_name2sym(struct proc_handle *p, const char *object, const char *symbol,
GElf_Sym *symcopy)
{
Elf *e;
Elf_Scn *scn, *dynsymscn = NULL, *symtabscn = NULL;
Elf_Data *data;
GElf_Shdr shdr;
GElf_Sym sym;
GElf_Ehdr ehdr;
int fd, error = -1;
size_t i;
prmap_t *map;
char *s;
unsigned long symtabstridx = 0, dynsymstridx = 0;
if ((map = proc_name2map(p, object)) == NULL) {
DPRINTF("ERROR: couldn't find object %s", object);
goto err0;
}
if ((fd = open(map->pr_mapname, O_RDONLY, 0)) < 0) {
DPRINTF("ERROR: open %s failed", map->pr_mapname);
goto err0;
}
if ((e = elf_begin(fd, ELF_C_READ, NULL)) == NULL) {
warn("ERROR: elf_begin() failed");
goto err1;
}
if (gelf_getehdr(e, &ehdr) == NULL) {
warn("ERROR: gelf_getehdr() failed");
goto err2;
}
/*
* Find the index of the STRTAB and SYMTAB sections to locate
* symbol names.
*/
scn = NULL;
while ((scn = elf_nextscn(e, scn)) != NULL) {
gelf_getshdr(scn, &shdr);
switch (shdr.sh_type) {
case SHT_SYMTAB:
symtabscn = scn;
symtabstridx = shdr.sh_link;
break;
case SHT_DYNSYM:
dynsymscn = scn;
dynsymstridx = shdr.sh_link;
break;
default:
break;
}
}
/*
* Iterate over the Dynamic Symbols table to find the symbol.
* Then look up the string name in STRTAB (.dynstr)
*/
if ((data = elf_getdata(dynsymscn, NULL)) == NULL) {
DPRINTF("ERROR: elf_getdata() failed");
goto err2;
}
i = 0;
while (gelf_getsym(data, i++, &sym) != NULL) {
s = elf_strptr(e, dynsymstridx, sym.st_name);
if (s && strcmp(s, symbol) == 0) {
memcpy(symcopy, &sym, sizeof(sym));
symcopy->st_value = map->pr_vaddr + sym.st_value;
error = 0;
goto out;
}
}
/*
* Iterate over the Symbols Table to find the symbol.
* Then look up the string name in STRTAB (.dynstr)
*/
if (symtabscn == NULL)
goto err2;
if ((data = elf_getdata(symtabscn, NULL)) == NULL) {
DPRINTF("ERROR: elf_getdata() failed");
goto err2;
}
i = 0;
while (gelf_getsym(data, i++, &sym) != NULL) {
s = elf_strptr(e, symtabstridx, sym.st_name);
if (s && strcmp(s, symbol) == 0) {
memcpy(symcopy, &sym, sizeof(sym));
error = 0;
goto out;
}
}
out:
err2:
elf_end(e);
err1:
close(fd);
err0:
free(map);
return (error);
}
int
proc_iter_symbyaddr(struct proc_handle *p, const char *object, int which,
int mask, proc_sym_f *func, void *cd)
{
Elf *e;
int i, fd;
prmap_t *map;
Elf_Scn *scn, *foundscn = NULL;
Elf_Data *data;
GElf_Shdr shdr;
GElf_Sym sym;
unsigned long stridx = -1;
char *s;
int error = -1;
if ((map = proc_name2map(p, object)) == NULL)
return (-1);
if ((fd = open(map->pr_mapname, O_RDONLY)) < 0) {
warn("ERROR: open %s failed", map->pr_mapname);
goto err0;
}
if ((e = elf_begin(fd, ELF_C_READ, NULL)) == NULL) {
warn("ERROR: elf_begin() failed");
goto err1;
}
/*
* Find the section we are looking for.
*/
scn = NULL;
while ((scn = elf_nextscn(e, scn)) != NULL) {
gelf_getshdr(scn, &shdr);
if (which == PR_SYMTAB &&
shdr.sh_type == SHT_SYMTAB) {
foundscn = scn;
break;
} else if (which == PR_DYNSYM &&
shdr.sh_type == SHT_DYNSYM) {
foundscn = scn;
break;
}
}
if (!foundscn)
return (-1);
stridx = shdr.sh_link;
if ((data = elf_getdata(foundscn, NULL)) == NULL) {
DPRINTF("ERROR: elf_getdata() failed");
goto err2;
}
i = 0;
while (gelf_getsym(data, i++, &sym) != NULL) {
if (GELF_ST_BIND(sym.st_info) == STB_LOCAL &&
(mask & BIND_LOCAL) == 0)
continue;
if (GELF_ST_BIND(sym.st_info) == STB_GLOBAL &&
(mask & BIND_GLOBAL) == 0)
continue;
if (GELF_ST_BIND(sym.st_info) == STB_WEAK &&
(mask & BIND_WEAK) == 0)
continue;
if (GELF_ST_TYPE(sym.st_info) == STT_NOTYPE &&
(mask & TYPE_NOTYPE) == 0)
continue;
if (GELF_ST_TYPE(sym.st_info) == STT_OBJECT &&
(mask & TYPE_OBJECT) == 0)
continue;
if (GELF_ST_TYPE(sym.st_info) == STT_FUNC &&
(mask & TYPE_FUNC) == 0)
continue;
if (GELF_ST_TYPE(sym.st_info) == STT_SECTION &&
(mask & TYPE_SECTION) == 0)
continue;
if (GELF_ST_TYPE(sym.st_info) == STT_FILE &&
(mask & TYPE_FILE) == 0)
continue;
s = elf_strptr(e, stridx, sym.st_name);
sym.st_value += map->pr_vaddr;
(*func)(cd, &sym, s);
}
error = 0;
err2:
elf_end(e);
err1:
close(fd);
err0:
free(map);
return (error);
}