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);
}
/*
* Wait for the specified process to hit a breakpoint at the specified symbol.
*/
static void
verify_bkpt(struct proc_handle *phdl, GElf_Sym *sym, const char *symname,
const char *mapname)
{
char mapbname[MAXPATHLEN], *name;
GElf_Sym tsym;
prmap_t *map;
size_t namesz;
u_long addr;
int error, state;
state = proc_wstatus(phdl);
ATF_REQUIRE_EQ_MSG(state, PS_STOP, "process has state %d", state);
/* Get the program counter and decrement it. */
error = proc_regget(phdl, REG_PC, &addr);
ATF_REQUIRE_EQ_MSG(error, 0, "failed to obtain PC for '%s'",
target_prog_file);
proc_bkptregadj(&addr);
/*
* Make sure the PC matches the expected value obtained from the symbol
* definition we looked up earlier.
*/
ATF_CHECK_EQ_MSG(addr, sym->st_value,
"program counter 0x%lx doesn't match expected value 0x%jx",
addr, (uintmax_t)sym->st_value);
/*
* Ensure we can look up the r_debug_state symbol using its starting
* address and that the resulting symbol matches the one we found using
* a name lookup.
*/
namesz = strlen(symname) + 1;
name = malloc(namesz);
ATF_REQUIRE(name != NULL);
error = proc_addr2sym(phdl, addr, name, namesz, &tsym);
ATF_REQUIRE_EQ_MSG(error, 0, "failed to look up symbol at 0x%lx", addr);
ATF_REQUIRE_EQ(memcmp(sym, &tsym, sizeof(*sym)), 0);
ATF_REQUIRE_EQ_MSG(strcmp(symname, name), 0,
"expected symbol name '%s' doesn't match '%s'", symname, name);
free(name);
map = proc_addr2map(phdl, addr);
ATF_REQUIRE_MSG(map != NULL, "failed to look up map for address 0x%lx",
addr);
basename_r(map->pr_mapname, mapbname);
ATF_REQUIRE_EQ_MSG(strcmp(mapname, mapbname), 0,
"expected map name '%s' doesn't match '%s'", mapname, mapbname);
}
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 symtab;
}
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) {
if (s[0] == '_' && s[1] == 'Z' && s[2])
demangle(s, name, namesz);
else
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;
}
}
}
symtab:
/*
* 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) {
if (s[0] == '_' && s[1] == 'Z' && s[2])
demangle(s, name, namesz);
else
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);
}
int
proc_addr2sym(struct proc_handle *p, uintptr_t addr, char *name,
size_t namesz, GElf_Sym *symcopy)
{
GElf_Ehdr ehdr;
GElf_Shdr shdr;
Elf *e;
Elf_Scn *scn, *dynsymscn = NULL, *symtabscn = NULL;
prmap_t *map;
const char *s;
uintptr_t off;
u_long symtabstridx = 0, dynsymstridx = 0;
int fd, error = -1;
if ((map = proc_addr2map(p, addr)) == NULL)
return (-1);
if ((fd = find_dbg_obj(map->pr_mapname)) < 0) {
DPRINTF("ERROR: open %s failed", map->pr_mapname);
goto err0;
}
if ((e = elf_begin(fd, ELF_C_READ, NULL)) == NULL) {
DPRINTFX("ERROR: elf_begin() failed: %s", elf_errmsg(-1));
goto err1;
}
if (gelf_getehdr(e, &ehdr) == NULL) {
DPRINTFX("ERROR: gelf_getehdr() failed: %s", elf_errmsg(-1));
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;
}
}
off = ehdr.e_type == ET_EXEC ? 0 : map->pr_vaddr;
/*
* First look up the symbol in the dynsymtab, and fall back to the
* symtab if the lookup fails.
*/
error = lookup_addr(e, dynsymscn, dynsymstridx, off, addr, &s, symcopy);
if (error == 0)
goto out;
error = lookup_addr(e, symtabscn, symtabstridx, off, addr, &s, symcopy);
if (error != 0)
goto err2;
out:
demangle(s, name, namesz);
err2:
elf_end(e);
err1:
close(fd);
err0:
free(map);
return (error);
}
