#include <sys/cdefs.h>
__RCSID("$NetBSD: t_rtld_r_debug.c,v 1.12 2025/04/16 12:05:52 riastradh Exp $");
#include <sys/types.h>
#include <atf-c.h>
#include <dlfcn.h>
#include <link_elf.h>
#include <stdbool.h>
#include "h_macros.h"
static long int
getauxval(unsigned int type)
{
const AuxInfo *aux;
for (aux = _dlauxinfo(); aux->a_type != AT_NULL; ++aux) {
if (type == aux->a_type)
return aux->a_v;
}
return 0;
}
static Elf_Dyn *
get_dynamic_section(void)
{
uintptr_t relocbase = (uintptr_t)~0U;
const Elf_Phdr *phdr;
Elf_Half phnum;
const Elf_Phdr *phlimit, *dynphdr;
phdr = (void *)getauxval(AT_PHDR);
phnum = (Elf_Half)getauxval(AT_PHNUM);
printf("AT_PHDR=%p\n", phdr);
printf("AT_PHNUM=%d\n", phnum);
ATF_REQUIRE(phdr != NULL);
ATF_REQUIRE(phnum != (Elf_Half)~0);
phlimit = phdr + phnum;
dynphdr = NULL;
for (; phdr < phlimit; ++phdr) {
printf("phdr %p: type=%d flags=0x%x"
" vaddr=0x%lx paddr=0x%lx"
" filesz=0x%lx memsz=0x%lx"
" align=0x%lx\n",
phdr, phdr->p_type, phdr->p_flags,
(long)phdr->p_vaddr, (long)phdr->p_paddr,
(long)phdr->p_filesz, (long)phdr->p_memsz,
(long)phdr->p_align);
if (phdr->p_type == PT_DYNAMIC)
dynphdr = phdr;
if (phdr->p_type == PT_PHDR)
relocbase = (uintptr_t)phdr - phdr->p_vaddr;
}
return (Elf_Dyn *)((uint8_t *)dynphdr->p_vaddr + relocbase);
}
static const struct r_debug *
get_rtld_r_debug(void)
{
const struct r_debug *debug = NULL;
Elf_Dyn *dynp;
for (dynp = get_dynamic_section(); dynp->d_tag != DT_NULL; dynp++) {
printf("dynp %p: tag=%ld val=0x%lx\n", dynp,
(long)dynp->d_tag, (long)dynp->d_un.d_val);
#ifdef __mips__
if (dynp->d_tag == DT_MIPS_RLD_MAP) {
debug = (const void *)*(Elf_Addr *)dynp->d_un.d_ptr;
break;
}
if (dynp->d_tag == DT_MIPS_RLD_MAP_REL) {
debug = (const void *)*(Elf_Addr *)((Elf_Addr)dynp +
dynp->d_un.d_val);
break;
}
#else
if (dynp->d_tag == DT_DEBUG) {
debug = (void *)dynp->d_un.d_val;
break;
}
#endif
}
ATF_REQUIRE(debug != NULL);
return debug;
}
static void
check_r_debug_return_link_map(const char *name, const struct link_map **rmap)
{
const struct r_debug *debug;
const struct link_map *map;
void *loader;
bool found;
loader = NULL;
debug = get_rtld_r_debug();
ATF_REQUIRE(debug != NULL);
ATF_CHECK_EQ_MSG(debug->r_version, R_DEBUG_VERSION,
"debug->r_version=%d R_DEBUG_VERSION=%d",
debug->r_version, R_DEBUG_VERSION);
map = debug->r_map;
ATF_CHECK(map != NULL);
for (found = false; map; map = map->l_next) {
if (strstr(map->l_name, name) != NULL) {
if (rmap)
*rmap = map;
found = true;
} else if (strstr(map->l_name, "ld.elf_so") != NULL) {
loader = (void *)map->l_addr;
}
}
ATF_CHECK(found);
ATF_CHECK(loader != NULL);
ATF_CHECK(debug->r_brk != NULL);
ATF_CHECK_EQ_MSG(debug->r_state, RT_CONSISTENT,
"debug->r_state=%d RT_CONSISTENT=%d",
debug->r_state, RT_CONSISTENT);
ATF_CHECK_EQ_MSG(debug->r_ldbase, loader,
"debug->r_ldbase=%p loader=%p",
debug->r_ldbase, loader);
}
ATF_TC(self);
ATF_TC_HEAD(self, tc)
{
atf_tc_set_md_var(tc, "descr", "check whether r_debug is well-formed");
}
ATF_TC_BODY(self, tc)
{
check_r_debug_return_link_map("t_rtld_r_debug", NULL);
}
ATF_TC(dlopen);
ATF_TC_HEAD(dlopen, tc)
{
atf_tc_set_md_var(tc, "descr",
"check whether r_debug is well-formed after a dlopen(3) call");
}
ATF_TC_BODY(dlopen, tc)
{
void *handle;
const struct link_map *r_map, *map;
handle = dlopen("libutil.so", RTLD_LAZY);
ATF_REQUIRE_MSG(handle, "dlopen: %s", dlerror());
check_r_debug_return_link_map("libutil.so", &r_map);
ATF_REQUIRE_EQ_MSG(dlinfo(handle, RTLD_DI_LINKMAP, &map), 0,
"dlinfo: %s", dlerror());
ATF_CHECK_EQ_MSG(map, r_map, "map=%p r_map=%p", map, r_map);
ATF_CHECK_EQ_MSG(dlclose(handle), 0, "dlclose: %s", dlerror());
}
ATF_TP_ADD_TCS(tp)
{
ATF_TP_ADD_TC(tp, self);
ATF_TP_ADD_TC(tp, dlopen);
return atf_no_error();
}