ld: implement an actual program loader

This commit is contained in:
2026-03-21 10:54:50 +00:00
parent ed138d581e
commit cc15bb54f3
14 changed files with 3123 additions and 60 deletions

View File

@@ -1,7 +1,10 @@
#define MSG_IMPLEMENTATION
#define MSG_NO_MALLOC
#include "elf.h"
#include <errno.h>
#include <fcntl.h>
#include <heap/heap.h>
#include <mango/log.h>
#include <mango/msg.h>
@@ -10,6 +13,7 @@
#include <mango/vm.h>
#include <rosetta/bootstrap.h>
#include <rosetta/fs.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@@ -17,84 +21,204 @@
#include <sys/remote.h>
#include <unistd.h>
static const char *search_paths[] = {
"/usr/lib",
};
static const size_t nr_search_paths
= sizeof search_paths / sizeof search_paths[0];
static void report_error(const char *name, int err, const char *msg, ...)
{
char buf[1024];
va_list arg;
va_start(arg, msg);
vsnprintf(buf, sizeof buf, msg, arg);
va_end(arg);
kern_tracef("%s: %s: %s", name, buf, strerror(err));
}
static const char *get_image_name(const char *path)
{
const char *last_slash = NULL;
for (size_t i = 0; path[i]; i++) {
if (path[i] == '/') {
last_slash = path + i;
}
}
return last_slash ? last_slash + 1 : path;
}
static int find_image(struct elf_image *img)
{
const char *name = img->e_leaf.l_name;
char path[4096];
for (size_t i = 0; i < nr_search_paths; i++) {
snprintf(path, sizeof path, "%s/%s", search_paths[i], name);
int fd = open(path, O_RDONLY);
if (fd < 0) {
continue;
}
kern_tracef("found %s -> %s", name, path);
img->e_fd = fd;
img->e_status = ELF_IMAGE_OPEN;
return SUCCESS;
}
return ENOENT;
}
static int load_images(struct image_list *list)
{
int status = SUCCESS;
struct image_list_iterator it;
image_list_iterator_begin(&it, list);
while (it.it_leaf) {
struct elf_image *image
= QUEUE_CONTAINER(struct elf_image, e_leaf, it.it_leaf);
kern_tracef(
"image: %s [%s]",
it.it_leaf->l_name,
elf_image_status_to_string(image->e_status));
int new_dependencies = 0;
switch (image->e_status) {
case ELF_IMAGE_NONE:
/* Find the image using its name */
status = find_image(image);
if (status != SUCCESS) {
return status;
}
case ELF_IMAGE_OPEN:
/* parse the image */
status = elf_image_parse(image);
if (status != SUCCESS) {
return status;
}
case ELF_IMAGE_PARSED:
/* load the image */
status = elf_image_load(image);
if (status != SUCCESS) {
return status;
}
case ELF_IMAGE_LOADED:
/* collect dependencies */
new_dependencies
= elf_image_collect_dependencies(image, list);
default:
break;
}
if (new_dependencies < 0) {
return -new_dependencies;
}
if (new_dependencies > 0) {
image_list_iterator_begin(&it, list);
} else {
image_list_iterator_move_next(&it);
}
}
return SUCCESS;
}
static int link_images(struct image_list *list)
{
int status = SUCCESS;
struct image_list_iterator it;
image_list_iterator_begin(&it, list);
kern_trace("linking all images");
while (it.it_leaf) {
struct elf_image *image
= QUEUE_CONTAINER(struct elf_image, e_leaf, it.it_leaf);
kern_tracef(
"image: %s [%s]",
it.it_leaf->l_name,
elf_image_status_to_string(image->e_status));
status = elf_image_link(image);
image_list_iterator_move_next(&it);
}
return SUCCESS;
}
int main(const struct rosetta_bootstrap *bs)
{
kern_logf("ld");
kern_tracef("ld");
for (size_t i = 0; i < bs->bs_argc; i++) {
kern_logf("argv[%zu]: %s", i, bs->bs_argv[i]);
kern_tracef("argv[%zu]: %s", i, bs->bs_argv[i]);
}
sys_remote_set(SYS_REMOTE_NSD, 0, 0);
const char *path = "/usr/lib/libc.so";
int flags = 4;
const char *exec_path = bs->bs_argv[1];
const char *task_name = bs->bs_argv[2];
const char *image_name = get_image_name(exec_path);
kern_logf("sending msg: open(%s, %d)", path, flags);
int fd = open(path, flags);
struct image_list images;
image_list_init(&images);
if (fd < 0) {
kern_logf(
"open(%s, %d) = %s (%s)",
path,
flags,
strerror_code(fd),
strerror(fd));
struct elf_image *exec = NULL;
int err = elf_image_open(exec_path, &exec);
if (err != SUCCESS) {
report_error(
task_name,
err,
"error while loading %s",
exec_path);
return -1;
}
kern_logf(
"open(%s, %d) = %s (%s)",
path,
flags,
strerror_code(SUCCESS),
strerror(SUCCESS));
snprintf(
exec->e_leaf.l_name,
sizeof exec->e_leaf.l_name,
"%s",
image_name);
unsigned char buf[32] = {0};
int nr = read(fd, buf, sizeof buf);
if (nr < 0) {
kern_logf("read call failed (%s)", strerror(nr));
image_list_put(&images, &exec->e_leaf);
err = load_images(&images);
if (err != SUCCESS) {
report_error(
task_name,
err,
"error while loading %s",
exec_path);
return -1;
}
kern_logf("data: %x %c %c %c", buf[0], buf[1], buf[2], buf[3]);
void *p
= mmap(NULL,
0x1000,
PROT_READ | PROT_WRITE,
MAP_ANONYMOUS | MAP_PRIVATE,
-1,
0);
if (p != MAP_FAILED) {
memset(p, 0x0, 0x1000);
kern_logf("mmap'd buffer at %p", p);
} else {
kern_logf("mmap buffer failed");
err = link_images(&images);
if (err != SUCCESS) {
report_error(
task_name,
err,
"error while loading %s",
exec_path);
return -1;
}
void *lib
= mmap(NULL, 0x2000, PROT_READ | PROT_EXEC, MAP_PRIVATE, fd, 0);
if (lib != MAP_FAILED) {
kern_logf("mmap'd %s at %p", path, lib);
unsigned char *tmp = lib;
kern_logf(
"data[0]: %x %c %c %c",
tmp[0],
tmp[1],
tmp[2],
tmp[3]);
tmp += 0x1000;
kern_logf(
"data[0x1000]: %02x %02x %02x %02x",
tmp[0],
tmp[1],
tmp[2],
tmp[3]);
} else {
kern_logf("mmap lib failed");
struct image_list_iterator it;
image_list_iterator_begin(&it, &images);
while (it.it_leaf) {
struct elf_image *image
= QUEUE_CONTAINER(struct elf_image, e_leaf, it.it_leaf);
kern_tracef(
"image: %s [%s]",
it.it_leaf->l_name,
elf_image_status_to_string(image->e_status));
image_list_iterator_move_next(&it);
}
kern_logf("ld finished");
return 0;
kern_tracef("ld finished");
int (*entry)(int, const char **)
= (int (*)(int, const char **))exec->e_entry;
return entry(bs->bs_argc - 2, bs->bs_argv + 2);
}