Add /lib/ld execution for dynamic binaries

arch/amd64/binfmt_elf.c

@@ -104,6 +104,39 @@ int binfmt_is_elf(const char *ident, size_t len) {
     return !strncmp(ident, "\x7F""ELF", 4);
 }
 
+int elf_is_dynamic(struct vfs_ioctx *ioctx, struct ofile *fd, int *is_dynamic) {
+    Elf64_Ehdr ehdr;
+    Elf64_Phdr phdr;
+    int res;
+
+    *is_dynamic = 0;
+
+    if ((res = elf_read(ioctx, fd, 0, &ehdr, sizeof(Elf64_Ehdr))) != 0) {
+        return res;
+    }
+
+    if (ehdr.e_ident[EI_CLASS] != ELFCLASS64) {
+        return -ENOEXEC;
+    }
+
+    for (size_t i = 0; i < ehdr.e_phnum; ++i) {
+        if ((res = elf_read(ioctx,
+                            fd,
+                            ehdr.e_phoff + i * ehdr.e_phentsize,
+                            &phdr,
+                            ehdr.e_phentsize)) != 0) {
+            return res;
+        }
+
+        if (phdr.p_type == PT_DYNAMIC) {
+            *is_dynamic = 1;
+            break;
+        }
+    }
+
+    return 0;
+}
+
 int elf_load(struct process *proc, struct vfs_ioctx *ctx, struct ofile *fd, uintptr_t *entry) {
     int res;
     ssize_t bread;

include/sys/binfmt_elf.h

@@ -6,3 +6,4 @@ struct ofile;
 
 int elf_load(struct process *proc, struct vfs_ioctx *ctx, struct ofile *fd, uintptr_t *entry);
 int binfmt_is_elf(const char *guess, size_t len);
+int elf_is_dynamic(struct vfs_ioctx *ioctx, struct ofile *fd, int *is_dynamic);

sys/execve.c

@@ -171,12 +171,32 @@ int sys_execve(const char *path, const char **argv, const char **envp) {
             }
             argv_new[argc] = NULL;
 
-            for (int i = 0; i < argc; ++i) {
-                kdebug("[%d]: %s\n", i, argv_new[i]);
-            }
-
             return sys_execve(shebang + 2, argv_new, envp);
         }
+    } else {
+        int is_dynamic = 0;
+        if ((res = elf_is_dynamic(&proc->ioctx, &fd, &is_dynamic)) != 0) {
+            kerror("%s: %s\n", path, kstrerror(res));
+            vfs_close(&proc->ioctx, &fd);
+            return -EINVAL;
+        }
+
+        if (is_dynamic) {
+            vfs_close(&proc->ioctx, &fd);
+
+            int argc;
+            for (argc = 0; argv[argc]; ++argc);
+
+            const char *argv_new[argc + 3];
+            argv_new[0] = "/lib/ld";
+            argv_new[1] = path;
+            for (int i = 0; i < argc; ++i) {
+                argv_new[i + 2] = argv[i];
+            }
+            argv_new[argc + 2] = NULL;
+
+            return sys_execve(argv_new[0], argv_new, envp);
+        }
     }
 
     const char *e = strrchr(path, '/');