syscalls: chdir

kernel-src/arch/x86-64/syscall.asm

@@ -20,6 +20,7 @@ extern syscall_dup
 extern syscall_dup2
 extern syscall_dup3
 extern syscall_fcntl
+extern syscall_chdir
 syscalltab:
 dq syscall_print
 dq syscall_mmap
@@ -42,7 +43,8 @@ dq syscall_dup
 dq syscall_dup2
 dq syscall_dup3
 dq syscall_fcntl
-syscallcount equ 21
+dq syscall_chdir
+syscallcount equ 22
 section .text
 global arch_syscall_entry
 ; on entry:

kernel-src/sys/syscalls/chdir.c

@@ -0,0 +1,43 @@
+#include <kernel/syscalls.h>
+#include <kernel/scheduler.h>
+#include <kernel/vfs.h>
+#include <kernel/alloc.h>
+#include <errno.h>
+
+syscallret_t syscall_chdir(context_t *, const char *upath) {
+	syscallret_t ret = {
+		.ret = -1
+	};
+
+	if (upath > (char *)USERSPACE_END) {
+		ret.errno = EFAULT;
+		return ret;
+	}
+
+	// TODO safe string ops
+	char *path = alloc(strlen(upath) + 1);
+	strcpy(path, upath);
+
+	vnode_t *ref = path[0] == '/' ? sched_getroot() : sched_getcwd();
+	vnode_t *new = NULL;
+
+	ret.errno = vfs_lookup(&new, ref, path, NULL, 0);
+	if (ret.errno)
+		goto cleanup;
+
+	if (new->type != V_TYPE_DIR) {
+		ret.errno = ENOTDIR;
+		goto cleanup;
+	}
+
+	sched_setcwd(new);
+
+	cleanup:
+	if (new)
+		VOP_RELEASE(new);
+
+	free(path);
+	VOP_RELEASE(ref);
+
+	return ret;
+}

patches/mlibc/jinx-working-patch.patch

@@ -133,10 +133,10 @@ index 0000000..e5b087a
 +
 diff --git mlibc-workdir/sysdeps/astral/generic/generic.cpp mlibc-workdir/sysdeps/astral/generic/generic.cpp
 new file mode 100644
-index 0000000..74b6be1
+index 0000000..ce76c73
 --- /dev/null
 +++ mlibc-workdir/sysdeps/astral/generic/generic.cpp
-@@ -0,0 +1,226 @@
+@@ -0,0 +1,231 @@
 +#include <bits/ensure.h>
 +#include <mlibc/debug.hpp>
 +#include <mlibc/all-sysdeps.hpp>
@@ -192,6 +192,11 @@ index 0000000..74b6be1
 +		return 0;
 +	}
 +
++	int sys_chdir(const char *path) {
++		long ret;
++		return syscall(SYSCALL_CHDIR, &ret, (uint64_t)path);
++	}
++
 +	int sys_fcntl(int fd, int request, va_list args, int *result) {
 +		long arg = va_arg(args, uint64_t);
 +		long ret;
@@ -382,10 +387,10 @@ index 0000000..990eca0
 +#endif
 diff --git mlibc-workdir/sysdeps/astral/include/astral/syscall.h mlibc-workdir/sysdeps/astral/include/astral/syscall.h
 new file mode 100644
-index 0000000..f884f36
+index 0000000..e768d90
 --- /dev/null
 +++ mlibc-workdir/sysdeps/astral/include/astral/syscall.h
-@@ -0,0 +1,44 @@
+@@ -0,0 +1,45 @@
 +#ifndef _SYSCALL_H_INCLUDE
 +#define _SYSCALL_H_INCLUDE
 +
@@ -410,6 +415,7 @@ index 0000000..f884f36
 +#define SYSCALL_DUP2 18
 +#define SYSCALL_DUP3 19
 +#define SYSCALL_FCNTL 20
++#define SYSCALL_CHDIR 21
 +
 +#include <stddef.h>
 +#include <stdint.h>