kernel: seek syscall

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

@@ -3,12 +3,14 @@ extern syscall_print
 extern syscall_mmap
 extern syscall_openat
 extern syscall_read
+extern syscall_seek
 syscalltab:
 dq syscall_print
 dq syscall_mmap
 dq syscall_openat
 dq syscall_read
-syscallcount equ 4
+dq syscall_seek
+syscallcount equ 5
 section .text
 global arch_syscall_entry
 ; on entry:

kernel-src/sys/syscalls/seek.c

@@ -0,0 +1,68 @@
+#include <kernel/syscalls.h>
+#include <kernel/file.h>
+#include <kernel/vfs.h>
+#include <errno.h>
+
+#define SEEK_SET 0
+#define SEEK_CUR 1
+#define SEEK_END 2
+
+syscallret_t syscall_seek(context_t *context, int fd, off_t offset, int whence) {
+	syscallret_t ret = {
+		.ret = -1
+	};
+
+	if (whence > 2) {
+		ret.errno = EINVAL;
+		return ret;
+	}
+
+	file_t *file = fd_get(fd);
+	if (file == NULL) {
+		ret.errno = EBADF;
+		return ret;
+	}
+
+	if (file->vnode->type == V_TYPE_SOCKET || file->vnode->type == V_TYPE_FIFO) {
+		ret.errno = ESPIPE;
+		goto cleanup;
+	}
+
+	// TODO device check seek
+
+	switch (whence) {
+		case SEEK_SET:
+		file->offset = offset;
+		break;
+		case SEEK_CUR: {
+			uintmax_t newoffset = file->offset + offset;
+			if (offset > 0 && newoffset < file->offset) {
+				ret.errno = EOVERFLOW;
+				goto cleanup;
+			}
+			if (offset < 0 && newoffset > file->offset) {
+				ret.errno = EINVAL;
+				goto cleanup;
+			}
+			file->offset = newoffset;
+			break;
+		}
+		case SEEK_END: {
+			vattr_t attr;
+			VOP_LOCK(file->vnode);
+			ret.errno = VOP_GETATTR(file->vnode, &attr, &_cpu()->thread->proc->cred);
+			VOP_UNLOCK(file->vnode);
+			if (ret.errno) 
+				goto cleanup;
+			file->offset = attr.size;
+			break;
+		}
+	}
+
+	ret.ret = file->offset;
+	ret.errno = 0;
+
+	cleanup:
+	fd_release(file);
+	return ret;
+}

patches/mlibc/jinx-working-patch.patch

@@ -113,10 +113,10 @@ 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..80a5884
+index 0000000..b92f59e
 --- /dev/null
 +++ mlibc-workdir/sysdeps/astral/generic/generic.cpp
-@@ -0,0 +1,148 @@
+@@ -0,0 +1,151 @@
 +#include <bits/ensure.h>
 +#include <mlibc/debug.hpp>
 +#include <mlibc/all-sysdeps.hpp>
@@ -237,7 +237,10 @@ index 0000000..80a5884
 +		return ENOSYS;
 +	}
 +	int sys_seek(int fd, off_t offset, int whence, off_t *new_offset) {
-+		return ENOSYS;
++		long ret = 0;
++		long error = syscall(SYSCALL_SEEK, &ret, fd, offset, whence);
++		*new_offset = ret;
++		return error;
 +	}
 +	
 +	int sys_close(int fd) {
@@ -284,10 +287,10 @@ 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..17c0045
+index 0000000..1947f70
 --- /dev/null
 +++ mlibc-workdir/sysdeps/astral/include/astral/syscall.h
-@@ -0,0 +1,27 @@
+@@ -0,0 +1,28 @@
 +#ifndef _SYSCALL_H_INCLUDE
 +#define _SYSCALL_H_INCLUDE
 +
@@ -295,6 +298,7 @@ index 0000000..17c0045
 +#define SYSCALL_MMAP 1
 +#define SYSCALL_OPENAT 2
 +#define SYSCALL_READ 3
++#define SYSCALL_SEEK 4
 +
 +#include <stddef.h>
 +#include <stdint.h>