syscalls: readv writev

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

@@ -96,6 +96,8 @@ extern syscall_nice
 extern syscall_flock
 extern syscall_getcpu
 extern syscall_sysinfo
+extern syscall_writev
+extern syscall_readv
 syscalltab:
 dq syscall_print
 dq syscall_mmap
@@ -194,7 +196,9 @@ dq syscall_nice
 dq syscall_flock
 dq syscall_getcpu
 dq syscall_sysinfo
-syscallcount equ 97
+dq syscall_writev
+dq syscall_readv
+syscallcount equ 99
 section .text
 global arch_syscall_entry
 ; on entry:

kernel-src/arch/x86-64/syscalllog.c

@@ -5,7 +5,7 @@
 
 #ifdef SYSCALL_LOGGING
 
-#define SYSCALL_COUNT 97
+#define SYSCALL_COUNT 99
 #define LOGSTR(x) arch_e9_puts(x)
 
 static char *name[] = {
@@ -105,7 +105,9 @@ static char *name[] = {
 	"nice",
 	"flock",
 	"getcpu",
-	"sysinfo"
+	"sysinfo",
+	"writev",
+	"readv"
 };
 
 static char *args[] = {
@@ -206,6 +208,8 @@ static char *args[] = {
 	"fd %d op %d", // flock
 	"N/A", // getcpu
 	"ptr %p", // sysinfo
+	"fd %d iov %p iovcnt %d", // writev
+	"fd %d iov %p iovcnt %d", // readv
 };
 
 #endif

kernel-src/sys/syscalls/readv.c

@@ -0,0 +1,63 @@
+#include <kernel/syscalls.h>
+#include <kernel/vfs.h>
+#include <kernel/file.h>
+#include <arch/cpu.h>
+#include <errno.h>
+#include <logging.h>
+#include <kernel/alloc.h>
+
+syscallret_t syscall_readv(context_t *context, int fd, iovec_t *uiov, int iovec_count) {
+	syscallret_t ret = {
+		.ret = -1
+	};
+	file_t *file = NULL;
+
+	iovec_t *iovec = alloc(sizeof(iovec_t) * iovec_count);
+	if (iovec == NULL) {
+		ret.errno = ENOMEM;
+		return ret;
+	}
+
+	ret.errno = usercopy_fromuser(iovec, uiov, sizeof(iovec_t) * iovec_count);
+	if (ret.errno)
+		goto cleanup;
+
+	size_t buffer_size = iovec_size(iovec, iovec_count);
+	if (buffer_size == 0) {
+		ret.errno = 0;
+		ret.ret = 0;
+		goto cleanup;
+	}
+
+	if (iovec_user_check(iovec, iovec_count) == false) {
+		ret.errno = EFAULT;
+		goto cleanup;
+	}
+
+	file = fd_get(fd);
+	if (file == NULL || (file->flags & FILE_READ) == 0) {
+		ret.errno = EBADF;
+		goto cleanup;
+	}
+
+	iovec_iterator_t iovec_iterator;
+	iovec_iterator_init(&iovec_iterator, iovec, iovec_count);
+
+	size_t bytes_read;
+	uintmax_t offset = file->offset;
+	ret.errno = vfs_read_iovec(file->vnode, &iovec_iterator, buffer_size, offset, &bytes_read, fileflagstovnodeflags(file->flags));
+
+	if (ret.errno)
+		goto cleanup;
+
+	file->offset = offset + bytes_read;
+	ret.ret = bytes_read;
+
+cleanup:
+	if (file)
+		fd_release(file);
+
+	free(iovec);
+
+	return ret;
+}

kernel-src/sys/syscalls/writev.c

@@ -0,0 +1,75 @@
+#include <kernel/syscalls.h>
+#include <kernel/vfs.h>
+#include <kernel/file.h>
+#include <arch/cpu.h>
+#include <errno.h>
+#include <logging.h>
+#include <kernel/alloc.h>
+
+syscallret_t syscall_writev(context_t *context, int fd, iovec_t *uiov, int iovec_count) {
+	syscallret_t ret = {
+		.ret = -1
+	};
+	file_t *file = NULL;
+
+	iovec_t *iovec = alloc(sizeof(iovec_t) * iovec_count);
+	if (iovec == NULL) {
+		ret.errno = ENOMEM;
+		return ret;
+	}
+
+	ret.errno = usercopy_fromuser(iovec, uiov, sizeof(iovec_t) * iovec_count);
+	if (ret.errno)
+		goto cleanup;
+
+	size_t buffer_size = iovec_size(iovec, iovec_count);
+	if (buffer_size == 0) {
+		ret.errno = 0;
+		ret.ret = 0;
+		goto cleanup;
+	}
+
+	if (iovec_user_check(iovec, iovec_count) == false) {
+		ret.errno = EFAULT;
+		goto cleanup;
+	}
+
+	file = fd_get(fd);
+	if (file == NULL || (file->flags & FILE_WRITE) == 0) {
+		ret.errno = EBADF;
+		goto cleanup;
+	}
+
+	uintmax_t offset = file->offset;
+	if (file->flags & O_APPEND) {
+		vattr_t attr;
+		// TODO racey
+		VOP_LOCK(file->vnode);
+		ret.errno = VOP_GETATTR(file->vnode, &attr, &current_thread()->proc->cred);
+		VOP_UNLOCK(file->vnode);
+		if (ret.errno)
+			goto cleanup;
+
+		offset = attr.size;
+	}
+
+	iovec_iterator_t iovec_iterator;
+	iovec_iterator_init(&iovec_iterator, iovec, iovec_count);
+
+	size_t bytes_written;
+	ret.errno = vfs_write_iovec(file->vnode, &iovec_iterator, buffer_size, offset, &bytes_written, fileflagstovnodeflags(file->flags));
+
+	if (ret.errno)
+		goto cleanup;
+
+	file->offset = offset + bytes_written;
+	ret.ret = bytes_written;
+
+cleanup:
+	if (file)
+		fd_release(file);
+
+	free(iovec);
+
+	return ret;
+}