tools/nolibc: add uio.h with readv and writev

This is generally useful and struct iovec is also needed for other
purposes such as ptrace.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>

4 files changed, 60 insertions, 0 deletions

diff --git a/tools/include/nolibc/Makefile b/tools/include/nolibc/Makefile
index 143c2d2c2ba6..9bbbba32dac6 100644
--- a/tools/include/nolibc/Makefile
+++ b/tools/include/nolibc/Makefile
@@ -62,6 +62,7 @@ all_files := \
 		sys/time.h \
 		sys/timerfd.h \
 		sys/types.h \
+		sys/uio.h \
 		sys/utsname.h \
 		sys/wait.h \
 		time.h \
diff --git a/tools/include/nolibc/nolibc.h b/tools/include/nolibc/nolibc.h
index d2f5aa085f8e..05e2d655c43e 100644
--- a/tools/include/nolibc/nolibc.h
+++ b/tools/include/nolibc/nolibc.h
@@ -109,6 +109,7 @@
 #include "sys/sysmacros.h"
 #include "sys/time.h"
 #include "sys/timerfd.h"
+#include "sys/uio.h"
 #include "sys/utsname.h"
 #include "sys/wait.h"
 #include "ctype.h"
diff --git a/tools/include/nolibc/sys/uio.h b/tools/include/nolibc/sys/uio.h
new file mode 100644
index 000000000000..7ad42b927d2f
--- /dev/null
+++ b/tools/include/nolibc/sys/uio.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * uio for NOLIBC
+ * Copyright (C) 2017-2021 Willy Tarreau <w@1wt.eu>
+ * Copyright (C) 2025 Intel Corporation
+ */
+
+/* make sure to include all global symbols */
+#include "../nolibc.h"
+
+#ifndef _NOLIBC_SYS_UIO_H
+#define _NOLIBC_SYS_UIO_H
+
+#include "../sys.h"
+#include <linux/uio.h>
+
+
+/*
+ * ssize_t readv(int fd, const struct iovec *iovec, int count);
+ */
+static __attribute__((unused))
+ssize_t sys_readv(int fd, const struct iovec *iovec, int count)
+{
+	return my_syscall3(__NR_readv, fd, iovec, count);
+}
+
+static __attribute__((unused))
+ssize_t readv(int fd, const struct iovec *iovec, int count)
+{
+	return __sysret(sys_readv(fd, iovec, count));
+}
+
+/*
+ * ssize_t writev(int fd, const struct iovec *iovec, int count);
+ */
+static __attribute__((unused))
+ssize_t sys_writev(int fd, const struct iovec *iovec, int count)
+{
+	return my_syscall3(__NR_writev, fd, iovec, count);
+}
+
+static __attribute__((unused))
+ssize_t writev(int fd, const struct iovec *iovec, int count)
+{
+	return __sysret(sys_writev(fd, iovec, count));
+}
+
+
+#endif /* _NOLIBC_SYS_UIO_H */
diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index 29de21595fc9..f1fc00d6fef5 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -25,6 +25,7 @@
 #include <sys/sysmacros.h>
 #include <sys/time.h>
 #include <sys/timerfd.h>
+#include <sys/uio.h>
 #include <sys/utsname.h>
 #include <sys/wait.h>
 #include <dirent.h>
@@ -1282,6 +1283,10 @@ int run_syscall(int min, int max)
 	int proc;
 	int test;
 	int tmp;
+	struct iovec iov_one = {
+		.iov_base = &tmp,
+		.iov_len = 1,
+	};
 	int ret = 0;
 	void *p1, *p2;
 	int has_gettid = 1;
@@ -1395,6 +1400,10 @@ int run_syscall(int min, int max)
 		CASE_TEST(waitpid_child);     EXPECT_SYSER(1, waitpid(getpid(), &tmp, WNOHANG), -1, ECHILD); break;
 		CASE_TEST(write_badf);        EXPECT_SYSER(1, write(-1, &tmp, 1), -1, EBADF); break;
 		CASE_TEST(write_zero);        EXPECT_SYSZR(1, write(1, &tmp, 0)); break;
+		CASE_TEST(readv_badf);        EXPECT_SYSER(1, readv(-1, &iov_one, 1), -1, EBADF); break;
+		CASE_TEST(readv_zero);        EXPECT_SYSZR(1, readv(1, NULL, 0)); break;
+		CASE_TEST(writev_badf);       EXPECT_SYSER(1, writev(-1, &iov_one, 1), -1, EBADF); break;
+		CASE_TEST(writev_zero);       EXPECT_SYSZR(1, writev(1, NULL, 0)); break;
 		CASE_TEST(syscall_noargs);    EXPECT_SYSEQ(1, syscall(__NR_getpid), getpid()); break;
 		CASE_TEST(syscall_args);      EXPECT_SYSER(1, syscall(__NR_statx, 0, NULL, 0, 0, NULL), -1, EFAULT); break;
 		CASE_TEST(namespace);         EXPECT_SYSZR(euid0 && proc, test_namespace()); break;