diff mbox series

[v2,12/15] tools/nolibc: add namespace functionality

Message ID 20250428-nolibc-misc-v2-12-3c043eeab06c@linutronix.de
State New
Headers show
Series tools/nolibc: various new functions | expand

Commit Message

Thomas Weißschuh April 28, 2025, 12:40 p.m. UTC 
This is used in various selftests and will be handy when integrating
those with nolibc.

Not all configurations support namespaces, so skip the tests where
necessary.  Also if the tests are running without privileges.
Enable the namespace configuration for those architectures where it is not
enabled by default.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Acked-by: Willy Tarreau <w@1wt.eu>
---
 tools/include/nolibc/Makefile                |  1 +
 tools/include/nolibc/nolibc.h                |  1 +
 tools/include/nolibc/sched.h                 | 50 +++++++++++++++++++++
 tools/testing/selftests/nolibc/Makefile      |  2 +
 tools/testing/selftests/nolibc/nolibc-test.c | 67 ++++++++++++++++++++++++++++
 5 files changed, 121 insertions(+)
diff mbox series

Patch

diff --git a/tools/include/nolibc/Makefile b/tools/include/nolibc/Makefile
index d54646387872d3b0d0158a35c4122f4713c435ce..48f89567c03fb3cbcbe1d20accb9d293056d4142 100644
--- a/tools/include/nolibc/Makefile
+++ b/tools/include/nolibc/Makefile
@@ -37,6 +37,7 @@  all_files := \
 		limits.h \
 		math.h \
 		nolibc.h \
+		sched.h \
 		signal.h \
 		stackprotector.h \
 		std.h \
diff --git a/tools/include/nolibc/nolibc.h b/tools/include/nolibc/nolibc.h
index 13628261b9cc92d545745acc9ebef541b185f2bd..d6722e22f441956e70340dcab004aa73a3125691 100644
--- a/tools/include/nolibc/nolibc.h
+++ b/tools/include/nolibc/nolibc.h
@@ -106,6 +106,7 @@ 
 #include "sys/wait.h"
 #include "ctype.h"
 #include "elf.h"
+#include "sched.h"
 #include "signal.h"
 #include "unistd.h"
 #include "stdio.h"
diff --git a/tools/include/nolibc/sched.h b/tools/include/nolibc/sched.h
new file mode 100644
index 0000000000000000000000000000000000000000..32221562c1663f6d1d78fab82bb6e8d05ad68da9
--- /dev/null
+++ b/tools/include/nolibc/sched.h
@@ -0,0 +1,50 @@ 
+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * sched function definitions for NOLIBC
+ * Copyright (C) 2025 Thomas Weißschuh <linux@weissschuh.net>
+ */
+
+/* make sure to include all global symbols */
+#include "nolibc.h"
+
+#ifndef _NOLIBC_SCHED_H
+#define _NOLIBC_SCHED_H
+
+#include "sys.h"
+
+#include <linux/sched.h>
+
+/*
+ * int setns(int fd, int nstype);
+ */
+
+static __attribute__((unused))
+int sys_setns(int fd, int nstype)
+{
+	return my_syscall2(__NR_setns, fd, nstype);
+}
+
+static __attribute__((unused))
+int setns(int fd, int nstype)
+{
+	return __sysret(sys_setns(fd, nstype));
+}
+
+
+/*
+ * int unshare(int flags);
+ */
+
+static __attribute__((unused))
+int sys_unshare(int flags)
+{
+	return my_syscall1(__NR_unshare, flags);
+}
+
+static __attribute__((unused))
+int unshare(int flags)
+{
+	return __sysret(sys_unshare(flags));
+}
+
+#endif /* _NOLIBC_SCHED_H */
diff --git a/tools/testing/selftests/nolibc/Makefile b/tools/testing/selftests/nolibc/Makefile
index 2671383045dbb51682fd62ac8c8df9c317157317..94176ffe46463548cc9bc787933b6cefa83d6502 100644
--- a/tools/testing/selftests/nolibc/Makefile
+++ b/tools/testing/selftests/nolibc/Makefile
@@ -109,6 +109,8 @@  DEFCONFIG            = $(DEFCONFIG_$(XARCH))
 
 EXTRACONFIG_m68k      = -e CONFIG_BLK_DEV_INITRD
 EXTRACONFIG           = $(EXTRACONFIG_$(XARCH))
+EXTRACONFIG_arm       = -e CONFIG_NAMESPACES
+EXTRACONFIG_armthumb  = -e CONFIG_NAMESPACES
 
 # optional tests to run (default = all)
 TEST =
diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index 665d7631fbc6e9ecae469a4b143440ec0a43d4aa..d1157319b5d715dbc94ff9203b1d2a2e932aabcf 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -1172,6 +1172,72 @@  int test_openat(void)
 	return 0;
 }
 
+int test_namespace(void)
+{
+	int original_ns, new_ns, ret;
+	ino_t original_ns_ino;
+	struct stat stat_buf;
+
+	original_ns = open("/proc/self/ns/uts", O_RDONLY);
+	if (original_ns == -1)
+		return -1;
+
+	ret = fstat(original_ns, &stat_buf);
+	if (ret)
+		goto out;
+
+	original_ns_ino = stat_buf.st_ino;
+
+	ret = unshare(CLONE_NEWUTS);
+	if (ret)
+		goto out;
+
+	new_ns = open("/proc/self/ns/uts", O_RDONLY);
+	if (new_ns == -1) {
+		ret = new_ns;
+		goto out;
+	}
+
+	ret = fstat(new_ns, &stat_buf);
+	close(new_ns);
+	if (ret)
+		goto out;
+
+	if (stat_buf.st_ino == original_ns_ino) {
+		errno = EINVAL;
+		ret = -1;
+		goto out;
+	}
+
+	ret = setns(original_ns, CLONE_NEWUTS);
+	if (ret)
+		goto out;
+
+	new_ns = open("/proc/self/ns/uts", O_RDONLY);
+	if (new_ns == -1) {
+		ret = new_ns;
+		goto out;
+	}
+
+	ret = fstat(new_ns, &stat_buf);
+	if (ret)
+		goto out;
+
+	close(new_ns);
+
+	if (stat_buf.st_ino != original_ns_ino) {
+		errno = EINVAL;
+		ret = -1;
+		goto out;
+	}
+
+	ret = 0;
+
+out:
+	close(original_ns);
+	return ret;
+}
+
 /* Run syscall tests between IDs <min> and <max>.
  * Return 0 on success, non-zero on failure.
  */
@@ -1296,6 +1362,7 @@  int run_syscall(int min, int max)
 		CASE_TEST(write_zero);        EXPECT_SYSZR(1, write(1, &tmp, 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;
 		case __LINE__:
 			return ret; /* must be last */
 		/* note: do not set any defaults so as to permit holes above */