All supported kernels are assumed to use struct new_utsname. This is validated in test_uname().

uname(2) can for example be used in ksft_min_kernel_version() from the kernels selftest framework.

Link: https://lore.kernel.org/lkml/20240412123536.GA32444@redhat.com/ Signed-off-by: Thomas Weißschuh linux@weissschuh.net --- tools/include/nolibc/sys.h | 27 ++++++++++++++++++ tools/testing/selftests/nolibc/nolibc-test.c | 42 ++++++++++++++++++++++++++++ 2 files changed, 69 insertions(+)

diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h index dda9dffd1d74..7b82bc3cf107 100644 --- a/tools/include/nolibc/sys.h +++ b/tools/include/nolibc/sys.h @@ -22,6 +22,7 @@ #include <linux/stat.h> /* for statx() */ #include <linux/prctl.h> #include <linux/resource.h> +#include <linux/utsname.h>

#include "arch.h" #include "errno.h" @@ -1139,6 +1140,32 @@ int umount2(const char *path, int flags) }

+/* + * int uname(struct utsname *buf); + */ + +struct utsname { + char sysname[65]; + char nodename[65]; + char release[65]; + char version[65]; + char machine[65]; + char domainname[65]; +}; + +static __attribute__((unused)) +int sys_uname(struct utsname *buf) +{ + return my_syscall1(__NR_uname, buf); +} + +static __attribute__((unused)) +int uname(struct utsname *buf) +{ + return __sysret(sys_uname(buf)); +} + + /* * int unlink(const char *path); */ diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c index 6ba4f8275ac4..3c9a9bd38194 100644 --- a/tools/testing/selftests/nolibc/nolibc-test.c +++ b/tools/testing/selftests/nolibc/nolibc-test.c @@ -27,6 +27,7 @@ #include <sys/syscall.h> #include <sys/sysmacros.h> #include <sys/time.h> +#include <sys/utsname.h> #include <sys/wait.h> #include <dirent.h> #include <errno.h> @@ -761,6 +762,45 @@ int test_stat_timestamps(void) return 0; }

+int test_uname(void) +{ + struct utsname buf; + char osrelease[sizeof(buf.release)]; + ssize_t r; + int fd; + + memset(&buf.domainname, 'P', sizeof(buf.domainname)); + + if (uname(&buf)) + return 1; + + if (strncmp("Linux", buf.sysname, sizeof(buf.sysname))) + return 1; + + fd = open("/proc/sys/kernel/osrelease", O_RDONLY); + if (fd == -1) + return 1; + + r = read(fd, osrelease, sizeof(osrelease)); + if (r == -1) + return 1; + + close(fd); + + if (osrelease[r - 1] == '\n') + r--; + + /* Validate one of the later fields to ensure field sizes are correct */ + if (strncmp(osrelease, buf.release, r)) + return 1; + + /* Ensure the field domainname is set, it is missing from struct old_utsname */ + if (strnlen(buf.domainname, sizeof(buf.domainname)) == sizeof(buf.domainname)) + return 1; + + return 0; +} + int test_mmap_munmap(void) { int ret, fd, i, page_size; @@ -966,6 +1006,8 @@ int run_syscall(int min, int max) CASE_TEST(stat_fault); EXPECT_SYSER(1, stat(NULL, &stat_buf), -1, EFAULT); break; CASE_TEST(stat_timestamps); EXPECT_SYSZR(1, test_stat_timestamps()); break; CASE_TEST(symlink_root); EXPECT_SYSER(1, symlink("/", "/"), -1, EEXIST); break; + CASE_TEST(uname); EXPECT_SYSZR(1, test_uname()); break; + CASE_TEST(uname_fault); EXPECT_SYSER(1, uname(NULL), -1, EFAULT); break; CASE_TEST(unlink_root); EXPECT_SYSER(1, unlink("/"), -1, EISDIR); break; CASE_TEST(unlink_blah); EXPECT_SYSER(1, unlink("/proc/self/blah"), -1, ENOENT); break; CASE_TEST(wait_child); EXPECT_SYSER(1, wait(&tmp), -1, ECHILD); break;

--- base-commit: 4cece764965020c22cff7665b18a012006359095 change-id: 20240414-nolibc-uname-de3895a4425f

Best regards,