On s390 the first two arguments to the clone() syscall are swapped, as documented in clone(2).

Signed-off-by: Thomas Weißschuh linux@weissschuh.net --- tools/include/nolibc/arch-s390.h | 8 ++++++++ tools/include/nolibc/sys.h | 2 ++ 2 files changed, 10 insertions(+)

diff --git a/tools/include/nolibc/arch-s390.h b/tools/include/nolibc/arch-s390.h index 6b0e54ed543d..db4ea51a4dbb 100644 --- a/tools/include/nolibc/arch-s390.h +++ b/tools/include/nolibc/arch-s390.h @@ -5,6 +5,7 @@

#ifndef _NOLIBC_ARCH_S390_H #define _NOLIBC_ARCH_S390_H +#include <asm/signal.h> #include <asm/unistd.h>

/* The struct returned by the stat() syscall, equivalent to stat64(). The @@ -223,4 +224,11 @@ void *sys_mmap(void *addr, size_t length, int prot, int flags, int fd, return (void *)my_syscall1(__NR_mmap, &args); } #define sys_mmap sys_mmap + +static __attribute__((unused)) +pid_t sys_fork(void) +{ + return my_syscall5(__NR_clone, 0, SIGCHLD, 0, 0, 0); +} +#define sys_fork sys_fork #endif // _NOLIBC_ARCH_S390_H diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h index bea9760dbd16..f5a450153a63 100644 --- a/tools/include/nolibc/sys.h +++ b/tools/include/nolibc/sys.h @@ -336,6 +336,7 @@ void exit(int status) * pid_t fork(void); */

+#ifndef sys_fork static __attribute__((unused)) pid_t sys_fork(void) { @@ -351,6 +352,7 @@ pid_t sys_fork(void) #error Neither __NR_clone nor __NR_fork defined, cannot implement sys_fork() #endif } +#endif

static __attribute__((unused)) pid_t fork(void)

On s390 the arguments to clone() which is used by fork() are different than other archs. Make sure everything works correctly.

Signed-off-by: Thomas Weißschuh linux@weissschuh.net --- tools/testing/selftests/nolibc/nolibc-test.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c index 888da60eb5ba..d294338cf141 100644 --- a/tools/testing/selftests/nolibc/nolibc-test.c +++ b/tools/testing/selftests/nolibc/nolibc-test.c @@ -474,6 +474,25 @@ static int test_getpagesize(void) return !c; }

+static int test_fork(void) +{ + int status; + pid_t pid = fork(); + + switch (pid) { + case -1: + return 1; + + case 0: + exit(123); + + default: + pid = waitpid(pid, &status, 0); + + return pid == -1 || !WIFEXITED(status) || WEXITSTATUS(status) != 123; + } +} + /* Run syscall tests between IDs <min> and <max>. * Return 0 on success, non-zero on failure. */ @@ -530,6 +549,7 @@ int run_syscall(int min, int max) CASE_TEST(dup3_0); tmp = dup3(0, 100, 0); EXPECT_SYSNE(1, tmp, -1); close(tmp); break; CASE_TEST(dup3_m1); tmp = dup3(-1, 100, 0); EXPECT_SYSER(1, tmp, -1, EBADF); if (tmp != -1) close(tmp); break; CASE_TEST(execve_root); EXPECT_SYSER(1, execve("/", (char*[]){ [0] = "/", [1] = NULL }, NULL), -1, EACCES); break; + CASE_TEST(fork); EXPECT_SYSZR(1, test_fork()); break; CASE_TEST(getdents64_root); EXPECT_SYSNE(1, test_getdents64("/"), -1); break; CASE_TEST(getdents64_null); EXPECT_SYSER(1, test_getdents64("/dev/null"), -1, ENOTDIR); break; CASE_TEST(gettimeofday_null); EXPECT_SYSZR(1, gettimeofday(NULL, NULL)); break;