On 2025-06-10 13:29:45+0100, Mark Brown wrote:
To allow testing of vfork() support in the arm64 basic-gcs test provide an implementation for nolibc, using the vfork() syscall if one is available and otherwise clone3(). We implement in terms of clone3() since the order of the arguments for clone() varies between architectures.
Signed-off-by: Mark Brown broonie@kernel.org
tools/include/nolibc/sys.h | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+)
diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h index aabac97a7fb0..5932ae8828a1 100644 --- a/tools/include/nolibc/sys.h +++ b/tools/include/nolibc/sys.h @@ -22,6 +22,7 @@ #include <linux/time.h> #include <linux/auxvec.h> #include <linux/fcntl.h> /* for O_* and AT_* */ +#include <linux/sched.h> /* for clone_args */ #include <linux/stat.h> /* for statx() */ #include "errno.h" @@ -340,6 +341,32 @@ pid_t fork(void) return __sysret(sys_fork()); } +static __attribute__((unused)) +pid_t sys_vfork(void) +{ +#if defined(__NR_vfork)
- return my_syscall0(__NR_vfork);
+#elif defined(__NR_clone3)
- /*
* clone() could be used but has different argument orders per* architecture.*/- struct clone_args args = {
.flags = CLONE_VM | CLONE_VFORK,.exit_signal = SIGCHLD,- };
- return my_syscall2(__NR_clone3, &args, sizeof(args));
+#else
- return __nolibc_enosys(__func__);
+#endif +}
It seems that on SPARC __NR_vfork has the same non-standard return value as __NR_fork. It therefore needs the same special handling in arch-sparc.h. Maybe with a helper to avoid the duplication.
If you want I can fix this up when applying. Otherwise the series looks good.
+static __attribute__((unused)) +pid_t vfork(void) +{
- return __sysret(sys_vfork());
+} /*
- int fsync(int fd);
-- 2.39.5