move ppoll from src/linux to src/select reflecting future standardization

the ppoll function has been accepted as a future part of the standard
as the outcome of Austin Group tracker issue 1263. move the source
file to reflect this.

1 files changed, 26 insertions, 0 deletions

diff --git a/src/select/ppoll.c b/src/select/ppoll.c
new file mode 100644
index 00000000..e614600a
--- /dev/null
+++ b/src/select/ppoll.c
@@ -0,0 +1,26 @@
+#define _GNU_SOURCE
+#include <poll.h>
+#include <signal.h>
+#include <errno.h>
+#include "syscall.h"
+
+#define IS32BIT(x) !((x)+0x80000000ULL>>32)
+#define CLAMP(x) (int)(IS32BIT(x) ? (x) : 0x7fffffffU+((0ULL+(x))>>63))
+
+int ppoll(struct pollfd *fds, nfds_t n, const struct timespec *to, const sigset_t *mask)
+{
+	time_t s = to ? to->tv_sec : 0;
+	long ns = to ? to->tv_nsec : 0;
+#ifdef SYS_ppoll_time64
+	int r = -ENOSYS;
+	if (SYS_ppoll == SYS_ppoll_time64 || !IS32BIT(s))
+		r = __syscall_cp(SYS_ppoll_time64, fds, n,
+			to ? ((long long[]){s, ns}) : 0,
+			mask, _NSIG/8);
+	if (SYS_ppoll == SYS_ppoll_time64 || r != -ENOSYS)
+		return __syscall_ret(r);
+	s = CLAMP(s);
+#endif
+	return syscall_cp(SYS_ppoll, fds, n,
+		to ? ((long[]){s, ns}) : 0, mask, _NSIG/8);
+}