tools/nolibc: Implement poll() based on ppoll()

Some architectures like arm64 do not implement poll() and have to use
ppoll() instead. This commit therefore makes poll() use ppoll() when
available. This is a port of nolibc's upstream commit 800f75c13ede to
the Linux kernel.

Fixes: 66b6f755ad45 ("rcutorture: Import a copy of nolibc")
Tested-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com> [arm64]
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

diff --git a/tools/include/nolibc/nolibc.h b/tools/include/nolibc/nolibc.h
index fdd5524e0e543b68ee7ff24ff845d755a89829b7..833693faf53c35604c241a7bceb52bd580f188d6 100644 (file)
--- a/tools/include/nolibc/nolibc.h
+++ b/tools/include/nolibc/nolibc.h
@@ -1652,7 +1652,17 @@ int sys_pivot_root(const char *new, const char *old)
 static __attribute__((unused))
 int sys_poll(struct pollfd *fds, int nfds, int timeout)
 {
+#if defined(__NR_ppoll)
+       struct timespec t;
+
+       if (timeout >= 0) {
+               t.tv_sec  = timeout / 1000;
+               t.tv_nsec = (timeout % 1000) * 1000000;
+       }
+       return my_syscall4(__NR_ppoll, fds, nfds, (timeout >= 0) ? &t : NULL, NULL);
+#else
        return my_syscall3(__NR_poll, fds, nfds, timeout);
+#endif
 }
 
 static __attribute__((unused))