Very limited backport of the following upstream commit, to obtain
the definition of __getrandom_nocancel.

commit 6f4e0fcfa2d2b0915816a3a3a1d48b4763a7dee2
Author: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>
Date:   Thu Jul 21 10:04:59 2022 -0300

    stdlib: Add arc4random, arc4random_buf, and arc4random_uniform (BZ #4417)

With the INTERNAL_SYSCALL_CALL change from this patch already applied:

commit 609c9d0951da387cd523b5db42a82d38dabc37c4
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Thu Sep 29 16:18:06 2022 -0300

    malloc: Do not clobber errno on __getrandom_nocancel (BZ #29624)
    
    Use INTERNAL_SYSCALL_CALL instead of INLINE_SYSCALL_CALL.  This
    requires emulate the semantic for hurd call (so __arc4random_buf
    uses the fallback).
    
    Checked on x86_64-linux-gnu.
    
    Reviewed-by: Wilco Dijkstra  <Wilco.Dijkstra@arm.com>

diff --git a/sysdeps/generic/not-cancel.h b/sysdeps/generic/not-cancel.h
index 8a3772a1fe66271e..14188041c2c0ad57 100644
--- a/sysdeps/generic/not-cancel.h
+++ b/sysdeps/generic/not-cancel.h
@@ -49,5 +49,7 @@
   (void) __writev (fd, iov, n)
 #define __fcntl64_nocancel(fd, cmd, ...) \
   __fcntl64 (fd, cmd, __VA_ARGS__)
+#define __getrandom_nocancel(buf, size, flags) \
+  __getrandom (buf, size, flags)
 
 #endif /* NOT_CANCEL_H  */
diff --git a/sysdeps/mach/hurd/not-cancel.h b/sysdeps/mach/hurd/not-cancel.h
index cd320cb721e6ff7e..7a3d2cc3532cf866 100644
--- a/sysdeps/mach/hurd/not-cancel.h
+++ b/sysdeps/mach/hurd/not-cancel.h
@@ -75,6 +75,9 @@ __typeof (__fcntl) __fcntl_nocancel;
 #define __fcntl64_nocancel(...) \
   __fcntl_nocancel (__VA_ARGS__)
 
+#define __getrandom_nocancel(buf, size, flags) \
+  __getrandom (buf, size, flags)
+
 #if IS_IN (libc)
 hidden_proto (__close_nocancel)
 hidden_proto (__close_nocancel_nostatus)
diff --git a/sysdeps/unix/sysv/linux/not-cancel.h b/sysdeps/unix/sysv/linux/not-cancel.h
index f06d57426a40227e..d2bb59acddbcfee0 100644
--- a/sysdeps/unix/sysv/linux/not-cancel.h
+++ b/sysdeps/unix/sysv/linux/not-cancel.h
@@ -68,6 +68,13 @@ __writev_nocancel_nostatus (int fd, const struct iovec *iov, int iovcnt)
   INTERNAL_SYSCALL_CALL (writev, fd, iov, iovcnt);
 }
 
+static inline int
+__getrandom_nocancel (void *buf, size_t buflen, unsigned int flags)
+{
+  return INTERNAL_SYSCALL_CALL (getrandom, buf, buflen, flags);
+}
+
+
 /* Uncancelable fcntl.  */
 __typeof (__fcntl) __fcntl64_nocancel;