[PATCH v3] Make any 32-bit time based syscalls unavailable for TIMESIZE==64

[Vineet Gupta]

From: Vineet Gupta via Libc-alpha <libc-alpha@sourceware.org>

An older asm-generic syscall ABI may have kernel provide 32-bit
time syscalls, so undef them to not mix 32/64 in 64-bit time regime.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
Changes since v2
  - Made x32 safe

Changes since v1
  - don't redirect these to 64-bit variants
---
 sysdeps/unix/sysv/linux/generic/sysdep.h | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/sysdeps/unix/sysv/linux/generic/sysdep.h b/sysdeps/unix/sysv/linux/generic/sysdep.h
index 40b4b955ca1b..b83e17e1c9d1 100644
--- a/sysdeps/unix/sysv/linux/generic/sysdep.h
+++ b/sysdeps/unix/sysv/linux/generic/sysdep.h
@@ -17,6 +17,7 @@
    <https://www.gnu.org/licenses/>.  */
 
 #include <bits/wordsize.h>
+#include <bits/timesize.h>
 #include <kernel-features.h>
 #include <sysdeps/unix/sysdep.h>
 #include <sysdeps/unix/sysv/linux/sysdep.h>
@@ -25,3 +26,26 @@
 #ifdef __NR_llseek
 # define __NR__llseek __NR_llseek
 #endif
+
+#if (__TIMESIZE == 64 && __WORDSIZE == 32 \
+     && (!defined __SYSCALL_WORDSIZE || __SYSCALL_WORDSIZE == 32))
+
+/* Don't provide 32-bit time syscalls even if the kernel ABI provides
+   them (Older variants of asm-generic ABIs e.g. ARC).  */
+
+# undef __NR_futex
+# undef __NR_rt_sigtimedwait
+# undef __NR_ppoll
+# undef __NR_utimensat
+# undef __NR_pselect6
+# undef __NR_recvmmsg
+# undef __NR_semtimedop
+# undef __NR_mq_timedreceive
+# undef __NR_mq_timedsend
+# undef __NR_clock_getres
+# undef __NR_timerfd_settime
+# undef __NR_timerfd_gettime
+# undef __NR_sched_rr_get_interval
+# undef __NR_clock_adjtime
+
+#endif
-- 
2.20.1