[PATCH v2 09/13] tools/nolibc: sys_select: add pure 64bit select

[Zhangjin Wu <falcon@tinylab.org>]

It's time to provide 64bit time structs for all platforms, for y2038 is
near.

pselect6_time64 has been added from v4.20 and the last arch support is
at least from v5.0.0.

Suggested-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/linux-riscv/76a5f9a0-eec4-415a-9c5d-ac3bca4d4b0e@t-8ch.de/
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/linux-riscv/bf3e07c1-75f5-425b-9124-f3f2b230e63a@app.fastmail.com/
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
---
 tools/include/nolibc/arch-aarch64.h   |  3 ---
 tools/include/nolibc/arch-loongarch.h |  3 ---
 tools/include/nolibc/arch-riscv.h     |  3 ---
 tools/include/nolibc/sys.h            | 25 ++++++++++---------------
 4 files changed, 10 insertions(+), 24 deletions(-)

diff --git a/tools/include/nolibc/arch-aarch64.h b/tools/include/nolibc/arch-aarch64.h
index 11f294a406b7..53255a3a326f 100644
--- a/tools/include/nolibc/arch-aarch64.h
+++ b/tools/include/nolibc/arch-aarch64.h
@@ -47,10 +47,7 @@ struct sys_stat_struct {
  *   - the arguments are cast to long and assigned into the target registers
  *     which are then simply passed as registers to the asm code, so that we
  *     don't have to experience issues with register constraints.
- *
- * On aarch64, select() is not implemented so we have to use pselect6().
  */
-#define __ARCH_WANT_SYS_PSELECT6
 
 #define my_syscall0(num)                                                      \
 ({                                                                            \
diff --git a/tools/include/nolibc/arch-loongarch.h b/tools/include/nolibc/arch-loongarch.h
index ad3f266e7093..973fdca96651 100644
--- a/tools/include/nolibc/arch-loongarch.h
+++ b/tools/include/nolibc/arch-loongarch.h
@@ -18,10 +18,7 @@
  *   - the arguments are cast to long and assigned into the target
  *     registers which are then simply passed as registers to the asm code,
  *     so that we don't have to experience issues with register constraints.
- *
- * On LoongArch, select() is not implemented so we have to use pselect6().
  */
-#define __ARCH_WANT_SYS_PSELECT6
 
 #define my_syscall0(num)                                                      \
 ({                                                                            \
diff --git a/tools/include/nolibc/arch-riscv.h b/tools/include/nolibc/arch-riscv.h
index a2e8564e66d6..713eb9d2c91d 100644
--- a/tools/include/nolibc/arch-riscv.h
+++ b/tools/include/nolibc/arch-riscv.h
@@ -53,10 +53,7 @@ struct sys_stat_struct {
  *   - the arguments are cast to long and assigned into the target
  *     registers which are then simply passed as registers to the asm code,
  *     so that we don't have to experience issues with register constraints.
- *
- * On riscv, select() is not implemented so we have to use pselect6().
  */
-#define __ARCH_WANT_SYS_PSELECT6
 
 #define my_syscall0(num)                                                      \
 ({                                                                            \
diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
index 1b3675d4c5fc..db648b5b9a1c 100644
--- a/tools/include/nolibc/sys.h
+++ b/tools/include/nolibc/sys.h
@@ -1046,28 +1046,23 @@ int sched_yield(void)
 static __attribute__((unused))
 int sys_select(int nfds, fd_set *rfds, fd_set *wfds, fd_set *efds, struct timeval *timeout)
 {
-#if defined(__ARCH_WANT_SYS_OLD_SELECT) && !defined(__NR__newselect)
-	struct sel_arg_struct {
-		unsigned long n;
-		fd_set *r, *w, *e;
-		struct timeval *t;
-	} arg = { .n = nfds, .r = rfds, .w = wfds, .e = efds, .t = timeout };
-	return my_syscall1(__NR_select, &arg);
-#elif defined(__ARCH_WANT_SYS_PSELECT6) && defined(__NR_pselect6)
+#if defined(__NR_pselect6) || defined(__NR_pselect6_time64)
+#ifdef __NR_pselect6_time64
+	const long nr_pselect = __NR_pselect6_time64;
+#elif __SIZEOF_LONG__ == 8
+	const long nr_pselect = __NR_pselect6;
+#else
+#error No __NR_pselect6_time64 defined, cannot implement time64 sys_select()
+#endif
 	struct timespec t;
 
 	if (timeout) {
 		t.tv_sec  = timeout->tv_sec;
 		t.tv_nsec = timeout->tv_usec * 1000;
 	}
-	return my_syscall6(__NR_pselect6, nfds, rfds, wfds, efds, timeout ? &t : NULL, NULL);
-#elif defined(__NR__newselect) || defined(__NR_select)
-#ifndef __NR__newselect
-#define __NR__newselect __NR_select
-#endif
-	return my_syscall5(__NR__newselect, nfds, rfds, wfds, efds, timeout);
+	return my_syscall6(nr_pselect, nfds, rfds, wfds, efds, timeout ? &t : NULL, NULL);
 #else
-#error None of __NR_select, __NR_pselect6, nor __NR__newselect defined, cannot implement sys_select()
+#error Neither __NR_pselect6 nor __NR_pselect6_time64 defined, cannot implement sys_select()
 #endif
 }
 
-- 
2.25.1