Hi, Arnd
On Wed, May 24, 2023, at 19:59, Zhangjin Wu wrote:
diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h index c0335a84f880..00c7197dcd50 100644 --- a/tools/include/nolibc/sys.h +++ b/tools/include/nolibc/sys.h @@ -1041,8 +1041,13 @@ int sys_select(int nfds, fd_set *rfds, fd_set *wfds, fd_set *efds, struct timeva 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) +#elif defined(__ARCH_WANT_SYS_PSELECT6) && (defined(__NR_pselect6) || defined(__NR_pselect6_time64)) +#ifdef __NR_pselect6 struct timespec t; +#else
- struct timespec64 t;
+#define __NR_pselect6 __NR_pselect6_time64 +#endif
Overriding the __NR_pselect6 constant seems wrong here, this can easily lead to more bugs, as pselect6 and pselect6_time64 are not compatible because of the different arguments, so anything using the constant after including sys.h will be broken.
Yes, thanks, Thomas also pointed out this issue in another reply of this message thread, it has been fixed locally with his suggestion, it looks like this:
#ifdef __NR_pselect6 struct timespec t; const long nr_pselect = __NR_pselect6; #else struct timespec64 t; const long nr_pselect = __NR_pselect6_time64; #endif
if (timeout) { t.tv_sec = timeout->tv_sec; t.tv_nsec = timeout->tv_usec * 1000; } return my_syscall6(nr_pselect, nfds, rfds, wfds, efds, timeout ? &t : NULL, NULL);
I have applied this method for ppoll_time64 and clock_gettime64 too, this method can save several duplicated lines for us, I have prepared v2 patches locally for them.
I would just use __kernel_timespec64 unconditionally and then use __NR_pselect6_time64 on all 32-bit architectures here, but use __NR_pselect6 on 32-bit architectures.
The 2nd 32-bit you mean is 64-bit?
This is related to the timespec64/time64_t definitions as you commented in another reply. I will learn how to use the one from <linux/time_types.h>, it may require to clean up the existing files in tools/include/nolibc/ at first.
I think we can also kill off the oldselect and newselect cases, using pselect6/pselect6_time64 unconditionally here, and no longer care about building against pre-5.1 kernel headers, at least for the copy of nolibc that ships with the kernel.
As Willy commented in another reply, users may want to copy the recent one and use them with an old kernel, even if want to drop them, a standalone patch may be preferable.
Thanks very much, Zhangjin
Arnd