Re: [PATCH v1] futex: Add compat_sys_futex_waitv for 32bit compatibility

[André Almeida]

[+CC Arnd]

Hi Wei,

Em 23/11/2023 02:31, Wei Gao escreveu:
> From: wei gao <wegao@xxxxxxxx>
>
> Current implementation lead LTP test case futex_waitv failed when compiled with
> -m32. This patch add new compat_sys_futex_waitv to handle m32 mode syscall.
>
> The failure reason is futex_waitv in m32 mode will deliver kernel with struct
> old_timespec32 timeout, but this struct type can not directly used by current
> sys_futex_waitv implementation.
>
> The new function copy main logic of current sys_futex_waitv, just update parameter
> type from "struct __kernel_timespec __user *" to "struct old_timespec32 __user *,"
> and use get_old_timespec32 within the new function to get timeout value.

From, what I recall, we don't want to add new syscalls with 
old_timespec32, giving that they will have a limited lifetime. Instead, 
userspace should be able to come up with a 64-bit timespec 
implementation for -m32.

Thanks,
	André