Re: [PATCH v2] linux-user: Disable static assert involving __SIGRTMAX if it is missing

[Laurent Vivier <laurent@vivier.eu>]

Le 26/05/2021 à 21:02, Michael Forney a écrit :
> This check is to ensure that the loop in signal_table_init() from
> SIGRTMIN to SIGRTMAX falls within the bounds of host_to_target_signal_table
> (_NSIG). However, it is not critical, since _NSIG is already defined
> to be the one larger than the largest signal supported by the system
> (as specified in the upcoming POSIX revision[0]).
> 
> musl libc does not define __SIGRTMAX, so disabling this check when
> it is missing fixes one of the last remaining errors when building
> qemu.
> 
> [0] https://www.austingroupbugs.net/view.php?id=741
> 
> Signed-off-by: Michael Forney <mforney@mforney.org>
> ---
> Changes since v2:
> * Guard check by #ifdef __SIGRTMAX instead of removing it.
> 
>  linux-user/signal.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/linux-user/signal.c b/linux-user/signal.c
> index 9016896dcd..0f19c59dee 100644
> --- a/linux-user/signal.c
> +++ b/linux-user/signal.c
> @@ -38,7 +38,9 @@ static void host_signal_handler(int host_signum, siginfo_t *info,
>   * Signal number 0 is reserved for use as kill(pid, 0), to test whether
>   * a process exists without sending it a signal.
>   */
> +#ifdef __SIGRTMAX
>  QEMU_BUILD_BUG_ON(__SIGRTMAX + 1 != _NSIG);
> +#endif
>  static uint8_t host_to_target_signal_table[_NSIG] = {
>      [SIGHUP] = TARGET_SIGHUP,
>      [SIGINT] = TARGET_SIGINT,
> 

Reviewed-by: Laurent Vivier <laurent@vivier.eu>