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

Michael Forney posted 1 patch 2 years, 11 months ago
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/next-importer-push tags/patchew/20210526190203.4255-1-mforney@mforney.org
Maintainers: Laurent Vivier <laurent@vivier.eu>
linux-user/signal.c | 2 ++
1 file changed, 2 insertions(+)
[PATCH v2] linux-user: Disable static assert involving __SIGRTMAX if it is missing
Posted by Michael Forney 2 years, 11 months ago
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,
-- 
2.31.1


Re: [PATCH v2] linux-user: Disable static assert involving __SIGRTMAX if it is missing
Posted by Laurent Vivier 2 years, 11 months ago
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>