Re: git: d07acc58d898 - main - systm: Relax __result_use_check annotations

just make it conditional on being compiled with clang

On 1/12/24, Mark Johnston <markj@freebsd.org> wrote:
> The branch main has been updated by markj:
>
> URL:
> https://cgit.FreeBSD.org/src/commit/?id=d07acc58d8987e8e1205f4a82b77e847ea2d60d3
>
> commit d07acc58d8987e8e1205f4a82b77e847ea2d60d3
> Author:     Mark Johnston <markj@FreeBSD.org>
> AuthorDate: 2024-01-12 15:07:28 +0000
> Commit:     Mark Johnston <markj@FreeBSD.org>
> CommitDate: 2024-01-12 20:56:00 +0000
>
>     systm: Relax __result_use_check annotations
>
>     When compiling with gcc, functions annotated this way can not have
> their
>     return values cast away, e.g., with `(void)copyout(...)`.  clang
> permits
>     it but gcc does not.  Since we have a number of such casts for calls
>     which copy data out of the kernel, and since failing to check for
> errors
>     when copying *in* is a much more severe bug, remove some of the
>     annotations in order to make the gcc build happy.
>
>     Reviewed by:    kib
>     Reported by:    Jenkins
>     Fixes:  8e36732e6eb5 ("systm: Annotate copyin() and related functions
> with __result_use_check")
>     Differential Revision:  https://reviews.freebsd.org/D43418
> ---
>  sys/sys/systm.h | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/sys/sys/systm.h b/sys/sys/systm.h
> index 2da177af91f0..508690cd639e 100644
> --- a/sys/sys/systm.h
> +++ b/sys/sys/systm.h
> @@ -289,9 +289,9 @@ int __result_use_check copyin(const void * __restrict
> udaddr,
>      void * _Nonnull __restrict kaddr, size_t len);
>  int __result_use_check copyin_nofault(const void * __restrict udaddr,
>      void * _Nonnull __restrict kaddr, size_t len);
> -int __result_use_check copyout(const void * _Nonnull __restrict kaddr,
> +int copyout(const void * _Nonnull __restrict kaddr,
>      void * __restrict udaddr, size_t len);
> -int __result_use_check copyout_nofault(const void * _Nonnull __restrict
> kaddr,
> +int copyout_nofault(const void * _Nonnull __restrict kaddr,
>      void * __restrict udaddr, size_t len);
>
>  #ifdef SAN_NEEDS_INTERCEPTORS
> @@ -313,11 +313,11 @@ int64_t	fuword64(volatile const void *base);
>  int __result_use_check fueword(volatile const void *base, long *val);
>  int __result_use_check fueword32(volatile const void *base, int32_t *val);
>  int __result_use_check fueword64(volatile const void *base, int64_t *val);
> -int __result_use_check subyte(volatile void *base, int byte);
> -int __result_use_check suword(volatile void *base, long word);
> -int __result_use_check suword16(volatile void *base, int word);
> -int __result_use_check suword32(volatile void *base, int32_t word);
> -int __result_use_check suword64(volatile void *base, int64_t word);
> +int subyte(volatile void *base, int byte);
> +int suword(volatile void *base, long word);
> +int suword16(volatile void *base, int word);
> +int suword32(volatile void *base, int32_t word);
> +int suword64(volatile void *base, int64_t word);
>  uint32_t casuword32(volatile uint32_t *base, uint32_t oldval, uint32_t
> newval);
>  u_long	casuword(volatile u_long *p, u_long oldval, u_long newval);
>  int	casueword32(volatile uint32_t *base, uint32_t oldval, uint32_t
> *oldvalp,
>


-- 
Mateusz Guzik <mjguzik gmail.com>