Re: [PATCH 2/2] xen/bug: Complete outstanding TODO

[Julien Grall <julien@xxxxxxx>]

Hi Andrew,

On 15/12/2023 18:14, Andrew Cooper wrote:
> Since this TODO was written, BUILD_BUG_ON() has been moved out of xen/lib.h
> into xen/macros.h, which has done all the hard work.
>
> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> ---
> CC: George Dunlap <George.Dunlap@xxxxxxxxxx>
> CC: Jan Beulich <JBeulich@xxxxxxxx>
> CC: Stefano Stabellini <sstabellini@xxxxxxxxxx>
> CC: Wei Liu <wl@xxxxxxx>
> CC: Julien Grall <julien@xxxxxxx>
> CC: Federico Serafini <federico.serafini@xxxxxxxxxxx>
> ---
>   xen/include/xen/bug.h | 16 +++++++---------
>   1 file changed, 7 insertions(+), 9 deletions(-)
>
> diff --git a/xen/include/xen/bug.h b/xen/include/xen/bug.h
> index cb5138410ea7..8cca4486a477 100644
> --- a/xen/include/xen/bug.h
> +++ b/xen/include/xen/bug.h
> @@ -20,7 +20,8 @@
>   #define BUG_DEBUGGER_TRAP_FATAL(regs) 0
>   #endif
>   
> -#include <xen/lib.h>
> +#include <xen/macros.h>
> +#include <xen/types.h>
>   
>   #ifndef BUG_FRAME_STRUCT
>   
> @@ -104,14 +105,11 @@ typedef void bug_fn_t(const struct cpu_user_regs *regs);
>   
>   #ifndef run_in_exception_handler
>   
> -/*
> - * TODO: untangle header dependences, break BUILD_BUG_ON() out of xen/lib.h,
> - * and use a real static inline here to get proper type checking of fn().
> - */
> -#define run_in_exception_handler(fn) do {                   \
> -    (void)((fn) == (void (*)(struct cpu_user_regs *))NULL); \
> -    BUG_FRAME(BUGFRAME_run_fn, 0, fn, 0, NULL);             \
> -} while ( false )
> +static void always_inline run_in_exception_handler(
> +    void (*fn)(struct cpu_user_regs *regs))
Based on the other threads, shouldn't this be using bug_fn_t?

Also coding style NIT: I was under the impression we would format 
prototype like that:
static void always_inline
run_in_exception_handler(void (*fn)(struct cpu_user_regs *regs))

Anyway, that comment would be moot if we were using bug_fn_t.

Cheers,

--
Julien Grall