Re: [PATCH 17/20] x86/smap: Use named asm operands in smap_{save,restore}()

[Andrew Cooper]

On 14/03/2025 9:41 pm, Josh Poimboeuf wrote:
> @@ -50,9 +50,9 @@ static __always_inline unsigned long smap_save(void)
>  static __always_inline void smap_restore(unsigned long flags)
>  {
>  	asm volatile ("# smap_restore\n\t"
> -		      ALTERNATIVE("", "push %0; popf\n\t",
> -				  X86_FEATURE_SMAP)
> -		      : : "g" (flags) : "memory", "cc");
> +		      ALTERNATIVE("",
> +				  "push %[flags]; popf\n\t", X86_FEATURE_SMAP)
> +		      : : [flags] "g" (flags) : "memory", "cc");
>  }
>  
>  /* These macros can be used in asm() statements */

The problem with ASM_CALL_CONSTRAINT and asm_call() is that it's not
just call instructions.  It's any transient stack adjustment.

Peeking forwards the other half of the series, you convert IRET to
asm_call(), but leave these alone.

These need converting, and hopefully someone can think of a better name
than "call" to be used for the wrapper.

~Andrew