On 03/16, Borislav Petkov wrote: > > On Sun, Mar 15, 2015 at 05:49:48PM +0100, Oleg Nesterov wrote: > > > > And I agree with Quentin, user_insn/check_insn can be improved to allow > > clobbers, more flexible "output", etc. But imo they already can make this > > code look a bit better, and "xstate_fault" must die eventually. > > FWIW, I did poke at that but there's still something wrong with my macros, > will > take a look when I get a chance:
Sure, I won't argue if we use the new macros instead. But we already have check_insn/user_insn, why not use them? For example, > +#define XSTATE_XSAVE(st, lmask, hmask, err) \ > + asm volatile(ALTERNATIVE_2(XSAVE, \ > + XSAVEOPT, X86_FEATURE_XSAVEOPT, \ > + XSAVES, X86_FEATURE_XSAVES) \ > + "\n" \ > + ".pushsection .fixup,\"ax\"\n" \ > + "3: movl $-1, %[err]\n" \ > + "jmp " alt_end_marker "b\n" \ > + ".popsection\n" \ > + _ASM_EXTABLE(661b, 3b) \ > + : [err] "=r" (err) \ > + : "D" (st), "a" (lmask), "d" (hmask) \ > + : "memory") > + to me check_insn(ALTERNATIVE_2(...)) looks better. Except we need the clobber. It is not easy to read the code like this, imo it would be better to avoid copy-and-paste and use the helpers we already have. Just we need to improve them. But let me repeat, I leave this to you and others, I do not understand asm enough. Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
