Commit 5736b1b7 authored by Kees Cook's avatar Kees Cook Committed by Peter Zijlstra
Browse files

x86/paravirt: Remove clobber bitmask from .parainstructions 



The u16 "clobber" value is not used in .parainstructions since commit
27876f38 ("x86/paravirt: Remove clobbers from struct paravirt_patch_site")

Remove the u16 from the section macro, the argument from all macros, and
all now-unused CLBR_* macros.

Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
Reviewed-by: default avatarJuergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20220903073706.3193746-1-keescook@chromium.org
parent 0ce096db

arch/x86/include/asm/paravirt_types.h

+12 −49
Original line number Diff line number Diff line
@@ -20,37 +20,6 @@ enum paravirt_lazy_mode { 


#ifdef CONFIG_PARAVIRT



/* Bitmask of what can be clobbered: usually at least eax. */

#define CLBR_EAX  (1 << 0)

#define CLBR_ECX  (1 << 1)

#define CLBR_EDX  (1 << 2)

#define CLBR_EDI  (1 << 3)



#ifdef CONFIG_X86_32

/* CLBR_ANY should match all regs platform has. For i386, that's just it */

#define CLBR_ANY  ((1 << 4) - 1)



#define CLBR_ARG_REGS	(CLBR_EAX | CLBR_EDX | CLBR_ECX)

#define CLBR_RET_REG	(CLBR_EAX | CLBR_EDX)

#else

#define CLBR_RAX  CLBR_EAX

#define CLBR_RCX  CLBR_ECX

#define CLBR_RDX  CLBR_EDX

#define CLBR_RDI  CLBR_EDI

#define CLBR_RSI  (1 << 4)

#define CLBR_R8   (1 << 5)

#define CLBR_R9   (1 << 6)

#define CLBR_R10  (1 << 7)

#define CLBR_R11  (1 << 8)



#define CLBR_ANY  ((1 << 9) - 1)



#define CLBR_ARG_REGS	(CLBR_RDI | CLBR_RSI | CLBR_RDX | \

			 CLBR_RCX | CLBR_R8 | CLBR_R9)

#define CLBR_RET_REG	(CLBR_RAX)



#endif /* X86_64 */



#ifndef __ASSEMBLY__



#include <asm/desc_defs.h>
@@ -297,27 +266,23 @@ extern struct paravirt_patch_template pv_ops; 
#define paravirt_type(op)				\

	[paravirt_typenum] "i" (PARAVIRT_PATCH(op)),	\

	[paravirt_opptr] "m" (pv_ops.op)

#define paravirt_clobber(clobber)		\

	[paravirt_clobber] "i" (clobber)



/*

 * Generate some code, and mark it as patchable by the

 * apply_paravirt() alternate instruction patcher.

 */

#define _paravirt_alt(insn_string, type, clobber)	\

#define _paravirt_alt(insn_string, type)		\

	"771:\n\t" insn_string "\n" "772:\n"		\

	".pushsection .parainstructions,\"a\"\n"	\

	_ASM_ALIGN "\n"					\

	_ASM_PTR " 771b\n"				\

	"  .byte " type "\n"				\

	"  .byte 772b-771b\n"				\

	"  .short " clobber "\n"			\

	_ASM_ALIGN "\n"					\

	".popsection\n"



/* Generate patchable code, with the default asm parameters. */

#define paravirt_alt(insn_string)					\

	_paravirt_alt(insn_string, "%c[paravirt_typenum]", "%c[paravirt_clobber]")

	_paravirt_alt(insn_string, "%c[paravirt_typenum]")



/* Simple instruction patching code. */

#define NATIVE_LABEL(a,x,b) "\n\t.globl " a #x "_" #b "\n" a #x "_" #b ":\n\t"
@@ -469,20 +434,19 @@ int paravirt_disable_iospace(void); 
	})





#define ____PVOP_CALL(ret, op, clbr, call_clbr, extra_clbr, ...)	\

#define ____PVOP_CALL(ret, op, call_clbr, extra_clbr, ...)	\

	({								\

		PVOP_CALL_ARGS;						\

		PVOP_TEST_NULL(op);					\

		asm volatile(paravirt_alt(PARAVIRT_CALL)		\

			     : call_clbr, ASM_CALL_CONSTRAINT		\

			     : paravirt_type(op),			\

			       paravirt_clobber(clbr),			\

			       ##__VA_ARGS__				\

			     : "memory", "cc" extra_clbr);		\

		ret;							\

	})



#define ____PVOP_ALT_CALL(ret, op, alt, cond, clbr, call_clbr,		\

#define ____PVOP_ALT_CALL(ret, op, alt, cond, call_clbr,		\

			  extra_clbr, ...)				\

	({								\

		PVOP_CALL_ARGS;						\
@@ -491,45 +455,44 @@ int paravirt_disable_iospace(void); 
					 alt, cond)			\

			     : call_clbr, ASM_CALL_CONSTRAINT		\

			     : paravirt_type(op),			\

			       paravirt_clobber(clbr),			\

			       ##__VA_ARGS__				\

			     : "memory", "cc" extra_clbr);		\

		ret;							\

	})



#define __PVOP_CALL(rettype, op, ...)					\

	____PVOP_CALL(PVOP_RETVAL(rettype), op, CLBR_ANY,		\

	____PVOP_CALL(PVOP_RETVAL(rettype), op,				\

		      PVOP_CALL_CLOBBERS, EXTRA_CLOBBERS, ##__VA_ARGS__)



#define __PVOP_ALT_CALL(rettype, op, alt, cond, ...)			\

	____PVOP_ALT_CALL(PVOP_RETVAL(rettype), op, alt, cond, CLBR_ANY,\

	____PVOP_ALT_CALL(PVOP_RETVAL(rettype), op, alt, cond,		\

			  PVOP_CALL_CLOBBERS, EXTRA_CLOBBERS,		\

			  ##__VA_ARGS__)



#define __PVOP_CALLEESAVE(rettype, op, ...)				\

	____PVOP_CALL(PVOP_RETVAL(rettype), op.func, CLBR_RET_REG,	\

	____PVOP_CALL(PVOP_RETVAL(rettype), op.func,			\

		      PVOP_CALLEE_CLOBBERS, , ##__VA_ARGS__)



#define __PVOP_ALT_CALLEESAVE(rettype, op, alt, cond, ...)		\

	____PVOP_ALT_CALL(PVOP_RETVAL(rettype), op.func, alt, cond,	\

			  CLBR_RET_REG, PVOP_CALLEE_CLOBBERS, , ##__VA_ARGS__)

			  PVOP_CALLEE_CLOBBERS, , ##__VA_ARGS__)





#define __PVOP_VCALL(op, ...)						\

	(void)____PVOP_CALL(, op, CLBR_ANY, PVOP_VCALL_CLOBBERS,	\

	(void)____PVOP_CALL(, op, PVOP_VCALL_CLOBBERS,			\

		       VEXTRA_CLOBBERS, ##__VA_ARGS__)



#define __PVOP_ALT_VCALL(op, alt, cond, ...)				\

	(void)____PVOP_ALT_CALL(, op, alt, cond, CLBR_ANY,		\

	(void)____PVOP_ALT_CALL(, op, alt, cond,			\

				PVOP_VCALL_CLOBBERS, VEXTRA_CLOBBERS,	\

				##__VA_ARGS__)



#define __PVOP_VCALLEESAVE(op, ...)					\

	(void)____PVOP_CALL(, op.func, CLBR_RET_REG,			\

	(void)____PVOP_CALL(, op.func,					\

			    PVOP_VCALLEE_CLOBBERS, , ##__VA_ARGS__)



#define __PVOP_ALT_VCALLEESAVE(op, alt, cond, ...)			\

	(void)____PVOP_ALT_CALL(, op.func, alt, cond, CLBR_RET_REG,	\

	(void)____PVOP_ALT_CALL(, op.func, alt, cond,			\

				PVOP_VCALLEE_CLOBBERS, , ##__VA_ARGS__)