Commit 33634e42 authored by Juergen Gross's avatar Juergen Gross Committed by Borislav Petkov
Browse files

x86/paravirt: Remove no longer needed 32-bit pvops cruft 



PVOP_VCALL4() is only used for Xen PV, while PVOP_CALL4() isn't used
at all. Keep PVOP_CALL4() for 64 bits due to symmetry reasons.

This allows to remove the 32-bit definitions of those macros leading
to a substantial simplification of the paravirt macros, as those were
the only ones needing non-empty "pre" and "post" parameters.

PVOP_CALLEE2() and PVOP_VCALLEE2() are used nowhere, so remove them.

Another no longer needed case is special handling of return types
larger than unsigned long. Replace that with a BUILD_BUG_ON().

DISABLE_INTERRUPTS() is used in 32-bit code only, so it can just be
replaced by cli.

INTERRUPT_RETURN in 32-bit code can be replaced by iret.

ENABLE_INTERRUPTS is used nowhere, so it can be removed.

Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210311142319.4723-10-jgross@suse.com
parent 4e629211

arch/x86/entry/entry_32.S

+2 −2
Original line number Diff line number Diff line
@@ -430,7 +430,7 @@ 
	 * will soon execute iret and the tracer was already set to

	 * the irqstate after the IRET:

	 */

	DISABLE_INTERRUPTS(CLBR_ANY)

	cli

	lss	(%esp), %esp			/* switch to espfix segment */

.Lend_\@:

#endif /* CONFIG_X86_ESPFIX32 */
@@ -1077,7 +1077,7 @@ restore_all_switch_stack: 
	 * when returning from IPI handler and when returning from

	 * scheduler to user-space.

	 */

	INTERRUPT_RETURN

	iret



.section .fixup, "ax"

SYM_CODE_START(asm_iret_error)

arch/x86/include/asm/irqflags.h

+0 −5
Original line number Diff line number Diff line
@@ -109,9 +109,6 @@ static __always_inline unsigned long arch_local_irq_save(void) 
}

#else



#define ENABLE_INTERRUPTS(x)	sti

#define DISABLE_INTERRUPTS(x)	cli



#ifdef CONFIG_X86_64

#ifdef CONFIG_DEBUG_ENTRY

#define SAVE_FLAGS(x)		pushfq; popq %rax
@@ -119,8 +116,6 @@ static __always_inline unsigned long arch_local_irq_save(void) 


#define INTERRUPT_RETURN	jmp native_iret



#else

#define INTERRUPT_RETURN		iret

#endif



#endif /* __ASSEMBLY__ */

arch/x86/include/asm/paravirt.h

+1 −34
Original line number Diff line number Diff line
@@ -719,6 +719,7 @@ extern void default_banner(void); 
	.if ((~(set)) & mask); pop %reg; .endif



#ifdef CONFIG_X86_64

#ifdef CONFIG_PARAVIRT_XXL



#define PV_SAVE_REGS(set)			\

	COND_PUSH(set, CLBR_RAX, rax);		\
@@ -744,46 +745,12 @@ extern void default_banner(void); 
#define PARA_PATCH(off)		((off) / 8)

#define PARA_SITE(ptype, ops)	_PVSITE(ptype, ops, .quad, 8)

#define PARA_INDIRECT(addr)	*addr(%rip)

#else

#define PV_SAVE_REGS(set)			\

	COND_PUSH(set, CLBR_EAX, eax);		\

	COND_PUSH(set, CLBR_EDI, edi);		\

	COND_PUSH(set, CLBR_ECX, ecx);		\

	COND_PUSH(set, CLBR_EDX, edx)

#define PV_RESTORE_REGS(set)			\

	COND_POP(set, CLBR_EDX, edx);		\

	COND_POP(set, CLBR_ECX, ecx);		\

	COND_POP(set, CLBR_EDI, edi);		\

	COND_POP(set, CLBR_EAX, eax)



#define PARA_PATCH(off)		((off) / 4)

#define PARA_SITE(ptype, ops)	_PVSITE(ptype, ops, .long, 4)

#define PARA_INDIRECT(addr)	*%cs:addr

#endif



#ifdef CONFIG_PARAVIRT_XXL

#define INTERRUPT_RETURN						\

	PARA_SITE(PARA_PATCH(PV_CPU_iret),				\

		  ANNOTATE_RETPOLINE_SAFE;				\

		  jmp PARA_INDIRECT(pv_ops+PV_CPU_iret);)



#define DISABLE_INTERRUPTS(clobbers)					\

	PARA_SITE(PARA_PATCH(PV_IRQ_irq_disable),			\

		  PV_SAVE_REGS(clobbers | CLBR_CALLEE_SAVE);		\

		  ANNOTATE_RETPOLINE_SAFE;				\

		  call PARA_INDIRECT(pv_ops+PV_IRQ_irq_disable);	\

		  PV_RESTORE_REGS(clobbers | CLBR_CALLEE_SAVE);)



#define ENABLE_INTERRUPTS(clobbers)					\

	PARA_SITE(PARA_PATCH(PV_IRQ_irq_enable),			\

		  PV_SAVE_REGS(clobbers | CLBR_CALLEE_SAVE);		\

		  ANNOTATE_RETPOLINE_SAFE;				\

		  call PARA_INDIRECT(pv_ops+PV_IRQ_irq_enable);		\

		  PV_RESTORE_REGS(clobbers | CLBR_CALLEE_SAVE);)

#endif



#ifdef CONFIG_X86_64

#ifdef CONFIG_PARAVIRT_XXL

#ifdef CONFIG_DEBUG_ENTRY

#define SAVE_FLAGS(clobbers)                                        \

	PARA_SITE(PARA_PATCH(PV_IRQ_save_fl),			    \

arch/x86/include/asm/paravirt_types.h

+32 −80
Original line number Diff line number Diff line
@@ -470,55 +470,34 @@ int paravirt_disable_iospace(void); 
	})





#define ____PVOP_CALL(rettype, op, clbr, call_clbr, extra_clbr,		\

		      pre, post, ...)					\

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

	({								\

		rettype __ret;						\

		PVOP_CALL_ARGS;						\

		PVOP_TEST_NULL(op);					\

		/* This is 32-bit specific, but is okay in 64-bit */	\

		/* since this condition will never hold */		\

		if (sizeof(rettype) > sizeof(unsigned long)) {		\

			asm volatile(pre				\

				     paravirt_alt(PARAVIRT_CALL)	\

				     post				\

		BUILD_BUG_ON(sizeof(rettype) > sizeof(unsigned long));	\

		asm volatile(paravirt_alt(PARAVIRT_CALL)		\

			     : call_clbr, ASM_CALL_CONSTRAINT		\

			     : paravirt_type(op),			\

			       paravirt_clobber(clbr),			\

			       ##__VA_ARGS__				\

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

			__ret = (rettype)((((u64)__edx) << 32) | __eax); \

		} else {						\

			asm volatile(pre				\

				     paravirt_alt(PARAVIRT_CALL)	\

				     post				\

				     : call_clbr, ASM_CALL_CONSTRAINT	\

				     : paravirt_type(op),		\

				       paravirt_clobber(clbr),		\

				       ##__VA_ARGS__			\

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

			__ret = (rettype)(__eax & PVOP_RETMASK(rettype));	\

		}							\

		__ret;							\

		(rettype)(__eax & PVOP_RETMASK(rettype));		\

	})



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

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

	____PVOP_CALL(rettype, op, CLBR_ANY, PVOP_CALL_CLOBBERS,	\

		      EXTRA_CLOBBERS, pre, post, ##__VA_ARGS__)

		      EXTRA_CLOBBERS, ##__VA_ARGS__)



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

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

	____PVOP_CALL(rettype, op.func, CLBR_RET_REG,			\

		      PVOP_CALLEE_CLOBBERS, ,				\

		      pre, post, ##__VA_ARGS__)

		      PVOP_CALLEE_CLOBBERS, , ##__VA_ARGS__)





#define ____PVOP_VCALL(op, clbr, call_clbr, extra_clbr, pre, post, ...)	\

#define ____PVOP_VCALL(op, clbr, call_clbr, extra_clbr, ...)		\

	({								\

		PVOP_VCALL_ARGS;					\

		PVOP_TEST_NULL(op);					\

		asm volatile(pre					\

			     paravirt_alt(PARAVIRT_CALL)		\

			     post					\

		asm volatile(paravirt_alt(PARAVIRT_CALL)		\

			     : call_clbr, ASM_CALL_CONSTRAINT		\

			     : paravirt_type(op),			\

			       paravirt_clobber(clbr),			\
@@ -526,84 +505,57 @@ int paravirt_disable_iospace(void); 
			     : "memory", "cc" extra_clbr);		\

	})



#define __PVOP_VCALL(op, pre, post, ...)				\

#define __PVOP_VCALL(op, ...)						\

	____PVOP_VCALL(op, CLBR_ANY, PVOP_VCALL_CLOBBERS,		\

		       VEXTRA_CLOBBERS,					\

		       pre, post, ##__VA_ARGS__)

		       VEXTRA_CLOBBERS, ##__VA_ARGS__)



#define __PVOP_VCALLEESAVE(op, pre, post, ...)				\

#define __PVOP_VCALLEESAVE(op, ...)					\

	____PVOP_VCALL(op.func, CLBR_RET_REG,				\

		      PVOP_VCALLEE_CLOBBERS, ,				\

		      pre, post, ##__VA_ARGS__)

		      PVOP_VCALLEE_CLOBBERS, , ##__VA_ARGS__)







#define PVOP_CALL0(rettype, op)						\

	__PVOP_CALL(rettype, op, "", "")

	__PVOP_CALL(rettype, op)

#define PVOP_VCALL0(op)							\

	__PVOP_VCALL(op, "", "")

	__PVOP_VCALL(op)



#define PVOP_CALLEE0(rettype, op)					\

	__PVOP_CALLEESAVE(rettype, op, "", "")

	__PVOP_CALLEESAVE(rettype, op)

#define PVOP_VCALLEE0(op)						\

	__PVOP_VCALLEESAVE(op, "", "")

	__PVOP_VCALLEESAVE(op)





#define PVOP_CALL1(rettype, op, arg1)					\

	__PVOP_CALL(rettype, op, "", "", PVOP_CALL_ARG1(arg1))

	__PVOP_CALL(rettype, op, PVOP_CALL_ARG1(arg1))

#define PVOP_VCALL1(op, arg1)						\

	__PVOP_VCALL(op, "", "", PVOP_CALL_ARG1(arg1))

	__PVOP_VCALL(op, PVOP_CALL_ARG1(arg1))



#define PVOP_CALLEE1(rettype, op, arg1)					\

	__PVOP_CALLEESAVE(rettype, op, "", "", PVOP_CALL_ARG1(arg1))

	__PVOP_CALLEESAVE(rettype, op, PVOP_CALL_ARG1(arg1))

#define PVOP_VCALLEE1(op, arg1)						\

	__PVOP_VCALLEESAVE(op, "", "", PVOP_CALL_ARG1(arg1))

	__PVOP_VCALLEESAVE(op, PVOP_CALL_ARG1(arg1))





#define PVOP_CALL2(rettype, op, arg1, arg2)				\

	__PVOP_CALL(rettype, op, "", "", PVOP_CALL_ARG1(arg1),		\

		    PVOP_CALL_ARG2(arg2))

	__PVOP_CALL(rettype, op, PVOP_CALL_ARG1(arg1), PVOP_CALL_ARG2(arg2))

#define PVOP_VCALL2(op, arg1, arg2)					\

	__PVOP_VCALL(op, "", "", PVOP_CALL_ARG1(arg1),			\

		     PVOP_CALL_ARG2(arg2))



#define PVOP_CALLEE2(rettype, op, arg1, arg2)				\

	__PVOP_CALLEESAVE(rettype, op, "", "", PVOP_CALL_ARG1(arg1),	\

			  PVOP_CALL_ARG2(arg2))

#define PVOP_VCALLEE2(op, arg1, arg2)					\

	__PVOP_VCALLEESAVE(op, "", "", PVOP_CALL_ARG1(arg1),		\

			   PVOP_CALL_ARG2(arg2))



	__PVOP_VCALL(op, PVOP_CALL_ARG1(arg1), PVOP_CALL_ARG2(arg2))



#define PVOP_CALL3(rettype, op, arg1, arg2, arg3)			\

	__PVOP_CALL(rettype, op, "", "", PVOP_CALL_ARG1(arg1),		\

	__PVOP_CALL(rettype, op, PVOP_CALL_ARG1(arg1),			\

		    PVOP_CALL_ARG2(arg2), PVOP_CALL_ARG3(arg3))

#define PVOP_VCALL3(op, arg1, arg2, arg3)				\

	__PVOP_VCALL(op, "", "", PVOP_CALL_ARG1(arg1),			\

	__PVOP_VCALL(op, PVOP_CALL_ARG1(arg1),				\

		     PVOP_CALL_ARG2(arg2), PVOP_CALL_ARG3(arg3))



/* This is the only difference in x86_64. We can make it much simpler */

#ifdef CONFIG_X86_32

#define PVOP_CALL4(rettype, op, arg1, arg2, arg3, arg4)			\

	__PVOP_CALL(rettype, op,					\

		    "push %[_arg4];", "lea 4(%%esp),%%esp;",		\

		    PVOP_CALL_ARG1(arg1), PVOP_CALL_ARG2(arg2),		\

		    PVOP_CALL_ARG3(arg3), [_arg4] "mr" ((u32)(arg4)))

#define PVOP_VCALL4(op, arg1, arg2, arg3, arg4)				\

	__PVOP_VCALL(op,						\

		    "push %[_arg4];", "lea 4(%%esp),%%esp;",		\

		    "0" ((u32)(arg1)), "1" ((u32)(arg2)),		\

		    "2" ((u32)(arg3)), [_arg4] "mr" ((u32)(arg4)))

#else

#define PVOP_CALL4(rettype, op, arg1, arg2, arg3, arg4)			\

	__PVOP_CALL(rettype, op, "", "",				\

		    PVOP_CALL_ARG1(arg1), PVOP_CALL_ARG2(arg2),		\

		    PVOP_CALL_ARG3(arg3), PVOP_CALL_ARG4(arg4))

#define PVOP_VCALL4(op, arg1, arg2, arg3, arg4)				\

	__PVOP_VCALL(op, "", "",					\

		     PVOP_CALL_ARG1(arg1), PVOP_CALL_ARG2(arg2),	\

	__PVOP_VCALL(op, PVOP_CALL_ARG1(arg1), PVOP_CALL_ARG2(arg2),	\

		     PVOP_CALL_ARG3(arg3), PVOP_CALL_ARG4(arg4))

#endif



/* Lazy mode for batching updates / context switch */

enum paravirt_lazy_mode {

arch/x86/kernel/asm-offsets.c

+0 −2
Original line number Diff line number Diff line
@@ -63,8 +63,6 @@ static void __used common(void) 


#ifdef CONFIG_PARAVIRT_XXL

	BLANK();

	OFFSET(PV_IRQ_irq_disable, paravirt_patch_template, irq.irq_disable);

	OFFSET(PV_IRQ_irq_enable, paravirt_patch_template, irq.irq_enable);

	OFFSET(PV_CPU_iret, paravirt_patch_template, cpu.iret);

#endif