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Commit 6dd85fbb authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

s390: move expoline assembler macros to a header 



To be able to use the expoline branches in different assembler
files move the associated macros from entry.S to a new header
nospec-insn.h.

While we are at it make the macros a bit nicer to use.

Cc: stable@vger.kernel.org # 4.16
Fixes: f19fbd5e ("s390: introduce execute-trampolines for branches")
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent d66a7355

arch/s390/include/asm/nospec-insn.h

0 → 100644
+127 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

#ifndef _ASM_S390_NOSPEC_ASM_H

#define _ASM_S390_NOSPEC_ASM_H



#include <asm/dwarf.h>



#ifdef __ASSEMBLY__



#ifdef CONFIG_EXPOLINE



/*

 * The expoline macros are used to create thunks in the same format

 * as gcc generates them. The 'comdat' section flag makes sure that

 * the various thunks are merged into a single copy.

 */

	.macro __THUNK_PROLOG_NAME name

	.pushsection .text.\name,"axG",@progbits,\name,comdat

	.globl \name

	.hidden \name

	.type \name,@function

\name:

	CFI_STARTPROC

	.endm



	.macro __THUNK_EPILOG

	CFI_ENDPROC

	.popsection

	.endm



	.macro __THUNK_PROLOG_BR r1,r2

	__THUNK_PROLOG_NAME __s390x_indirect_jump_r\r2\()use_r\r1

	.endm



	.macro __THUNK_BR r1,r2

	jg	__s390x_indirect_jump_r\r2\()use_r\r1

	.endm



	.macro __THUNK_BRASL r1,r2,r3

	brasl	\r1,__s390x_indirect_jump_r\r3\()use_r\r2

	.endm



	.macro	__DECODE_RR expand,reg,ruse

	.set __decode_fail,1

	.irp r1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15

	.ifc \reg,%r\r1

	.irp r2,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15

	.ifc \ruse,%r\r2

	\expand \r1,\r2

	.set __decode_fail,0

	.endif

	.endr

	.endif

	.endr

	.if __decode_fail == 1

	.error "__DECODE_RR failed"

	.endif

	.endm



	.macro	__DECODE_RRR expand,rsave,rtarget,ruse

	.set __decode_fail,1

	.irp r1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15

	.ifc \rsave,%r\r1

	.irp r2,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15

	.ifc \rtarget,%r\r2

	.irp r3,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15

	.ifc \ruse,%r\r3

	\expand \r1,\r2,\r3

	.set __decode_fail,0

	.endif

	.endr

	.endif

	.endr

	.endif

	.endr

	.if __decode_fail == 1

	.error "__DECODE_RRR failed"

	.endif

	.endm



	.macro __THUNK_EX_BR reg,ruse

#ifdef CONFIG_HAVE_MARCH_Z10_FEATURES

	exrl	0,555f

	j	.

#else

	larl	\ruse,555f

	ex	0,0(\ruse)

	j	.

#endif

555:	br	\reg

	.endm



	.macro GEN_BR_THUNK reg,ruse=%r1

	__DECODE_RR __THUNK_PROLOG_BR,\reg,\ruse

	__THUNK_EX_BR \reg,\ruse

	__THUNK_EPILOG

	.endm



	.macro BR_EX reg,ruse=%r1

557:	__DECODE_RR __THUNK_BR,\reg,\ruse

	.pushsection .s390_indirect_branches,"a",@progbits

	.long	557b-.

	.popsection

	.endm



	.macro BASR_EX rsave,rtarget,ruse=%r1

559:	__DECODE_RRR __THUNK_BRASL,\rsave,\rtarget,\ruse

	.pushsection .s390_indirect_branches,"a",@progbits

	.long	559b-.

	.popsection

	.endm



#else

	.macro GEN_BR_THUNK reg,ruse=%r1

	.endm



	 .macro BR_EX reg,ruse=%r1

	br	\reg

	.endm



	.macro BASR_EX rsave,rtarget,ruse=%r1

	basr	\rsave,\rtarget

	.endm

#endif



#endif /* __ASSEMBLY__ */



#endif /* _ASM_S390_NOSPEC_ASM_H */

arch/s390/kernel/entry.S

+24 −81
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
#include <asm/setup.h>

#include <asm/nmi.h>

#include <asm/export.h>

#include <asm/nospec-insn.h>



__PT_R0      =	__PT_GPRS

__PT_R1      =	__PT_GPRS + 8
@@ -183,67 +184,9 @@ _LPP_OFFSET = __LC_LPP 
		    "jnz .+8; .long 0xb2e8d000", 82

	.endm



#ifdef CONFIG_EXPOLINE



	.macro GEN_BR_THUNK name,reg,tmp

	.section .text.\name,"axG",@progbits,\name,comdat

	.globl \name

	.hidden \name

	.type \name,@function

\name:

	CFI_STARTPROC

#ifdef CONFIG_HAVE_MARCH_Z10_FEATURES

	exrl	0,0f

#else

	larl	\tmp,0f

	ex	0,0(\tmp)

#endif

	j	.

0:	br	\reg

	CFI_ENDPROC

	.endm



	GEN_BR_THUNK __s390x_indirect_jump_r1use_r9,%r9,%r1

	GEN_BR_THUNK __s390x_indirect_jump_r1use_r14,%r14,%r1

	GEN_BR_THUNK __s390x_indirect_jump_r11use_r14,%r14,%r11



	.macro BASR_R14_R9

0:	brasl	%r14,__s390x_indirect_jump_r1use_r9

	.pushsection .s390_indirect_branches,"a",@progbits

	.long	0b-.

	.popsection

	.endm



	.macro BR_R1USE_R14

0:	jg	__s390x_indirect_jump_r1use_r14

	.pushsection .s390_indirect_branches,"a",@progbits

	.long	0b-.

	.popsection

	.endm



	.macro BR_R11USE_R14

0:	jg	__s390x_indirect_jump_r11use_r14

	.pushsection .s390_indirect_branches,"a",@progbits

	.long	0b-.

	.popsection

	.endm



#else	/* CONFIG_EXPOLINE */



	.macro BASR_R14_R9

	basr	%r14,%r9

	.endm



	.macro BR_R1USE_R14

	br	%r14

	.endm



	.macro BR_R11USE_R14

	br	%r14

	.endm



#endif /* CONFIG_EXPOLINE */



	GEN_BR_THUNK %r9

	GEN_BR_THUNK %r14

	GEN_BR_THUNK %r14,%r11



	.section .kprobes.text, "ax"

.Ldummy:
@@ -260,7 +203,7 @@ _LPP_OFFSET = __LC_LPP 
ENTRY(__bpon)

	.globl __bpon

	BPON

	BR_R1USE_R14

	BR_EX	%r14



/*

 * Scheduler resume function, called by switch_to
@@ -284,7 +227,7 @@ ENTRY(__switch_to) 
	mvc	__LC_CURRENT_PID(4,%r0),0(%r3)	# store pid of next

	lmg	%r6,%r15,__SF_GPRS(%r15)	# load gprs of next task

	ALTERNATIVE "", ".insn s,0xb2800000,_LPP_OFFSET", 40

	BR_R1USE_R14

	BR_EX	%r14



.L__critical_start:
@@ -351,7 +294,7 @@ sie_exit: 
	xgr	%r5,%r5

	lmg	%r6,%r14,__SF_GPRS(%r15)	# restore kernel registers

	lg	%r2,__SF_SIE_REASON(%r15)	# return exit reason code

	BR_R1USE_R14

	BR_EX	%r14

.Lsie_fault:

	lghi	%r14,-EFAULT

	stg	%r14,__SF_SIE_REASON(%r15)	# set exit reason code
@@ -410,7 +353,7 @@ ENTRY(system_call) 
	lgf	%r9,0(%r8,%r10)			# get system call add.

	TSTMSK	__TI_flags(%r12),_TIF_TRACE

	jnz	.Lsysc_tracesys

	BASR_R14_R9				# call sys_xxxx

	BASR_EX	%r14,%r9			# call sys_xxxx

	stg	%r2,__PT_R2(%r11)		# store return value



.Lsysc_return:
@@ -595,7 +538,7 @@ ENTRY(system_call) 
	lmg	%r3,%r7,__PT_R3(%r11)

	stg	%r7,STACK_FRAME_OVERHEAD(%r15)

	lg	%r2,__PT_ORIG_GPR2(%r11)

	BASR_R14_R9			# call sys_xxx

	BASR_EX	%r14,%r9		# call sys_xxx

	stg	%r2,__PT_R2(%r11)	# store return value

.Lsysc_tracenogo:

	TSTMSK	__TI_flags(%r12),_TIF_TRACE
@@ -619,7 +562,7 @@ ENTRY(ret_from_fork) 
	lmg	%r9,%r10,__PT_R9(%r11)	# load gprs

ENTRY(kernel_thread_starter)

	la	%r2,0(%r10)

	BASR_R14_R9

	BASR_EX	%r14,%r9

	j	.Lsysc_tracenogo



/*
@@ -701,7 +644,7 @@ ENTRY(pgm_check_handler) 
	je	.Lpgm_return

	lgf	%r9,0(%r10,%r1)		# load address of handler routine

	lgr	%r2,%r11		# pass pointer to pt_regs

	BASR_R14_R9			# branch to interrupt-handler

	BASR_EX	%r14,%r9		# branch to interrupt-handler

.Lpgm_return:

	LOCKDEP_SYS_EXIT

	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
@@ -1019,7 +962,7 @@ ENTRY(psw_idle) 
	stpt	__TIMER_IDLE_ENTER(%r2)

.Lpsw_idle_lpsw:

	lpswe	__SF_EMPTY(%r15)

	BR_R1USE_R14

	BR_EX	%r14

.Lpsw_idle_end:



/*
@@ -1061,7 +1004,7 @@ ENTRY(save_fpu_regs) 
.Lsave_fpu_regs_done:

	oi	__LC_CPU_FLAGS+7,_CIF_FPU

.Lsave_fpu_regs_exit:

	BR_R1USE_R14

	BR_EX	%r14

.Lsave_fpu_regs_end:

EXPORT_SYMBOL(save_fpu_regs)
@@ -1107,7 +1050,7 @@ load_fpu_regs: 
.Lload_fpu_regs_done:

	ni	__LC_CPU_FLAGS+7,255-_CIF_FPU

.Lload_fpu_regs_exit:

	BR_R1USE_R14

	BR_EX	%r14

.Lload_fpu_regs_end:



.L__critical_end:
@@ -1322,7 +1265,7 @@ cleanup_critical: 
	jl	0f

	clg	%r9,BASED(.Lcleanup_table+104)	# .Lload_fpu_regs_end

	jl	.Lcleanup_load_fpu_regs

0:	BR_R11USE_R14

0:	BR_EX	%r14



	.align	8

.Lcleanup_table:
@@ -1358,7 +1301,7 @@ cleanup_critical: 
	ni	__SIE_PROG0C+3(%r9),0xfe	# no longer in SIE

	lctlg	%c1,%c1,__LC_USER_ASCE		# load primary asce

	larl	%r9,sie_exit			# skip forward to sie_exit

	BR_R11USE_R14

	BR_EX	%r14

#endif



.Lcleanup_system_call:
@@ -1412,7 +1355,7 @@ cleanup_critical: 
	stg	%r15,56(%r11)		# r15 stack pointer

	# set new psw address and exit

	larl	%r9,.Lsysc_do_svc

	BR_R11USE_R14

	BR_EX	%r14,%r11

.Lcleanup_system_call_insn:

	.quad	system_call

	.quad	.Lsysc_stmg
@@ -1424,7 +1367,7 @@ cleanup_critical: 


.Lcleanup_sysc_tif:

	larl	%r9,.Lsysc_tif

	BR_R11USE_R14

	BR_EX	%r14,%r11



.Lcleanup_sysc_restore:

	# check if stpt has been executed
@@ -1441,14 +1384,14 @@ cleanup_critical: 
	mvc	0(64,%r11),__PT_R8(%r9)

	lmg	%r0,%r7,__PT_R0(%r9)

1:	lmg	%r8,%r9,__LC_RETURN_PSW

	BR_R11USE_R14

	BR_EX	%r14,%r11

.Lcleanup_sysc_restore_insn:

	.quad	.Lsysc_exit_timer

	.quad	.Lsysc_done - 4



.Lcleanup_io_tif:

	larl	%r9,.Lio_tif

	BR_R11USE_R14

	BR_EX	%r14,%r11



.Lcleanup_io_restore:

	# check if stpt has been executed
@@ -1462,7 +1405,7 @@ cleanup_critical: 
	mvc	0(64,%r11),__PT_R8(%r9)

	lmg	%r0,%r7,__PT_R0(%r9)

1:	lmg	%r8,%r9,__LC_RETURN_PSW

	BR_R11USE_R14

	BR_EX	%r14,%r11

.Lcleanup_io_restore_insn:

	.quad	.Lio_exit_timer

	.quad	.Lio_done - 4
@@ -1515,17 +1458,17 @@ cleanup_critical: 
	# prepare return psw

	nihh	%r8,0xfcfd		# clear irq & wait state bits

	lg	%r9,48(%r11)		# return from psw_idle

	BR_R11USE_R14

	BR_EX	%r14,%r11

.Lcleanup_idle_insn:

	.quad	.Lpsw_idle_lpsw



.Lcleanup_save_fpu_regs:

	larl	%r9,save_fpu_regs

	BR_R11USE_R14

	BR_EX	%r14,%r11



.Lcleanup_load_fpu_regs:

	larl	%r9,load_fpu_regs

	BR_R11USE_R14

	BR_EX	%r14,%r11



/*

 * Integer constants