Commit f33f2d4c authored by Heiko Carstens's avatar Heiko Carstens Committed by Vasily Gorbik
Browse files

s390/bp: remove TIF_ISOLATE_BP 



TIF_ISOLATE_BP is unused since it was introduced with commit 6b73044b
("s390: run user space and KVM guests with modified branch prediction").
Given that there is no use case remove it again.

Acked-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: default avatarSven Schnelle <svens@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent fed626db

arch/s390/include/asm/processor.h

+0 −1
Original line number Diff line number Diff line
@@ -329,7 +329,6 @@ static __always_inline void __noreturn disabled_wait(void) 


#define ARCH_LOW_ADDRESS_LIMIT	0x7fffffffUL



extern int s390_isolate_bp(void);

extern int s390_isolate_bp_guest(void);



static __always_inline bool regs_irqs_disabled(struct pt_regs *regs)

arch/s390/include/asm/thread_info.h

+0 −2
Original line number Diff line number Diff line
@@ -70,7 +70,6 @@ void arch_setup_new_exec(void); 
#define TIF_PATCH_PENDING	5	/* pending live patching update */

#define TIF_PGSTE		6	/* New mm's will use 4K page tables */

#define TIF_NOTIFY_SIGNAL	7	/* signal notifications exist */

#define TIF_ISOLATE_BP		8	/* Run process with isolated BP */

#define TIF_ISOLATE_BP_GUEST	9	/* Run KVM guests with isolated BP */

#define TIF_PER_TRAP		10	/* Need to handle PER trap on exit to usermode */
@@ -94,7 +93,6 @@ void arch_setup_new_exec(void); 
#define _TIF_UPROBE		BIT(TIF_UPROBE)

#define _TIF_GUARDED_STORAGE	BIT(TIF_GUARDED_STORAGE)

#define _TIF_PATCH_PENDING	BIT(TIF_PATCH_PENDING)

#define _TIF_ISOLATE_BP		BIT(TIF_ISOLATE_BP)

#define _TIF_ISOLATE_BP_GUEST	BIT(TIF_ISOLATE_BP_GUEST)

#define _TIF_PER_TRAP		BIT(TIF_PER_TRAP)

arch/s390/kernel/entry.S

+13 −23
Original line number Diff line number Diff line
@@ -227,7 +227,7 @@ ENTRY(__sie64a) 
	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU

	jo	.Lsie_skip			# exit if fp/vx regs changed

	lg	%r14,__SF_SIE_CONTROL_PHYS(%r15)	# get sie block phys addr

	BPEXIT	__SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST)

	BPEXIT	__SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST

.Lsie_entry:

	sie	0(%r14)

# Let the next instruction be NOP to avoid triggering a machine check
@@ -235,7 +235,7 @@ ENTRY(__sie64a) 
	nopr	7

.Lsie_leave:

	BPOFF

	BPENTER	__SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST)

	BPENTER	__SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST

.Lsie_skip:

	lg	%r14,__SF_SIE_CONTROL(%r15)	# get control block pointer

	ni	__SIE_PROG0C+3(%r14),0xfe	# no longer in SIE
@@ -291,11 +291,9 @@ ENTRY(system_call) 
.Lsysc_per:

	STBEAR	__LC_LAST_BREAK

	lctlg	%c1,%c1,__LC_KERNEL_ASCE

	lg	%r12,__LC_CURRENT

	lg	%r15,__LC_KERNEL_STACK

	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)

	stmg	%r0,%r7,STACK_FRAME_OVERHEAD+__PT_R0(%r15)

	BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP

	# clear user controlled register to prevent speculative use

	xgr	%r0,%r0

	xgr	%r1,%r1
@@ -314,7 +312,7 @@ ENTRY(system_call) 
	brasl	%r14,__do_syscall

	lctlg	%c1,%c1,__LC_USER_ASCE

	mvc	__LC_RETURN_PSW(16),STACK_FRAME_OVERHEAD+__PT_PSW(%r15)

	BPEXIT __TI_flags(%r12),_TIF_ISOLATE_BP

	BPON

	LBEAR	STACK_FRAME_OVERHEAD+__PT_LAST_BREAK(%r15)

	lmg	%r0,%r15,STACK_FRAME_OVERHEAD+__PT_R0(%r15)

	stpt	__LC_EXIT_TIMER
@@ -329,7 +327,7 @@ ENTRY(ret_from_fork) 
	brasl	%r14,__ret_from_fork

	lctlg	%c1,%c1,__LC_USER_ASCE

	mvc	__LC_RETURN_PSW(16),STACK_FRAME_OVERHEAD+__PT_PSW(%r15)

	BPEXIT __TI_flags(%r12),_TIF_ISOLATE_BP

	BPON

	LBEAR	STACK_FRAME_OVERHEAD+__PT_LAST_BREAK(%r15)

	lmg	%r0,%r15,STACK_FRAME_OVERHEAD+__PT_R0(%r15)

	stpt	__LC_EXIT_TIMER
@@ -344,7 +342,6 @@ ENTRY(pgm_check_handler) 
	stpt	__LC_SYS_ENTER_TIMER

	BPOFF

	stmg	%r8,%r15,__LC_SAVE_AREA_SYNC

	lg	%r12,__LC_CURRENT

	lghi	%r10,0

	lmg	%r8,%r9,__LC_PGM_OLD_PSW

	tmhh	%r8,0x0001		# coming from user space?
@@ -355,7 +352,7 @@ ENTRY(pgm_check_handler) 
#if IS_ENABLED(CONFIG_KVM)

	# cleanup critical section for program checks in __sie64a

	OUTSIDE	%r9,.Lsie_gmap,.Lsie_done,1f

	BPENTER	__SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST)

	BPENTER	__SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST

	SIEEXIT

	lghi	%r10,_PIF_GUEST_FAULT

#endif
@@ -367,8 +364,7 @@ ENTRY(pgm_check_handler) 
	aghi	%r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)

	# CHECK_VMAP_STACK branches to stack_overflow or 4f

	CHECK_VMAP_STACK __LC_SAVE_AREA_SYNC,4f

3:	BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP

	lg	%r15,__LC_KERNEL_STACK

3:	lg	%r15,__LC_KERNEL_STACK

4:	la	%r11,STACK_FRAME_OVERHEAD(%r15)

	stg	%r10,__PT_FLAGS(%r11)

	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
@@ -390,7 +386,7 @@ ENTRY(pgm_check_handler) 
	tmhh	%r8,0x0001		# returning to user space?

	jno	.Lpgm_exit_kernel

	lctlg	%c1,%c1,__LC_USER_ASCE

	BPEXIT __TI_flags(%r12),_TIF_ISOLATE_BP

	BPON

	stpt	__LC_EXIT_TIMER

.Lpgm_exit_kernel:

	mvc	__LC_RETURN_PSW(16),STACK_FRAME_OVERHEAD+__PT_PSW(%r15)
@@ -420,20 +416,18 @@ ENTRY(\name) 
	STBEAR	__LC_LAST_BREAK

	BPOFF

	stmg	%r8,%r15,__LC_SAVE_AREA_ASYNC

	lg	%r12,__LC_CURRENT

	lmg	%r8,%r9,\lc_old_psw

	tmhh	%r8,0x0001			# interrupting from user ?

	jnz	1f

#if IS_ENABLED(CONFIG_KVM)

	OUTSIDE	%r9,.Lsie_gmap,.Lsie_done,0f

	BPENTER	__SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST)

	BPENTER	__SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST

	SIEEXIT

#endif

0:	CHECK_STACK __LC_SAVE_AREA_ASYNC

	aghi	%r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)

	j	2f

1:	BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP

	lctlg	%c1,%c1,__LC_KERNEL_ASCE

1:	lctlg	%c1,%c1,__LC_KERNEL_ASCE

	lg	%r15,__LC_KERNEL_STACK

2:	xc	__SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)

	la	%r11,STACK_FRAME_OVERHEAD(%r15)
@@ -457,7 +451,7 @@ ENTRY(\name) 
	tmhh	%r8,0x0001		# returning to user ?

	jno	2f

	lctlg	%c1,%c1,__LC_USER_ASCE

	BPEXIT	__TI_flags(%r12),_TIF_ISOLATE_BP

	BPON

	stpt	__LC_EXIT_TIMER

2:	LBEAR	__PT_LAST_BREAK(%r11)

	lmg	%r0,%r15,__PT_R0(%r11)
@@ -502,7 +496,6 @@ ENTRY(mcck_int_handler) 
	spt	__LC_CPU_TIMER_SAVE_AREA-4095(%r1)	# validate cpu timer

	LBEAR	__LC_LAST_BREAK_SAVE_AREA-4095(%r1)		# validate bear

	lmg	%r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)# validate gprs

	lg	%r12,__LC_CURRENT

	lmg	%r8,%r9,__LC_MCK_OLD_PSW

	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_SYSTEM_DAMAGE

	jo	.Lmcck_panic		# yes -> rest of mcck code invalid
@@ -531,16 +524,13 @@ ENTRY(mcck_int_handler) 
	TSTMSK	__LC_MCCK_CODE,MCCK_CODE_PSW_IA_VALID

	jno	.Lmcck_panic

#if IS_ENABLED(CONFIG_KVM)

	OUTSIDE	%r9,.Lsie_gmap,.Lsie_done,.Lmcck_stack

	OUTSIDE	%r9,.Lsie_gmap,.Lsie_done,.Lmcck_user

	OUTSIDE	%r9,.Lsie_entry,.Lsie_leave,4f

	oi	__LC_CPU_FLAGS+7, _CIF_MCCK_GUEST

4:	BPENTER	__SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST)

4:	BPENTER	__SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST

	SIEEXIT

	j	.Lmcck_stack

#endif

.Lmcck_user:

	BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP

.Lmcck_stack:

	lg	%r15,__LC_MCCK_STACK

	la	%r11,STACK_FRAME_OVERHEAD(%r15)

	stctg	%c1,%c1,__PT_CR1(%r11)
@@ -568,7 +558,7 @@ ENTRY(mcck_int_handler) 
	mvc	__LC_RETURN_MCCK_PSW(16),__PT_PSW(%r11) # move return PSW

	tm	__LC_RETURN_MCCK_PSW+1,0x01 # returning to user ?

	jno	0f

	BPEXIT	__TI_flags(%r12),_TIF_ISOLATE_BP

	BPON

	stpt	__LC_EXIT_TIMER

0:	ALTERNATIVE "nop", __stringify(lghi %r12,__LC_LAST_BREAK_SAVE_AREA),193

	LBEAR	0(%r12)

arch/s390/kernel/processor.c

+0 −9
Original line number Diff line number Diff line
@@ -365,15 +365,6 @@ const struct seq_operations cpuinfo_op = { 
	.show	= show_cpuinfo,

};



int s390_isolate_bp(void)

{

	if (!test_facility(82))

		return -EOPNOTSUPP;

	set_thread_flag(TIF_ISOLATE_BP);

	return 0;

}

EXPORT_SYMBOL(s390_isolate_bp);



int s390_isolate_bp_guest(void)

{

	if (!test_facility(82))