Commit 9e1e275f authored by Sven Schnelle's avatar Sven Schnelle Committed by Vasily Gorbik
Browse files

s390/entry: Make pgm_check_handler() ready for lowcore relocation 



In preparation of having lowcore at different address than zero,
add the base register to all lowcore accesses in pgm_check_handler().

Reviewed-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarSven Schnelle <svens@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 86e08d64

arch/s390/include/asm/lowcore.h

+6 −0
Original line number Diff line number Diff line
@@ -244,5 +244,11 @@ static inline void set_prefix(__u32 address) 
		ALT_LOWCORE

.endm



.macro STMG_LC start, end, savearea

	ALTERNATIVE "stmg	\start, \end, \savearea",				\

		__stringify(stmg	\start, \end, LOWCORE_ALT_ADDRESS + \savearea),	\

		ALT_LOWCORE

.endm



#endif /* __ASSEMBLY__ */

#endif /* _ASM_S390_LOWCORE_H */

arch/s390/kernel/entry.S

+26 −21
Original line number Diff line number Diff line
@@ -41,7 +41,10 @@ _LPP_OFFSET = __LC_LPP 
	.endm



	.macro LPSWEY address, lpswe

	ALTERNATIVE "b \lpswe; nopr", ".insn siy,0xeb0000000071,\address,0", ALT_FACILITY(193)

	ALTERNATIVE_2 "b \lpswe;nopr", \

		".insn siy,0xeb0000000071,\address,0", ALT_FACILITY_EARLY(193),		\

		__stringify(.insn siy,0xeb0000000071,LOWCORE_ALT_ADDRESS+\address,0),	\

		ALT_LOWCORE

	.endm



	.macro MBEAR reg, lowcore
@@ -317,39 +320,40 @@ SYM_CODE_END(ret_from_fork) 
 */



SYM_CODE_START(pgm_check_handler)

	stpt	__LC_SYS_ENTER_TIMER

	STMG_LC	%r8,%r15,__LC_SAVE_AREA_SYNC

	GET_LC	%r13

	stpt	__LC_SYS_ENTER_TIMER(%r13)

	BPOFF

	stmg	%r8,%r15,__LC_SAVE_AREA_SYNC

	lgr	%r10,%r15

	lmg	%r8,%r9,__LC_PGM_OLD_PSW

	lmg	%r8,%r9,__LC_PGM_OLD_PSW(%r13)

	tmhh	%r8,0x0001		# coming from user space?

	jno	.Lpgm_skip_asce

	lctlg	%c1,%c1,__LC_KERNEL_ASCE

	lctlg	%c1,%c1,__LC_KERNEL_ASCE(%r13)

	j	3f			# -> fault in user space

.Lpgm_skip_asce:

1:	tmhh	%r8,0x4000		# PER bit set in old PSW ?

	jnz	2f			# -> enabled, can't be a double fault

	tm	__LC_PGM_ILC+3,0x80	# check for per exception

	tm	__LC_PGM_ILC+3(%r13),0x80	# check for per exception

	jnz	.Lpgm_svcper		# -> single stepped svc

2:	CHECK_STACK __LC_SAVE_AREA_SYNC,%r0

2:	CHECK_STACK __LC_SAVE_AREA_SYNC,%r13

	aghi	%r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)

	# CHECK_VMAP_STACK branches to stack_overflow or 4f

	CHECK_VMAP_STACK __LC_SAVE_AREA_SYNC,%r0,4f

3:	lg	%r15,__LC_KERNEL_STACK

	CHECK_VMAP_STACK __LC_SAVE_AREA_SYNC,%r13,4f

3:	lg	%r15,__LC_KERNEL_STACK(%r13)

4:	la	%r11,STACK_FRAME_OVERHEAD(%r15)

	xc	__PT_FLAGS(8,%r11),__PT_FLAGS(%r11)

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

	stmg	%r0,%r7,__PT_R0(%r11)

	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_SYNC

	mvc	__PT_LAST_BREAK(8,%r11),__LC_PGM_LAST_BREAK

	mvc	__PT_R8(64,%r11),__LC_SAVE_AREA_SYNC(%r13)

	mvc	__PT_LAST_BREAK(8,%r11),__LC_PGM_LAST_BREAK(%r13)

	stctg	%c1,%c1,__PT_CR1(%r11)

#if IS_ENABLED(CONFIG_KVM)

	ltg	%r12,__LC_GMAP

	ltg	%r12,__LC_GMAP(%r13)

	jz	5f

	clc	__GMAP_ASCE(8,%r12), __PT_CR1(%r11)

	jne	5f

	BPENTER	__SF_SIE_FLAGS(%r10),_TIF_ISOLATE_BP_GUEST

	SIEEXIT __SF_SIE_CONTROL(%r10),%r0

	SIEEXIT __SF_SIE_CONTROL(%r10),%r13

#endif

5:	stmg	%r8,%r9,__PT_PSW(%r11)

	# clear user controlled registers to prevent speculative use
@@ -365,11 +369,11 @@ SYM_CODE_START(pgm_check_handler) 
	tmhh	%r8,0x0001		# returning to user space?

	jno	.Lpgm_exit_kernel

	STACKLEAK_ERASE

	lctlg	%c1,%c1,__LC_USER_ASCE

	lctlg	%c1,%c1,__LC_USER_ASCE(%r13)

	BPON

	stpt	__LC_EXIT_TIMER

	stpt	__LC_EXIT_TIMER(%r13)

.Lpgm_exit_kernel:

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

	mvc	__LC_RETURN_PSW(16,%r13),STACK_FRAME_OVERHEAD+__PT_PSW(%r15)

	LBEAR	STACK_FRAME_OVERHEAD+__PT_LAST_BREAK(%r15)

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

	LPSWEY	__LC_RETURN_PSW,__LC_RETURN_LPSWE
@@ -378,11 +382,11 @@ SYM_CODE_START(pgm_check_handler) 
# single stepped system call

#

.Lpgm_svcper:

	mvc	__LC_RETURN_PSW(8),__LC_SVC_NEW_PSW

	mvc	__LC_RETURN_PSW(8,%r13),__LC_SVC_NEW_PSW(%r13)

	larl	%r14,.Lsysc_per

	stg	%r14,__LC_RETURN_PSW+8

	stg	%r14,__LC_RETURN_PSW+8(%r13)

	lghi	%r14,1

	LBEAR	__LC_PGM_LAST_BREAK

	LBEAR	__LC_PGM_LAST_BREAK(%r13)

	LPSWEY	__LC_RETURN_PSW,__LC_RETURN_LPSWE # branch to .Lsysc_per

SYM_CODE_END(pgm_check_handler)
@@ -596,7 +600,8 @@ SYM_CODE_END(restart_int_handler) 
 * Setup a pt_regs so that show_trace can provide a good call trace.

 */

SYM_CODE_START(stack_overflow)

	lg	%r15,__LC_NODAT_STACK	# change to panic stack

	GET_LC	%r15

	lg	%r15,__LC_NODAT_STACK(%r15) # change to panic stack

	la	%r11,STACK_FRAME_OVERHEAD(%r15)

	stmg	%r0,%r7,__PT_R0(%r11)

	stmg	%r8,%r9,__PT_PSW(%r11)