android_kernel_samsung_sm8650/arch/s390/kernel/base.S
Heiko Carstens cfa45c5e0d s390/base: pass pt_regs to early program check handler
Pass pt_regs to early program check handler like it is done for every
other interrupt and exception handler.

Also the passed pt_regs can be changed by the called function and the
changes register contents and psw contents will be taken into account
when returning. In addition the return psw will not be copied to the
program check old psw in lowcore, but to the usual return psw
location, like it is also done by the regular program check handler.
This allows also to get rid of the code that disabled lowcore
protection when changing the return address.

Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-03-08 00:33:00 +01:00

51 lines
1.2 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* arch/s390/kernel/base.S
*
* Copyright IBM Corp. 2006, 2007
* Author(s): Michael Holzheu <holzheu@de.ibm.com>
*/
#include <linux/linkage.h>
#include <asm/asm-offsets.h>
#include <asm/nospec-insn.h>
#include <asm/ptrace.h>
GEN_BR_THUNK %r9
GEN_BR_THUNK %r14
__PT_R0 = __PT_GPRS
__PT_R8 = __PT_GPRS + 64
ENTRY(s390_base_pgm_handler)
stmg %r8,%r15,__LC_SAVE_AREA_SYNC
aghi %r15,-(STACK_FRAME_OVERHEAD+__PT_SIZE)
la %r11,STACK_FRAME_OVERHEAD(%r15)
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
stmg %r0,%r7,__PT_R0(%r11)
mvc __PT_PSW(16,%r11),__LC_PGM_OLD_PSW
mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
lgr %r2,%r11
larl %r1,s390_base_pgm_handler_fn
lg %r9,0(%r1)
ltgr %r9,%r9
jz 1f
BASR_EX %r14,%r9
mvc __LC_RETURN_PSW(16),STACK_FRAME_OVERHEAD+__PT_PSW(%r15)
lmg %r0,%r15,STACK_FRAME_OVERHEAD+__PT_R0(%r15)
lpswe __LC_RETURN_PSW
1: larl %r13,disabled_wait_psw
lpswe 0(%r13)
ENDPROC(s390_base_pgm_handler)
.align 8
disabled_wait_psw:
.quad 0x0002000180000000,0x0000000000000000 + s390_base_pgm_handler
.section .bss
.align 8
.globl s390_base_pgm_handler_fn
s390_base_pgm_handler_fn:
.quad 0
.previous