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| author |   Alexander Gordeev <agordeev@linux.ibm.com> | 2021-06-18 08:17:16 +0200 |
|---|---|---|
| committer |   Vasily Gorbik <gor@linux.ibm.com> | 2021-07-05 12:44:23 +0200 |
| commit | d35925b34996196d22a4357dc5212ab03af75151 (patch) | |
| tree | a2e4001cb410ce8e71cc8f93b333e1304170bd69 /arch/s390/kernel/entry.S | |
| parent | s390/mcck: always enter C handler with DAT enabled (diff) | |
| download | linux-dev-d35925b34996196d22a4357dc5212ab03af75151.tar.xz linux-dev-d35925b34996196d22a4357dc5212ab03af75151.zip | |
s390/mcck: move storage error checks to assembler
The current storage errors tackling is wrong - the DAT is
enabled in assembler code before the actual storage checks
in C half are executed. In case the page tables themselves
are damaged such approach is not going to work.
With this update unrecoverable storage errors are not
passed to C code for handling, but rather the machine
is stopped right away. The only exception to this flow
is when a machine check occurred in KVM guest - in this
case the errors are reinjected by the handler.
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'arch/s390/kernel/entry.S')
| -rw-r--r-- | arch/s390/kernel/entry.S | 43 |
1 files changed, 32 insertions, 11 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index 6bc8ed800458..8f72a8f9bc33 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -129,6 +129,24 @@ _LPP_OFFSET = __LC_LPP "jnz .+8; .long 0xb2e8d000", 82 .endm + /* + * The CHKSTG macro jumps to the provided label in case the + * machine check interruption code reports one of unrecoverable + * storage errors: + * - Storage error uncorrected + * - Storage key error uncorrected + * - Storage degradation with Failing-storage-address validity + */ + .macro CHKSTG errlabel + TSTMSK __LC_MCCK_CODE,(MCCK_CODE_STG_ERROR|MCCK_CODE_STG_KEY_ERROR) + jnz \errlabel + TSTMSK __LC_MCCK_CODE,MCCK_CODE_STG_DEGRAD + jz oklabel\@ + TSTMSK __LC_MCCK_CODE,MCCK_CODE_STG_FAIL_ADDR + jnz \errlabel +oklabel\@: + .endm + #if IS_ENABLED(CONFIG_KVM) /* * The OUTSIDE macro jumps to the provided label in case the value @@ -550,23 +568,26 @@ ENTRY(mcck_int_handler) 3: TSTMSK __LC_MCCK_CODE,MCCK_CODE_PSW_MWP_VALID jno .Lmcck_panic tmhh %r8,0x0001 # interrupting from user ? - jnz 4f + jnz 6f TSTMSK __LC_MCCK_CODE,MCCK_CODE_PSW_IA_VALID jno .Lmcck_panic -4: ssm __LC_PGM_NEW_PSW # turn dat on, keep irqs off - tmhh %r8,0x0001 # interrupting from user ? #if IS_ENABLED(CONFIG_KVM) - jnz .Lmcck_user - OUTSIDE %r9,.Lsie_gmap,.Lsie_done,.Lmcck_stack - OUTSIDE %r9,.Lsie_entry,.Lsie_skip,5f + OUTSIDE %r9,.Lsie_gmap,.Lsie_done,6f + OUTSIDE %r9,.Lsie_entry,.Lsie_skip,4f oi __LC_CPU_FLAGS+7, _CIF_MCCK_GUEST -5: BPENTER __SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST) + j 5f +4: CHKSTG .Lmcck_panic +5: larl %r14,.Lstosm_tmp + stosm 0(%r14),0x04 # turn dat on, keep irqs off + BPENTER __SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST) SIEEXIT j .Lmcck_stack -#else - jz .Lmcck_stack #endif -.Lmcck_user: +6: CHKSTG .Lmcck_panic + larl %r14,.Lstosm_tmp + stosm 0(%r14),0x04 # turn dat on, keep irqs off + tmhh %r8,0x0001 # interrupting from user ? + jz .Lmcck_stack BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP .Lmcck_stack: lg %r15,__LC_MCCK_STACK @@ -692,7 +713,7 @@ ENDPROC(stack_overflow) .align 4 .Lstop_lock: .long 0 .Lthis_cpu: .short 0 - +.Lstosm_tmp: .byte 0 .section .rodata, "a" #define SYSCALL(esame,emu) .quad __s390x_ ## esame .globl sys_call_table |