diff options
Diffstat (limited to 'arch/s390/kernel/entry.S')
| -rw-r--r-- | arch/s390/kernel/entry.S | 73 |
1 files changed, 31 insertions, 42 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index fc5277eab554b..787394978bc0f 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -119,33 +119,11 @@ _LPP_OFFSET = __LC_LPP .endm #if IS_ENABLED(CONFIG_KVM) - /* - * The OUTSIDE macro jumps to the provided label in case the value - * in the provided register is outside of the provided range. The - * macro is useful for checking whether a PSW stored in a register - * pair points inside or outside of a block of instructions. - * @reg: register to check - * @start: start of the range - * @end: end of the range - * @outside_label: jump here if @reg is outside of [@start..@end) - */ - .macro OUTSIDE reg,start,end,outside_label - lgr %r14,\reg - larl %r13,\start - slgr %r14,%r13 - clgfrl %r14,.Lrange_size\@ - jhe \outside_label - .section .rodata, "a" - .balign 4 -.Lrange_size\@: - .long \end - \start - .previous - .endm - - .macro SIEEXIT - lg %r9,__SF_SIE_CONTROL(%r15) # get control block pointer + .macro SIEEXIT sie_control + lg %r9,\sie_control # get control block pointer ni __SIE_PROG0C+3(%r9),0xfe # no longer in SIE lctlg %c1,%c1,__LC_KERNEL_ASCE # load primary asce + ni __LC_CPU_FLAGS+7,255-_CIF_SIE larl %r9,sie_exit # skip forward to sie_exit .endm #endif @@ -214,6 +192,7 @@ SYM_FUNC_START(__sie64a) lg %r14,__LC_GMAP # get gmap pointer ltgr %r14,%r14 jz .Lsie_gmap + oi __LC_CPU_FLAGS+7,_CIF_SIE lctlg %c1,%c1,__GMAP_ASCE(%r14) # load primary asce .Lsie_gmap: lg %r14,__SF_SIE_CONTROL(%r15) # get control block pointer @@ -234,7 +213,7 @@ SYM_FUNC_START(__sie64a) lg %r14,__SF_SIE_CONTROL(%r15) # get control block pointer ni __SIE_PROG0C+3(%r14),0xfe # no longer in SIE lctlg %c1,%c1,__LC_KERNEL_ASCE # load primary asce -.Lsie_done: + ni __LC_CPU_FLAGS+7,255-_CIF_SIE # some program checks are suppressing. C code (e.g. do_protection_exception) # will rewind the PSW by the ILC, which is often 4 bytes in case of SIE. There # are some corner cases (e.g. runtime instrumentation) where ILC is unpredictable. @@ -337,20 +316,13 @@ SYM_CODE_START(pgm_check_handler) stpt __LC_SYS_ENTER_TIMER BPOFF stmg %r8,%r15,__LC_SAVE_AREA_SYNC - lghi %r10,0 + lgr %r10,%r15 lmg %r8,%r9,__LC_PGM_OLD_PSW tmhh %r8,0x0001 # coming from user space? jno .Lpgm_skip_asce lctlg %c1,%c1,__LC_KERNEL_ASCE j 3f # -> fault in user space .Lpgm_skip_asce: -#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_GUEST - SIEEXIT - lghi %r10,_PIF_GUEST_FAULT -#endif 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 @@ -361,13 +333,20 @@ SYM_CODE_START(pgm_check_handler) CHECK_VMAP_STACK __LC_SAVE_AREA_SYNC,4f 3: lg %r15,__LC_KERNEL_STACK 4: la %r11,STACK_FRAME_OVERHEAD(%r15) - stg %r10,__PT_FLAGS(%r11) + 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 - stmg %r8,%r9,__PT_PSW(%r11) - + stctg %c1,%c1,__PT_CR1(%r11) +#if IS_ENABLED(CONFIG_KVM) + lg %r12,__LC_GMAP + clc __GMAP_ASCE(8,%r12), __PT_CR1(%r11) + jne 5f + BPENTER __SF_SIE_FLAGS(%r10),_TIF_ISOLATE_BP_GUEST + SIEEXIT __SF_SIE_CONTROL(%r10) +#endif +5: stmg %r8,%r9,__PT_PSW(%r11) # clear user controlled registers to prevent speculative use xgr %r0,%r0 xgr %r1,%r1 @@ -416,9 +395,10 @@ SYM_CODE_START(\name) tmhh %r8,0x0001 # interrupting from user ? jnz 1f #if IS_ENABLED(CONFIG_KVM) - OUTSIDE %r9,.Lsie_gmap,.Lsie_done,0f + TSTMSK __LC_CPU_FLAGS,_CIF_SIE + jz 0f BPENTER __SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST - SIEEXIT + SIEEXIT __SF_SIE_CONTROL(%r15) #endif 0: CHECK_STACK __LC_SAVE_AREA_ASYNC aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) @@ -513,11 +493,20 @@ SYM_CODE_START(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_user - OUTSIDE %r9,.Lsie_entry,.Lsie_leave,4f + TSTMSK __LC_CPU_FLAGS,_CIF_SIE + jz .Lmcck_user + # Need to compare the address instead of a CIF_SIE* flag. + # Otherwise there would be a race between setting the flag + # and entering SIE (or leaving and clearing the flag). This + # would cause machine checks targeted at the guest to be + # handled by the host. + larl %r14,.Lsie_entry + clgrjl %r9,%r14, 4f + larl %r14,.Lsie_leave + clgrjhe %r9,%r14, 4f oi __LC_CPU_FLAGS+7, _CIF_MCCK_GUEST 4: BPENTER __SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST - SIEEXIT + SIEEXIT __SF_SIE_CONTROL(%r15) #endif .Lmcck_user: lg %r15,__LC_MCCK_STACK |