mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-10-02 15:18:19 +00:00
Code Issues Releases Wiki Activity

s390: open code SWITCH_KERNEL macro

Browse source 
This is a preparation patch for two later bugfixes. In the past both
int_handler and machine check handler used SWITCH_KERNEL to switch to
the kernel stack. However, SWITCH_KERNEL doesn't work properly in machine
check context. So instead of adding more complexity to this macro, just
remove it.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Cc: <stable@kernel.org> # v5.8+
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This commit is contained in:
Sven Schnelle 2021-01-28 13:06:05 +01:00 committed by Vasily Gorbik
parent 1c7673476b
commit b0d31159a4
1 changed files with 46 additions and 28 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

74
arch/s390/kernel/entry.S
View file

@ -81,32 +81,6 @@ _LPP_OFFSET = __LC_LPP
#endif
.endm
.macro SWITCH_KERNEL savearea
tmhh %r8,0x0001 # interrupting from user ?
jnz 1f
#if IS_ENABLED(CONFIG_KVM)
lgr %r14,%r9
larl %r13,.Lsie_gmap
slgr %r14,%r13
lghi %r13,.Lsie_done - .Lsie_gmap
clgr %r14,%r13
jhe 0f
lghi %r11,\savearea # inside critical section, do cleanup
brasl %r14,.Lcleanup_sie
#endif
0: CHECK_STACK \savearea
lgr %r11,%r15
aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
stg %r11,__SF_BACKCHAIN(%r15)
j 2f
1: BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP
lctlg %c1,%c1,__LC_KERNEL_ASCE
lg %r15,__LC_KERNEL_STACK
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
2: la %r11,STACK_FRAME_OVERHEAD(%r15)
.endm
# Use STORE CLOCK by default, switch to STORE CLOCK FAST if available.
.macro STCK savearea
ALTERNATIVE ".insn s,0xb2050000,\savearea", \
".insn s,0xb27c0000,\savearea", 25
@ -413,7 +387,28 @@ ENTRY(\name)
stmg %r8,%r15,__LC_SAVE_AREA_ASYNC
lg %r12,__LC_CURRENT
lmg %r8,%r9,\lc_old_psw
SWITCH_KERNEL __LC_SAVE_AREA_ASYNC
tmhh %r8,0x0001 # interrupting from user ?
jnz 1f
#if IS_ENABLED(CONFIG_KVM)
lgr %r14,%r9
larl %r13,.Lsie_gmap
slgr %r14,%r13
lghi %r13,.Lsie_done - .Lsie_gmap
clgr %r14,%r13
jhe 0f
lghi %r11,__LC_SAVE_AREA_ASYNC # inside critical section, do cleanup
brasl %r14,.Lcleanup_sie
#endif
0: CHECK_STACK __LC_SAVE_AREA_ASYNC
lgr %r11,%r15
aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
stg %r11,__SF_BACKCHAIN(%r15)
j 2f
1: BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP
lctlg %c1,%c1,__LC_KERNEL_ASCE
lg %r15,__LC_KERNEL_STACK
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
2: la %r11,STACK_FRAME_OVERHEAD(%r15)
stmg %r0,%r7,__PT_R0(%r11)
# clear user controlled registers to prevent speculative use
xgr %r0,%r0
@ -542,7 +537,30 @@ ENTRY(mcck_int_handler)
TSTMSK __LC_MCCK_CODE,MCCK_CODE_PSW_IA_VALID
jno .Lmcck_panic
4: ssm __LC_PGM_NEW_PSW # turn dat on, keep irqs off
SWITCH_KERNEL __LC_GPREGS_SAVE_AREA+64
tmhh %r8,0x0001 # interrupting from user ?
jnz .Lmcck_user
#if IS_ENABLED(CONFIG_KVM)
lgr %r14,%r9
larl %r13,.Lsie_gmap
slgr %r14,%r13
lghi %r13,.Lsie_done - .Lsie_gmap
clgr %r14,%r13
jhe .Lmcck_stack
lghi %r11,__LC_GPREGS_SAVE_AREA+64 # inside critical section, do cleanup
brasl %r14,.Lcleanup_sie
.Lmcck_stack:
#endif
CHECK_STACK __LC_GPREGS_SAVE_AREA+64
lgr %r11,%r15
aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
stg %r11,__SF_BACKCHAIN(%r15)
j 5f
.Lmcck_user:
BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP
lctlg %c1,%c1,__LC_KERNEL_ASCE
lg %r15,__LC_KERNEL_STACK
xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15)
5: la %r11,STACK_FRAME_OVERHEAD(%r15)
.Lmcck_skip:
lghi %r14,__LC_GPREGS_SAVE_AREA+64
stmg %r0,%r7,__PT_R0(%r11)