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-rw-r--r--arch/s390/kernel/entry.S249
1 files changed, 224 insertions, 25 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 6cd444d25545..13a133a6015c 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -107,6 +107,7 @@ _PIF_WORK = (_PIF_PER_TRAP | _PIF_SYSCALL_RESTART)
aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
j 3f
1: UPDATE_VTIME %r14,%r15,\timer
+ BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP
2: lg %r15,__LC_ASYNC_STACK # load async stack
3: la %r11,STACK_FRAME_OVERHEAD(%r15)
.endm
@@ -159,6 +160,130 @@ _PIF_WORK = (_PIF_PER_TRAP | _PIF_SYSCALL_RESTART)
tm off+\addr, \mask
.endm
+ .macro BPOFF
+ .pushsection .altinstr_replacement, "ax"
+660: .long 0xb2e8c000
+ .popsection
+661: .long 0x47000000
+ .pushsection .altinstructions, "a"
+ .long 661b - .
+ .long 660b - .
+ .word 82
+ .byte 4
+ .byte 4
+ .popsection
+ .endm
+
+ .macro BPON
+ .pushsection .altinstr_replacement, "ax"
+662: .long 0xb2e8d000
+ .popsection
+663: .long 0x47000000
+ .pushsection .altinstructions, "a"
+ .long 663b - .
+ .long 662b - .
+ .word 82
+ .byte 4
+ .byte 4
+ .popsection
+ .endm
+
+ .macro BPENTER tif_ptr,tif_mask
+ .pushsection .altinstr_replacement, "ax"
+662: .word 0xc004, 0x0000, 0x0000 # 6 byte nop
+ .word 0xc004, 0x0000, 0x0000 # 6 byte nop
+ .popsection
+664: TSTMSK \tif_ptr,\tif_mask
+ jz . + 8
+ .long 0xb2e8d000
+ .pushsection .altinstructions, "a"
+ .long 664b - .
+ .long 662b - .
+ .word 82
+ .byte 12
+ .byte 12
+ .popsection
+ .endm
+
+ .macro BPEXIT tif_ptr,tif_mask
+ TSTMSK \tif_ptr,\tif_mask
+ .pushsection .altinstr_replacement, "ax"
+662: jnz . + 8
+ .long 0xb2e8d000
+ .popsection
+664: jz . + 8
+ .long 0xb2e8c000
+ .pushsection .altinstructions, "a"
+ .long 664b - .
+ .long 662b - .
+ .word 82
+ .byte 8
+ .byte 8
+ .popsection
+ .endm
+
+#ifdef CONFIG_EXPOLINE
+
+ .macro GEN_BR_THUNK name,reg,tmp
+ .section .text.\name,"axG",@progbits,\name,comdat
+ .globl \name
+ .hidden \name
+ .type \name,@function
+\name:
+ .cfi_startproc
+#ifdef CONFIG_HAVE_MARCH_Z10_FEATURES
+ exrl 0,0f
+#else
+ larl \tmp,0f
+ ex 0,0(\tmp)
+#endif
+ j .
+0: br \reg
+ .cfi_endproc
+ .endm
+
+ GEN_BR_THUNK __s390x_indirect_jump_r1use_r9,%r9,%r1
+ GEN_BR_THUNK __s390x_indirect_jump_r1use_r14,%r14,%r1
+ GEN_BR_THUNK __s390x_indirect_jump_r11use_r14,%r14,%r11
+
+ .macro BASR_R14_R9
+0: brasl %r14,__s390x_indirect_jump_r1use_r9
+ .pushsection .s390_indirect_branches,"a",@progbits
+ .long 0b-.
+ .popsection
+ .endm
+
+ .macro BR_R1USE_R14
+0: jg __s390x_indirect_jump_r1use_r14
+ .pushsection .s390_indirect_branches,"a",@progbits
+ .long 0b-.
+ .popsection
+ .endm
+
+ .macro BR_R11USE_R14
+0: jg __s390x_indirect_jump_r11use_r14
+ .pushsection .s390_indirect_branches,"a",@progbits
+ .long 0b-.
+ .popsection
+ .endm
+
+#else /* CONFIG_EXPOLINE */
+
+ .macro BASR_R14_R9
+ basr %r14,%r9
+ .endm
+
+ .macro BR_R1USE_R14
+ br %r14
+ .endm
+
+ .macro BR_R11USE_R14
+ br %r14
+ .endm
+
+#endif /* CONFIG_EXPOLINE */
+
+
.section .kprobes.text, "ax"
.Ldummy:
/*
@@ -171,6 +296,11 @@ _PIF_WORK = (_PIF_PER_TRAP | _PIF_SYSCALL_RESTART)
*/
nop 0
+ENTRY(__bpon)
+ .globl __bpon
+ BPON
+ BR_R1USE_R14
+
/*
* Scheduler resume function, called by switch_to
* gpr2 = (task_struct *) prev
@@ -193,9 +323,9 @@ ENTRY(__switch_to)
mvc __LC_CURRENT_PID(4,%r0),0(%r3) # store pid of next
lmg %r6,%r15,__SF_GPRS(%r15) # load gprs of next task
TSTMSK __LC_MACHINE_FLAGS,MACHINE_FLAG_LPP
- bzr %r14
+ jz 0f
.insn s,0xb2800000,__LC_LPP # set program parameter
- br %r14
+0: BR_R1USE_R14
.L__critical_start:
@@ -207,9 +337,11 @@ ENTRY(__switch_to)
*/
ENTRY(sie64a)
stmg %r6,%r14,__SF_GPRS(%r15) # save kernel registers
+ lg %r12,__LC_CURRENT
stg %r2,__SF_EMPTY(%r15) # save control block pointer
stg %r3,__SF_EMPTY+8(%r15) # save guest register save area
xc __SF_EMPTY+16(8,%r15),__SF_EMPTY+16(%r15) # reason code = 0
+ mvc __SF_EMPTY+24(8,%r15),__TI_flags(%r12) # copy thread flags
TSTMSK __LC_CPU_FLAGS,_CIF_FPU # load guest fp/vx registers ?
jno .Lsie_load_guest_gprs
brasl %r14,load_fpu_regs # load guest fp/vx regs
@@ -226,8 +358,12 @@ ENTRY(sie64a)
jnz .Lsie_skip
TSTMSK __LC_CPU_FLAGS,_CIF_FPU
jo .Lsie_skip # exit if fp/vx regs changed
+ BPEXIT __SF_EMPTY+24(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST)
.Lsie_entry:
sie 0(%r14)
+.Lsie_exit:
+ BPOFF
+ BPENTER __SF_EMPTY+24(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST)
.Lsie_skip:
ni __SIE_PROG0C+3(%r14),0xfe # no longer in SIE
lctlg %c1,%c1,__LC_USER_ASCE # load primary asce
@@ -248,9 +384,15 @@ ENTRY(sie64a)
sie_exit:
lg %r14,__SF_EMPTY+8(%r15) # load guest register save area
stmg %r0,%r13,0(%r14) # save guest gprs 0-13
+ xgr %r0,%r0 # clear guest registers to
+ xgr %r1,%r1 # prevent speculative use
+ xgr %r2,%r2
+ xgr %r3,%r3
+ xgr %r4,%r4
+ xgr %r5,%r5
lmg %r6,%r14,__SF_GPRS(%r15) # restore kernel registers
lg %r2,__SF_EMPTY+16(%r15) # return exit reason code
- br %r14
+ BR_R1USE_R14
.Lsie_fault:
lghi %r14,-EFAULT
stg %r14,__SF_EMPTY+16(%r15) # set exit reason code
@@ -273,6 +415,7 @@ ENTRY(system_call)
stpt __LC_SYNC_ENTER_TIMER
.Lsysc_stmg:
stmg %r8,%r15,__LC_SAVE_AREA_SYNC
+ BPOFF
lg %r12,__LC_CURRENT
lghi %r13,__TASK_thread
lghi %r14,_PIF_SYSCALL
@@ -281,7 +424,10 @@ ENTRY(system_call)
la %r11,STACK_FRAME_OVERHEAD(%r15) # pointer to pt_regs
.Lsysc_vtime:
UPDATE_VTIME %r8,%r9,__LC_SYNC_ENTER_TIMER
+ BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP
stmg %r0,%r7,__PT_R0(%r11)
+ # clear user controlled register to prevent speculative use
+ xgr %r0,%r0
mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
mvc __PT_PSW(16,%r11),__LC_SVC_OLD_PSW
mvc __PT_INT_CODE(4,%r11),__LC_SVC_ILC
@@ -305,7 +451,7 @@ ENTRY(system_call)
lgf %r9,0(%r8,%r10) # get system call add.
TSTMSK __TI_flags(%r12),_TIF_TRACE
jnz .Lsysc_tracesys
- basr %r14,%r9 # call sys_xxxx
+ BASR_R14_R9 # call sys_xxxx
stg %r2,__PT_R2(%r11) # store return value
.Lsysc_return:
@@ -317,6 +463,7 @@ ENTRY(system_call)
jnz .Lsysc_work # check for work
TSTMSK __LC_CPU_FLAGS,_CIF_WORK
jnz .Lsysc_work
+ BPEXIT __TI_flags(%r12),_TIF_ISOLATE_BP
.Lsysc_restore:
lg %r14,__LC_VDSO_PER_CPU
lmg %r0,%r10,__PT_R0(%r11)
@@ -489,7 +636,7 @@ ENTRY(system_call)
lmg %r3,%r7,__PT_R3(%r11)
stg %r7,STACK_FRAME_OVERHEAD(%r15)
lg %r2,__PT_ORIG_GPR2(%r11)
- basr %r14,%r9 # call sys_xxx
+ BASR_R14_R9 # call sys_xxx
stg %r2,__PT_R2(%r11) # store return value
.Lsysc_tracenogo:
TSTMSK __TI_flags(%r12),_TIF_TRACE
@@ -513,7 +660,7 @@ ENTRY(ret_from_fork)
lmg %r9,%r10,__PT_R9(%r11) # load gprs
ENTRY(kernel_thread_starter)
la %r2,0(%r10)
- basr %r14,%r9
+ BASR_R14_R9
j .Lsysc_tracenogo
/*
@@ -522,6 +669,7 @@ ENTRY(kernel_thread_starter)
ENTRY(pgm_check_handler)
stpt __LC_SYNC_ENTER_TIMER
+ BPOFF
stmg %r8,%r15,__LC_SAVE_AREA_SYNC
lg %r10,__LC_LAST_BREAK
lg %r12,__LC_CURRENT
@@ -550,6 +698,7 @@ ENTRY(pgm_check_handler)
aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE)
j 4f
2: UPDATE_VTIME %r14,%r15,__LC_SYNC_ENTER_TIMER
+ BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP
lg %r15,__LC_KERNEL_STACK
lgr %r14,%r12
aghi %r14,__TASK_thread # pointer to thread_struct
@@ -561,6 +710,15 @@ ENTRY(pgm_check_handler)
4: lgr %r13,%r11
la %r11,STACK_FRAME_OVERHEAD(%r15)
stmg %r0,%r7,__PT_R0(%r11)
+ # clear user controlled registers to prevent speculative use
+ xgr %r0,%r0
+ xgr %r1,%r1
+ xgr %r2,%r2
+ xgr %r3,%r3
+ xgr %r4,%r4
+ xgr %r5,%r5
+ xgr %r6,%r6
+ xgr %r7,%r7
mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC
stmg %r8,%r9,__PT_PSW(%r11)
mvc __PT_INT_CODE(4,%r11),__LC_PGM_ILC
@@ -582,9 +740,9 @@ ENTRY(pgm_check_handler)
nill %r10,0x007f
sll %r10,2
je .Lpgm_return
- lgf %r1,0(%r10,%r1) # load address of handler routine
+ lgf %r9,0(%r10,%r1) # load address of handler routine
lgr %r2,%r11 # pass pointer to pt_regs
- basr %r14,%r1 # branch to interrupt-handler
+ BASR_R14_R9 # branch to interrupt-handler
.Lpgm_return:
LOCKDEP_SYS_EXIT
tm __PT_PSW+1(%r11),0x01 # returning to user ?
@@ -620,12 +778,23 @@ ENTRY(pgm_check_handler)
ENTRY(io_int_handler)
STCK __LC_INT_CLOCK
stpt __LC_ASYNC_ENTER_TIMER
+ BPOFF
stmg %r8,%r15,__LC_SAVE_AREA_ASYNC
lg %r12,__LC_CURRENT
larl %r13,cleanup_critical
lmg %r8,%r9,__LC_IO_OLD_PSW
SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER
stmg %r0,%r7,__PT_R0(%r11)
+ # clear user controlled registers to prevent speculative use
+ xgr %r0,%r0
+ xgr %r1,%r1
+ xgr %r2,%r2
+ xgr %r3,%r3
+ xgr %r4,%r4
+ xgr %r5,%r5
+ xgr %r6,%r6
+ xgr %r7,%r7
+ xgr %r10,%r10
mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
stmg %r8,%r9,__PT_PSW(%r11)
mvc __PT_INT_CODE(12,%r11),__LC_SUBCHANNEL_ID
@@ -660,9 +829,13 @@ ENTRY(io_int_handler)
lg %r14,__LC_VDSO_PER_CPU
lmg %r0,%r10,__PT_R0(%r11)
mvc __LC_RETURN_PSW(16),__PT_PSW(%r11)
+ tm __PT_PSW+1(%r11),0x01 # returning to user ?
+ jno .Lio_exit_kernel
+ BPEXIT __TI_flags(%r12),_TIF_ISOLATE_BP
.Lio_exit_timer:
stpt __LC_EXIT_TIMER
mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
+.Lio_exit_kernel:
lmg %r11,%r15,__PT_R11(%r11)
lpswe __LC_RETURN_PSW
.Lio_done:
@@ -833,12 +1006,23 @@ ENTRY(io_int_handler)
ENTRY(ext_int_handler)
STCK __LC_INT_CLOCK
stpt __LC_ASYNC_ENTER_TIMER
+ BPOFF
stmg %r8,%r15,__LC_SAVE_AREA_ASYNC
lg %r12,__LC_CURRENT
larl %r13,cleanup_critical
lmg %r8,%r9,__LC_EXT_OLD_PSW
SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_ENTER_TIMER
stmg %r0,%r7,__PT_R0(%r11)
+ # clear user controlled registers to prevent speculative use
+ xgr %r0,%r0
+ xgr %r1,%r1
+ xgr %r2,%r2
+ xgr %r3,%r3
+ xgr %r4,%r4
+ xgr %r5,%r5
+ xgr %r6,%r6
+ xgr %r7,%r7
+ xgr %r10,%r10
mvc __PT_R8(64,%r11),__LC_SAVE_AREA_ASYNC
stmg %r8,%r9,__PT_PSW(%r11)
lghi %r1,__LC_EXT_PARAMS2
@@ -871,11 +1055,12 @@ ENTRY(psw_idle)
.Lpsw_idle_stcctm:
#endif
oi __LC_CPU_FLAGS+7,_CIF_ENABLED_WAIT
+ BPON
STCK __CLOCK_IDLE_ENTER(%r2)
stpt __TIMER_IDLE_ENTER(%r2)
.Lpsw_idle_lpsw:
lpswe __SF_EMPTY(%r15)
- br %r14
+ BR_R1USE_R14
.Lpsw_idle_end:
/*
@@ -889,7 +1074,7 @@ ENTRY(save_fpu_regs)
lg %r2,__LC_CURRENT
aghi %r2,__TASK_thread
TSTMSK __LC_CPU_FLAGS,_CIF_FPU
- bor %r14
+ jo .Lsave_fpu_regs_exit
stfpc __THREAD_FPU_fpc(%r2)
lg %r3,__THREAD_FPU_regs(%r2)
TSTMSK __LC_MACHINE_FLAGS,MACHINE_FLAG_VX
@@ -916,7 +1101,8 @@ ENTRY(save_fpu_regs)
std 15,120(%r3)
.Lsave_fpu_regs_done:
oi __LC_CPU_FLAGS+7,_CIF_FPU
- br %r14
+.Lsave_fpu_regs_exit:
+ BR_R1USE_R14
.Lsave_fpu_regs_end:
EXPORT_SYMBOL(save_fpu_regs)
@@ -934,7 +1120,7 @@ load_fpu_regs:
lg %r4,__LC_CURRENT
aghi %r4,__TASK_thread
TSTMSK __LC_CPU_FLAGS,_CIF_FPU
- bnor %r14
+ jno .Lload_fpu_regs_exit
lfpc __THREAD_FPU_fpc(%r4)
TSTMSK __LC_MACHINE_FLAGS,MACHINE_FLAG_VX
lg %r4,__THREAD_FPU_regs(%r4) # %r4 <- reg save area
@@ -961,7 +1147,8 @@ load_fpu_regs:
ld 15,120(%r4)
.Lload_fpu_regs_done:
ni __LC_CPU_FLAGS+7,255-_CIF_FPU
- br %r14
+.Lload_fpu_regs_exit:
+ BR_R1USE_R14
.Lload_fpu_regs_end:
.L__critical_end:
@@ -971,6 +1158,7 @@ load_fpu_regs:
*/
ENTRY(mcck_int_handler)
STCK __LC_MCCK_CLOCK
+ BPOFF
la %r1,4095 # validate r1
spt __LC_CPU_TIMER_SAVE_AREA-4095(%r1) # validate cpu timer
sckc __LC_CLOCK_COMPARATOR # validate comparator
@@ -1046,6 +1234,16 @@ ENTRY(mcck_int_handler)
.Lmcck_skip:
lghi %r14,__LC_GPREGS_SAVE_AREA+64
stmg %r0,%r7,__PT_R0(%r11)
+ # clear user controlled registers to prevent speculative use
+ xgr %r0,%r0
+ xgr %r1,%r1
+ xgr %r2,%r2
+ xgr %r3,%r3
+ xgr %r4,%r4
+ xgr %r5,%r5
+ xgr %r6,%r6
+ xgr %r7,%r7
+ xgr %r10,%r10
mvc __PT_R8(64,%r11),0(%r14)
stmg %r8,%r9,__PT_PSW(%r11)
xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11)
@@ -1071,6 +1269,7 @@ ENTRY(mcck_int_handler)
mvc __LC_RETURN_MCCK_PSW(16),__PT_PSW(%r11) # move return PSW
tm __LC_RETURN_MCCK_PSW+1,0x01 # returning to user ?
jno 0f
+ BPEXIT __TI_flags(%r12),_TIF_ISOLATE_BP
stpt __LC_EXIT_TIMER
mvc __VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
0: lmg %r11,%r15,__PT_R11(%r11)
@@ -1166,7 +1365,7 @@ cleanup_critical:
jl 0f
clg %r9,BASED(.Lcleanup_table+104) # .Lload_fpu_regs_end
jl .Lcleanup_load_fpu_regs
-0: br %r14
+0: BR_R11USE_R14
.align 8
.Lcleanup_table:
@@ -1197,11 +1396,12 @@ cleanup_critical:
clg %r9,BASED(.Lsie_crit_mcck_length)
jh 1f
oi __LC_CPU_FLAGS+7, _CIF_MCCK_GUEST
-1: lg %r9,__SF_EMPTY(%r15) # get control block pointer
+1: BPENTER __SF_EMPTY+24(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST)
+ lg %r9,__SF_EMPTY(%r15) # get control block pointer
ni __SIE_PROG0C+3(%r9),0xfe # no longer in SIE
lctlg %c1,%c1,__LC_USER_ASCE # load primary asce
larl %r9,sie_exit # skip forward to sie_exit
- br %r14
+ BR_R11USE_R14
#endif
.Lcleanup_system_call:
@@ -1254,7 +1454,7 @@ cleanup_critical:
stg %r15,56(%r11) # r15 stack pointer
# set new psw address and exit
larl %r9,.Lsysc_do_svc
- br %r14
+ BR_R11USE_R14
.Lcleanup_system_call_insn:
.quad system_call
.quad .Lsysc_stmg
@@ -1266,7 +1466,7 @@ cleanup_critical:
.Lcleanup_sysc_tif:
larl %r9,.Lsysc_tif
- br %r14
+ BR_R11USE_R14
.Lcleanup_sysc_restore:
# check if stpt has been executed
@@ -1283,14 +1483,14 @@ cleanup_critical:
mvc 0(64,%r11),__PT_R8(%r9)
lmg %r0,%r7,__PT_R0(%r9)
1: lmg %r8,%r9,__LC_RETURN_PSW
- br %r14
+ BR_R11USE_R14
.Lcleanup_sysc_restore_insn:
.quad .Lsysc_exit_timer
.quad .Lsysc_done - 4
.Lcleanup_io_tif:
larl %r9,.Lio_tif
- br %r14
+ BR_R11USE_R14
.Lcleanup_io_restore:
# check if stpt has been executed
@@ -1304,7 +1504,7 @@ cleanup_critical:
mvc 0(64,%r11),__PT_R8(%r9)
lmg %r0,%r7,__PT_R0(%r9)
1: lmg %r8,%r9,__LC_RETURN_PSW
- br %r14
+ BR_R11USE_R14
.Lcleanup_io_restore_insn:
.quad .Lio_exit_timer
.quad .Lio_done - 4
@@ -1357,17 +1557,17 @@ cleanup_critical:
# prepare return psw
nihh %r8,0xfcfd # clear irq & wait state bits
lg %r9,48(%r11) # return from psw_idle
- br %r14
+ BR_R11USE_R14
.Lcleanup_idle_insn:
.quad .Lpsw_idle_lpsw
.Lcleanup_save_fpu_regs:
larl %r9,save_fpu_regs
- br %r14
+ BR_R11USE_R14
.Lcleanup_load_fpu_regs:
larl %r9,load_fpu_regs
- br %r14
+ BR_R11USE_R14
/*
* Integer constants
@@ -1387,7 +1587,6 @@ cleanup_critical:
.Lsie_crit_mcck_length:
.quad .Lsie_skip - .Lsie_entry
#endif
-
.section .rodata, "a"
#define SYSCALL(esame,emu) .long esame
.globl sys_call_table
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-01 21:35:53 +0300