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authorLinus Torvalds <torvalds@linux-foundation.org>2018-04-09 19:04:10 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-04-09 19:04:10 +0300
commitbecdce1c66b21ce1c0452e16127182ef692f47ba (patch)
treea37f26fbbc43fad56b12881f6d57dc4a0fdb8d98 /arch/s390/kernel/entry.S
parentf8cf2f16a7c95acce497bfafa90e7c6d8397d653 (diff)
parent92fa7a13c845c91f6a8177250474bbcab7fcf45e (diff)
downloadlinux-becdce1c66b21ce1c0452e16127182ef692f47ba.tar.xz
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Martin Schwidefsky: - Improvements for the spectre defense: * The spectre related code is consolidated to a single file nospec-branch.c * Automatic enable/disable for the spectre v2 defenses (expoline vs. nobp) * Syslog messages for specve v2 are added * Enable CONFIG_GENERIC_CPU_VULNERABILITIES and define the attribute functions for spectre v1 and v2 - Add helper macros for assembler alternatives and use them to shorten the code in entry.S. - Add support for persistent configuration data via the SCLP Store Data interface. The H/W interface requires a page table that uses 4K pages only, the code to setup such an address space is added as well. - Enable virtio GPU emulation in QEMU. To do this the depends statements for a few common Kconfig options are modified. - Add support for format-3 channel path descriptors and add a binary sysfs interface to export the associated utility strings. - Add a sysfs attribute to control the IFCC handling in case of constant channel errors. - The vfio-ccw changes from Cornelia. - Bug fixes and cleanups. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (40 commits) s390/kvm: improve stack frame constants in entry.S s390/lpp: use assembler alternatives for the LPP instruction s390/entry.S: use assembler alternatives s390: add assembler macros for CPU alternatives s390: add sysfs attributes for spectre s390: report spectre mitigation via syslog s390: add automatic detection of the spectre defense s390: move nobp parameter functions to nospec-branch.c s390/cio: add util_string sysfs attribute s390/chsc: query utility strings via fmt3 channel path descriptor s390/cio: rename struct channel_path_desc s390/cio: fix unbind of io_subchannel_driver s390/qdio: split up CCQ handling for EQBS / SQBS s390/qdio: don't retry EQBS after CCQ 96 s390/qdio: restrict buffer merging to eligible devices s390/qdio: don't merge ERROR output buffers s390/qdio: simplify math in get_*_buffer_frontier() s390/decompressor: trim uncompressed image head during the build s390/crypto: Fix kernel crash on aes_s390 module remove. s390/defkeymap: fix global init to zero ...
Diffstat (limited to 'arch/s390/kernel/entry.S')
-rw-r--r--arch/s390/kernel/entry.S96
1 files changed, 26 insertions, 70 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index a5621ea6d123..3f22f139a041 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -11,6 +11,7 @@
#include <linux/init.h>
#include <linux/linkage.h>
+#include <asm/alternative-asm.h>
#include <asm/processor.h>
#include <asm/cache.h>
#include <asm/ctl_reg.h>
@@ -57,6 +58,8 @@ _CIF_WORK = (_CIF_MCCK_PENDING | _CIF_ASCE_PRIMARY | \
_CIF_ASCE_SECONDARY | _CIF_FPU)
_PIF_WORK = (_PIF_PER_TRAP | _PIF_SYSCALL_RESTART)
+_LPP_OFFSET = __LC_LPP
+
#define BASED(name) name-cleanup_critical(%r13)
.macro TRACE_IRQS_ON
@@ -162,65 +165,22 @@ _PIF_WORK = (_PIF_PER_TRAP | _PIF_SYSCALL_RESTART)
.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
+ ALTERNATIVE "", ".long 0xb2e8c000", 82
.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
+ ALTERNATIVE "", ".long 0xb2e8d000", 82
.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
+ ALTERNATIVE "TSTMSK \tif_ptr,\tif_mask; jz .+8; .long 0xb2e8d000", \
+ "", 82
.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
+ ALTERNATIVE "jz .+8; .long 0xb2e8c000", \
+ "jnz .+8; .long 0xb2e8d000", 82
.endm
#ifdef CONFIG_EXPOLINE
@@ -323,10 +283,8 @@ ENTRY(__switch_to)
aghi %r3,__TASK_pid
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
- jz 0f
- .insn s,0xb2800000,__LC_LPP # set program parameter
-0: BR_R1USE_R14
+ ALTERNATIVE "", ".insn s,0xb2800000,_LPP_OFFSET", 40
+ BR_R1USE_R14
.L__critical_start:
@@ -339,10 +297,10 @@ 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
+ stg %r2,__SF_SIE_CONTROL(%r15) # save control block pointer
+ stg %r3,__SF_SIE_SAVEAREA(%r15) # save guest register save area
+ xc __SF_SIE_REASON(8,%r15),__SF_SIE_REASON(%r15) # reason code = 0
+ mvc __SF_SIE_FLAGS(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
@@ -353,18 +311,18 @@ ENTRY(sie64a)
jz .Lsie_gmap
lctlg %c1,%c1,__GMAP_ASCE(%r14) # load primary asce
.Lsie_gmap:
- lg %r14,__SF_EMPTY(%r15) # get control block pointer
+ lg %r14,__SF_SIE_CONTROL(%r15) # get control block pointer
oi __SIE_PROG0C+3(%r14),1 # we are going into SIE now
tm __SIE_PROG20+3(%r14),3 # last exit...
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)
+ BPEXIT __SF_SIE_FLAGS(%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)
+ BPENTER __SF_SIE_FLAGS(%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
@@ -383,7 +341,7 @@ ENTRY(sie64a)
nopr 7
.globl sie_exit
sie_exit:
- lg %r14,__SF_EMPTY+8(%r15) # load guest register save area
+ lg %r14,__SF_SIE_SAVEAREA(%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
@@ -392,11 +350,11 @@ sie_exit:
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
+ lg %r2,__SF_SIE_REASON(%r15) # return exit reason code
BR_R1USE_R14
.Lsie_fault:
lghi %r14,-EFAULT
- stg %r14,__SF_EMPTY+16(%r15) # set exit reason code
+ stg %r14,__SF_SIE_REASON(%r15) # set exit reason code
j sie_exit
EX_TABLE(.Lrewind_pad6,.Lsie_fault)
@@ -685,7 +643,7 @@ ENTRY(pgm_check_handler)
slg %r14,BASED(.Lsie_critical_start)
clg %r14,BASED(.Lsie_critical_length)
jhe 0f
- lg %r14,__SF_EMPTY(%r15) # get control block pointer
+ lg %r14,__SF_SIE_CONTROL(%r15) # get control block pointer
ni __SIE_PROG0C+3(%r14),0xfe # no longer in SIE
lctlg %c1,%c1,__LC_USER_ASCE # load primary asce
larl %r9,sie_exit # skip forward to sie_exit
@@ -1285,10 +1243,8 @@ ENTRY(mcck_int_handler)
# PSW restart interrupt handler
#
ENTRY(restart_int_handler)
- TSTMSK __LC_MACHINE_FLAGS,MACHINE_FLAG_LPP
- jz 0f
- .insn s,0xb2800000,__LC_LPP
-0: stg %r15,__LC_SAVE_AREA_RESTART
+ ALTERNATIVE "", ".insn s,0xb2800000,_LPP_OFFSET", 40
+ stg %r15,__LC_SAVE_AREA_RESTART
lg %r15,__LC_RESTART_STACK
aghi %r15,-__PT_SIZE # create pt_regs on stack
xc 0(__PT_SIZE,%r15),0(%r15)
@@ -1397,8 +1353,8 @@ cleanup_critical:
clg %r9,BASED(.Lsie_crit_mcck_length)
jh 1f
oi __LC_CPU_FLAGS+7, _CIF_MCCK_GUEST
-1: BPENTER __SF_EMPTY+24(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST)
- lg %r9,__SF_EMPTY(%r15) # get control block pointer
+1: BPENTER __SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST)
+ lg %r9,__SF_SIE_CONTROL(%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