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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org,
	Martin Schwidefsky <schwidefsky@de.ibm.com>
Subject: [PATCH 4.14 49/80] s390: run user space and KVM guests with modified branch prediction
Date: Fri, 27 Apr 2018 15:58:42 +0200	[thread overview]
Message-ID: <20180427135735.447977232@linuxfoundation.org> (raw)
In-Reply-To: <20180427135732.928644313@linuxfoundation.org>

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Martin Schwidefsky <schwidefsky@de.ibm.com>


[ Upstream commit 6b73044b2b0081ee3dd1cd6eaab7dee552601efb ]

Define TIF_ISOLATE_BP and TIF_ISOLATE_BP_GUEST and add the necessary
plumbing in entry.S to be able to run user space and KVM guests with
limited branch prediction.

To switch a user space process to limited branch prediction the
s390_isolate_bp() function has to be call, and to run a vCPU of a KVM
guest associated with the current task with limited branch prediction
call s390_isolate_bp_guest().

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/s390/include/asm/processor.h   |    3 ++
 arch/s390/include/asm/thread_info.h |    4 ++
 arch/s390/kernel/entry.S            |   51 ++++++++++++++++++++++++++++++++----
 arch/s390/kernel/processor.c        |   18 ++++++++++++
 4 files changed, 71 insertions(+), 5 deletions(-)

--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -378,6 +378,9 @@ extern void memcpy_absolute(void *, void
 	memcpy_absolute(&(dest), &__tmp, sizeof(__tmp));	\
 } while (0)
 
+extern int s390_isolate_bp(void);
+extern int s390_isolate_bp_guest(void);
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* __ASM_S390_PROCESSOR_H */
--- a/arch/s390/include/asm/thread_info.h
+++ b/arch/s390/include/asm/thread_info.h
@@ -60,6 +60,8 @@ int arch_dup_task_struct(struct task_str
 #define TIF_GUARDED_STORAGE	4	/* load guarded storage control block */
 #define TIF_PATCH_PENDING	5	/* pending live patching update */
 #define TIF_PGSTE		6	/* New mm's will use 4K page tables */
+#define TIF_ISOLATE_BP		8	/* Run process with isolated BP */
+#define TIF_ISOLATE_BP_GUEST	9	/* Run KVM guests with isolated BP */
 
 #define TIF_31BIT		16	/* 32bit process */
 #define TIF_MEMDIE		17	/* is terminating due to OOM killer */
@@ -80,6 +82,8 @@ int arch_dup_task_struct(struct task_str
 #define _TIF_UPROBE		_BITUL(TIF_UPROBE)
 #define _TIF_GUARDED_STORAGE	_BITUL(TIF_GUARDED_STORAGE)
 #define _TIF_PATCH_PENDING	_BITUL(TIF_PATCH_PENDING)
+#define _TIF_ISOLATE_BP		_BITUL(TIF_ISOLATE_BP)
+#define _TIF_ISOLATE_BP_GUEST	_BITUL(TIF_ISOLATE_BP_GUEST)
 
 #define _TIF_31BIT		_BITUL(TIF_31BIT)
 #define _TIF_SINGLE_STEP	_BITUL(TIF_SINGLE_STEP)
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -106,6 +106,7 @@ _PIF_WORK	= (_PIF_PER_TRAP | _PIF_SYSCAL
 	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
@@ -186,6 +187,40 @@ _PIF_WORK	= (_PIF_PER_TRAP | _PIF_SYSCAL
 	.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
+
 	.section .kprobes.text, "ax"
 .Ldummy:
 	/*
@@ -240,9 +275,11 @@ 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
@@ -259,11 +296,12 @@ ENTRY(sie64a)
 	jnz	.Lsie_skip
 	TSTMSK	__LC_CPU_FLAGS,_CIF_FPU
 	jo	.Lsie_skip			# exit if fp/vx regs changed
-	BPON
+	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
@@ -324,6 +362,7 @@ 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
@@ -362,7 +401,7 @@ ENTRY(system_call)
 	jnz	.Lsysc_work			# check for work
 	TSTMSK	__LC_CPU_FLAGS,_CIF_WORK
 	jnz	.Lsysc_work
-	BPON
+	BPEXIT	__TI_flags(%r12),_TIF_ISOLATE_BP
 .Lsysc_restore:
 	lg	%r14,__LC_VDSO_PER_CPU
 	lmg	%r0,%r10,__PT_R0(%r11)
@@ -587,6 +626,7 @@ 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
@@ -718,7 +758,7 @@ ENTRY(io_int_handler)
 	mvc	__LC_RETURN_PSW(16),__PT_PSW(%r11)
 	tm	__PT_PSW+1(%r11),0x01	# returning to user ?
 	jno	.Lio_exit_kernel
-	BPON
+	BPEXIT	__TI_flags(%r12),_TIF_ISOLATE_BP
 .Lio_exit_timer:
 	stpt	__LC_EXIT_TIMER
 	mvc	__VDSO_ECTG_BASE(16,%r14),__LC_EXIT_TIMER
@@ -1101,7 +1141,7 @@ 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
-	BPON
+	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)
@@ -1228,7 +1268,8 @@ 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
--- a/arch/s390/kernel/processor.c
+++ b/arch/s390/kernel/processor.c
@@ -197,3 +197,21 @@ const struct seq_operations cpuinfo_op =
 	.stop	= c_stop,
 	.show	= show_cpuinfo,
 };
+
+int s390_isolate_bp(void)
+{
+	if (!test_facility(82))
+		return -EOPNOTSUPP;
+	set_thread_flag(TIF_ISOLATE_BP);
+	return 0;
+}
+EXPORT_SYMBOL(s390_isolate_bp);
+
+int s390_isolate_bp_guest(void)
+{
+	if (!test_facility(82))
+		return -EOPNOTSUPP;
+	set_thread_flag(TIF_ISOLATE_BP_GUEST);
+	return 0;
+}
+EXPORT_SYMBOL(s390_isolate_bp_guest);

  parent reply	other threads:[~2018-04-27 14:07 UTC|newest]

Thread overview: 90+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-27 13:57 [PATCH 4.14 00/80] 4.14.38-stable review Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 4.14 01/80] Revert "pinctrl: intel: Initialize GPIO properly when used through irqchip" Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 4.14 02/80] drm: bridge: dw-hdmi: Fix overflow workaround for Amlogic Meson GX SoCs Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 4.14 03/80] i40e: Fix attach VF to VM issue Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 4.14 04/80] tpm: cmd_ready command can be issued only after granting locality Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 4.14 05/80] tpm: tpm-interface: fix tpm_transmit/_cmd kdoc Greg Kroah-Hartman
2018-04-27 13:57 ` [PATCH 4.14 06/80] tpm: add retry logic Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 07/80] Revert "ath10k: send (re)assoc peer command when NSS changed" Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 08/80] bonding: do not set slave_dev npinfo before slave_enable_netpoll in bond_enslave Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 09/80] ipv6: add RTA_TABLE and RTA_PREFSRC to rtm_ipv6_policy Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 10/80] ipv6: sr: fix NULL pointer dereference in seg6_do_srh_encap()- v4 pkts Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 11/80] KEYS: DNS: limit the length of option strings Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 12/80] l2tp: check sockaddr length in pppol2tp_connect() Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 13/80] net: validate attribute sizes in neigh_dump_table() Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 14/80] llc: delete timers synchronously in llc_sk_free() Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 15/80] tcp: dont read out-of-bounds opsize Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 16/80] net: af_packet: fix race in PACKET_{R|T}X_RING Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 17/80] tcp: md5: reject TCP_MD5SIG or TCP_MD5SIG_EXT on established sockets Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 18/80] net: fix deadlock while clearing neighbor proxy table Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 19/80] team: avoid adding twice the same option to the event list Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 20/80] net/smc: fix shutdown in state SMC_LISTEN Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 21/80] team: fix netconsole setup over team Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 22/80] packet: fix bitfield update race Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 23/80] tipc: add policy for TIPC_NLA_NET_ADDR Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 24/80] pppoe: check sockaddr length in pppoe_connect() Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 25/80] vlan: Fix reading memory beyond skb->tail in skb_vlan_tagged_multi Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 26/80] amd-xgbe: Add pre/post auto-negotiation phy hooks Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 27/80] sctp: do not check port in sctp_inet6_cmp_addr Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 28/80] amd-xgbe: Improve KR auto-negotiation and training Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 29/80] strparser: Do not call mod_delayed_work with a timeout of LONG_MAX Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 30/80] amd-xgbe: Only use the SFP supported transceiver signals Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 31/80] strparser: Fix incorrect strp->need_bytes value Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 32/80] net: sched: ife: signal not finding metaid Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 33/80] tcp: clear tp->packets_out when purging write queue Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 34/80] net: sched: ife: handle malformed tlv length Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 35/80] net: sched: ife: check on metadata length Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 36/80] llc: hold llc_sap before release_sock() Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 37/80] llc: fix NULL pointer deref for SOCK_ZAPPED Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 38/80] net: ethernet: ti: cpsw: fix tx vlan priority mapping Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 39/80] virtio_net: split out ctrl buffer Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 40/80] virtio_net: fix adding vids on big-endian Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 41/80] Revert "microblaze: fix endian handling" Greg Kroah-Hartman
2018-04-27 15:43   ` Guenter Roeck
2018-04-27 16:25   ` Guenter Roeck
2018-04-28  5:50     ` Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 42/80] s390: introduce CPU alternatives Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 43/80] s390: enable CPU alternatives unconditionally Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 44/80] KVM: s390: wire up bpb feature Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 45/80] s390: scrub registers on kernel entry and KVM exit Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 46/80] s390: add optimized array_index_mask_nospec Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 47/80] s390/alternative: use a copy of the facility bit mask Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 48/80] s390: add options to change branch prediction behaviour for the kernel Greg Kroah-Hartman
2018-04-27 13:58 ` Greg Kroah-Hartman [this message]
2018-04-27 13:58 ` [PATCH 4.14 50/80] s390: introduce execute-trampolines for branches Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 51/80] KVM: s390: force bp isolation for VSIE Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 52/80] s390: Replace IS_ENABLED(EXPOLINE_*) with IS_ENABLED(CONFIG_EXPOLINE_*) Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 53/80] s390: do not bypass BPENTER for interrupt system calls Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 54/80] s390/entry.S: fix spurious zeroing of r0 Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 55/80] s390: move nobp parameter functions to nospec-branch.c Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 56/80] s390: add automatic detection of the spectre defense Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 57/80] s390: report spectre mitigation via syslog Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 58/80] s390: add sysfs attributes for spectre Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 59/80] s390: correct nospec auto detection init order Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 60/80] s390: correct module section names for expoline code revert Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 61/80] microblaze: Setup dependencies for ASM optimized lib functions Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 62/80] arm64: dts: rockchip: remove vdd_log from rk3399-puma Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 63/80] Revert "mm/hmm: fix header file if/else/endif maze" Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 64/80] commoncap: Handle memory allocation failure Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 65/80] scsi: mptsas: Disable WRITE SAME Greg Kroah-Hartman
2018-04-27 13:58 ` [PATCH 4.14 66/80] cdrom: information leak in cdrom_ioctl_media_changed() Greg Kroah-Hartman
2018-04-27 13:59 ` [PATCH 4.14 67/80] fsnotify: Fix fsnotify_mark_connector race Greg Kroah-Hartman
2018-04-27 13:59 ` [PATCH 4.14 68/80] m68k/mac: Dont remap SWIM MMIO region Greg Kroah-Hartman
2018-04-27 13:59 ` [PATCH 4.14 69/80] block/swim: Check drive type Greg Kroah-Hartman
2018-04-27 13:59 ` [PATCH 4.14 70/80] block/swim: Dont log an error message for an invalid ioctl Greg Kroah-Hartman
2018-04-27 13:59 ` [PATCH 4.14 71/80] block/swim: Remove extra put_disk() call from error path Greg Kroah-Hartman
2018-04-27 13:59 ` [PATCH 4.14 72/80] block/swim: Rename macros to avoid inconsistent inverted logic Greg Kroah-Hartman
2018-04-27 13:59 ` [PATCH 4.14 73/80] block/swim: Select appropriate drive on device open Greg Kroah-Hartman
2018-04-27 13:59 ` [PATCH 4.14 74/80] block/swim: Fix array bounds check Greg Kroah-Hartman
2018-04-27 13:59 ` [PATCH 4.14 75/80] block/swim: Fix IO error at end of medium Greg Kroah-Hartman
2018-04-27 13:59 ` [PATCH 4.14 76/80] tracing: Fix missing tab for hwlat_detector print format Greg Kroah-Hartman
2018-04-27 13:59 ` [PATCH 4.14 77/80] s390/cio: update chpid descriptor after resource accessibility event Greg Kroah-Hartman
2018-04-27 13:59 ` [PATCH 4.14 78/80] s390/dasd: fix IO error for newly defined devices Greg Kroah-Hartman
2018-04-27 13:59 ` [PATCH 4.14 79/80] s390/uprobes: implement arch_uretprobe_is_alive() Greg Kroah-Hartman
2018-04-27 13:59 ` [PATCH 4.14 80/80] ACPI / video: Only default only_lcd to true on Win8-ready _desktops_ Greg Kroah-Hartman
2018-04-27 18:14 ` [PATCH 4.14 00/80] 4.14.38-stable review Shuah Khan
2018-04-27 19:24 ` kernelci.org bot
2018-04-27 19:33 ` Nathan Chancellor
2018-04-28  5:06   ` Greg Kroah-Hartman
2018-04-27 20:37 ` Dan Rue
2018-04-28 14:28 ` Guenter Roeck

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