From 84edb315cf766e7c8e09d473d63aaccd1637bbda Mon Sep 17 00:00:00 2001 From: Harald Freudenberger Date: Mon, 23 Apr 2018 11:14:28 +0200 Subject: [PATCH 01/16] MAINTAINERS: update s390 zcrypt maintainers email address Signed-off-by: Harald Freudenberger Signed-off-by: Martin Schwidefsky --- MAINTAINERS | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/MAINTAINERS b/MAINTAINERS index dd66ae9a847e1..2ad33062c9e3b 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -12239,7 +12239,7 @@ F: Documentation/s390/vfio-ccw.txt F: include/uapi/linux/vfio_ccw.h S390 ZCRYPT DRIVER -M: Harald Freudenberger +M: Harald Freudenberger L: linux-s390@vger.kernel.org W: http://www.ibm.com/developerworks/linux/linux390/ S: Supported From d14be68fd1be2b33e362594b831eef6f007febe5 Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Thu, 26 Apr 2018 14:31:52 +0200 Subject: [PATCH 02/16] s390: update defconfigs Change the following to y: arch/s390/configs/performance_defconfig:262:warning: symbol value 'm' invalid for NF_TABLES_IPV4 arch/s390/configs/performance_defconfig:264:warning: symbol value 'm' invalid for NF_TABLES_ARP arch/s390/configs/performance_defconfig:285:warning: symbol value 'm' invalid for NF_TABLES_IPV6 arch/s390/configs/performance_defconfig:306:warning: symbol value 'm' invalid for NF_TABLES_BRIDGE Signed-off-by: Sebastian Ott Signed-off-by: Martin Schwidefsky --- arch/s390/configs/debug_defconfig | 9 ++++----- arch/s390/configs/performance_defconfig | 8 ++++---- 2 files changed, 8 insertions(+), 9 deletions(-) diff --git a/arch/s390/configs/debug_defconfig b/arch/s390/configs/debug_defconfig index 6176fe9795caf..941d8cc6c9f59 100644 --- a/arch/s390/configs/debug_defconfig +++ b/arch/s390/configs/debug_defconfig @@ -261,9 +261,9 @@ CONFIG_IP_VS_NQ=m CONFIG_IP_VS_FTP=m CONFIG_IP_VS_PE_SIP=m CONFIG_NF_CONNTRACK_IPV4=m -CONFIG_NF_TABLES_IPV4=m +CONFIG_NF_TABLES_IPV4=y CONFIG_NFT_CHAIN_ROUTE_IPV4=m -CONFIG_NF_TABLES_ARP=m +CONFIG_NF_TABLES_ARP=y CONFIG_NFT_CHAIN_NAT_IPV4=m CONFIG_IP_NF_IPTABLES=m CONFIG_IP_NF_MATCH_AH=m @@ -284,7 +284,7 @@ CONFIG_IP_NF_ARPTABLES=m CONFIG_IP_NF_ARPFILTER=m CONFIG_IP_NF_ARP_MANGLE=m CONFIG_NF_CONNTRACK_IPV6=m -CONFIG_NF_TABLES_IPV6=m +CONFIG_NF_TABLES_IPV6=y CONFIG_NFT_CHAIN_ROUTE_IPV6=m CONFIG_NFT_CHAIN_NAT_IPV6=m CONFIG_IP6_NF_IPTABLES=m @@ -305,7 +305,7 @@ CONFIG_IP6_NF_RAW=m CONFIG_IP6_NF_SECURITY=m CONFIG_IP6_NF_NAT=m CONFIG_IP6_NF_TARGET_MASQUERADE=m -CONFIG_NF_TABLES_BRIDGE=m +CONFIG_NF_TABLES_BRIDGE=y CONFIG_RDS=m CONFIG_RDS_RDMA=m CONFIG_RDS_TCP=m @@ -604,7 +604,6 @@ CONFIG_DETECT_HUNG_TASK=y CONFIG_WQ_WATCHDOG=y CONFIG_PANIC_ON_OOPS=y CONFIG_DEBUG_TIMEKEEPING=y -CONFIG_DEBUG_WW_MUTEX_SLOWPATH=y CONFIG_PROVE_LOCKING=y CONFIG_LOCK_STAT=y CONFIG_DEBUG_LOCKDEP=y diff --git a/arch/s390/configs/performance_defconfig b/arch/s390/configs/performance_defconfig index c105bcc6d7a6f..eb6f75f242089 100644 --- a/arch/s390/configs/performance_defconfig +++ b/arch/s390/configs/performance_defconfig @@ -259,9 +259,9 @@ CONFIG_IP_VS_NQ=m CONFIG_IP_VS_FTP=m CONFIG_IP_VS_PE_SIP=m CONFIG_NF_CONNTRACK_IPV4=m -CONFIG_NF_TABLES_IPV4=m +CONFIG_NF_TABLES_IPV4=y CONFIG_NFT_CHAIN_ROUTE_IPV4=m -CONFIG_NF_TABLES_ARP=m +CONFIG_NF_TABLES_ARP=y CONFIG_NFT_CHAIN_NAT_IPV4=m CONFIG_IP_NF_IPTABLES=m CONFIG_IP_NF_MATCH_AH=m @@ -282,7 +282,7 @@ CONFIG_IP_NF_ARPTABLES=m CONFIG_IP_NF_ARPFILTER=m CONFIG_IP_NF_ARP_MANGLE=m CONFIG_NF_CONNTRACK_IPV6=m -CONFIG_NF_TABLES_IPV6=m +CONFIG_NF_TABLES_IPV6=y CONFIG_NFT_CHAIN_ROUTE_IPV6=m CONFIG_NFT_CHAIN_NAT_IPV6=m CONFIG_IP6_NF_IPTABLES=m @@ -303,7 +303,7 @@ CONFIG_IP6_NF_RAW=m CONFIG_IP6_NF_SECURITY=m CONFIG_IP6_NF_NAT=m CONFIG_IP6_NF_TARGET_MASQUERADE=m -CONFIG_NF_TABLES_BRIDGE=m +CONFIG_NF_TABLES_BRIDGE=y CONFIG_RDS=m CONFIG_RDS_RDMA=m CONFIG_RDS_TCP=m From 598d76562cc2329ef2fdd95475e287b60ba9463f Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Wed, 25 Apr 2018 12:39:06 +0200 Subject: [PATCH 03/16] s390/kexec_file: add declaration of purgatory related globals Fix the following sparse complaints: arch/s390/purgatory/purgatory.c:18:5: warning: symbol 'kernel_entry' was not declared. Should it be static? arch/s390/purgatory/purgatory.c:19:5: warning: symbol 'kernel_type' was not declared. Should it be static? arch/s390/purgatory/purgatory.c:21:5: warning: symbol 'crash_start' was not declared. Should it be static? arch/s390/purgatory/purgatory.c:22:5: warning: symbol 'crash_size' was not declared. Should it be static? Signed-off-by: Sebastian Ott Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/purgatory.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/s390/include/asm/purgatory.h b/arch/s390/include/asm/purgatory.h index e297bcfc476f6..6090670df51fc 100644 --- a/arch/s390/include/asm/purgatory.h +++ b/arch/s390/include/asm/purgatory.h @@ -13,5 +13,11 @@ int verify_sha256_digest(void); +extern u64 kernel_entry; +extern u64 kernel_type; + +extern u64 crash_start; +extern u64 crash_size; + #endif /* __ASSEMBLY__ */ #endif /* _S390_PURGATORY_H_ */ From d66a7355717ec903d455277a550d930ba13df4a8 Mon Sep 17 00:00:00 2001 From: Halil Pasic Date: Tue, 24 Apr 2018 13:26:56 +0200 Subject: [PATCH 04/16] vfio: ccw: fix cleanup if cp_prefetch fails If the translation of a channel program fails, we may end up attempting to clean up (free, unpin) stuff that never got translated (and allocated, pinned) in the first place. By adjusting the lengths of the chains accordingly (so the element that failed, and all subsequent elements are excluded) cleanup activities based on false assumptions can be avoided. Let's make sure cp_free works properly after cp_prefetch returns with an error by setting ch_len of a ccw chain to the number of the translated CCWs on that chain. Cc: stable@vger.kernel.org #v4.12+ Acked-by: Pierre Morel Reviewed-by: Dong Jia Shi Signed-off-by: Halil Pasic Signed-off-by: Dong Jia Shi Message-Id: <20180423110113.59385-2-bjsdjshi@linux.vnet.ibm.com> [CH: fixed typos] Signed-off-by: Cornelia Huck Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/vfio_ccw_cp.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/s390/cio/vfio_ccw_cp.c b/drivers/s390/cio/vfio_ccw_cp.c index 2c7550797ec2f..dce92b2a895d6 100644 --- a/drivers/s390/cio/vfio_ccw_cp.c +++ b/drivers/s390/cio/vfio_ccw_cp.c @@ -715,6 +715,10 @@ void cp_free(struct channel_program *cp) * and stores the result to ccwchain list. @cp must have been * initialized by a previous call with cp_init(). Otherwise, undefined * behavior occurs. + * For each chain composing the channel program: + * - On entry ch_len holds the count of CCWs to be translated. + * - On exit ch_len is adjusted to the count of successfully translated CCWs. + * This allows cp_free to find in ch_len the count of CCWs to free in a chain. * * The S/390 CCW Translation APIS (prefixed by 'cp_') are introduced * as helpers to do ccw chain translation inside the kernel. Basically @@ -749,11 +753,18 @@ int cp_prefetch(struct channel_program *cp) for (idx = 0; idx < len; idx++) { ret = ccwchain_fetch_one(chain, idx, cp); if (ret) - return ret; + goto out_err; } } return 0; +out_err: + /* Only cleanup the chain elements that were actually translated. */ + chain->ch_len = idx; + list_for_each_entry_continue(chain, &cp->ccwchain_list, next) { + chain->ch_len = 0; + } + return ret; } /** From 6dd85fbb87d1d6b87a3b1f02ca28d7b2abd2e7ba Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 20 Apr 2018 16:49:46 +0200 Subject: [PATCH 05/16] s390: move expoline assembler macros to a header To be able to use the expoline branches in different assembler files move the associated macros from entry.S to a new header nospec-insn.h. While we are at it make the macros a bit nicer to use. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/nospec-insn.h | 127 ++++++++++++++++++++++++++++ arch/s390/kernel/entry.S | 105 ++++++----------------- 2 files changed, 151 insertions(+), 81 deletions(-) create mode 100644 arch/s390/include/asm/nospec-insn.h diff --git a/arch/s390/include/asm/nospec-insn.h b/arch/s390/include/asm/nospec-insn.h new file mode 100644 index 0000000000000..440689cbcf51b --- /dev/null +++ b/arch/s390/include/asm/nospec-insn.h @@ -0,0 +1,127 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_S390_NOSPEC_ASM_H +#define _ASM_S390_NOSPEC_ASM_H + +#include + +#ifdef __ASSEMBLY__ + +#ifdef CONFIG_EXPOLINE + +/* + * The expoline macros are used to create thunks in the same format + * as gcc generates them. The 'comdat' section flag makes sure that + * the various thunks are merged into a single copy. + */ + .macro __THUNK_PROLOG_NAME name + .pushsection .text.\name,"axG",@progbits,\name,comdat + .globl \name + .hidden \name + .type \name,@function +\name: + CFI_STARTPROC + .endm + + .macro __THUNK_EPILOG + CFI_ENDPROC + .popsection + .endm + + .macro __THUNK_PROLOG_BR r1,r2 + __THUNK_PROLOG_NAME __s390x_indirect_jump_r\r2\()use_r\r1 + .endm + + .macro __THUNK_BR r1,r2 + jg __s390x_indirect_jump_r\r2\()use_r\r1 + .endm + + .macro __THUNK_BRASL r1,r2,r3 + brasl \r1,__s390x_indirect_jump_r\r3\()use_r\r2 + .endm + + .macro __DECODE_RR expand,reg,ruse + .set __decode_fail,1 + .irp r1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 + .ifc \reg,%r\r1 + .irp r2,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 + .ifc \ruse,%r\r2 + \expand \r1,\r2 + .set __decode_fail,0 + .endif + .endr + .endif + .endr + .if __decode_fail == 1 + .error "__DECODE_RR failed" + .endif + .endm + + .macro __DECODE_RRR expand,rsave,rtarget,ruse + .set __decode_fail,1 + .irp r1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 + .ifc \rsave,%r\r1 + .irp r2,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 + .ifc \rtarget,%r\r2 + .irp r3,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 + .ifc \ruse,%r\r3 + \expand \r1,\r2,\r3 + .set __decode_fail,0 + .endif + .endr + .endif + .endr + .endif + .endr + .if __decode_fail == 1 + .error "__DECODE_RRR failed" + .endif + .endm + + .macro __THUNK_EX_BR reg,ruse +#ifdef CONFIG_HAVE_MARCH_Z10_FEATURES + exrl 0,555f + j . +#else + larl \ruse,555f + ex 0,0(\ruse) + j . +#endif +555: br \reg + .endm + + .macro GEN_BR_THUNK reg,ruse=%r1 + __DECODE_RR __THUNK_PROLOG_BR,\reg,\ruse + __THUNK_EX_BR \reg,\ruse + __THUNK_EPILOG + .endm + + .macro BR_EX reg,ruse=%r1 +557: __DECODE_RR __THUNK_BR,\reg,\ruse + .pushsection .s390_indirect_branches,"a",@progbits + .long 557b-. + .popsection + .endm + + .macro BASR_EX rsave,rtarget,ruse=%r1 +559: __DECODE_RRR __THUNK_BRASL,\rsave,\rtarget,\ruse + .pushsection .s390_indirect_branches,"a",@progbits + .long 559b-. + .popsection + .endm + +#else + .macro GEN_BR_THUNK reg,ruse=%r1 + .endm + + .macro BR_EX reg,ruse=%r1 + br \reg + .endm + + .macro BASR_EX rsave,rtarget,ruse=%r1 + basr \rsave,\rtarget + .endm +#endif + +#endif /* __ASSEMBLY__ */ + +#endif /* _ASM_S390_NOSPEC_ASM_H */ diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index 3f22f139a0413..f03402efab4b4 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -28,6 +28,7 @@ #include #include #include +#include __PT_R0 = __PT_GPRS __PT_R1 = __PT_GPRS + 8 @@ -183,67 +184,9 @@ _LPP_OFFSET = __LC_LPP "jnz .+8; .long 0xb2e8d000", 82 .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 */ - + GEN_BR_THUNK %r9 + GEN_BR_THUNK %r14 + GEN_BR_THUNK %r14,%r11 .section .kprobes.text, "ax" .Ldummy: @@ -260,7 +203,7 @@ _LPP_OFFSET = __LC_LPP ENTRY(__bpon) .globl __bpon BPON - BR_R1USE_R14 + BR_EX %r14 /* * Scheduler resume function, called by switch_to @@ -284,7 +227,7 @@ 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 ALTERNATIVE "", ".insn s,0xb2800000,_LPP_OFFSET", 40 - BR_R1USE_R14 + BR_EX %r14 .L__critical_start: @@ -351,7 +294,7 @@ sie_exit: xgr %r5,%r5 lmg %r6,%r14,__SF_GPRS(%r15) # restore kernel registers lg %r2,__SF_SIE_REASON(%r15) # return exit reason code - BR_R1USE_R14 + BR_EX %r14 .Lsie_fault: lghi %r14,-EFAULT stg %r14,__SF_SIE_REASON(%r15) # set exit reason code @@ -410,7 +353,7 @@ 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_EX %r14,%r9 # call sys_xxxx stg %r2,__PT_R2(%r11) # store return value .Lsysc_return: @@ -595,7 +538,7 @@ 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_EX %r14,%r9 # call sys_xxx stg %r2,__PT_R2(%r11) # store return value .Lsysc_tracenogo: TSTMSK __TI_flags(%r12),_TIF_TRACE @@ -619,7 +562,7 @@ ENTRY(ret_from_fork) lmg %r9,%r10,__PT_R9(%r11) # load gprs ENTRY(kernel_thread_starter) la %r2,0(%r10) - BASR_R14_R9 + BASR_EX %r14,%r9 j .Lsysc_tracenogo /* @@ -701,7 +644,7 @@ ENTRY(pgm_check_handler) je .Lpgm_return lgf %r9,0(%r10,%r1) # load address of handler routine lgr %r2,%r11 # pass pointer to pt_regs - BASR_R14_R9 # branch to interrupt-handler + BASR_EX %r14,%r9 # branch to interrupt-handler .Lpgm_return: LOCKDEP_SYS_EXIT tm __PT_PSW+1(%r11),0x01 # returning to user ? @@ -1019,7 +962,7 @@ ENTRY(psw_idle) stpt __TIMER_IDLE_ENTER(%r2) .Lpsw_idle_lpsw: lpswe __SF_EMPTY(%r15) - BR_R1USE_R14 + BR_EX %r14 .Lpsw_idle_end: /* @@ -1061,7 +1004,7 @@ ENTRY(save_fpu_regs) .Lsave_fpu_regs_done: oi __LC_CPU_FLAGS+7,_CIF_FPU .Lsave_fpu_regs_exit: - BR_R1USE_R14 + BR_EX %r14 .Lsave_fpu_regs_end: EXPORT_SYMBOL(save_fpu_regs) @@ -1107,7 +1050,7 @@ load_fpu_regs: .Lload_fpu_regs_done: ni __LC_CPU_FLAGS+7,255-_CIF_FPU .Lload_fpu_regs_exit: - BR_R1USE_R14 + BR_EX %r14 .Lload_fpu_regs_end: .L__critical_end: @@ -1322,7 +1265,7 @@ cleanup_critical: jl 0f clg %r9,BASED(.Lcleanup_table+104) # .Lload_fpu_regs_end jl .Lcleanup_load_fpu_regs -0: BR_R11USE_R14 +0: BR_EX %r14 .align 8 .Lcleanup_table: @@ -1358,7 +1301,7 @@ cleanup_critical: 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_R11USE_R14 + BR_EX %r14 #endif .Lcleanup_system_call: @@ -1412,7 +1355,7 @@ cleanup_critical: stg %r15,56(%r11) # r15 stack pointer # set new psw address and exit larl %r9,.Lsysc_do_svc - BR_R11USE_R14 + BR_EX %r14,%r11 .Lcleanup_system_call_insn: .quad system_call .quad .Lsysc_stmg @@ -1424,7 +1367,7 @@ cleanup_critical: .Lcleanup_sysc_tif: larl %r9,.Lsysc_tif - BR_R11USE_R14 + BR_EX %r14,%r11 .Lcleanup_sysc_restore: # check if stpt has been executed @@ -1441,14 +1384,14 @@ cleanup_critical: mvc 0(64,%r11),__PT_R8(%r9) lmg %r0,%r7,__PT_R0(%r9) 1: lmg %r8,%r9,__LC_RETURN_PSW - BR_R11USE_R14 + BR_EX %r14,%r11 .Lcleanup_sysc_restore_insn: .quad .Lsysc_exit_timer .quad .Lsysc_done - 4 .Lcleanup_io_tif: larl %r9,.Lio_tif - BR_R11USE_R14 + BR_EX %r14,%r11 .Lcleanup_io_restore: # check if stpt has been executed @@ -1462,7 +1405,7 @@ cleanup_critical: mvc 0(64,%r11),__PT_R8(%r9) lmg %r0,%r7,__PT_R0(%r9) 1: lmg %r8,%r9,__LC_RETURN_PSW - BR_R11USE_R14 + BR_EX %r14,%r11 .Lcleanup_io_restore_insn: .quad .Lio_exit_timer .quad .Lio_done - 4 @@ -1515,17 +1458,17 @@ cleanup_critical: # prepare return psw nihh %r8,0xfcfd # clear irq & wait state bits lg %r9,48(%r11) # return from psw_idle - BR_R11USE_R14 + BR_EX %r14,%r11 .Lcleanup_idle_insn: .quad .Lpsw_idle_lpsw .Lcleanup_save_fpu_regs: larl %r9,save_fpu_regs - BR_R11USE_R14 + BR_EX %r14,%r11 .Lcleanup_load_fpu_regs: larl %r9,load_fpu_regs - BR_R11USE_R14 + BR_EX %r14,%r11 /* * Integer constants From 467a3bf219cee12259182c5cb4821f88fd518a51 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Mon, 23 Apr 2018 14:31:36 +0200 Subject: [PATCH 06/16] s390/crc32-vx: use expoline for indirect branches The return from the crc32_le_vgfm_16/crc32c_le_vgfm_16 and the crc32_be_vgfm_16 functions are done with "br %r14". These are indirect branches as well and need to use execute trampolines for CONFIG_EXPOLINE=y. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Reviewed-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky --- arch/s390/crypto/crc32be-vx.S | 5 ++++- arch/s390/crypto/crc32le-vx.S | 4 +++- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/s390/crypto/crc32be-vx.S b/arch/s390/crypto/crc32be-vx.S index e8077f0971f89..2bf01ba44107c 100644 --- a/arch/s390/crypto/crc32be-vx.S +++ b/arch/s390/crypto/crc32be-vx.S @@ -13,6 +13,7 @@ */ #include +#include #include /* Vector register range containing CRC-32 constants */ @@ -67,6 +68,8 @@ .previous + GEN_BR_THUNK %r14 + .text /* * The CRC-32 function(s) use these calling conventions: @@ -203,6 +206,6 @@ ENTRY(crc32_be_vgfm_16) .Ldone: VLGVF %r2,%v2,3 - br %r14 + BR_EX %r14 .previous diff --git a/arch/s390/crypto/crc32le-vx.S b/arch/s390/crypto/crc32le-vx.S index d8c67a58c0c53..7d6f568bd3ad1 100644 --- a/arch/s390/crypto/crc32le-vx.S +++ b/arch/s390/crypto/crc32le-vx.S @@ -14,6 +14,7 @@ */ #include +#include #include /* Vector register range containing CRC-32 constants */ @@ -76,6 +77,7 @@ .previous + GEN_BR_THUNK %r14 .text @@ -264,6 +266,6 @@ crc32_le_vgfm_generic: .Ldone: VLGVF %r2,%v2,2 - br %r14 + BR_EX %r14 .previous From 97489e0663fa700d6e7febddc43b58df98d7bcda Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Mon, 23 Apr 2018 14:31:36 +0200 Subject: [PATCH 07/16] s390/lib: use expoline for indirect branches The return from the memmove, memset, memcpy, __memset16, __memset32 and __memset64 functions are done with "br %r14". These are indirect branches as well and need to use execute trampolines for CONFIG_EXPOLINE=y. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Reviewed-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky --- arch/s390/lib/mem.S | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/arch/s390/lib/mem.S b/arch/s390/lib/mem.S index 495c9c4bacc7b..2311f15be9cf0 100644 --- a/arch/s390/lib/mem.S +++ b/arch/s390/lib/mem.S @@ -7,6 +7,9 @@ #include #include +#include + + GEN_BR_THUNK %r14 /* * void *memmove(void *dest, const void *src, size_t n) @@ -33,14 +36,14 @@ ENTRY(memmove) .Lmemmove_forward_remainder: larl %r5,.Lmemmove_mvc ex %r4,0(%r5) - br %r14 + BR_EX %r14 .Lmemmove_reverse: ic %r0,0(%r4,%r3) stc %r0,0(%r4,%r1) brctg %r4,.Lmemmove_reverse ic %r0,0(%r4,%r3) stc %r0,0(%r4,%r1) - br %r14 + BR_EX %r14 .Lmemmove_mvc: mvc 0(1,%r1),0(%r3) EXPORT_SYMBOL(memmove) @@ -77,7 +80,7 @@ ENTRY(memset) .Lmemset_clear_remainder: larl %r3,.Lmemset_xc ex %r4,0(%r3) - br %r14 + BR_EX %r14 .Lmemset_fill: cghi %r4,1 lgr %r1,%r2 @@ -95,10 +98,10 @@ ENTRY(memset) stc %r3,0(%r1) larl %r5,.Lmemset_mvc ex %r4,0(%r5) - br %r14 + BR_EX %r14 .Lmemset_fill_exit: stc %r3,0(%r1) - br %r14 + BR_EX %r14 .Lmemset_xc: xc 0(1,%r1),0(%r1) .Lmemset_mvc: @@ -121,7 +124,7 @@ ENTRY(memcpy) .Lmemcpy_remainder: larl %r5,.Lmemcpy_mvc ex %r4,0(%r5) - br %r14 + BR_EX %r14 .Lmemcpy_loop: mvc 0(256,%r1),0(%r3) la %r1,256(%r1) @@ -159,10 +162,10 @@ ENTRY(__memset\bits) \insn %r3,0(%r1) larl %r5,.L__memset_mvc\bits ex %r4,0(%r5) - br %r14 + BR_EX %r14 .L__memset_exit\bits: \insn %r3,0(%r2) - br %r14 + BR_EX %r14 .L__memset_mvc\bits: mvc \bytes(1,%r1),0(%r1) .endm From 23a4d7fd34856da8218c4cfc23dba7a6ec0a423a Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Wed, 25 Apr 2018 18:35:26 +0200 Subject: [PATCH 08/16] s390/ftrace: use expoline for indirect branches The return from the ftrace_stub, _mcount, ftrace_caller and return_to_handler functions is done with "br %r14" and "br %r1". These are indirect branches as well and need to use execute trampolines for CONFIG_EXPOLINE=y. The ftrace_caller function is a special case as it returns to the start of a function and may only use %r0 and %r1. For a pre z10 machine the standard execute trampoline uses a LARL + EX to do this, but this requires *two* registers in the range %r1..%r15. To get around this the 'br %r1' located in the lowcore is used, then the EX instruction does not need an address register. But the lowcore trick may only be used for pre z14 machines, with noexec=on the mapping for the first page may not contain instructions. The solution for that is an ALTERNATIVE in the expoline THUNK generated by 'GEN_BR_THUNK %r1' to switch to EXRL, this relies on the fact that a machine that supports noexec=on has EXRL as well. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/nospec-insn.h | 12 ++++++++++++ arch/s390/kernel/asm-offsets.c | 1 + arch/s390/kernel/mcount.S | 14 +++++++++----- 3 files changed, 22 insertions(+), 5 deletions(-) diff --git a/arch/s390/include/asm/nospec-insn.h b/arch/s390/include/asm/nospec-insn.h index 440689cbcf51b..7d7640e1cf90c 100644 --- a/arch/s390/include/asm/nospec-insn.h +++ b/arch/s390/include/asm/nospec-insn.h @@ -2,12 +2,16 @@ #ifndef _ASM_S390_NOSPEC_ASM_H #define _ASM_S390_NOSPEC_ASM_H +#include +#include #include #ifdef __ASSEMBLY__ #ifdef CONFIG_EXPOLINE +_LC_BR_R1 = __LC_BR_R1 + /* * The expoline macros are used to create thunks in the same format * as gcc generates them. The 'comdat' section flag makes sure that @@ -78,13 +82,21 @@ .endm .macro __THUNK_EX_BR reg,ruse + # Be very careful when adding instructions to this macro! + # The ALTERNATIVE replacement code has a .+10 which targets + # the "br \reg" after the code has been patched. #ifdef CONFIG_HAVE_MARCH_Z10_FEATURES exrl 0,555f j . #else + .ifc \reg,%r1 + ALTERNATIVE "ex %r0,_LC_BR_R1", ".insn ril,0xc60000000000,0,.+10", 35 + j . + .else larl \ruse,555f ex 0,0(\ruse) j . + .endif #endif 555: br \reg .endm diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c index eb2a5c0443cd9..11aea745a2a6e 100644 --- a/arch/s390/kernel/asm-offsets.c +++ b/arch/s390/kernel/asm-offsets.c @@ -181,6 +181,7 @@ int main(void) OFFSET(__LC_MACHINE_FLAGS, lowcore, machine_flags); OFFSET(__LC_PREEMPT_COUNT, lowcore, preempt_count); OFFSET(__LC_GMAP, lowcore, gmap); + OFFSET(__LC_BR_R1, lowcore, br_r1_trampoline); /* software defined ABI-relevant lowcore locations 0xe00 - 0xe20 */ OFFSET(__LC_DUMP_REIPL, lowcore, ipib); /* hardware defined lowcore locations 0x1000 - 0x18ff */ diff --git a/arch/s390/kernel/mcount.S b/arch/s390/kernel/mcount.S index 82df7d80fab22..27110f3294edc 100644 --- a/arch/s390/kernel/mcount.S +++ b/arch/s390/kernel/mcount.S @@ -9,13 +9,17 @@ #include #include #include +#include #include #include + GEN_BR_THUNK %r1 + GEN_BR_THUNK %r14 + .section .kprobes.text, "ax" ENTRY(ftrace_stub) - br %r14 + BR_EX %r14 #define STACK_FRAME_SIZE (STACK_FRAME_OVERHEAD + __PT_SIZE) #define STACK_PTREGS (STACK_FRAME_OVERHEAD) @@ -23,7 +27,7 @@ ENTRY(ftrace_stub) #define STACK_PTREGS_PSW (STACK_PTREGS + __PT_PSW) ENTRY(_mcount) - br %r14 + BR_EX %r14 EXPORT_SYMBOL(_mcount) @@ -53,7 +57,7 @@ ENTRY(ftrace_caller) #endif lgr %r3,%r14 la %r5,STACK_PTREGS(%r15) - basr %r14,%r1 + BASR_EX %r14,%r1 #ifdef CONFIG_FUNCTION_GRAPH_TRACER # The j instruction gets runtime patched to a nop instruction. # See ftrace_enable_ftrace_graph_caller. @@ -68,7 +72,7 @@ ftrace_graph_caller_end: #endif lg %r1,(STACK_PTREGS_PSW+8)(%r15) lmg %r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15) - br %r1 + BR_EX %r1 #ifdef CONFIG_FUNCTION_GRAPH_TRACER @@ -81,6 +85,6 @@ ENTRY(return_to_handler) aghi %r15,STACK_FRAME_OVERHEAD lgr %r14,%r2 lmg %r2,%r5,32(%r15) - br %r14 + BR_EX %r14 #endif From c50c84c3ac4d5db683904bdb3257798b6ef980ae Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Wed, 25 Apr 2018 18:41:30 +0200 Subject: [PATCH 09/16] s390/kernel: use expoline for indirect branches The assember code in arch/s390/kernel uses a few more indirect branches which need to be done with execute trampolines for CONFIG_EXPOLINE=y. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Reviewed-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/base.S | 24 ++++++++++++++---------- arch/s390/kernel/reipl.S | 7 +++++-- arch/s390/kernel/swsusp.S | 10 ++++++---- 3 files changed, 25 insertions(+), 16 deletions(-) diff --git a/arch/s390/kernel/base.S b/arch/s390/kernel/base.S index f6c56009e8224..b65874b0b412e 100644 --- a/arch/s390/kernel/base.S +++ b/arch/s390/kernel/base.S @@ -9,18 +9,22 @@ #include #include +#include #include #include + GEN_BR_THUNK %r9 + GEN_BR_THUNK %r14 + ENTRY(s390_base_mcck_handler) basr %r13,0 0: lg %r15,__LC_PANIC_STACK # load panic stack aghi %r15,-STACK_FRAME_OVERHEAD larl %r1,s390_base_mcck_handler_fn - lg %r1,0(%r1) - ltgr %r1,%r1 + lg %r9,0(%r1) + ltgr %r9,%r9 jz 1f - basr %r14,%r1 + BASR_EX %r14,%r9 1: la %r1,4095 lmg %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1) lpswe __LC_MCK_OLD_PSW @@ -37,10 +41,10 @@ ENTRY(s390_base_ext_handler) basr %r13,0 0: aghi %r15,-STACK_FRAME_OVERHEAD larl %r1,s390_base_ext_handler_fn - lg %r1,0(%r1) - ltgr %r1,%r1 + lg %r9,0(%r1) + ltgr %r9,%r9 jz 1f - basr %r14,%r1 + BASR_EX %r14,%r9 1: lmg %r0,%r15,__LC_SAVE_AREA_ASYNC ni __LC_EXT_OLD_PSW+1,0xfd # clear wait state bit lpswe __LC_EXT_OLD_PSW @@ -57,10 +61,10 @@ ENTRY(s390_base_pgm_handler) basr %r13,0 0: aghi %r15,-STACK_FRAME_OVERHEAD larl %r1,s390_base_pgm_handler_fn - lg %r1,0(%r1) - ltgr %r1,%r1 + lg %r9,0(%r1) + ltgr %r9,%r9 jz 1f - basr %r14,%r1 + BASR_EX %r14,%r9 lmg %r0,%r15,__LC_SAVE_AREA_SYNC lpswe __LC_PGM_OLD_PSW 1: lpswe disabled_wait_psw-0b(%r13) @@ -117,7 +121,7 @@ ENTRY(diag308_reset) larl %r4,.Lcontinue_psw # Restore PSW flags lpswe 0(%r4) .Lcontinue: - br %r14 + BR_EX %r14 .align 16 .Lrestart_psw: .long 0x00080000,0x80000000 + .Lrestart_part2 diff --git a/arch/s390/kernel/reipl.S b/arch/s390/kernel/reipl.S index 73cc3750f0d34..7f14adf512c6d 100644 --- a/arch/s390/kernel/reipl.S +++ b/arch/s390/kernel/reipl.S @@ -7,8 +7,11 @@ #include #include +#include #include + GEN_BR_THUNK %r9 + # # Issue "store status" for the current CPU to its prefix page # and call passed function afterwards @@ -67,9 +70,9 @@ ENTRY(store_status) st %r4,0(%r1) st %r5,4(%r1) stg %r2,8(%r1) - lgr %r1,%r2 + lgr %r9,%r2 lgr %r2,%r3 - br %r1 + BR_EX %r9 .section .bss .align 8 diff --git a/arch/s390/kernel/swsusp.S b/arch/s390/kernel/swsusp.S index e99187149f171..a049a7b9d6e89 100644 --- a/arch/s390/kernel/swsusp.S +++ b/arch/s390/kernel/swsusp.S @@ -13,6 +13,7 @@ #include #include #include +#include #include /* @@ -24,6 +25,8 @@ * (see below) in the resume process. * This function runs with disabled interrupts. */ + GEN_BR_THUNK %r14 + .section .text ENTRY(swsusp_arch_suspend) stmg %r6,%r15,__SF_GPRS(%r15) @@ -103,7 +106,7 @@ ENTRY(swsusp_arch_suspend) spx 0x318(%r1) lmg %r6,%r15,STACK_FRAME_OVERHEAD + __SF_GPRS(%r15) lghi %r2,0 - br %r14 + BR_EX %r14 /* * Restore saved memory image to correct place and restore register context. @@ -197,11 +200,10 @@ pgm_check_entry: larl %r15,init_thread_union ahi %r15,1<<(PAGE_SHIFT+THREAD_SIZE_ORDER) larl %r2,.Lpanic_string - larl %r3,sclp_early_printk lghi %r1,0 sam31 sigp %r1,%r0,SIGP_SET_ARCHITECTURE - basr %r14,%r3 + brasl %r14,sclp_early_printk larl %r3,.Ldisabled_wait_31 lpsw 0(%r3) 4: @@ -267,7 +269,7 @@ restore_registers: /* Return 0 */ lmg %r6,%r15,STACK_FRAME_OVERHEAD + __SF_GPRS(%r15) lghi %r2,0 - br %r14 + BR_EX %r14 .section .data..nosave,"aw",@progbits .align 8 From 4253b0e0627ee3461e64c2495c616f1c8f6b127b Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Tue, 24 Apr 2018 08:23:54 +0200 Subject: [PATCH 10/16] s390: move spectre sysfs attribute code The nospec-branch.c file is compiled without the gcc options to generate expoline thunks. The return branch of the sysfs show functions cpu_show_spectre_v1 and cpu_show_spectre_v2 is an indirect branch as well. These need to be compiled with expolines. Move the sysfs functions for spectre reporting to a separate file and loose an '.' for one of the messages. Cc: stable@vger.kernel.org # 4.16 Fixes: d424986f1d ("s390: add sysfs attributes for spectre") Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/Makefile | 1 + arch/s390/kernel/nospec-branch.c | 19 ------------------- arch/s390/kernel/nospec-sysfs.c | 21 +++++++++++++++++++++ 3 files changed, 22 insertions(+), 19 deletions(-) create mode 100644 arch/s390/kernel/nospec-sysfs.c diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile index 84ea6225efb4b..f92dd8ed3884a 100644 --- a/arch/s390/kernel/Makefile +++ b/arch/s390/kernel/Makefile @@ -65,6 +65,7 @@ obj-y += nospec-branch.o extra-y += head.o head64.o vmlinux.lds +obj-$(CONFIG_SYSFS) += nospec-sysfs.o CFLAGS_REMOVE_nospec-branch.o += $(CC_FLAGS_EXPOLINE) obj-$(CONFIG_MODULES) += module.o diff --git a/arch/s390/kernel/nospec-branch.c b/arch/s390/kernel/nospec-branch.c index 46d49a11663f5..834cf29f25999 100644 --- a/arch/s390/kernel/nospec-branch.c +++ b/arch/s390/kernel/nospec-branch.c @@ -1,7 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 #include #include -#include #include static int __init nobp_setup_early(char *str) @@ -44,24 +43,6 @@ static int __init nospec_report(void) } arch_initcall(nospec_report); -#ifdef CONFIG_SYSFS -ssize_t cpu_show_spectre_v1(struct device *dev, - struct device_attribute *attr, char *buf) -{ - return sprintf(buf, "Mitigation: __user pointer sanitization\n"); -} - -ssize_t cpu_show_spectre_v2(struct device *dev, - struct device_attribute *attr, char *buf) -{ - if (IS_ENABLED(CC_USING_EXPOLINE) && !nospec_disable) - return sprintf(buf, "Mitigation: execute trampolines\n"); - if (__test_facility(82, S390_lowcore.alt_stfle_fac_list)) - return sprintf(buf, "Mitigation: limited branch prediction.\n"); - return sprintf(buf, "Vulnerable\n"); -} -#endif - #ifdef CONFIG_EXPOLINE int nospec_disable = IS_ENABLED(CONFIG_EXPOLINE_OFF); diff --git a/arch/s390/kernel/nospec-sysfs.c b/arch/s390/kernel/nospec-sysfs.c new file mode 100644 index 0000000000000..8affad5f18cb5 --- /dev/null +++ b/arch/s390/kernel/nospec-sysfs.c @@ -0,0 +1,21 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include + +ssize_t cpu_show_spectre_v1(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "Mitigation: __user pointer sanitization\n"); +} + +ssize_t cpu_show_spectre_v2(struct device *dev, + struct device_attribute *attr, char *buf) +{ + if (IS_ENABLED(CC_USING_EXPOLINE) && !nospec_disable) + return sprintf(buf, "Mitigation: execute trampolines\n"); + if (__test_facility(82, S390_lowcore.alt_stfle_fac_list)) + return sprintf(buf, "Mitigation: limited branch prediction\n"); + return sprintf(buf, "Vulnerable\n"); +} From 9f18fff63cfd6f559daa1eaae60640372c65f84b Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Tue, 24 Apr 2018 11:18:49 +0200 Subject: [PATCH 11/16] s390: remove indirect branch from do_softirq_own_stack The inline assembly to call __do_softirq on the irq stack uses an indirect branch. This can be replaced with a normal relative branch. Cc: stable@vger.kernel.org # 4.16 Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches") Reviewed-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/irq.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c index 94f2099bceb04..3d17c41074ca5 100644 --- a/arch/s390/kernel/irq.c +++ b/arch/s390/kernel/irq.c @@ -176,10 +176,9 @@ void do_softirq_own_stack(void) new -= STACK_FRAME_OVERHEAD; ((struct stack_frame *) new)->back_chain = old; asm volatile(" la 15,0(%0)\n" - " basr 14,%2\n" + " brasl 14,__do_softirq\n" " la 15,0(%1)\n" - : : "a" (new), "a" (old), - "a" (__do_softirq) + : : "a" (new), "a" (old) : "0", "1", "2", "3", "4", "5", "14", "cc", "memory" ); } else { From 6deaa3bbca804b2a3627fd685f75de64da7be535 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Tue, 24 Apr 2018 15:32:08 +0200 Subject: [PATCH 12/16] s390: extend expoline to BC instructions The BPF JIT uses a 'b (%r)' instruction in the definition of the sk_load_word and sk_load_half functions. Add support for branch-on-condition instructions contained in the thunk code of an expoline. Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/nospec-insn.h | 57 +++++++++++++++++++++++++++++ arch/s390/kernel/nospec-branch.c | 25 ++++++++++--- 2 files changed, 77 insertions(+), 5 deletions(-) diff --git a/arch/s390/include/asm/nospec-insn.h b/arch/s390/include/asm/nospec-insn.h index 7d7640e1cf90c..a01f81186e86a 100644 --- a/arch/s390/include/asm/nospec-insn.h +++ b/arch/s390/include/asm/nospec-insn.h @@ -35,10 +35,18 @@ _LC_BR_R1 = __LC_BR_R1 __THUNK_PROLOG_NAME __s390x_indirect_jump_r\r2\()use_r\r1 .endm + .macro __THUNK_PROLOG_BC d0,r1,r2 + __THUNK_PROLOG_NAME __s390x_indirect_branch_\d0\()_\r2\()use_\r1 + .endm + .macro __THUNK_BR r1,r2 jg __s390x_indirect_jump_r\r2\()use_r\r1 .endm + .macro __THUNK_BC d0,r1,r2 + jg __s390x_indirect_branch_\d0\()_\r2\()use_\r1 + .endm + .macro __THUNK_BRASL r1,r2,r3 brasl \r1,__s390x_indirect_jump_r\r3\()use_r\r2 .endm @@ -81,6 +89,23 @@ _LC_BR_R1 = __LC_BR_R1 .endif .endm + .macro __DECODE_DRR expand,disp,reg,ruse + .set __decode_fail,1 + .irp r1,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 + .ifc \reg,%r\r1 + .irp r2,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 + .ifc \ruse,%r\r2 + \expand \disp,\r1,\r2 + .set __decode_fail,0 + .endif + .endr + .endif + .endr + .if __decode_fail == 1 + .error "__DECODE_DRR failed" + .endif + .endm + .macro __THUNK_EX_BR reg,ruse # Be very careful when adding instructions to this macro! # The ALTERNATIVE replacement code has a .+10 which targets @@ -101,17 +126,42 @@ _LC_BR_R1 = __LC_BR_R1 555: br \reg .endm + .macro __THUNK_EX_BC disp,reg,ruse +#ifdef CONFIG_HAVE_MARCH_Z10_FEATURES + exrl 0,556f + j . +#else + larl \ruse,556f + ex 0,0(\ruse) + j . +#endif +556: b \disp(\reg) + .endm + .macro GEN_BR_THUNK reg,ruse=%r1 __DECODE_RR __THUNK_PROLOG_BR,\reg,\ruse __THUNK_EX_BR \reg,\ruse __THUNK_EPILOG .endm + .macro GEN_B_THUNK disp,reg,ruse=%r1 + __DECODE_DRR __THUNK_PROLOG_BC,\disp,\reg,\ruse + __THUNK_EX_BC \disp,\reg,\ruse + __THUNK_EPILOG + .endm + .macro BR_EX reg,ruse=%r1 557: __DECODE_RR __THUNK_BR,\reg,\ruse .pushsection .s390_indirect_branches,"a",@progbits .long 557b-. .popsection + .endm + + .macro B_EX disp,reg,ruse=%r1 +558: __DECODE_DRR __THUNK_BC,\disp,\reg,\ruse + .pushsection .s390_indirect_branches,"a",@progbits + .long 558b-. + .popsection .endm .macro BASR_EX rsave,rtarget,ruse=%r1 @@ -123,10 +173,17 @@ _LC_BR_R1 = __LC_BR_R1 #else .macro GEN_BR_THUNK reg,ruse=%r1 + .endm + + .macro GEN_B_THUNK disp,reg,ruse=%r1 .endm .macro BR_EX reg,ruse=%r1 br \reg + .endm + + .macro B_EX disp,reg,ruse=%r1 + b \disp(\reg) .endm .macro BASR_EX rsave,rtarget,ruse=%r1 diff --git a/arch/s390/kernel/nospec-branch.c b/arch/s390/kernel/nospec-branch.c index 834cf29f25999..8ad6a7128b3a5 100644 --- a/arch/s390/kernel/nospec-branch.c +++ b/arch/s390/kernel/nospec-branch.c @@ -93,7 +93,6 @@ static void __init_or_module __nospec_revert(s32 *start, s32 *end) s32 *epo; /* Second part of the instruction replace is always a nop */ - memcpy(insnbuf + 2, (char[]) { 0x47, 0x00, 0x00, 0x00 }, 4); for (epo = start; epo < end; epo++) { instr = (u8 *) epo + *epo; if (instr[0] == 0xc0 && (instr[1] & 0x0f) == 0x04) @@ -114,18 +113,34 @@ static void __init_or_module __nospec_revert(s32 *start, s32 *end) br = thunk + (*(int *)(thunk + 2)) * 2; else continue; - if (br[0] != 0x07 || (br[1] & 0xf0) != 0xf0) + /* Check for unconditional branch 0x07f? or 0x47f???? */ + if ((br[0] & 0xbf) != 0x07 || (br[1] & 0xf0) != 0xf0) continue; + + memcpy(insnbuf + 2, (char[]) { 0x47, 0x00, 0x07, 0x00 }, 4); switch (type) { case BRCL_EXPOLINE: - /* brcl to thunk, replace with br + nop */ insnbuf[0] = br[0]; insnbuf[1] = (instr[1] & 0xf0) | (br[1] & 0x0f); + if (br[0] == 0x47) { + /* brcl to b, replace with bc + nopr */ + insnbuf[2] = br[2]; + insnbuf[3] = br[3]; + } else { + /* brcl to br, replace with bcr + nop */ + } break; case BRASL_EXPOLINE: - /* brasl to thunk, replace with basr + nop */ - insnbuf[0] = 0x0d; insnbuf[1] = (instr[1] & 0xf0) | (br[1] & 0x0f); + if (br[0] == 0x47) { + /* brasl to b, replace with bas + nopr */ + insnbuf[0] = 0x4d; + insnbuf[2] = br[2]; + insnbuf[3] = br[3]; + } else { + /* brasl to br, replace with basr + nop */ + insnbuf[0] = 0x0d; + } break; } From de5cb6eb514ebe241e3edeb290cb41deb380b81d Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Mon, 23 Apr 2018 14:31:36 +0200 Subject: [PATCH 13/16] s390: use expoline thunks in the BPF JIT The BPF JIT need safe guarding against spectre v2 in the sk_load_xxx assembler stubs and the indirect branches generated by the JIT itself need to be converted to expolines. Signed-off-by: Martin Schwidefsky --- arch/s390/net/bpf_jit.S | 16 +++++---- arch/s390/net/bpf_jit_comp.c | 63 ++++++++++++++++++++++++++++++++++-- 2 files changed, 71 insertions(+), 8 deletions(-) diff --git a/arch/s390/net/bpf_jit.S b/arch/s390/net/bpf_jit.S index 25bb4643c4f46..9f794869c1b09 100644 --- a/arch/s390/net/bpf_jit.S +++ b/arch/s390/net/bpf_jit.S @@ -9,6 +9,7 @@ */ #include +#include #include "bpf_jit.h" /* @@ -54,7 +55,7 @@ ENTRY(sk_load_##NAME##_pos); \ clg %r3,STK_OFF_HLEN(%r15); /* Offset + SIZE > hlen? */ \ jh sk_load_##NAME##_slow; \ LOAD %r14,-SIZE(%r3,%r12); /* Get data from skb */ \ - b OFF_OK(%r6); /* Return */ \ + B_EX OFF_OK,%r6; /* Return */ \ \ sk_load_##NAME##_slow:; \ lgr %r2,%r7; /* Arg1 = skb pointer */ \ @@ -64,11 +65,14 @@ sk_load_##NAME##_slow:; \ brasl %r14,skb_copy_bits; /* Get data from skb */ \ LOAD %r14,STK_OFF_TMP(%r15); /* Load from temp bufffer */ \ ltgr %r2,%r2; /* Set cc to (%r2 != 0) */ \ - br %r6; /* Return */ + BR_EX %r6; /* Return */ sk_load_common(word, 4, llgf) /* r14 = *(u32 *) (skb->data+offset) */ sk_load_common(half, 2, llgh) /* r14 = *(u16 *) (skb->data+offset) */ + GEN_BR_THUNK %r6 + GEN_B_THUNK OFF_OK,%r6 + /* * Load 1 byte from SKB (optimized version) */ @@ -80,7 +84,7 @@ ENTRY(sk_load_byte_pos) clg %r3,STK_OFF_HLEN(%r15) # Offset >= hlen? jnl sk_load_byte_slow llgc %r14,0(%r3,%r12) # Get byte from skb - b OFF_OK(%r6) # Return OK + B_EX OFF_OK,%r6 # Return OK sk_load_byte_slow: lgr %r2,%r7 # Arg1 = skb pointer @@ -90,7 +94,7 @@ sk_load_byte_slow: brasl %r14,skb_copy_bits # Get data from skb llgc %r14,STK_OFF_TMP(%r15) # Load result from temp buffer ltgr %r2,%r2 # Set cc to (%r2 != 0) - br %r6 # Return cc + BR_EX %r6 # Return cc #define sk_negative_common(NAME, SIZE, LOAD) \ sk_load_##NAME##_slow_neg:; \ @@ -104,7 +108,7 @@ sk_load_##NAME##_slow_neg:; \ jz bpf_error; \ LOAD %r14,0(%r2); /* Get data from pointer */ \ xr %r3,%r3; /* Set cc to zero */ \ - br %r6; /* Return cc */ + BR_EX %r6; /* Return cc */ sk_negative_common(word, 4, llgf) sk_negative_common(half, 2, llgh) @@ -113,4 +117,4 @@ sk_negative_common(byte, 1, llgc) bpf_error: # force a return 0 from jit handler ltgr %r15,%r15 # Set condition code - br %r6 + BR_EX %r6 diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index 78a19c93b3802..dd2bcf0e7d00d 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -25,6 +25,8 @@ #include #include #include +#include +#include #include #include "bpf_jit.h" @@ -41,6 +43,8 @@ struct bpf_jit { int base_ip; /* Base address for literal pool */ int ret0_ip; /* Address of return 0 */ int exit_ip; /* Address of exit */ + int r1_thunk_ip; /* Address of expoline thunk for 'br %r1' */ + int r14_thunk_ip; /* Address of expoline thunk for 'br %r14' */ int tail_call_start; /* Tail call start offset */ int labels[1]; /* Labels for local jumps */ }; @@ -250,6 +254,19 @@ static inline void reg_set_seen(struct bpf_jit *jit, u32 b1) REG_SET_SEEN(b2); \ }) +#define EMIT6_PCREL_RILB(op, b, target) \ +({ \ + int rel = (target - jit->prg) / 2; \ + _EMIT6(op | reg_high(b) << 16 | rel >> 16, rel & 0xffff); \ + REG_SET_SEEN(b); \ +}) + +#define EMIT6_PCREL_RIL(op, target) \ +({ \ + int rel = (target - jit->prg) / 2; \ + _EMIT6(op | rel >> 16, rel & 0xffff); \ +}) + #define _EMIT6_IMM(op, imm) \ ({ \ unsigned int __imm = (imm); \ @@ -469,8 +486,45 @@ static void bpf_jit_epilogue(struct bpf_jit *jit, u32 stack_depth) EMIT4(0xb9040000, REG_2, BPF_REG_0); /* Restore registers */ save_restore_regs(jit, REGS_RESTORE, stack_depth); + if (IS_ENABLED(CC_USING_EXPOLINE) && !nospec_disable) { + jit->r14_thunk_ip = jit->prg; + /* Generate __s390_indirect_jump_r14 thunk */ + if (test_facility(35)) { + /* exrl %r0,.+10 */ + EMIT6_PCREL_RIL(0xc6000000, jit->prg + 10); + } else { + /* larl %r1,.+14 */ + EMIT6_PCREL_RILB(0xc0000000, REG_1, jit->prg + 14); + /* ex 0,0(%r1) */ + EMIT4_DISP(0x44000000, REG_0, REG_1, 0); + } + /* j . */ + EMIT4_PCREL(0xa7f40000, 0); + } /* br %r14 */ _EMIT2(0x07fe); + + if (IS_ENABLED(CC_USING_EXPOLINE) && !nospec_disable && + (jit->seen & SEEN_FUNC)) { + jit->r1_thunk_ip = jit->prg; + /* Generate __s390_indirect_jump_r1 thunk */ + if (test_facility(35)) { + /* exrl %r0,.+10 */ + EMIT6_PCREL_RIL(0xc6000000, jit->prg + 10); + /* j . */ + EMIT4_PCREL(0xa7f40000, 0); + /* br %r1 */ + _EMIT2(0x07f1); + } else { + /* larl %r1,.+14 */ + EMIT6_PCREL_RILB(0xc0000000, REG_1, jit->prg + 14); + /* ex 0,S390_lowcore.br_r1_tampoline */ + EMIT4_DISP(0x44000000, REG_0, REG_0, + offsetof(struct lowcore, br_r1_trampoline)); + /* j . */ + EMIT4_PCREL(0xa7f40000, 0); + } + } } /* @@ -966,8 +1020,13 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i /* lg %w1,(%l) */ EMIT6_DISP_LH(0xe3000000, 0x0004, REG_W1, REG_0, REG_L, EMIT_CONST_U64(func)); - /* basr %r14,%w1 */ - EMIT2(0x0d00, REG_14, REG_W1); + if (IS_ENABLED(CC_USING_EXPOLINE) && !nospec_disable) { + /* brasl %r14,__s390_indirect_jump_r1 */ + EMIT6_PCREL_RILB(0xc0050000, REG_14, jit->r1_thunk_ip); + } else { + /* basr %r14,%w1 */ + EMIT2(0x0d00, REG_14, REG_W1); + } /* lgr %b0,%r2: load return value into %b0 */ EMIT4(0xb9040000, BPF_REG_0, REG_2); if ((jit->seen & SEEN_SKB) && From 4bbaf2584b86b0772413edeac22ff448f36351b1 Mon Sep 17 00:00:00 2001 From: Hendrik Brueckner Date: Thu, 3 May 2018 15:56:15 +0200 Subject: [PATCH 14/16] s390/cpum_sf: ensure sample frequency of perf event attributes is non-zero Correct a trinity finding for the perf_event_open() system call with a perf event attribute structure that uses a frequency but has the sampling frequency set to zero. This causes a FP divide exception during the sample rate initialization for the hardware sampling facility. Fixes: 8c069ff4bd606 ("s390/perf: add support for the CPU-Measurement Sampling Facility") Cc: stable@vger.kernel.org # 3.14+ Reviewed-by: Heiko Carstens Signed-off-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/perf_cpum_sf.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c index 1c9ddd7aa5ec8..0292d68e7dded 100644 --- a/arch/s390/kernel/perf_cpum_sf.c +++ b/arch/s390/kernel/perf_cpum_sf.c @@ -753,6 +753,10 @@ static int __hw_perf_event_init(struct perf_event *event) */ rate = 0; if (attr->freq) { + if (!attr->sample_freq) { + err = -EINVAL; + goto out; + } rate = freq_to_sample_rate(&si, attr->sample_freq); rate = hw_limit_rate(&si, rate); attr->freq = 0; From e521813468f786271a87e78e8644243bead48fad Mon Sep 17 00:00:00 2001 From: Julian Wiedmann Date: Wed, 2 May 2018 08:48:43 +0200 Subject: [PATCH 15/16] s390/qdio: fix access to uninitialized qdio_q fields Ever since CQ/QAOB support was added, calling qdio_free() straight after qdio_alloc() results in qdio_release_memory() accessing uninitialized memory (ie. q->u.out.use_cq and q->u.out.aobs). Followed by a kmem_cache_free() on the random AOB addresses. For older kernels that don't have 6e30c549f6ca, the same applies if qdio_establish() fails in the DEV_STATE_ONLINE check. While initializing q->u.out.use_cq would be enough to fix this particular bug, the more future-proof change is to just zero-alloc the whole struct. Fixes: 104ea556ee7f ("qdio: support asynchronous delivery of storage blocks") Cc: #v3.2+ Signed-off-by: Julian Wiedmann Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/qdio_setup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/s390/cio/qdio_setup.c b/drivers/s390/cio/qdio_setup.c index 439991d71b146..22ddb49e0f500 100644 --- a/drivers/s390/cio/qdio_setup.c +++ b/drivers/s390/cio/qdio_setup.c @@ -141,7 +141,7 @@ static int __qdio_allocate_qs(struct qdio_q **irq_ptr_qs, int nr_queues) int i; for (i = 0; i < nr_queues; i++) { - q = kmem_cache_alloc(qdio_q_cache, GFP_KERNEL); + q = kmem_cache_zalloc(qdio_q_cache, GFP_KERNEL); if (!q) return -ENOMEM; From 2e68adcd2fb21b7188ba449f0fab3bee2910e500 Mon Sep 17 00:00:00 2001 From: Julian Wiedmann Date: Wed, 2 May 2018 08:28:34 +0200 Subject: [PATCH 16/16] s390/qdio: don't release memory in qdio_setup_irq() Calling qdio_release_memory() on error is just plain wrong. It frees the main qdio_irq struct, when following code still uses it. Also, no other error path in qdio_establish() does this. So trust callers to clean up via qdio_free() if some step of the QDIO initialization fails. Fixes: 779e6e1c724d ("[S390] qdio: new qdio driver.") Cc: #v2.6.27+ Signed-off-by: Julian Wiedmann Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/qdio_setup.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) diff --git a/drivers/s390/cio/qdio_setup.c b/drivers/s390/cio/qdio_setup.c index 22ddb49e0f500..4c14ce428e92d 100644 --- a/drivers/s390/cio/qdio_setup.c +++ b/drivers/s390/cio/qdio_setup.c @@ -456,7 +456,6 @@ int qdio_setup_irq(struct qdio_initialize *init_data) { struct ciw *ciw; struct qdio_irq *irq_ptr = init_data->cdev->private->qdio_data; - int rc; memset(&irq_ptr->qib, 0, sizeof(irq_ptr->qib)); memset(&irq_ptr->siga_flag, 0, sizeof(irq_ptr->siga_flag)); @@ -493,16 +492,14 @@ int qdio_setup_irq(struct qdio_initialize *init_data) ciw = ccw_device_get_ciw(init_data->cdev, CIW_TYPE_EQUEUE); if (!ciw) { DBF_ERROR("%4x NO EQ", irq_ptr->schid.sch_no); - rc = -EINVAL; - goto out_err; + return -EINVAL; } irq_ptr->equeue = *ciw; ciw = ccw_device_get_ciw(init_data->cdev, CIW_TYPE_AQUEUE); if (!ciw) { DBF_ERROR("%4x NO AQ", irq_ptr->schid.sch_no); - rc = -EINVAL; - goto out_err; + return -EINVAL; } irq_ptr->aqueue = *ciw; @@ -512,9 +509,6 @@ int qdio_setup_irq(struct qdio_initialize *init_data) init_data->cdev->handler = qdio_int_handler; spin_unlock_irq(get_ccwdev_lock(irq_ptr->cdev)); return 0; -out_err: - qdio_release_memory(irq_ptr); - return rc; } void qdio_print_subchannel_info(struct qdio_irq *irq_ptr,