From 9dd78194a3722fa6712192cdd4f7032d45112a9a Mon Sep 17 00:00:00 2001 From: "Russell King (Oracle)" Date: Fri, 11 Feb 2022 16:45:54 +0000 Subject: ARM: report Spectre v2 status through sysfs As per other architectures, add support for reporting the Spectre vulnerability status via sysfs CPU. Acked-by: Catalin Marinas Signed-off-by: Russell King (Oracle) --- arch/arm/include/asm/spectre.h | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) create mode 100644 arch/arm/include/asm/spectre.h (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/spectre.h b/arch/arm/include/asm/spectre.h new file mode 100644 index 000000000000..8a9019e08dba --- /dev/null +++ b/arch/arm/include/asm/spectre.h @@ -0,0 +1,28 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#ifndef __ASM_SPECTRE_H +#define __ASM_SPECTRE_H + +enum { + SPECTRE_UNAFFECTED, + SPECTRE_MITIGATED, + SPECTRE_VULNERABLE, +}; + +enum { + __SPECTRE_V2_METHOD_BPIALL, + __SPECTRE_V2_METHOD_ICIALLU, + __SPECTRE_V2_METHOD_SMC, + __SPECTRE_V2_METHOD_HVC, +}; + +enum { + SPECTRE_V2_METHOD_BPIALL = BIT(__SPECTRE_V2_METHOD_BPIALL), + SPECTRE_V2_METHOD_ICIALLU = BIT(__SPECTRE_V2_METHOD_ICIALLU), + SPECTRE_V2_METHOD_SMC = BIT(__SPECTRE_V2_METHOD_SMC), + SPECTRE_V2_METHOD_HVC = BIT(__SPECTRE_V2_METHOD_HVC), +}; + +void spectre_v2_update_state(unsigned int state, unsigned int methods); + +#endif -- cgit v1.2.3 From 8d9d651ff2270a632e9dc497b142db31e8911315 Mon Sep 17 00:00:00 2001 From: "Russell King (Oracle)" Date: Fri, 11 Feb 2022 19:49:50 +0000 Subject: ARM: use LOADADDR() to get load address of sections Use the linker's LOADADDR() macro to get the load address of the sections, and provide a macro to set the start and end symbols. Acked-by: Catalin Marinas Signed-off-by: Russell King (Oracle) --- arch/arm/include/asm/vmlinux.lds.h | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/vmlinux.lds.h b/arch/arm/include/asm/vmlinux.lds.h index 4a91428c324d..e02710d17cf9 100644 --- a/arch/arm/include/asm/vmlinux.lds.h +++ b/arch/arm/include/asm/vmlinux.lds.h @@ -26,6 +26,11 @@ #define ARM_MMU_DISCARD(x) x #endif +/* Set start/end symbol names to the LMA for the section */ +#define ARM_LMA(sym, section) \ + sym##_start = LOADADDR(section); \ + sym##_end = LOADADDR(section) + SIZEOF(section) + #define PROC_INFO \ . = ALIGN(4); \ __proc_info_begin = .; \ @@ -110,19 +115,19 @@ * only thing that matters is their relative offsets */ #define ARM_VECTORS \ - __vectors_start = .; \ + __vectors_lma = .; \ .vectors 0xffff0000 : AT(__vectors_start) { \ *(.vectors) \ } \ - . = __vectors_start + SIZEOF(.vectors); \ - __vectors_end = .; \ + ARM_LMA(__vectors, .vectors); \ + . = __vectors_lma + SIZEOF(.vectors); \ \ - __stubs_start = .; \ - .stubs ADDR(.vectors) + 0x1000 : AT(__stubs_start) { \ + __stubs_lma = .; \ + .stubs ADDR(.vectors) + 0x1000 : AT(__stubs_lma) { \ *(.stubs) \ } \ - . = __stubs_start + SIZEOF(.stubs); \ - __stubs_end = .; \ + ARM_LMA(__stubs, .stubs); \ + . = __stubs_lma + SIZEOF(.stubs); \ \ PROVIDE(vector_fiq_offset = vector_fiq - ADDR(.vectors)); -- cgit v1.2.3 From b9baf5c8c5c356757f4f9d8180b5e9d234065bc3 Mon Sep 17 00:00:00 2001 From: "Russell King (Oracle)" Date: Thu, 10 Feb 2022 16:05:45 +0000 Subject: ARM: Spectre-BHB workaround Workaround the Spectre BHB issues for Cortex-A15, Cortex-A57, Cortex-A72, Cortex-A73 and Cortex-A75. We also include Brahma B15 as well to be safe, which is affected by Spectre V2 in the same ways as Cortex-A15. Reviewed-by: Catalin Marinas Signed-off-by: Russell King (Oracle) --- arch/arm/include/asm/assembler.h | 10 ++++++++++ arch/arm/include/asm/spectre.h | 4 ++++ arch/arm/include/asm/vmlinux.lds.h | 18 +++++++++++++++--- 3 files changed, 29 insertions(+), 3 deletions(-) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h index 7d23d4bb2168..49ea603fc8e3 100644 --- a/arch/arm/include/asm/assembler.h +++ b/arch/arm/include/asm/assembler.h @@ -107,6 +107,16 @@ .endm #endif +#if __LINUX_ARM_ARCH__ < 7 + .macro dsb, args + mcr p15, 0, r0, c7, c10, 4 + .endm + + .macro isb, args + mcr p15, 0, r0, c7, r5, 4 + .endm +#endif + .macro asm_trace_hardirqs_off, save=1 #if defined(CONFIG_TRACE_IRQFLAGS) .if \save diff --git a/arch/arm/include/asm/spectre.h b/arch/arm/include/asm/spectre.h index 8a9019e08dba..d1fa5607d3aa 100644 --- a/arch/arm/include/asm/spectre.h +++ b/arch/arm/include/asm/spectre.h @@ -14,6 +14,7 @@ enum { __SPECTRE_V2_METHOD_ICIALLU, __SPECTRE_V2_METHOD_SMC, __SPECTRE_V2_METHOD_HVC, + __SPECTRE_V2_METHOD_LOOP8, }; enum { @@ -21,8 +22,11 @@ enum { SPECTRE_V2_METHOD_ICIALLU = BIT(__SPECTRE_V2_METHOD_ICIALLU), SPECTRE_V2_METHOD_SMC = BIT(__SPECTRE_V2_METHOD_SMC), SPECTRE_V2_METHOD_HVC = BIT(__SPECTRE_V2_METHOD_HVC), + SPECTRE_V2_METHOD_LOOP8 = BIT(__SPECTRE_V2_METHOD_LOOP8), }; void spectre_v2_update_state(unsigned int state, unsigned int methods); +int spectre_bhb_update_vectors(unsigned int method); + #endif diff --git a/arch/arm/include/asm/vmlinux.lds.h b/arch/arm/include/asm/vmlinux.lds.h index e02710d17cf9..0ef21bfae9f6 100644 --- a/arch/arm/include/asm/vmlinux.lds.h +++ b/arch/arm/include/asm/vmlinux.lds.h @@ -116,11 +116,23 @@ */ #define ARM_VECTORS \ __vectors_lma = .; \ - .vectors 0xffff0000 : AT(__vectors_start) { \ - *(.vectors) \ + OVERLAY 0xffff0000 : NOCROSSREFS AT(__vectors_lma) { \ + .vectors { \ + *(.vectors) \ + } \ + .vectors.bhb.loop8 { \ + *(.vectors.bhb.loop8) \ + } \ + .vectors.bhb.bpiall { \ + *(.vectors.bhb.bpiall) \ + } \ } \ ARM_LMA(__vectors, .vectors); \ - . = __vectors_lma + SIZEOF(.vectors); \ + ARM_LMA(__vectors_bhb_loop8, .vectors.bhb.loop8); \ + ARM_LMA(__vectors_bhb_bpiall, .vectors.bhb.bpiall); \ + . = __vectors_lma + SIZEOF(.vectors) + \ + SIZEOF(.vectors.bhb.loop8) + \ + SIZEOF(.vectors.bhb.bpiall); \ \ __stubs_lma = .; \ .stubs ADDR(.vectors) + 0x1000 : AT(__stubs_lma) { \ -- cgit v1.2.3 From 33970b031dc4653cc9dc80f2886976706c4c8ef1 Mon Sep 17 00:00:00 2001 From: "Russell King (Oracle)" Date: Wed, 9 Mar 2022 19:08:42 +0000 Subject: ARM: fix co-processor register typo In the recent Spectre BHB patches, there was a typo that is only exposed in certain configurations: mcr p15,0,XX,c7,r5,4 should have been mcr p15,0,XX,c7,c5,4 Reported-by: kernel test robot Fixes: b9baf5c8c5c3 ("ARM: Spectre-BHB workaround") Signed-off-by: Russell King (Oracle) Acked-by: Catalin Marinas Signed-off-by: Linus Torvalds --- arch/arm/include/asm/assembler.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h index b50cc0169d5c..aee73ef5b3dc 100644 --- a/arch/arm/include/asm/assembler.h +++ b/arch/arm/include/asm/assembler.h @@ -113,7 +113,7 @@ .endm .macro isb, args - mcr p15, 0, r0, c7, r5, 4 + mcr p15, 0, r0, c7, c5, 4 .endm #endif -- cgit v1.2.3 From 36168e387fa7d0f1fe0cd5cf76c8cea7aee714fa Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Wed, 9 Mar 2022 15:07:27 -0700 Subject: ARM: Do not use NOCROSSREFS directive with ld.lld ld.lld does not support the NOCROSSREFS directive at the moment, which breaks the build after commit b9baf5c8c5c3 ("ARM: Spectre-BHB workaround"): ld.lld: error: ./arch/arm/kernel/vmlinux.lds:34: AT expected, but got NOCROSSREFS Support for this directive will eventually be implemented, at which point a version check can be added. To avoid breaking the build in the meantime, just define NOCROSSREFS to nothing when using ld.lld, with a link to the issue for tracking. Cc: stable@vger.kernel.org Fixes: b9baf5c8c5c3 ("ARM: Spectre-BHB workaround") Link: https://github.com/ClangBuiltLinux/linux/issues/1609 Signed-off-by: Nathan Chancellor Signed-off-by: Linus Torvalds --- arch/arm/include/asm/vmlinux.lds.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/vmlinux.lds.h b/arch/arm/include/asm/vmlinux.lds.h index 0ef21bfae9f6..fad45c884e98 100644 --- a/arch/arm/include/asm/vmlinux.lds.h +++ b/arch/arm/include/asm/vmlinux.lds.h @@ -26,6 +26,14 @@ #define ARM_MMU_DISCARD(x) x #endif +/* + * ld.lld does not support NOCROSSREFS: + * https://github.com/ClangBuiltLinux/linux/issues/1609 + */ +#ifdef CONFIG_LD_IS_LLD +#define NOCROSSREFS +#endif + /* Set start/end symbol names to the LMA for the section */ #define ARM_LMA(sym, section) \ sym##_start = LOADADDR(section); \ -- cgit v1.2.3 From 68453767131a5deec1e8f9ac92a9042f929e585d Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Fri, 11 Mar 2022 11:49:12 -0800 Subject: ARM: Spectre-BHB: provide empty stub for non-config When CONFIG_GENERIC_CPU_VULNERABILITIES is not set, references to spectre_v2_update_state() cause a build error, so provide an empty stub for that function when the Kconfig option is not set. Fixes this build error: arm-linux-gnueabi-ld: arch/arm/mm/proc-v7-bugs.o: in function `cpu_v7_bugs_init': proc-v7-bugs.c:(.text+0x52): undefined reference to `spectre_v2_update_state' arm-linux-gnueabi-ld: proc-v7-bugs.c:(.text+0x82): undefined reference to `spectre_v2_update_state' Fixes: b9baf5c8c5c3 ("ARM: Spectre-BHB workaround") Signed-off-by: Randy Dunlap Reported-by: kernel test robot Cc: Russell King Cc: Catalin Marinas Cc: linux-arm-kernel@lists.infradead.org Cc: patches@armlinux.org.uk Acked-by: Russell King (Oracle) Signed-off-by: Linus Torvalds --- arch/arm/include/asm/spectre.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch/arm/include') diff --git a/arch/arm/include/asm/spectre.h b/arch/arm/include/asm/spectre.h index d1fa5607d3aa..85f9e538fb32 100644 --- a/arch/arm/include/asm/spectre.h +++ b/arch/arm/include/asm/spectre.h @@ -25,7 +25,13 @@ enum { SPECTRE_V2_METHOD_LOOP8 = BIT(__SPECTRE_V2_METHOD_LOOP8), }; +#ifdef CONFIG_GENERIC_CPU_VULNERABILITIES void spectre_v2_update_state(unsigned int state, unsigned int methods); +#else +static inline void spectre_v2_update_state(unsigned int state, + unsigned int methods) +{} +#endif int spectre_bhb_update_vectors(unsigned int method); -- cgit v1.2.3