diff options
| author |   Mike Pagano <mpagano@gentoo.org> | 2023-08-08 14:41:09 -0400 |
|---|---|---|
| committer | Mike Pagano <mpagano@gentoo.org> | 2023-08-08 14:41:09 -0400 |
| commit | 650f4d77c86ae0799488b167ba510cb4d09bacb8 (patch) | |
| tree | 67debf4e13c55eb5420c599a4e30e9d957f27b11 | |
| parent | Linux patch 5.15.124 (diff) | |
| download | linux-patches-5.15-131.tar.gz linux-patches-5.15-131.tar.bz2 linux-patches-5.15-131.zip | |
Linux patch 5.15.1255.15-131
Signed-off-by: Mike Pagano <mpagano@gentoo.org>
| -rw-r--r-- | 0000_README | 4 | ||||
| -rw-r--r-- | 1124_linux-5.15.125.patch | 2808 |
2 files changed, 2812 insertions, 0 deletions
diff --git a/0000_README b/0000_README index 223cbbbf..25b6fa31 100644 --- a/0000_README +++ b/0000_README @@ -539,6 +539,10 @@ Patch: 1123_linux-5.15.124.patch From: https://www.kernel.org Desc: Linux 5.15.124 +Patch: 1124_linux-5.15.125.patch +From: https://www.kernel.org +Desc: Linux 5.15.125 + Patch: 1500_XATTR_USER_PREFIX.patch From: https://bugs.gentoo.org/show_bug.cgi?id=470644 Desc: Support for namespace user.pax.* on tmpfs. diff --git a/1124_linux-5.15.125.patch b/1124_linux-5.15.125.patch new file mode 100644 index 00000000..771efcfa --- /dev/null +++ b/1124_linux-5.15.125.patch @@ -0,0 +1,2808 @@ +diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu +index a7362b1096c4d..eecbd16033493 100644 +--- a/Documentation/ABI/testing/sysfs-devices-system-cpu ++++ b/Documentation/ABI/testing/sysfs-devices-system-cpu +@@ -511,17 +511,18 @@ Description: information about CPUs heterogeneity. + cpu_capacity: capacity of cpu#. + + What: /sys/devices/system/cpu/vulnerabilities ++ /sys/devices/system/cpu/vulnerabilities/gather_data_sampling ++ /sys/devices/system/cpu/vulnerabilities/itlb_multihit ++ /sys/devices/system/cpu/vulnerabilities/l1tf ++ /sys/devices/system/cpu/vulnerabilities/mds + /sys/devices/system/cpu/vulnerabilities/meltdown ++ /sys/devices/system/cpu/vulnerabilities/mmio_stale_data ++ /sys/devices/system/cpu/vulnerabilities/retbleed ++ /sys/devices/system/cpu/vulnerabilities/spec_store_bypass + /sys/devices/system/cpu/vulnerabilities/spectre_v1 + /sys/devices/system/cpu/vulnerabilities/spectre_v2 +- /sys/devices/system/cpu/vulnerabilities/spec_store_bypass +- /sys/devices/system/cpu/vulnerabilities/l1tf +- /sys/devices/system/cpu/vulnerabilities/mds + /sys/devices/system/cpu/vulnerabilities/srbds + /sys/devices/system/cpu/vulnerabilities/tsx_async_abort +- /sys/devices/system/cpu/vulnerabilities/itlb_multihit +- /sys/devices/system/cpu/vulnerabilities/mmio_stale_data +- /sys/devices/system/cpu/vulnerabilities/retbleed + Date: January 2018 + Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org> + Description: Information about CPU vulnerabilities +diff --git a/Documentation/admin-guide/hw-vuln/gather_data_sampling.rst b/Documentation/admin-guide/hw-vuln/gather_data_sampling.rst +new file mode 100644 +index 0000000000000..264bfa937f7de +--- /dev/null ++++ b/Documentation/admin-guide/hw-vuln/gather_data_sampling.rst +@@ -0,0 +1,109 @@ ++.. SPDX-License-Identifier: GPL-2.0 ++ ++GDS - Gather Data Sampling ++========================== ++ ++Gather Data Sampling is a hardware vulnerability which allows unprivileged ++speculative access to data which was previously stored in vector registers. ++ ++Problem ++------- ++When a gather instruction performs loads from memory, different data elements ++are merged into the destination vector register. However, when a gather ++instruction that is transiently executed encounters a fault, stale data from ++architectural or internal vector registers may get transiently forwarded to the ++destination vector register instead. This will allow a malicious attacker to ++infer stale data using typical side channel techniques like cache timing ++attacks. GDS is a purely sampling-based attack. ++ ++The attacker uses gather instructions to infer the stale vector register data. ++The victim does not need to do anything special other than use the vector ++registers. The victim does not need to use gather instructions to be ++vulnerable. ++ ++Because the buffers are shared between Hyper-Threads cross Hyper-Thread attacks ++are possible. ++ ++Attack scenarios ++---------------- ++Without mitigation, GDS can infer stale data across virtually all ++permission boundaries: ++ ++ Non-enclaves can infer SGX enclave data ++ Userspace can infer kernel data ++ Guests can infer data from hosts ++ Guest can infer guest from other guests ++ Users can infer data from other users ++ ++Because of this, it is important to ensure that the mitigation stays enabled in ++lower-privilege contexts like guests and when running outside SGX enclaves. ++ ++The hardware enforces the mitigation for SGX. Likewise, VMMs should ensure ++that guests are not allowed to disable the GDS mitigation. If a host erred and ++allowed this, a guest could theoretically disable GDS mitigation, mount an ++attack, and re-enable it. ++ ++Mitigation mechanism ++-------------------- ++This issue is mitigated in microcode. The microcode defines the following new ++bits: ++ ++ ================================ === ============================ ++ IA32_ARCH_CAPABILITIES[GDS_CTRL] R/O Enumerates GDS vulnerability ++ and mitigation support. ++ IA32_ARCH_CAPABILITIES[GDS_NO] R/O Processor is not vulnerable. ++ IA32_MCU_OPT_CTRL[GDS_MITG_DIS] R/W Disables the mitigation ++ 0 by default. ++ IA32_MCU_OPT_CTRL[GDS_MITG_LOCK] R/W Locks GDS_MITG_DIS=0. Writes ++ to GDS_MITG_DIS are ignored ++ Can't be cleared once set. ++ ================================ === ============================ ++ ++GDS can also be mitigated on systems that don't have updated microcode by ++disabling AVX. This can be done by setting gather_data_sampling="force" or ++"clearcpuid=avx" on the kernel command-line. ++ ++If used, these options will disable AVX use by turning off XSAVE YMM support. ++However, the processor will still enumerate AVX support. Userspace that ++does not follow proper AVX enumeration to check both AVX *and* XSAVE YMM ++support will break. ++ ++Mitigation control on the kernel command line ++--------------------------------------------- ++The mitigation can be disabled by setting "gather_data_sampling=off" or ++"mitigations=off" on the kernel command line. Not specifying either will default ++to the mitigation being enabled. Specifying "gather_data_sampling=force" will ++use the microcode mitigation when available or disable AVX on affected systems ++where the microcode hasn't been updated to include the mitigation. ++ ++GDS System Information ++------------------------ ++The kernel provides vulnerability status information through sysfs. For ++GDS this can be accessed by the following sysfs file: ++ ++/sys/devices/system/cpu/vulnerabilities/gather_data_sampling ++ ++The possible values contained in this file are: ++ ++ ============================== ============================================= ++ Not affected Processor not vulnerable. ++ Vulnerable Processor vulnerable and mitigation disabled. ++ Vulnerable: No microcode Processor vulnerable and microcode is missing ++ mitigation. ++ Mitigation: AVX disabled, ++ no microcode Processor is vulnerable and microcode is missing ++ mitigation. AVX disabled as mitigation. ++ Mitigation: Microcode Processor is vulnerable and mitigation is in ++ effect. ++ Mitigation: Microcode (locked) Processor is vulnerable and mitigation is in ++ effect and cannot be disabled. ++ Unknown: Dependent on ++ hypervisor status Running on a virtual guest processor that is ++ affected but with no way to know if host ++ processor is mitigated or vulnerable. ++ ============================== ============================================= ++ ++GDS Default mitigation ++---------------------- ++The updated microcode will enable the mitigation by default. The kernel's ++default action is to leave the mitigation enabled. +diff --git a/Documentation/admin-guide/hw-vuln/index.rst b/Documentation/admin-guide/hw-vuln/index.rst +index e0614760a99e7..6828102baaa7a 100644 +--- a/Documentation/admin-guide/hw-vuln/index.rst ++++ b/Documentation/admin-guide/hw-vuln/index.rst +@@ -19,3 +19,5 @@ are configurable at compile, boot or run time. + l1d_flush.rst + processor_mmio_stale_data.rst + cross-thread-rsb.rst ++ gather_data_sampling.rst ++ srso +diff --git a/Documentation/admin-guide/hw-vuln/srso.rst b/Documentation/admin-guide/hw-vuln/srso.rst +new file mode 100644 +index 0000000000000..2f923c805802f +--- /dev/null ++++ b/Documentation/admin-guide/hw-vuln/srso.rst +@@ -0,0 +1,133 @@ ++.. SPDX-License-Identifier: GPL-2.0 ++ ++Speculative Return Stack Overflow (SRSO) ++======================================== ++ ++This is a mitigation for the speculative return stack overflow (SRSO) ++vulnerability found on AMD processors. The mechanism is by now the well ++known scenario of poisoning CPU functional units - the Branch Target ++Buffer (BTB) and Return Address Predictor (RAP) in this case - and then ++tricking the elevated privilege domain (the kernel) into leaking ++sensitive data. ++ ++AMD CPUs predict RET instructions using a Return Address Predictor (aka ++Return Address Stack/Return Stack Buffer). In some cases, a non-architectural ++CALL instruction (i.e., an instruction predicted to be a CALL but is ++not actually a CALL) can create an entry in the RAP which may be used ++to predict the target of a subsequent RET instruction. ++ ++The specific circumstances that lead to this varies by microarchitecture ++but the concern is that an attacker can mis-train the CPU BTB to predict ++non-architectural CALL instructions in kernel space and use this to ++control the speculative target of a subsequent kernel RET, potentially ++leading to information disclosure via a speculative side-channel. ++ ++The issue is tracked under CVE-2023-20569. ++ ++Affected processors ++------------------- ++ ++AMD Zen, generations 1-4. That is, all families 0x17 and 0x19. Older ++processors have not been investigated. ++ ++System information and options ++------------------------------ ++ ++First of all, it is required that the latest microcode be loaded for ++mitigations to be effective. ++ ++The sysfs file showing SRSO mitigation status is: ++ ++ /sys/devices/system/cpu/vulnerabilities/spec_rstack_overflow ++ ++The possible values in this file are: ++ ++ - 'Not affected' The processor is not vulnerable ++ ++ - 'Vulnerable: no microcode' The processor is vulnerable, no ++ microcode extending IBPB functionality ++ to address the vulnerability has been ++ applied. ++ ++ - 'Mitigation: microcode' Extended IBPB functionality microcode ++ patch has been applied. It does not ++ address User->Kernel and Guest->Host ++ transitions protection but it does ++ address User->User and VM->VM attack ++ vectors. ++ ++ (spec_rstack_overflow=microcode) ++ ++ - 'Mitigation: safe RET' Software-only mitigation. It complements ++ the extended IBPB microcode patch ++ functionality by addressing User->Kernel ++ and Guest->Host transitions protection. ++ ++ Selected by default or by ++ spec_rstack_overflow=safe-ret ++ ++ - 'Mitigation: IBPB' Similar protection as "safe RET" above ++ but employs an IBPB barrier on privilege ++ domain crossings (User->Kernel, ++ Guest->Host). ++ ++ (spec_rstack_overflow=ibpb) ++ ++ - 'Mitigation: IBPB on VMEXIT' Mitigation addressing the cloud provider ++ scenario - the Guest->Host transitions ++ only. ++ ++ (spec_rstack_overflow=ibpb-vmexit) ++ ++In order to exploit vulnerability, an attacker needs to: ++ ++ - gain local access on the machine ++ ++ - break kASLR ++ ++ - find gadgets in the running kernel in order to use them in the exploit ++ ++ - potentially create and pin an additional workload on the sibling ++ thread, depending on the microarchitecture (not necessary on fam 0x19) ++ ++ - run the exploit ++ ++Considering the performance implications of each mitigation type, the ++default one is 'Mitigation: safe RET' which should take care of most ++attack vectors, including the local User->Kernel one. ++ ++As always, the user is advised to keep her/his system up-to-date by ++applying software updates regularly. ++ ++The default setting will be reevaluated when needed and especially when ++new attack vectors appear. ++ ++As one can surmise, 'Mitigation: safe RET' does come at the cost of some ++performance depending on the workload. If one trusts her/his userspace ++and does not want to suffer the performance impact, one can always ++disable the mitigation with spec_rstack_overflow=off. ++ ++Similarly, 'Mitigation: IBPB' is another full mitigation type employing ++an indrect branch prediction barrier after having applied the required ++microcode patch for one's system. This mitigation comes also at ++a performance cost. ++ ++Mitigation: safe RET ++-------------------- ++ ++The mitigation works by ensuring all RET instructions speculate to ++a controlled location, similar to how speculation is controlled in the ++retpoline sequence. To accomplish this, the __x86_return_thunk forces ++the CPU to mispredict every function return using a 'safe return' ++sequence. ++ ++To ensure the safety of this mitigation, the kernel must ensure that the ++safe return sequence is itself free from attacker interference. In Zen3 ++and Zen4, this is accomplished by creating a BTB alias between the ++untraining function srso_untrain_ret_alias() and the safe return ++function srso_safe_ret_alias() which results in evicting a potentially ++poisoned BTB entry and using that safe one for all function returns. ++ ++In older Zen1 and Zen2, this is accomplished using a reinterpretation ++technique similar to Retbleed one: srso_untrain_ret() and ++srso_safe_ret(). +diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt +index 962180711bd8b..bb78526120f3d 100644 +--- a/Documentation/admin-guide/kernel-parameters.txt ++++ b/Documentation/admin-guide/kernel-parameters.txt +@@ -1501,6 +1501,26 @@ + Format: off | on + default: on + ++ gather_data_sampling= ++ [X86,INTEL] Control the Gather Data Sampling (GDS) ++ mitigation. ++ ++ Gather Data Sampling is a hardware vulnerability which ++ allows unprivileged speculative access to data which was ++ previously stored in vector registers. ++ ++ This issue is mitigated by default in updated microcode. ++ The mitigation may have a performance impact but can be ++ disabled. On systems without the microcode mitigation ++ disabling AVX serves as a mitigation. ++ ++ force: Disable AVX to mitigate systems without ++ microcode mitigation. No effect if the microcode ++ mitigation is present. Known to cause crashes in ++ userspace with buggy AVX enumeration. ++ ++ off: Disable GDS mitigation. ++ + gcov_persist= [GCOV] When non-zero (default), profiling data for + kernel modules is saved and remains accessible via + debugfs, even when the module is unloaded/reloaded. +@@ -3034,22 +3054,23 @@ + Disable all optional CPU mitigations. This + improves system performance, but it may also + expose users to several CPU vulnerabilities. +- Equivalent to: nopti [X86,PPC] ++ Equivalent to: gather_data_sampling=off [X86] + kpti=0 [ARM64] +- nospectre_v1 [X86,PPC] +- nobp=0 [S390] +- nospectre_v2 [X86,PPC,S390,ARM64] +- spectre_v2_user=off [X86] +- spec_store_bypass_disable=off [X86,PPC] +- ssbd=force-off [ARM64] ++ kvm.nx_huge_pages=off [X86] + l1tf=off [X86] + mds=off [X86] +- tsx_async_abort=off [X86] +- kvm.nx_huge_pages=off [X86] ++ mmio_stale_data=off [X86] + no_entry_flush [PPC] + no_uaccess_flush [PPC] +- mmio_stale_data=off [X86] ++ nobp=0 [S390] ++ nopti [X86,PPC] ++ nospectre_v1 [X86,PPC] ++ nospectre_v2 [X86,PPC,S390,ARM64] + retbleed=off [X86] ++ spec_store_bypass_disable=off [X86,PPC] ++ spectre_v2_user=off [X86] ++ ssbd=force-off [ARM64] ++ tsx_async_abort=off [X86] + + Exceptions: + This does not have any effect on +@@ -5429,6 +5450,17 @@ + Not specifying this option is equivalent to + spectre_v2_user=auto. + ++ spec_rstack_overflow= ++ [X86] Control RAS overflow mitigation on AMD Zen CPUs ++ ++ off - Disable mitigation ++ microcode - Enable microcode mitigation only ++ safe-ret - Enable sw-only safe RET mitigation (default) ++ ibpb - Enable mitigation by issuing IBPB on ++ kernel entry ++ ibpb-vmexit - Issue IBPB only on VMEXIT ++ (cloud-specific mitigation) ++ + spec_store_bypass_disable= + [HW] Control Speculative Store Bypass (SSB) Disable mitigation + (Speculative Store Bypass vulnerability) +diff --git a/Makefile b/Makefile +index 6fb94face8d7d..a90f955e14ab3 100644 +--- a/Makefile ++++ b/Makefile +@@ -1,7 +1,7 @@ + # SPDX-License-Identifier: GPL-2.0 + VERSION = 5 + PATCHLEVEL = 15 +-SUBLEVEL = 124 ++SUBLEVEL = 125 + EXTRAVERSION = + NAME = Trick or Treat + +diff --git a/arch/Kconfig b/arch/Kconfig +index 5987363b41c28..b45c699c2bac3 100644 +--- a/arch/Kconfig ++++ b/arch/Kconfig +@@ -264,6 +264,9 @@ config ARCH_HAS_DMA_SET_UNCACHED + config ARCH_HAS_DMA_CLEAR_UNCACHED + bool + ++config ARCH_HAS_CPU_FINALIZE_INIT ++ bool ++ + # Select if arch init_task must go in the __init_task_data section + config ARCH_TASK_STRUCT_ON_STACK + bool +diff --git a/arch/alpha/include/asm/bugs.h b/arch/alpha/include/asm/bugs.h +deleted file mode 100644 +index 78030d1c7e7e0..0000000000000 +--- a/arch/alpha/include/asm/bugs.h ++++ /dev/null +@@ -1,20 +0,0 @@ +-/* +- * include/asm-alpha/bugs.h +- * +- * Copyright (C) 1994 Linus Torvalds +- */ +- +-/* +- * This is included by init/main.c to check for architecture-dependent bugs. +- * +- * Needs: +- * void check_bugs(void); +- */ +- +-/* +- * I don't know of any alpha bugs yet.. Nice chip +- */ +- +-static void check_bugs(void) +-{ +-} +diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig +index a8ae17f5740d9..f2fbb170d813c 100644 +--- a/arch/arm/Kconfig ++++ b/arch/arm/Kconfig +@@ -4,6 +4,7 @@ config ARM + default y + select ARCH_32BIT_OFF_T + select ARCH_HAS_BINFMT_FLAT ++ select ARCH_HAS_CPU_FINALIZE_INIT if MMU + select ARCH_HAS_DEBUG_VIRTUAL if MMU + select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE + select ARCH_HAS_ELF_RANDOMIZE +diff --git a/arch/arm/include/asm/bugs.h b/arch/arm/include/asm/bugs.h +index 97a312ba08401..fe385551edeca 100644 +--- a/arch/arm/include/asm/bugs.h ++++ b/arch/arm/include/asm/bugs.h +@@ -1,7 +1,5 @@ + /* SPDX-License-Identifier: GPL-2.0-only */ + /* +- * arch/arm/include/asm/bugs.h +- * + * Copyright (C) 1995-2003 Russell King + */ + #ifndef __ASM_BUGS_H +@@ -10,10 +8,8 @@ + extern void check_writebuffer_bugs(void); + + #ifdef CONFIG_MMU +-extern void check_bugs(void); + extern void check_other_bugs(void); + #else +-#define check_bugs() do { } while (0) + #define check_other_bugs() do { } while (0) + #endif + +diff --git a/arch/arm/kernel/bugs.c b/arch/arm/kernel/bugs.c +index 14c8dbbb7d2df..087bce6ec8e9b 100644 +--- a/arch/arm/kernel/bugs.c ++++ b/arch/arm/kernel/bugs.c +@@ -1,5 +1,6 @@ + // SPDX-License-Identifier: GPL-2.0 + #include <linux/init.h> ++#include <linux/cpu.h> + #include <asm/bugs.h> + #include <asm/proc-fns.h> + +@@ -11,7 +12,7 @@ void check_other_bugs(void) + #endif + } + +-void __init check_bugs(void) ++void __init arch_cpu_finalize_init(void) + { + check_writebuffer_bugs(); + check_other_bugs(); +diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig +index b1f2b6ac9b1d5..89869aff8ca29 100644 +--- a/arch/ia64/Kconfig ++++ b/arch/ia64/Kconfig +@@ -8,6 +8,7 @@ menu "Processor type and features" + + config IA64 + bool ++ select ARCH_HAS_CPU_FINALIZE_INIT + select ARCH_HAS_DMA_MARK_CLEAN + select ARCH_HAS_STRNCPY_FROM_USER + select ARCH_HAS_STRNLEN_USER +diff --git a/arch/ia64/include/asm/bugs.h b/arch/ia64/include/asm/bugs.h +deleted file mode 100644 +index 0d6b9bded56c6..0000000000000 +--- a/arch/ia64/include/asm/bugs.h ++++ /dev/null +@@ -1,20 +0,0 @@ +-/* SPDX-License-Identifier: GPL-2.0 */ +-/* +- * This is included by init/main.c to check for architecture-dependent bugs. +- * +- * Needs: +- * void check_bugs(void); +- * +- * Based on <asm-alpha/bugs.h>. +- * +- * Modified 1998, 1999, 2003 +- * David Mosberger-Tang <davidm@hpl.hp.com>, Hewlett-Packard Co. +- */ +-#ifndef _ASM_IA64_BUGS_H +-#define _ASM_IA64_BUGS_H +- +-#include <asm/processor.h> +- +-extern void check_bugs (void); +- +-#endif /* _ASM_IA64_BUGS_H */ +diff --git a/arch/ia64/kernel/setup.c b/arch/ia64/kernel/setup.c +index 31fb84de2d214..041681e5de472 100644 +--- a/arch/ia64/kernel/setup.c ++++ b/arch/ia64/kernel/setup.c +@@ -1070,8 +1070,7 @@ cpu_init (void) + } + } + +-void __init +-check_bugs (void) ++void __init arch_cpu_finalize_init(void) + { + ia64_patch_mckinley_e9((unsigned long) __start___mckinley_e9_bundles, + (unsigned long) __end___mckinley_e9_bundles); +diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig +index 0b50da08a9c56..810056d8ea678 100644 +--- a/arch/m68k/Kconfig ++++ b/arch/m68k/Kconfig +@@ -4,6 +4,7 @@ config M68K + default y + select ARCH_32BIT_OFF_T + select ARCH_HAS_BINFMT_FLAT ++ select ARCH_HAS_CPU_FINALIZE_INIT if MMU + select ARCH_HAS_DMA_PREP_COHERENT if HAS_DMA && MMU && !COLDFIRE + select ARCH_HAS_SYNC_DMA_FOR_DEVICE if HAS_DMA + select ARCH_HAVE_NMI_SAFE_CMPXCHG if RMW_INSNS +diff --git a/arch/m68k/include/asm/bugs.h b/arch/m68k/include/asm/bugs.h +deleted file mode 100644 +index 745530651e0bf..0000000000000 +--- a/arch/m68k/include/asm/bugs.h ++++ /dev/null +@@ -1,21 +0,0 @@ +-/* SPDX-License-Identifier: GPL-2.0 */ +-/* +- * include/asm-m68k/bugs.h +- * +- * Copyright (C) 1994 Linus Torvalds +- */ +- +-/* +- * This is included by init/main.c to check for architecture-dependent bugs. +- * +- * Needs: +- * void check_bugs(void); +- */ +- +-#ifdef CONFIG_MMU +-extern void check_bugs(void); /* in arch/m68k/kernel/setup.c */ +-#else +-static void check_bugs(void) +-{ +-} +-#endif +diff --git a/arch/m68k/kernel/setup_mm.c b/arch/m68k/kernel/setup_mm.c +index f24410a54dcb2..868641a536236 100644 +--- a/arch/m68k/kernel/setup_mm.c ++++ b/arch/m68k/kernel/setup_mm.c +@@ -10,6 +10,7 @@ + */ + + #include <linux/kernel.h> ++#include <linux/cpu.h> + #include <linux/mm.h> + #include <linux/sched.h> + #include <linux/delay.h> +@@ -512,7 +513,7 @@ static int __init proc_hardware_init(void) + module_init(proc_hardware_init); + #endif + +-void check_bugs(void) ++void __init arch_cpu_finalize_init(void) + { + #if defined(CONFIG_FPU) && !defined(CONFIG_M68KFPU_EMU) + if (m68k_fputype == 0) { +diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig +index 56c0f75e7a76e..13b09c7516e91 100644 +--- a/arch/mips/Kconfig ++++ b/arch/mips/Kconfig +@@ -4,6 +4,7 @@ config MIPS + default y + select ARCH_32BIT_OFF_T if !64BIT + select ARCH_BINFMT_ELF_STATE if MIPS_FP_SUPPORT ++ select ARCH_HAS_CPU_FINALIZE_INIT + select ARCH_HAS_DEBUG_VIRTUAL if !64BIT + select ARCH_HAS_FORTIFY_SOURCE + select ARCH_HAS_KCOV +diff --git a/arch/mips/include/asm/bugs.h b/arch/mips/include/asm/bugs.h +index d72dc6e1cf3cd..8d4cf29861b87 100644 +--- a/arch/mips/include/asm/bugs.h ++++ b/arch/mips/include/asm/bugs.h +@@ -1,17 +1,11 @@ + /* SPDX-License-Identifier: GPL-2.0 */ + /* +- * This is included by init/main.c to check for architecture-dependent bugs. +- * + * Copyright (C) 2007 Maciej W. Rozycki +- * +- * Needs: +- * void check_bugs(void); + */ + #ifndef _ASM_BUGS_H + #define _ASM_BUGS_H + + #include <linux/bug.h> +-#include <linux/delay.h> + #include <linux/smp.h> + + #include <asm/cpu.h> +@@ -30,17 +24,6 @@ static inline void check_bugs_early(void) + check_bugs64_early(); + } + +-static inline void check_bugs(void) +-{ +- unsigned int cpu = smp_processor_id(); +- +- cpu_data[cpu].udelay_val = loops_per_jiffy; +- check_bugs32(); +- +- if (IS_ENABLED(CONFIG_CPU_R4X00_BUGS64)) +- check_bugs64(); +-} +- + static inline int r4k_daddiu_bug(void) + { + if (!IS_ENABLED(CONFIG_CPU_R4X00_BUGS64)) +diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c +index c8d849d8a8440..145f905fb3623 100644 +--- a/arch/mips/kernel/setup.c ++++ b/arch/mips/kernel/setup.c +@@ -11,6 +11,8 @@ + * Copyright (C) 2000, 2001, 2002, 2007 Maciej W. Rozycki + */ + #include <linux/init.h> ++#include <linux/cpu.h> ++#include <linux/delay.h> + #include <linux/ioport.h> + #include <linux/export.h> + #include <linux/screen_info.h> +@@ -810,3 +812,14 @@ static int __init setnocoherentio(char *str) + } + early_param("nocoherentio", setnocoherentio); + #endif ++ ++void __init arch_cpu_finalize_init(void) ++{ ++ unsigned int cpu = smp_processor_id(); ++ ++ cpu_data[cpu].udelay_val = loops_per_jiffy; ++ check_bugs32(); ++ ++ if (IS_ENABLED(CONFIG_CPU_R4X00_BUGS64)) ++ check_bugs64(); ++} +diff --git a/arch/parisc/include/asm/bugs.h b/arch/parisc/include/asm/bugs.h +deleted file mode 100644 +index 0a7f9db6bd1c7..0000000000000 +--- a/arch/parisc/include/asm/bugs.h ++++ /dev/null +@@ -1,20 +0,0 @@ +-/* SPDX-License-Identifier: GPL-2.0 */ +-/* +- * include/asm-parisc/bugs.h +- * +- * Copyright (C) 1999 Mike Shaver +- */ +- +-/* +- * This is included by init/main.c to check for architecture-dependent bugs. +- * +- * Needs: +- * void check_bugs(void); +- */ +- +-#include <asm/processor.h> +- +-static inline void check_bugs(void) +-{ +-// identify_cpu(&boot_cpu_data); +-} +diff --git a/arch/powerpc/include/asm/bugs.h b/arch/powerpc/include/asm/bugs.h +deleted file mode 100644 +index 01b8f6ca4dbbc..0000000000000 +--- a/arch/powerpc/include/asm/bugs.h ++++ /dev/null +@@ -1,15 +0,0 @@ +-/* SPDX-License-Identifier: GPL-2.0-or-later */ +-#ifndef _ASM_POWERPC_BUGS_H +-#define _ASM_POWERPC_BUGS_H +- +-/* +- */ +- +-/* +- * This file is included by 'init/main.c' to check for +- * architecture-dependent bugs. +- */ +- +-static inline void check_bugs(void) { } +- +-#endif /* _ASM_POWERPC_BUGS_H */ +diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig +index 6904f4bdbf004..101b95f26a91c 100644 +--- a/arch/sh/Kconfig ++++ b/arch/sh/Kconfig +@@ -7,6 +7,7 @@ config SUPERH + select ARCH_HAVE_CUSTOM_GPIO_H + select ARCH_HAVE_NMI_SAFE_CMPXCHG if (GUSA_RB || CPU_SH4A) + select ARCH_HAS_BINFMT_FLAT if !MMU ++ select ARCH_HAS_CPU_FINALIZE_INIT + select ARCH_HAS_GIGANTIC_PAGE + select ARCH_HAS_GCOV_PROFILE_ALL + select ARCH_HAS_PTE_SPECIAL +diff --git a/arch/sh/include/asm/bugs.h b/arch/sh/include/asm/bugs.h +deleted file mode 100644 +index fe52abb69cea3..0000000000000 +--- a/arch/sh/include/asm/bugs.h ++++ /dev/null +@@ -1,74 +0,0 @@ +-/* SPDX-License-Identifier: GPL-2.0 */ +-#ifndef __ASM_SH_BUGS_H +-#define __ASM_SH_BUGS_H +- +-/* +- * This is included by init/main.c to check for architecture-dependent bugs. +- * +- * Needs: +- * void check_bugs(void); +- */ +- +-/* +- * I don't know of any Super-H bugs yet. +- */ +- +-#include <asm/processor.h> +- +-extern void select_idle_routine(void); +- +-static void __init check_bugs(void) +-{ +- extern unsigned long loops_per_jiffy; +- char *p = &init_utsname()->machine[2]; /* "sh" */ +- +- select_idle_routine(); +- +- current_cpu_data.loops_per_jiffy = loops_per_jiffy; +- +- switch (current_cpu_data.family) { +- case CPU_FAMILY_SH2: +- *p++ = '2'; +- break; +- case CPU_FAMILY_SH2A: +- *p++ = '2'; +- *p++ = 'a'; +- break; +- case CPU_FAMILY_SH3: +- *p++ = '3'; +- break; +- case CPU_FAMILY_SH4: +- *p++ = '4'; +- break; +- case CPU_FAMILY_SH4A: +- *p++ = '4'; +- *p++ = 'a'; +- break; +- case CPU_FAMILY_SH4AL_DSP: +- *p++ = '4'; +- *p++ = 'a'; +- *p++ = 'l'; +- *p++ = '-'; +- *p++ = 'd'; +- *p++ = 's'; +- *p++ = 'p'; +- break; +- case CPU_FAMILY_UNKNOWN: +- /* +- * Specifically use CPU_FAMILY_UNKNOWN rather than +- * default:, so we're able to have the compiler whine +- * about unhandled enumerations. +- */ +- break; +- } +- +- printk("CPU: %s\n", get_cpu_subtype(¤t_cpu_data)); +- +-#ifndef __LITTLE_ENDIAN__ +- /* 'eb' means 'Endian Big' */ +- *p++ = 'e'; +- *p++ = 'b'; +-#endif +- *p = '\0'; +-} +-#endif /* __ASM_SH_BUGS_H */ +diff --git a/arch/sh/include/asm/processor.h b/arch/sh/include/asm/processor.h +index 3820d698846e0..97af2d9b02693 100644 +--- a/arch/sh/include/asm/processor.h ++++ b/arch/sh/include/asm/processor.h +@@ -167,6 +167,8 @@ extern unsigned int instruction_size(unsigned int insn); + #define instruction_size(insn) (2) + #endif + ++void select_idle_routine(void); ++ + #endif /* __ASSEMBLY__ */ + + #include <asm/processor_32.h> +diff --git a/arch/sh/kernel/idle.c b/arch/sh/kernel/idle.c +index f59814983bd59..a80b2a5b25c7f 100644 +--- a/arch/sh/kernel/idle.c ++++ b/arch/sh/kernel/idle.c +@@ -14,6 +14,7 @@ + #include <linux/irqflags.h> + #include <linux/smp.h> + #include <linux/atomic.h> ++#include <asm/processor.h> + #include <asm/smp.h> + #include <asm/bl_bit.h> + +diff --git a/arch/sh/kernel/setup.c b/arch/sh/kernel/setup.c +index af977ec4ca5e5..cf7c0f72f2935 100644 +--- a/arch/sh/kernel/setup.c ++++ b/arch/sh/kernel/setup.c +@@ -43,6 +43,7 @@ + #include <asm/smp.h> + #include <asm/mmu_context.h> + #include <asm/mmzone.h> ++#include <asm/processor.h> + #include <asm/sparsemem.h> + #include <asm/platform_early.h> + +@@ -354,3 +355,57 @@ int test_mode_pin(int pin) + { + return sh_mv.mv_mode_pins() & pin; + } ++ ++void __init arch_cpu_finalize_init(void) ++{ ++ char *p = &init_utsname()->machine[2]; /* "sh" */ ++ ++ select_idle_routine(); ++ ++ current_cpu_data.loops_per_jiffy = loops_per_jiffy; ++ ++ switch (current_cpu_data.family) { ++ case CPU_FAMILY_SH2: ++ *p++ = '2'; ++ break; ++ case CPU_FAMILY_SH2A: ++ *p++ = '2'; ++ *p++ = 'a'; ++ break; ++ case CPU_FAMILY_SH3: ++ *p++ = '3'; ++ break; ++ case CPU_FAMILY_SH4: ++ *p++ = '4'; ++ break; ++ case CPU_FAMILY_SH4A: ++ *p++ = '4'; ++ *p++ = 'a'; ++ break; ++ case CPU_FAMILY_SH4AL_DSP: ++ *p++ = '4'; ++ *p++ = 'a'; ++ *p++ = 'l'; ++ *p++ = '-'; ++ *p++ = 'd'; ++ *p++ = 's'; ++ *p++ = 'p'; ++ break; ++ case CPU_FAMILY_UNKNOWN: ++ /* ++ * Specifically use CPU_FAMILY_UNKNOWN rather than ++ * default:, so we're able to have the compiler whine ++ * about unhandled enumerations. ++ */ ++ break; ++ } ++ ++ pr_info("CPU: %s\n", get_cpu_subtype(¤t_cpu_data)); ++ ++#ifndef __LITTLE_ENDIAN__ ++ /* 'eb' means 'Endian Big' */ ++ *p++ = 'e'; ++ *p++ = 'b'; ++#endif ++ *p = '\0'; ++} +diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig +index eff9116bf7be3..1176f0de6a0f4 100644 +--- a/arch/sparc/Kconfig ++++ b/arch/sparc/Kconfig +@@ -52,6 +52,7 @@ config SPARC + config SPARC32 + def_bool !64BIT + select ARCH_32BIT_OFF_T ++ select ARCH_HAS_CPU_FINALIZE_INIT if !SMP + select ARCH_HAS_SYNC_DMA_FOR_CPU + select GENERIC_ATOMIC64 + select CLZ_TAB +diff --git a/arch/sparc/include/asm/bugs.h b/arch/sparc/include/asm/bugs.h +deleted file mode 100644 +index 02fa369b9c21f..0000000000000 +--- a/arch/sparc/include/asm/bugs.h ++++ /dev/null +@@ -1,18 +0,0 @@ +-/* SPDX-License-Identifier: GPL-2.0 */ +-/* include/asm/bugs.h: Sparc probes for various bugs. +- * +- * Copyright (C) 1996, 2007 David S. Miller (davem@davemloft.net) +- */ +- +-#ifdef CONFIG_SPARC32 +-#include <asm/cpudata.h> +-#endif +- +-extern unsigned long loops_per_jiffy; +- +-static void __init check_bugs(void) +-{ +-#if defined(CONFIG_SPARC32) && !defined(CONFIG_SMP) +- cpu_data(0).udelay_val = loops_per_jiffy; +-#endif +-} +diff --git a/arch/sparc/kernel/setup_32.c b/arch/sparc/kernel/setup_32.c +index c8e0dd99f3700..c9d1ba4f311b9 100644 +--- a/arch/sparc/kernel/setup_32.c ++++ b/arch/sparc/kernel/setup_32.c +@@ -412,3 +412,10 @@ static int __init topology_init(void) + } + + subsys_initcall(topology_init); ++ ++#if defined(CONFIG_SPARC32) && !defined(CONFIG_SMP) ++void __init arch_cpu_finalize_init(void) ++{ ++ cpu_data(0).udelay_val = loops_per_jiffy; ++} ++#endif +diff --git a/arch/um/Kconfig b/arch/um/Kconfig +index c18b45f75d41f..b0584453d2a0b 100644 +--- a/arch/um/Kconfig ++++ b/arch/um/Kconfig +@@ -6,6 +6,7 @@ config UML + bool + default y + select ARCH_EPHEMERAL_INODES ++ select ARCH_HAS_CPU_FINALIZE_INIT + select ARCH_HAS_KCOV + select ARCH_HAS_STRNCPY_FROM_USER + select ARCH_HAS_STRNLEN_USER +diff --git a/arch/um/include/asm/bugs.h b/arch/um/include/asm/bugs.h +deleted file mode 100644 +index 4473942a08397..0000000000000 +--- a/arch/um/include/asm/bugs.h ++++ /dev/null +@@ -1,7 +0,0 @@ +-/* SPDX-License-Identifier: GPL-2.0 */ +-#ifndef __UM_BUGS_H +-#define __UM_BUGS_H +- +-void check_bugs(void); +- +-#endif +diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c +index 4c8d2dc270846..748595b054c44 100644 +--- a/arch/um/kernel/um_arch.c ++++ b/arch/um/kernel/um_arch.c +@@ -3,6 +3,7 @@ + * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) + */ + ++#include <linux/cpu.h> + #include <linux/delay.h> + #include <linux/init.h> + #include <linux/mm.h> +@@ -423,7 +424,7 @@ void __init setup_arch(char **cmdline_p) + } + } + +-void __init check_bugs(void) ++void __init arch_cpu_finalize_init(void) + { + arch_check_bugs(); + os_check_bugs(); +diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig +index a08ce6360382a..cfb1edd25437d 100644 +--- a/arch/x86/Kconfig ++++ b/arch/x86/Kconfig +@@ -68,6 +68,7 @@ config X86 + select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE + select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI + select ARCH_HAS_CACHE_LINE_SIZE ++ select ARCH_HAS_CPU_FINALIZE_INIT + select ARCH_HAS_DEBUG_VIRTUAL + select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE + select ARCH_HAS_DEVMEM_IS_ALLOWED +@@ -2456,6 +2457,13 @@ config CPU_IBRS_ENTRY + This mitigates both spectre_v2 and retbleed at great cost to + performance. + ++config CPU_SRSO ++ bool "Mitigate speculative RAS overflow on AMD" ++ depends on CPU_SUP_AMD && X86_64 && RETHUNK ++ default y ++ help ++ Enable the SRSO mitigation needed on AMD Zen1-4 machines. ++ + config SLS + bool "Mitigate Straight-Line-Speculation" + depends on CC_HAS_SLS && X86_64 +@@ -2465,6 +2473,25 @@ config SLS + against straight line speculation. The kernel image might be slightly + larger. + ++config GDS_FORCE_MITIGATION ++ bool "Force GDS Mitigation" ++ depends on CPU_SUP_INTEL ++ default n ++ help ++ Gather Data Sampling (GDS) is a hardware vulnerability which allows ++ unprivileged speculative access to data which was previously stored in ++ vector registers. ++ ++ This option is equivalent to setting gather_data_sampling=force on the ++ command line. The microcode mitigation is used if present, otherwise ++ AVX is disabled as a mitigation. On affected systems that are missing ++ the microcode any userspace code that unconditionally uses AVX will ++ break with this option set. ++ ++ Setting this option on systems not vulnerable to GDS has no effect. ++ ++ If in doubt, say N. ++ + endif + + config ARCH_HAS_ADD_PAGES +diff --git a/arch/x86/include/asm/bugs.h b/arch/x86/include/asm/bugs.h +index 92ae283899409..f25ca2d709d40 100644 +--- a/arch/x86/include/asm/bugs.h ++++ b/arch/x86/include/asm/bugs.h +@@ -4,8 +4,6 @@ + + #include <asm/processor.h> + +-extern void check_bugs(void); +- + #if defined(CONFIG_CPU_SUP_INTEL) && defined(CONFIG_X86_32) + int ppro_with_ram_bug(void); + #else +diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h +index b0f206681fde3..cc3f62f5d5515 100644 +--- a/arch/x86/include/asm/cpufeature.h ++++ b/arch/x86/include/asm/cpufeature.h +@@ -32,6 +32,7 @@ enum cpuid_leafs + CPUID_8000_0007_EBX, + CPUID_7_EDX, + CPUID_8000_001F_EAX, ++ CPUID_8000_0021_EAX, + }; + + #ifdef CONFIG_X86_FEATURE_NAMES +@@ -91,8 +92,9 @@ extern const char * const x86_bug_flags[NBUGINTS*32]; + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 17, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 18, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 19, feature_bit) || \ ++ CHECK_BIT_IN_MASK_WORD(REQUIRED_MASK, 20, feature_bit) || \ + REQUIRED_MASK_CHECK || \ +- BUILD_BUG_ON_ZERO(NCAPINTS != 20)) ++ BUILD_BUG_ON_ZERO(NCAPINTS != 21)) + + #define DISABLED_MASK_BIT_SET(feature_bit) \ + ( CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 0, feature_bit) || \ +@@ -115,8 +117,9 @@ extern const char * const x86_bug_flags[NBUGINTS*32]; + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 17, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 18, feature_bit) || \ + CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 19, feature_bit) || \ ++ CHECK_BIT_IN_MASK_WORD(DISABLED_MASK, 20, feature_bit) || \ + DISABLED_MASK_CHECK || \ +- BUILD_BUG_ON_ZERO(NCAPINTS != 20)) ++ BUILD_BUG_ON_ZERO(NCAPINTS != 21)) + + #define cpu_has(c, bit) \ + (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \ +diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h +index e31c7e75d6b02..608ffc45fc0e1 100644 +--- a/arch/x86/include/asm/cpufeatures.h ++++ b/arch/x86/include/asm/cpufeatures.h +@@ -13,8 +13,8 @@ + /* + * Defines x86 CPU feature bits + */ +-#define NCAPINTS 20 /* N 32-bit words worth of info */ +-#define NBUGINTS 1 /* N 32-bit bug flags */ ++#define NCAPINTS 21 /* N 32-bit words worth of info */ ++#define NBUGINTS 2 /* N 32-bit bug flags */ + + /* + * Note: If the comment begins with a quoted string, that string is used +@@ -306,6 +306,10 @@ + + #define X86_FEATURE_MSR_TSX_CTRL (11*32+20) /* "" MSR IA32_TSX_CTRL (Intel) implemented */ + ++#define X86_FEATURE_SRSO (11*32+24) /* "" AMD BTB untrain RETs */ ++#define X86_FEATURE_SRSO_ALIAS (11*32+25) /* "" AMD BTB untrain RETs through aliasing */ ++#define X86_FEATURE_IBPB_ON_VMEXIT (11*32+26) /* "" Issue an IBPB only on VMEXIT */ ++ + /* Intel-defined CPU features, CPUID level 0x00000007:1 (EAX), word 12 */ + #define X86_FEATURE_AVX_VNNI (12*32+ 4) /* AVX VNNI instructions */ + #define X86_FEATURE_AVX512_BF16 (12*32+ 5) /* AVX512 BFLOAT16 instructions */ +@@ -412,6 +416,10 @@ + #define X86_FEATURE_SEV_ES (19*32+ 3) /* AMD Secure Encrypted Virtualization - Encrypted State */ + #define X86_FEATURE_SME_COHERENT (19*32+10) /* "" AMD hardware-enforced cache coherency */ + ++#define X86_FEATURE_SBPB (20*32+27) /* "" Selective Branch Prediction Barrier */ ++#define X86_FEATURE_IBPB_BRTYPE (20*32+28) /* "" MSR_PRED_CMD[IBPB] flushes all branch type predictions */ ++#define X86_FEATURE_SRSO_NO (20*32+29) /* "" CPU is not affected by SRSO */ ++ + /* + * BUG word(s) + */ +@@ -453,5 +461,8 @@ + #define X86_BUG_RETBLEED X86_BUG(27) /* CPU is affected by RETBleed */ + #define X86_BUG_EIBRS_PBRSB X86_BUG(28) /* EIBRS is vulnerable to Post Barrier RSB Predictions */ + #define X86_BUG_SMT_RSB X86_BUG(29) /* CPU is vulnerable to Cross-Thread Return Address Predictions */ ++#define X86_BUG_GDS X86_BUG(30) /* CPU is affected by Gather Data Sampling */ + ++/* BUG word 2 */ ++#define X86_BUG_SRSO X86_BUG(1*32 + 0) /* AMD SRSO bug */ + #endif /* _ASM_X86_CPUFEATURES_H */ +diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h +index 834a3b6d81e12..99a12012c66ee 100644 +--- a/arch/x86/include/asm/disabled-features.h ++++ b/arch/x86/include/asm/disabled-features.h +@@ -108,6 +108,7 @@ + #define DISABLED_MASK17 0 + #define DISABLED_MASK18 0 + #define DISABLED_MASK19 0 +-#define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 20) ++#define DISABLED_MASK20 0 ++#define DISABLED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 21) + + #endif /* _ASM_X86_DISABLED_FEATURES_H */ +diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h +index ce6fc4f8d1d11..d4201fb2c46d3 100644 +--- a/arch/x86/include/asm/fpu/internal.h ++++ b/arch/x86/include/asm/fpu/internal.h +@@ -43,7 +43,7 @@ extern void fpu_flush_thread(void); + extern void fpu__init_cpu(void); + extern void fpu__init_system_xstate(void); + extern void fpu__init_cpu_xstate(void); +-extern void fpu__init_system(struct cpuinfo_x86 *c); ++extern void fpu__init_system(void); + extern void fpu__init_check_bugs(void); + extern void fpu__resume_cpu(void); + +diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h +index 3fb9f5ebefa42..2356fdddd3e61 100644 +--- a/arch/x86/include/asm/mem_encrypt.h ++++ b/arch/x86/include/asm/mem_encrypt.h +@@ -47,14 +47,13 @@ int __init early_set_memory_encrypted(unsigned long vaddr, unsigned long size); + + void __init mem_encrypt_free_decrypted_mem(void); + +-/* Architecture __weak replacement functions */ +-void __init mem_encrypt_init(void); +- + void __init sev_es_init_vc_handling(void); + bool sme_active(void); + bool sev_active(void); + bool sev_es_active(void); + ++void __init mem_encrypt_init(void); ++ + #define __bss_decrypted __section(".bss..decrypted") + + #else /* !CONFIG_AMD_MEM_ENCRYPT */ +@@ -87,6 +86,8 @@ early_set_memory_encrypted(unsigned long vaddr, unsigned long size) { return 0; + + static inline void mem_encrypt_free_decrypted_mem(void) { } + ++static inline void mem_encrypt_init(void) { } ++ + #define __bss_decrypted + + #endif /* CONFIG_AMD_MEM_ENCRYPT */ +diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h +index e78755ed82cf5..91d8322af4139 100644 +--- a/arch/x86/include/asm/msr-index.h ++++ b/arch/x86/include/asm/msr-index.h +@@ -60,6 +60,7 @@ + + #define MSR_IA32_PRED_CMD 0x00000049 /* Prediction Command */ + #define PRED_CMD_IBPB BIT(0) /* Indirect Branch Prediction Barrier */ ++#define PRED_CMD_SBPB BIT(7) /* Selective Branch Prediction Barrier */ + + #define MSR_PPIN_CTL 0x0000004e + #define MSR_PPIN 0x0000004f +@@ -156,6 +157,15 @@ + * Not susceptible to Post-Barrier + * Return Stack Buffer Predictions. + */ ++#define ARCH_CAP_GDS_CTRL BIT(25) /* ++ * CPU is vulnerable to Gather ++ * Data Sampling (GDS) and ++ * has controls for mitigation. ++ */ ++#define ARCH_CAP_GDS_NO BIT(26) /* ++ * CPU is not vulnerable to Gather ++ * Data Sampling (GDS). ++ */ + + #define MSR_IA32_FLUSH_CMD 0x0000010b + #define L1D_FLUSH BIT(0) /* +@@ -174,6 +184,8 @@ + #define RNGDS_MITG_DIS BIT(0) /* SRBDS support */ + #define RTM_ALLOW BIT(1) /* TSX development mode */ + #define FB_CLEAR_DIS BIT(3) /* CPU Fill buffer clear disable */ ++#define GDS_MITG_DIS BIT(4) /* Disable GDS mitigation */ ++#define GDS_MITG_LOCKED BIT(5) /* GDS mitigation locked */ + + #define MSR_IA32_SYSENTER_CS 0x00000174 + #define MSR_IA32_SYSENTER_ESP 0x00000175 +diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h +index 06c9f0eaa9ed7..4a12dfdd317cb 100644 +--- a/arch/x86/include/asm/nospec-branch.h ++++ b/arch/x86/include/asm/nospec-branch.h +@@ -112,7 +112,7 @@ + * eventually turn into it's own annotation. + */ + .macro ANNOTATE_UNRET_END +-#ifdef CONFIG_DEBUG_ENTRY ++#if (defined(CONFIG_CPU_UNRET_ENTRY) || defined(CONFIG_CPU_SRSO)) + ANNOTATE_RETPOLINE_SAFE + nop + #endif +@@ -173,12 +173,18 @@ + * where we have a stack but before any RET instruction. + */ + .macro UNTRAIN_RET +-#if defined(CONFIG_CPU_UNRET_ENTRY) || defined(CONFIG_CPU_IBPB_ENTRY) ++#if defined(CONFIG_CPU_UNRET_ENTRY) || defined(CONFIG_CPU_IBPB_ENTRY) || \ ++ defined(CONFIG_CPU_SRSO) + ANNOTATE_UNRET_END + ALTERNATIVE_2 "", \ + CALL_ZEN_UNTRAIN_RET, X86_FEATURE_UNRET, \ + "call entry_ibpb", X86_FEATURE_ENTRY_IBPB + #endif ++ ++#ifdef CONFIG_CPU_SRSO ++ ALTERNATIVE_2 "", "call srso_untrain_ret", X86_FEATURE_SRSO, \ ++ "call srso_untrain_ret_alias", X86_FEATURE_SRSO_ALIAS ++#endif + .endm + + #else /* __ASSEMBLY__ */ +@@ -191,6 +197,8 @@ + + extern void __x86_return_thunk(void); + extern void zen_untrain_ret(void); ++extern void srso_untrain_ret(void); ++extern void srso_untrain_ret_alias(void); + extern void entry_ibpb(void); + + #ifdef CONFIG_RETPOLINE +@@ -300,11 +308,11 @@ void alternative_msr_write(unsigned int msr, u64 val, unsigned int feature) + : "memory"); + } + ++extern u64 x86_pred_cmd; ++ + static inline void indirect_branch_prediction_barrier(void) + { +- u64 val = PRED_CMD_IBPB; +- +- alternative_msr_write(MSR_IA32_PRED_CMD, val, X86_FEATURE_USE_IBPB); ++ alternative_msr_write(MSR_IA32_PRED_CMD, x86_pred_cmd, X86_FEATURE_USE_IBPB); + } + + /* The Intel SPEC CTRL MSR base value cache */ +diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h +index 3e3bd5b7d5dbe..747ccc2ae383f 100644 +--- a/arch/x86/include/asm/processor.h ++++ b/arch/x86/include/asm/processor.h +@@ -803,9 +803,11 @@ extern u16 get_llc_id(unsigned int cpu); + #ifdef CONFIG_CPU_SUP_AMD + extern u32 amd_get_nodes_per_socket(void); + extern u32 amd_get_highest_perf(void); ++extern bool cpu_has_ibpb_brtype_microcode(void); + #else + static inline u32 amd_get_nodes_per_socket(void) { return 0; } + static inline u32 amd_get_highest_perf(void) { return 0; } ++static inline bool cpu_has_ibpb_brtype_microcode(void) { return false; } + #endif + + static inline uint32_t hypervisor_cpuid_base(const char *sig, uint32_t leaves) +diff --git a/arch/x86/include/asm/required-features.h b/arch/x86/include/asm/required-features.h +index b2d504f119370..9bf60a8b9e9c2 100644 +--- a/arch/x86/include/asm/required-features.h ++++ b/arch/x86/include/asm/required-features.h +@@ -102,6 +102,7 @@ + #define REQUIRED_MASK17 0 + #define REQUIRED_MASK18 0 + #define REQUIRED_MASK19 0 +-#define REQUIRED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 20) ++#define REQUIRED_MASK20 0 ++#define REQUIRED_MASK_CHECK BUILD_BUG_ON_ZERO(NCAPINTS != 21) + + #endif /* _ASM_X86_REQUIRED_FEATURES_H */ +diff --git a/arch/x86/include/asm/sigframe.h b/arch/x86/include/asm/sigframe.h +index 5b1ed650b1248..84eab27248754 100644 +--- a/arch/x86/include/asm/sigframe.h ++++ b/arch/x86/include/asm/sigframe.h +@@ -85,6 +85,4 @@ struct rt_sigframe_x32 { + + #endif /* CONFIG_X86_64 */ + +-void __init init_sigframe_size(void); +- + #endif /* _ASM_X86_SIGFRAME_H */ +diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c +index 3daceadf5d1f0..1b90eb6ea5030 100644 +--- a/arch/x86/kernel/cpu/amd.c ++++ b/arch/x86/kernel/cpu/amd.c +@@ -1270,6 +1270,25 @@ u32 amd_get_highest_perf(void) + } + EXPORT_SYMBOL_GPL(amd_get_highest_perf); + ++bool cpu_has_ibpb_brtype_microcode(void) ++{ ++ switch (boot_cpu_data.x86) { ++ /* Zen1/2 IBPB flushes branch type predictions too. */ ++ case 0x17: ++ return boot_cpu_has(X86_FEATURE_AMD_IBPB); ++ case 0x19: ++ /* Poke the MSR bit on Zen3/4 to check its presence. */ ++ if (!wrmsrl_safe(MSR_IA32_PRED_CMD, PRED_CMD_SBPB)) { ++ setup_force_cpu_cap(X86_FEATURE_SBPB); ++ return true; ++ } else { ++ return false; ++ } ++ default: ++ return false; ++ } ++} ++ + static void zenbleed_check_cpu(void *unused) + { + struct cpuinfo_x86 *c = &cpu_data(smp_processor_id()); +diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c +index 2627e97e6e2e3..73dad1400633e 100644 +--- a/arch/x86/kernel/cpu/bugs.c ++++ b/arch/x86/kernel/cpu/bugs.c +@@ -9,7 +9,6 @@ + * - Andrew D. Balsa (code cleanup). + */ + #include <linux/init.h> +-#include <linux/utsname.h> + #include <linux/cpu.h> + #include <linux/module.h> + #include <linux/nospec.h> +@@ -27,8 +26,6 @@ + #include <asm/msr.h> + #include <asm/vmx.h> + #include <asm/paravirt.h> +-#include <asm/alternative.h> +-#include <asm/set_memory.h> + #include <asm/intel-family.h> + #include <asm/e820/api.h> + #include <asm/hypervisor.h> +@@ -49,6 +46,8 @@ static void __init taa_select_mitigation(void); + static void __init mmio_select_mitigation(void); + static void __init srbds_select_mitigation(void); + static void __init l1d_flush_select_mitigation(void); ++static void __init gds_select_mitigation(void); ++static void __init srso_select_mitigation(void); + + /* The base value of the SPEC_CTRL MSR without task-specific bits set */ + u64 x86_spec_ctrl_base; +@@ -58,6 +57,9 @@ EXPORT_SYMBOL_GPL(x86_spec_ctrl_base); + DEFINE_PER_CPU(u64, x86_spec_ctrl_current); + EXPORT_SYMBOL_GPL(x86_spec_ctrl_current); + ++u64 x86_pred_cmd __ro_after_init = PRED_CMD_IBPB; ++EXPORT_SYMBOL_GPL(x86_pred_cmd); ++ + static DEFINE_MUTEX(spec_ctrl_mutex); + + /* Update SPEC_CTRL MSR and its cached copy unconditionally */ +@@ -124,21 +126,8 @@ DEFINE_STATIC_KEY_FALSE(switch_mm_cond_l1d_flush); + DEFINE_STATIC_KEY_FALSE(mmio_stale_data_clear); + EXPORT_SYMBOL_GPL(mmio_stale_data_clear); + +-void __init check_bugs(void) ++void __init cpu_select_mitigations(void) + { +- identify_boot_cpu(); +- +- /* +- * identify_boot_cpu() initialized SMT support information, let the +- * core code know. +- */ +- cpu_smt_check_topology(); +- +- if (!IS_ENABLED(CONFIG_SMP)) { +- pr_info("CPU: "); +- print_cpu_info(&boot_cpu_data); +- } +- + /* + * Read the SPEC_CTRL MSR to account for reserved bits which may + * have unknown values. AMD64_LS_CFG MSR is cached in the early AMD +@@ -175,39 +164,8 @@ void __init check_bugs(void) + md_clear_select_mitigation(); + srbds_select_mitigation(); + l1d_flush_select_mitigation(); +- +- arch_smt_update(); +- +-#ifdef CONFIG_X86_32 +- /* +- * Check whether we are able to run this kernel safely on SMP. +- * +- * - i386 is no longer supported. +- * - In order to run on anything without a TSC, we need to be +- * compiled for a i486. +- */ +- if (boot_cpu_data.x86 < 4) +- panic("Kernel requires i486+ for 'invlpg' and other features"); +- +- init_utsname()->machine[1] = +- '0' + (boot_cpu_data.x86 > 6 ? 6 : boot_cpu_data.x86); +- alternative_instructions(); +- +- fpu__init_check_bugs(); +-#else /* CONFIG_X86_64 */ +- alternative_instructions(); +- +- /* +- * Make sure the first 2MB area is not mapped by huge pages +- * There are typically fixed size MTRRs in there and overlapping +- * MTRRs into large pages causes slow downs. +- * +- * Right now we don't do that with gbpages because there seems +- * very little benefit for that case. +- */ +- if (!direct_gbpages) +- set_memory_4k((unsigned long)__va(0), 1); +-#endif ++ gds_select_mitigation(); ++ srso_select_mitigation(); + } + + /* +@@ -693,6 +651,149 @@ static int __init l1d_flush_parse_cmdline(char *str) + } + early_param("l1d_flush", l1d_flush_parse_cmdline); + ++#undef pr_fmt ++#define pr_fmt(fmt) "GDS: " fmt ++ ++enum gds_mitigations { ++ GDS_MITIGATION_OFF, ++ GDS_MITIGATION_UCODE_NEEDED, ++ GDS_MITIGATION_FORCE, ++ GDS_MITIGATION_FULL, ++ GDS_MITIGATION_FULL_LOCKED, ++ GDS_MITIGATION_HYPERVISOR, ++}; ++ ++#if IS_ENABLED(CONFIG_GDS_FORCE_MITIGATION) ++static enum gds_mitigations gds_mitigation __ro_after_init = GDS_MITIGATION_FORCE; ++#else ++static enum gds_mitigations gds_mitigation __ro_after_init = GDS_MITIGATION_FULL; ++#endif ++ ++static const char * const gds_strings[] = { ++ [GDS_MITIGATION_OFF] = "Vulnerable", ++ [GDS_MITIGATION_UCODE_NEEDED] = "Vulnerable: No microcode", ++ [GDS_MITIGATION_FORCE] = "Mitigation: AVX disabled, no microcode", ++ [GDS_MITIGATION_FULL] = "Mitigation: Microcode", ++ [GDS_MITIGATION_FULL_LOCKED] = "Mitigation: Microcode (locked)", ++ [GDS_MITIGATION_HYPERVISOR] = "Unknown: Dependent on hypervisor status", ++}; ++ ++bool gds_ucode_mitigated(void) ++{ ++ return (gds_mitigation == GDS_MITIGATION_FULL || ++ gds_mitigation == GDS_MITIGATION_FULL_LOCKED); ++} ++EXPORT_SYMBOL_GPL(gds_ucode_mitigated); ++ ++void update_gds_msr(void) ++{ ++ u64 mcu_ctrl_after; ++ u64 mcu_ctrl; ++ ++ switch (gds_mitigation) { ++ case GDS_MITIGATION_OFF: ++ rdmsrl(MSR_IA32_MCU_OPT_CTRL, mcu_ctrl); ++ mcu_ctrl |= GDS_MITG_DIS; ++ break; ++ case GDS_MITIGATION_FULL_LOCKED: ++ /* ++ * The LOCKED state comes from the boot CPU. APs might not have ++ * the same state. Make sure the mitigation is enabled on all ++ * CPUs. ++ */ ++ case GDS_MITIGATION_FULL: ++ rdmsrl(MSR_IA32_MCU_OPT_CTRL, mcu_ctrl); ++ mcu_ctrl &= ~GDS_MITG_DIS; ++ break; ++ case GDS_MITIGATION_FORCE: ++ case GDS_MITIGATION_UCODE_NEEDED: ++ case GDS_MITIGATION_HYPERVISOR: ++ return; ++ }; ++ ++ wrmsrl(MSR_IA32_MCU_OPT_CTRL, mcu_ctrl); ++ ++ /* ++ * Check to make sure that the WRMSR value was not ignored. Writes to ++ * GDS_MITG_DIS will be ignored if this processor is locked but the boot ++ * processor was not. ++ */ ++ rdmsrl(MSR_IA32_MCU_OPT_CTRL, mcu_ctrl_after); ++ WARN_ON_ONCE(mcu_ctrl != mcu_ctrl_after); ++} ++ ++static void __init gds_select_mitigation(void) ++{ ++ u64 mcu_ctrl; ++ ++ if (!boot_cpu_has_bug(X86_BUG_GDS)) ++ return; ++ ++ if (boot_cpu_has(X86_FEATURE_HYPERVISOR)) { ++ gds_mitigation = GDS_MITIGATION_HYPERVISOR; ++ goto out; ++ } ++ ++ if (cpu_mitigations_off()) ++ gds_mitigation = GDS_MITIGATION_OFF; ++ /* Will verify below that mitigation _can_ be disabled */ ++ ++ /* No microcode */ ++ if (!(x86_read_arch_cap_msr() & ARCH_CAP_GDS_CTRL)) { ++ if (gds_mitigation == GDS_MITIGATION_FORCE) { ++ /* ++ * This only needs to be done on the boot CPU so do it ++ * here rather than in update_gds_msr() ++ */ ++ setup_clear_cpu_cap(X86_FEATURE_AVX); ++ pr_warn("Microcode update needed! Disabling AVX as mitigation.\n"); ++ } else { ++ gds_mitigation = GDS_MITIGATION_UCODE_NEEDED; ++ } ++ goto out; ++ } ++ ++ /* Microcode has mitigation, use it */ ++ if (gds_mitigation == GDS_MITIGATION_FORCE) ++ gds_mitigation = GDS_MITIGATION_FULL; ++ ++ rdmsrl(MSR_IA32_MCU_OPT_CTRL, mcu_ctrl); ++ if (mcu_ctrl & GDS_MITG_LOCKED) { ++ if (gds_mitigation == GDS_MITIGATION_OFF) ++ pr_warn("Mitigation locked. Disable failed.\n"); ++ ++ /* ++ * The mitigation is selected from the boot CPU. All other CPUs ++ * _should_ have the same state. If the boot CPU isn't locked ++ * but others are then update_gds_msr() will WARN() of the state ++ * mismatch. If the boot CPU is locked update_gds_msr() will ++ * ensure the other CPUs have the mitigation enabled. ++ */ ++ gds_mitigation = GDS_MITIGATION_FULL_LOCKED; ++ } ++ ++ update_gds_msr(); ++out: ++ pr_info("%s\n", gds_strings[gds_mitigation]); ++} ++ ++static int __init gds_parse_cmdline(char *str) ++{ ++ if (!str) ++ return -EINVAL; ++ ++ if (!boot_cpu_has_bug(X86_BUG_GDS)) ++ return 0; ++ ++ if (!strcmp(str, "off")) ++ gds_mitigation = GDS_MITIGATION_OFF; ++ else if (!strcmp(str, "force")) ++ gds_mitigation = GDS_MITIGATION_FORCE; ++ ++ return 0; ++} ++early_param("gather_data_sampling", gds_parse_cmdline); ++ + #undef pr_fmt + #define pr_fmt(fmt) "Spectre V1 : " fmt + +@@ -2207,6 +2308,165 @@ static int __init l1tf_cmdline(char *str) + } + early_param("l1tf", l1tf_cmdline); + ++#undef pr_fmt ++#define pr_fmt(fmt) "Speculative Return Stack Overflow: " fmt ++ ++enum srso_mitigation { ++ SRSO_MITIGATION_NONE, ++ SRSO_MITIGATION_MICROCODE, ++ SRSO_MITIGATION_SAFE_RET, ++ SRSO_MITIGATION_IBPB, ++ SRSO_MITIGATION_IBPB_ON_VMEXIT, ++}; ++ ++enum srso_mitigation_cmd { ++ SRSO_CMD_OFF, ++ SRSO_CMD_MICROCODE, ++ SRSO_CMD_SAFE_RET, ++ SRSO_CMD_IBPB, ++ SRSO_CMD_IBPB_ON_VMEXIT, ++}; ++ ++static const char * const srso_strings[] = { ++ [SRSO_MITIGATION_NONE] = "Vulnerable", ++ [SRSO_MITIGATION_MICROCODE] = "Mitigation: microcode", ++ [SRSO_MITIGATION_SAFE_RET] = "Mitigation: safe RET", ++ [SRSO_MITIGATION_IBPB] = "Mitigation: IBPB", ++ [SRSO_MITIGATION_IBPB_ON_VMEXIT] = "Mitigation: IBPB on VMEXIT only" ++}; ++ ++static enum srso_mitigation srso_mitigation __ro_after_init = SRSO_MITIGATION_NONE; ++static enum srso_mitigation_cmd srso_cmd __ro_after_init = SRSO_CMD_SAFE_RET; ++ ++static int __init srso_parse_cmdline(char *str) ++{ ++ if (!str) ++ return -EINVAL; ++ ++ if (!strcmp(str, "off")) ++ srso_cmd = SRSO_CMD_OFF; ++ else if (!strcmp(str, "microcode")) ++ srso_cmd = SRSO_CMD_MICROCODE; ++ else if (!strcmp(str, "safe-ret")) ++ srso_cmd = SRSO_CMD_SAFE_RET; ++ else if (!strcmp(str, "ibpb")) ++ srso_cmd = SRSO_CMD_IBPB; ++ else if (!strcmp(str, "ibpb-vmexit")) ++ srso_cmd = SRSO_CMD_IBPB_ON_VMEXIT; ++ else ++ pr_err("Ignoring unknown SRSO option (%s).", str); ++ ++ return 0; ++} ++early_param("spec_rstack_overflow", srso_parse_cmdline); ++ ++#define SRSO_NOTICE "WARNING: See https://kernel.org/doc/html/latest/admin-guide/hw-vuln/srso.html for mitigation options." ++ ++static void __init srso_select_mitigation(void) ++{ ++ bool has_microcode; ++ ++ if (!boot_cpu_has_bug(X86_BUG_SRSO) || cpu_mitigations_off()) ++ goto pred_cmd; ++ ++ /* ++ * The first check is for the kernel running as a guest in order ++ * for guests to verify whether IBPB is a viable mitigation. ++ */ ++ has_microcode = boot_cpu_has(X86_FEATURE_IBPB_BRTYPE) || cpu_has_ibpb_brtype_microcode(); ++ if (!has_microcode) { ++ pr_warn("IBPB-extending microcode not applied!\n"); ++ pr_warn(SRSO_NOTICE); ++ } else { ++ /* ++ * Enable the synthetic (even if in a real CPUID leaf) ++ * flags for guests. ++ */ ++ setup_force_cpu_cap(X86_FEATURE_IBPB_BRTYPE); ++ ++ /* ++ * Zen1/2 with SMT off aren't vulnerable after the right ++ * IBPB microcode has been applied. ++ */ ++ if ((boot_cpu_data.x86 < 0x19) && ++ (!cpu_smt_possible() || (cpu_smt_control == CPU_SMT_DISABLED))) ++ setup_force_cpu_cap(X86_FEATURE_SRSO_NO); ++ } ++ ++ if (retbleed_mitigation == RETBLEED_MITIGATION_IBPB) { ++ if (has_microcode) { ++ pr_err("Retbleed IBPB mitigation enabled, using same for SRSO\n"); ++ srso_mitigation = SRSO_MITIGATION_IBPB; ++ goto pred_cmd; ++ } ++ } ++ ++ switch (srso_cmd) { ++ case SRSO_CMD_OFF: ++ return; ++ ++ case SRSO_CMD_MICROCODE: ++ if (has_microcode) { ++ srso_mitigation = SRSO_MITIGATION_MICROCODE; ++ pr_warn(SRSO_NOTICE); ++ } ++ break; ++ ++ case SRSO_CMD_SAFE_RET: ++ if (IS_ENABLED(CONFIG_CPU_SRSO)) { ++ /* ++ * Enable the return thunk for generated code ++ * like ftrace, static_call, etc. ++ */ ++ setup_force_cpu_cap(X86_FEATURE_RETHUNK); ++ ++ if (boot_cpu_data.x86 == 0x19) ++ setup_force_cpu_cap(X86_FEATURE_SRSO_ALIAS); ++ else ++ setup_force_cpu_cap(X86_FEATURE_SRSO); ++ srso_mitigation = SRSO_MITIGATION_SAFE_RET; ++ } else { ++ pr_err("WARNING: kernel not compiled with CPU_SRSO.\n"); ++ goto pred_cmd; ++ } ++ break; ++ ++ case SRSO_CMD_IBPB: ++ if (IS_ENABLED(CONFIG_CPU_IBPB_ENTRY)) { ++ if (has_microcode) { ++ setup_force_cpu_cap(X86_FEATURE_ENTRY_IBPB); ++ srso_mitigation = SRSO_MITIGATION_IBPB; ++ } ++ } else { ++ pr_err("WARNING: kernel not compiled with CPU_IBPB_ENTRY.\n"); ++ goto pred_cmd; ++ } ++ break; ++ ++ case SRSO_CMD_IBPB_ON_VMEXIT: ++ if (IS_ENABLED(CONFIG_CPU_SRSO)) { ++ if (!boot_cpu_has(X86_FEATURE_ENTRY_IBPB) && has_microcode) { ++ setup_force_cpu_cap(X86_FEATURE_IBPB_ON_VMEXIT); ++ srso_mitigation = SRSO_MITIGATION_IBPB_ON_VMEXIT; ++ } ++ } else { ++ pr_err("WARNING: kernel not compiled with CPU_SRSO.\n"); ++ goto pred_cmd; ++ } ++ break; ++ ++ default: ++ break; ++ } ++ ++ pr_info("%s%s\n", srso_strings[srso_mitigation], (has_microcode ? "" : ", no microcode")); ++ ++pred_cmd: ++ if ((boot_cpu_has(X86_FEATURE_SRSO_NO) || srso_cmd == SRSO_CMD_OFF) && ++ boot_cpu_has(X86_FEATURE_SBPB)) ++ x86_pred_cmd = PRED_CMD_SBPB; ++} ++ + #undef pr_fmt + #define pr_fmt(fmt) fmt + +@@ -2405,6 +2665,18 @@ static ssize_t retbleed_show_state(char *buf) + return sprintf(buf, "%s\n", retbleed_strings[retbleed_mitigation]); + } + ++static ssize_t gds_show_state(char *buf) ++{ ++ return sysfs_emit(buf, "%s\n", gds_strings[gds_mitigation]); ++} ++ ++static ssize_t srso_show_state(char *buf) ++{ ++ return sysfs_emit(buf, "%s%s\n", ++ srso_strings[srso_mitigation], ++ (cpu_has_ibpb_brtype_microcode() ? "" : ", no microcode")); ++} ++ + static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr, + char *buf, unsigned int bug) + { +@@ -2454,6 +2726,12 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr + case X86_BUG_RETBLEED: + return retbleed_show_state(buf); + ++ case X86_BUG_GDS: ++ return gds_show_state(buf); ++ ++ case X86_BUG_SRSO: ++ return srso_show_state(buf); ++ + default: + break; + } +@@ -2518,4 +2796,14 @@ ssize_t cpu_show_retbleed(struct device *dev, struct device_attribute *attr, cha + { + return cpu_show_common(dev, attr, buf, X86_BUG_RETBLEED); + } ++ ++ssize_t cpu_show_gds(struct device *dev, struct device_attribute *attr, char *buf) ++{ ++ return cpu_show_common(dev, attr, buf, X86_BUG_GDS); ++} ++ ++ssize_t cpu_show_spec_rstack_overflow(struct device *dev, struct device_attribute *attr, char *buf) ++{ ++ return cpu_show_common(dev, attr, buf, X86_BUG_SRSO); ++} + #endif +diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c +index 69752745a5b12..54a0b3833ffea 100644 +--- a/arch/x86/kernel/cpu/common.c ++++ b/arch/x86/kernel/cpu/common.c +@@ -18,11 +18,15 @@ + #include <linux/init.h> + #include <linux/kprobes.h> + #include <linux/kgdb.h> ++#include <linux/mem_encrypt.h> + #include <linux/smp.h> ++#include <linux/cpu.h> + #include <linux/io.h> + #include <linux/syscore_ops.h> + #include <linux/pgtable.h> ++#include <linux/utsname.h> + ++#include <asm/alternative.h> + #include <asm/cmdline.h> + #include <asm/stackprotector.h> + #include <asm/perf_event.h> +@@ -58,7 +62,7 @@ + #include <asm/intel-family.h> + #include <asm/cpu_device_id.h> + #include <asm/uv/uv.h> +-#include <asm/sigframe.h> ++#include <asm/set_memory.h> + + #include "cpu.h" + +@@ -964,6 +968,9 @@ void get_cpu_cap(struct cpuinfo_x86 *c) + if (c->extended_cpuid_level >= 0x8000001f) + c->x86_capability[CPUID_8000_001F_EAX] = cpuid_eax(0x8000001f); + ++ if (c->extended_cpuid_level >= 0x80000021) ++ c->x86_capability[CPUID_8000_0021_EAX] = cpuid_eax(0x80000021); ++ + init_scattered_cpuid_features(c); + init_speculation_control(c); + +@@ -1127,6 +1134,10 @@ static const __initconst struct x86_cpu_id cpu_vuln_whitelist[] = { + #define RETBLEED BIT(3) + /* CPU is affected by SMT (cross-thread) return predictions */ + #define SMT_RSB BIT(4) ++/* CPU is affected by SRSO */ ++#define SRSO BIT(5) ++/* CPU is affected by GDS */ ++#define GDS BIT(6) + + static const struct x86_cpu_id cpu_vuln_blacklist[] __initconst = { + VULNBL_INTEL_STEPPINGS(IVYBRIDGE, X86_STEPPING_ANY, SRBDS), +@@ -1139,27 +1150,30 @@ static const struct x86_cpu_id cpu_vuln_blacklist[] __initconst = { + VULNBL_INTEL_STEPPINGS(BROADWELL_X, X86_STEPPING_ANY, MMIO), + VULNBL_INTEL_STEPPINGS(BROADWELL, X86_STEPPING_ANY, SRBDS), + VULNBL_INTEL_STEPPINGS(SKYLAKE_L, X86_STEPPING_ANY, SRBDS | MMIO | RETBLEED), +- VULNBL_INTEL_STEPPINGS(SKYLAKE_X, X86_STEPPING_ANY, MMIO | RETBLEED), ++ VULNBL_INTEL_STEPPINGS(SKYLAKE_X, X86_STEPPING_ANY, MMIO | RETBLEED | GDS), + VULNBL_INTEL_STEPPINGS(SKYLAKE, X86_STEPPING_ANY, SRBDS | MMIO | RETBLEED), +- VULNBL_INTEL_STEPPINGS(KABYLAKE_L, X86_STEPPING_ANY, SRBDS | MMIO | RETBLEED), +- VULNBL_INTEL_STEPPINGS(KABYLAKE, X86_STEPPING_ANY, SRBDS | MMIO | RETBLEED), ++ VULNBL_INTEL_STEPPINGS(KABYLAKE_L, X86_STEPPING_ANY, SRBDS | MMIO | RETBLEED | GDS), ++ VULNBL_INTEL_STEPPINGS(KABYLAKE, X86_STEPPING_ANY, SRBDS | MMIO | RETBLEED | GDS), + VULNBL_INTEL_STEPPINGS(CANNONLAKE_L, X86_STEPPING_ANY, RETBLEED), +- VULNBL_INTEL_STEPPINGS(ICELAKE_L, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RETBLEED), +- VULNBL_INTEL_STEPPINGS(ICELAKE_D, X86_STEPPING_ANY, MMIO), +- VULNBL_INTEL_STEPPINGS(ICELAKE_X, X86_STEPPING_ANY, MMIO), +- VULNBL_INTEL_STEPPINGS(COMETLAKE, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RETBLEED), ++ VULNBL_INTEL_STEPPINGS(ICELAKE_L, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RETBLEED | GDS), ++ VULNBL_INTEL_STEPPINGS(ICELAKE_D, X86_STEPPING_ANY, MMIO | GDS), ++ VULNBL_INTEL_STEPPINGS(ICELAKE_X, X86_STEPPING_ANY, MMIO | GDS), ++ VULNBL_INTEL_STEPPINGS(COMETLAKE, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RETBLEED | GDS), + VULNBL_INTEL_STEPPINGS(COMETLAKE_L, X86_STEPPINGS(0x0, 0x0), MMIO | RETBLEED), +- VULNBL_INTEL_STEPPINGS(COMETLAKE_L, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RETBLEED), ++ VULNBL_INTEL_STEPPINGS(COMETLAKE_L, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RETBLEED | GDS), ++ VULNBL_INTEL_STEPPINGS(TIGERLAKE_L, X86_STEPPING_ANY, GDS), ++ VULNBL_INTEL_STEPPINGS(TIGERLAKE, X86_STEPPING_ANY, GDS), + VULNBL_INTEL_STEPPINGS(LAKEFIELD, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RETBLEED), +- VULNBL_INTEL_STEPPINGS(ROCKETLAKE, X86_STEPPING_ANY, MMIO | RETBLEED), ++ VULNBL_INTEL_STEPPINGS(ROCKETLAKE, X86_STEPPING_ANY, MMIO | RETBLEED | GDS), + VULNBL_INTEL_STEPPINGS(ATOM_TREMONT, X86_STEPPING_ANY, MMIO | MMIO_SBDS), + VULNBL_INTEL_STEPPINGS(ATOM_TREMONT_D, X86_STEPPING_ANY, MMIO), + VULNBL_INTEL_STEPPINGS(ATOM_TREMONT_L, X86_STEPPING_ANY, MMIO | MMIO_SBDS), + + VULNBL_AMD(0x15, RETBLEED), + VULNBL_AMD(0x16, RETBLEED), +- VULNBL_AMD(0x17, RETBLEED | SMT_RSB), ++ VULNBL_AMD(0x17, RETBLEED | SMT_RSB | SRSO), + VULNBL_HYGON(0x18, RETBLEED | SMT_RSB), ++ VULNBL_AMD(0x19, SRSO), + {} + }; + +@@ -1280,6 +1294,21 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c) + if (cpu_matches(cpu_vuln_blacklist, SMT_RSB)) + setup_force_cpu_bug(X86_BUG_SMT_RSB); + ++ /* ++ * Check if CPU is vulnerable to GDS. If running in a virtual machine on ++ * an affected processor, the VMM may have disabled the use of GATHER by ++ * disabling AVX2. The only way to do this in HW is to clear XCR0[2], ++ * which means that AVX will be disabled. ++ */ ++ if (cpu_matches(cpu_vuln_blacklist, GDS) && !(ia32_cap & ARCH_CAP_GDS_NO) && ++ boot_cpu_has(X86_FEATURE_AVX)) ++ setup_force_cpu_bug(X86_BUG_GDS); ++ ++ if (!cpu_has(c, X86_FEATURE_SRSO_NO)) { ++ if (cpu_matches(cpu_vuln_blacklist, SRSO)) ++ setup_force_cpu_bug(X86_BUG_SRSO); ++ } ++ + if (cpu_matches(cpu_vuln_whitelist, NO_MELTDOWN)) + return; + +@@ -1421,10 +1450,6 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c) + + sld_setup(c); + +- fpu__init_system(c); +- +- init_sigframe_size(); +- + #ifdef CONFIG_X86_32 + /* + * Regardless of whether PCID is enumerated, the SDM says +@@ -1802,6 +1827,8 @@ void identify_secondary_cpu(struct cpuinfo_x86 *c) + validate_apic_and_package_id(c); + x86_spec_ctrl_setup_ap(); + update_srbds_msr(); ++ if (boot_cpu_has_bug(X86_BUG_GDS)) ++ update_gds_msr(); + + tsx_ap_init(); + } +@@ -2129,8 +2156,6 @@ void cpu_init(void) + + doublefault_init_cpu_tss(); + +- fpu__init_cpu(); +- + if (is_uv_system()) + uv_cpu_init(); + +@@ -2146,6 +2171,7 @@ void cpu_init_secondary(void) + */ + cpu_init_exception_handling(); + cpu_init(); ++ fpu__init_cpu(); + } + #endif + +@@ -2208,3 +2234,69 @@ void arch_smt_update(void) + /* Check whether IPI broadcasting can be enabled */ + apic_smt_update(); + } ++ ++void __init arch_cpu_finalize_init(void) ++{ ++ identify_boot_cpu(); ++ ++ /* ++ * identify_boot_cpu() initialized SMT support information, let the ++ * core code know. ++ */ ++ cpu_smt_check_topology(); ++ ++ if (!IS_ENABLED(CONFIG_SMP)) { ++ pr_info("CPU: "); ++ print_cpu_info(&boot_cpu_data); ++ } ++ ++ cpu_select_mitigations(); ++ ++ arch_smt_update(); ++ ++ if (IS_ENABLED(CONFIG_X86_32)) { ++ /* ++ * Check whether this is a real i386 which is not longer ++ * supported and fixup the utsname. ++ */ ++ if (boot_cpu_data.x86 < 4) ++ panic("Kernel requires i486+ for 'invlpg' and other features"); ++ ++ init_utsname()->machine[1] = ++ '0' + (boot_cpu_data.x86 > 6 ? 6 : boot_cpu_data.x86); ++ } ++ ++ /* ++ * Must be before alternatives because it might set or clear ++ * feature bits. ++ */ ++ fpu__init_system(); ++ fpu__init_cpu(); ++ ++ alternative_instructions(); ++ ++ if (IS_ENABLED(CONFIG_X86_64)) { ++ /* ++ * Make sure the first 2MB area is not mapped by huge pages ++ * There are typically fixed size MTRRs in there and overlapping ++ * MTRRs into large pages causes slow downs. ++ * ++ * Right now we don't do that with gbpages because there seems ++ * very little benefit for that case. ++ */ ++ if (!direct_gbpages) ++ set_memory_4k((unsigned long)__va(0), 1); ++ } else { ++ fpu__init_check_bugs(); ++ } ++ ++ /* ++ * This needs to be called before any devices perform DMA ++ * operations that might use the SWIOTLB bounce buffers. It will ++ * mark the bounce buffers as decrypted so that their usage will ++ * not cause "plain-text" data to be decrypted when accessed. It ++ * must be called after late_time_init() so that Hyper-V x86/x64 ++ * hypercalls work when the SWIOTLB bounce buffers are decrypted. ++ */ ++ mem_encrypt_init(); ++} +diff --git a/arch/x86/kernel/cpu/cpu.h b/arch/x86/kernel/cpu/cpu.h +index 7c9b5893c30ab..d9aeb335002dd 100644 +--- a/arch/x86/kernel/cpu/cpu.h ++++ b/arch/x86/kernel/cpu/cpu.h +@@ -79,9 +79,11 @@ extern void detect_ht(struct cpuinfo_x86 *c); + extern void check_null_seg_clears_base(struct cpuinfo_x86 *c); + + unsigned int aperfmperf_get_khz(int cpu); ++void cpu_select_mitigations(void); + + extern void x86_spec_ctrl_setup_ap(void); + extern void update_srbds_msr(void); ++extern void update_gds_msr(void); + + extern u64 x86_read_arch_cap_msr(void); + +diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c +index c949424a11c19..ddf65f1927e12 100644 +--- a/arch/x86/kernel/fpu/init.c ++++ b/arch/x86/kernel/fpu/init.c +@@ -49,7 +49,7 @@ void fpu__init_cpu(void) + fpu__init_cpu_xstate(); + } + +-static bool fpu__probe_without_cpuid(void) ++static bool __init fpu__probe_without_cpuid(void) + { + unsigned long cr0; + u16 fsw, fcw; +@@ -67,7 +67,7 @@ static bool fpu__probe_without_cpuid(void) + return fsw == 0 && (fcw & 0x103f) == 0x003f; + } + +-static void fpu__init_system_early_generic(struct cpuinfo_x86 *c) ++static void __init fpu__init_system_early_generic(void) + { + if (!boot_cpu_has(X86_FEATURE_CPUID) && + !test_bit(X86_FEATURE_FPU, (unsigned long *)cpu_caps_cleared)) { +@@ -226,9 +226,9 @@ static void __init fpu__init_system_ctx_switch(void) + * Called on the boot CPU once per system bootup, to set up the initial + * FPU state that is later cloned into all processes: + */ +-void __init fpu__init_system(struct cpuinfo_x86 *c) ++void __init fpu__init_system(void) + { +- fpu__init_system_early_generic(c); ++ fpu__init_system_early_generic(); + + /* + * The FPU has to be operational for some of the +diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c +index f4d21e4700835..bf10340a9b71d 100644 +--- a/arch/x86/kernel/signal.c ++++ b/arch/x86/kernel/signal.c +@@ -722,7 +722,7 @@ badframe: + /* max_frame_size tells userspace the worst case signal stack size. */ + static unsigned long __ro_after_init max_frame_size; + +-void __init init_sigframe_size(void) ++static int __init init_sigframe_size(void) + { + max_frame_size = MAX_FRAME_SIGINFO_UCTXT_SIZE + MAX_FRAME_PADDING; + +@@ -732,7 +732,9 @@ void __init init_sigframe_size(void) + max_frame_size = round_up(max_frame_size, FRAME_ALIGNMENT); + + pr_info("max sigframe size: %lu\n", max_frame_size); ++ return 0; + } ++early_initcall(init_sigframe_size); + + unsigned long get_sigframe_size(void) + { +diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S +index c1efcd194ad7b..50aaf0cd8f467 100644 +--- a/arch/x86/kernel/vmlinux.lds.S ++++ b/arch/x86/kernel/vmlinux.lds.S +@@ -133,7 +133,20 @@ SECTIONS + LOCK_TEXT + KPROBES_TEXT + ALIGN_ENTRY_TEXT_BEGIN ++#ifdef CONFIG_CPU_SRSO ++ *(.text.__x86.rethunk_untrain) ++#endif ++ + ENTRY_TEXT ++ ++#ifdef CONFIG_CPU_SRSO ++ /* ++ * See the comment above srso_untrain_ret_alias()'s ++ * definition. ++ */ ++ . = srso_untrain_ret_alias | (1 << 2) | (1 << 8) | (1 << 14) | (1 << 20); ++ *(.text.__x86.rethunk_safe) ++#endif + ALIGN_ENTRY_TEXT_END + SOFTIRQENTRY_TEXT + STATIC_CALL_TEXT +@@ -142,13 +155,15 @@ SECTIONS + + #ifdef CONFIG_RETPOLINE + __indirect_thunk_start = .; +- *(.text.__x86.*) ++ *(.text.__x86.indirect_thunk) ++ *(.text.__x86.return_thunk) + __indirect_thunk_end = .; + #endif + } :text =0xcccc + + /* End of text section, which should occupy whole number of pages */ + _etext = .; ++ + . = ALIGN(PAGE_SIZE); + + X86_ALIGN_RODATA_BEGIN +@@ -496,6 +511,21 @@ INIT_PER_CPU(irq_stack_backing_store); + "fixed_percpu_data is not at start of per-cpu area"); + #endif + ++ #ifdef CONFIG_RETHUNK ++. = ASSERT((__ret & 0x3f) == 0, "__ret not cacheline-aligned"); ++. = ASSERT((srso_safe_ret & 0x3f) == 0, "srso_safe_ret not cacheline-aligned"); ++#endif ++ ++#ifdef CONFIG_CPU_SRSO ++/* ++ * GNU ld cannot do XOR so do: (A | B) - (A & B) in order to compute the XOR ++ * of the two function addresses: ++ */ ++. = ASSERT(((srso_untrain_ret_alias | srso_safe_ret_alias) - ++ (srso_untrain_ret_alias & srso_safe_ret_alias)) == ((1 << 2) | (1 << 8) | (1 << 14) | (1 << 20)), ++ "SRSO function pair won't alias"); ++#endif ++ + #endif /* CONFIG_X86_64 */ + + #ifdef CONFIG_KEXEC_CORE +diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c +index 528437e3e2f3f..b939b94d931f7 100644 +--- a/arch/x86/kvm/cpuid.c ++++ b/arch/x86/kvm/cpuid.c +@@ -544,6 +544,9 @@ void kvm_set_cpu_caps(void) + F(PMM) | F(PMM_EN) + ); + ++ if (cpu_feature_enabled(X86_FEATURE_SRSO_NO)) ++ kvm_cpu_cap_set(X86_FEATURE_SRSO_NO); ++ + /* + * Hide RDTSCP and RDPID if either feature is reported as supported but + * probing MSR_TSC_AUX failed. This is purely a sanity check and +diff --git a/arch/x86/kvm/reverse_cpuid.h b/arch/x86/kvm/reverse_cpuid.h +index a19d473d01847..7eeade35a425b 100644 +--- a/arch/x86/kvm/reverse_cpuid.h ++++ b/arch/x86/kvm/reverse_cpuid.h +@@ -48,6 +48,7 @@ static const struct cpuid_reg reverse_cpuid[] = { + [CPUID_7_1_EAX] = { 7, 1, CPUID_EAX}, + [CPUID_12_EAX] = {0x00000012, 0, CPUID_EAX}, + [CPUID_8000_001F_EAX] = {0x8000001f, 0, CPUID_EAX}, ++ [CPUID_8000_0021_EAX] = {0x80000021, 0, CPUID_EAX}, + }; + + /* +diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c +index 302a4669c5a15..d63c3843e4935 100644 +--- a/arch/x86/kvm/svm/svm.c ++++ b/arch/x86/kvm/svm/svm.c +@@ -1489,7 +1489,9 @@ static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu) + + if (sd->current_vmcb != svm->vmcb) { + sd->current_vmcb = svm->vmcb; +- indirect_branch_prediction_barrier(); ++ ++ if (!cpu_feature_enabled(X86_FEATURE_IBPB_ON_VMEXIT)) ++ indirect_branch_prediction_barrier(); + } + if (kvm_vcpu_apicv_active(vcpu)) + avic_vcpu_load(vcpu, cpu); +diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S +index 723f8534986c3..f960608555226 100644 +--- a/arch/x86/kvm/svm/vmenter.S ++++ b/arch/x86/kvm/svm/vmenter.S +@@ -119,6 +119,9 @@ SYM_FUNC_START(__svm_vcpu_run) + */ + UNTRAIN_RET + ++ /* SRSO */ ++ ALTERNATIVE "", "call entry_ibpb", X86_FEATURE_IBPB_ON_VMEXIT ++ + /* + * Clear all general purpose registers except RSP and RAX to prevent + * speculative use of the guest's values, even those that are reloaded +diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c +index 285ba12be8ce3..2686c4dcdb1a0 100644 +--- a/arch/x86/kvm/x86.c ++++ b/arch/x86/kvm/x86.c +@@ -303,6 +303,8 @@ static struct kmem_cache *x86_fpu_cache; + + static struct kmem_cache *x86_emulator_cache; + ++extern bool gds_ucode_mitigated(void); ++ + /* + * When called, it means the previous get/set msr reached an invalid msr. + * Return true if we want to ignore/silent this failed msr access. +@@ -1498,7 +1500,7 @@ static unsigned int num_msr_based_features; + ARCH_CAP_SKIP_VMENTRY_L1DFLUSH | ARCH_CAP_SSB_NO | ARCH_CAP_MDS_NO | \ + ARCH_CAP_PSCHANGE_MC_NO | ARCH_CAP_TSX_CTRL_MSR | ARCH_CAP_TAA_NO | \ + ARCH_CAP_SBDR_SSDP_NO | ARCH_CAP_FBSDP_NO | ARCH_CAP_PSDP_NO | \ +- ARCH_CAP_FB_CLEAR | ARCH_CAP_RRSBA | ARCH_CAP_PBRSB_NO) ++ ARCH_CAP_FB_CLEAR | ARCH_CAP_RRSBA | ARCH_CAP_PBRSB_NO | ARCH_CAP_GDS_NO) + + static u64 kvm_get_arch_capabilities(void) + { +@@ -1555,6 +1557,9 @@ static u64 kvm_get_arch_capabilities(void) + */ + } + ++ if (!boot_cpu_has_bug(X86_BUG_GDS) || gds_ucode_mitigated()) ++ data |= ARCH_CAP_GDS_NO; ++ + return data; + } + +diff --git a/arch/x86/lib/retpoline.S b/arch/x86/lib/retpoline.S +index 1221bb099afb4..5f7eed97487ec 100644 +--- a/arch/x86/lib/retpoline.S ++++ b/arch/x86/lib/retpoline.S +@@ -9,6 +9,7 @@ + #include <asm/nospec-branch.h> + #include <asm/unwind_hints.h> + #include <asm/frame.h> ++#include <asm/nops.h> + + .section .text.__x86.indirect_thunk + +@@ -73,6 +74,45 @@ SYM_CODE_END(__x86_indirect_thunk_array) + */ + #ifdef CONFIG_RETHUNK + ++/* ++ * srso_untrain_ret_alias() and srso_safe_ret_alias() are placed at ++ * special addresses: ++ * ++ * - srso_untrain_ret_alias() is 2M aligned ++ * - srso_safe_ret_alias() is also in the same 2M page but bits 2, 8, 14 ++ * and 20 in its virtual address are set (while those bits in the ++ * srso_untrain_ret_alias() function are cleared). ++ * ++ * This guarantees that those two addresses will alias in the branch ++ * target buffer of Zen3/4 generations, leading to any potential ++ * poisoned entries at that BTB slot to get evicted. ++ * ++ * As a result, srso_safe_ret_alias() becomes a safe return. ++ */ ++#ifdef CONFIG_CPU_SRSO ++ .section .text.__x86.rethunk_untrain ++ ++SYM_START(srso_untrain_ret_alias, SYM_L_GLOBAL, SYM_A_NONE) ++ ASM_NOP2 ++ lfence ++ jmp __x86_return_thunk ++SYM_FUNC_END(srso_untrain_ret_alias) ++__EXPORT_THUNK(srso_untrain_ret_alias) ++ ++ .section .text.__x86.rethunk_safe ++#endif ++ ++/* Needs a definition for the __x86_return_thunk alternative below. */ ++SYM_START(srso_safe_ret_alias, SYM_L_GLOBAL, SYM_A_NONE) ++#ifdef CONFIG_CPU_SRSO ++ add $8, %_ASM_SP ++ UNWIND_HINT_FUNC ++#endif ++ ANNOTATE_UNRET_SAFE ++ ret ++ int3 ++SYM_FUNC_END(srso_safe_ret_alias) ++ + .section .text.__x86.return_thunk + + /* +@@ -85,7 +125,7 @@ SYM_CODE_END(__x86_indirect_thunk_array) + * from re-poisioning the BTB prediction. + */ + .align 64 +- .skip 63, 0xcc ++ .skip 64 - (__ret - zen_untrain_ret), 0xcc + SYM_FUNC_START_NOALIGN(zen_untrain_ret); + + /* +@@ -117,10 +157,10 @@ SYM_FUNC_START_NOALIGN(zen_untrain_ret); + * evicted, __x86_return_thunk will suffer Straight Line Speculation + * which will be contained safely by the INT3. + */ +-SYM_INNER_LABEL(__x86_return_thunk, SYM_L_GLOBAL) ++SYM_INNER_LABEL(__ret, SYM_L_GLOBAL) + ret + int3 +-SYM_CODE_END(__x86_return_thunk) ++SYM_CODE_END(__ret) + + /* + * Ensure the TEST decoding / BTB invalidation is complete. +@@ -131,11 +171,44 @@ SYM_CODE_END(__x86_return_thunk) + * Jump back and execute the RET in the middle of the TEST instruction. + * INT3 is for SLS protection. + */ +- jmp __x86_return_thunk ++ jmp __ret + int3 + SYM_FUNC_END(zen_untrain_ret) + __EXPORT_THUNK(zen_untrain_ret) + ++/* ++ * SRSO untraining sequence for Zen1/2, similar to zen_untrain_ret() ++ * above. On kernel entry, srso_untrain_ret() is executed which is a ++ * ++ * movabs $0xccccccc308c48348,%rax ++ * ++ * and when the return thunk executes the inner label srso_safe_ret() ++ * later, it is a stack manipulation and a RET which is mispredicted and ++ * thus a "safe" one to use. ++ */ ++ .align 64 ++ .skip 64 - (srso_safe_ret - srso_untrain_ret), 0xcc ++SYM_START(srso_untrain_ret, SYM_L_GLOBAL, SYM_A_NONE) ++ .byte 0x48, 0xb8 ++ ++SYM_INNER_LABEL(srso_safe_ret, SYM_L_GLOBAL) ++ add $8, %_ASM_SP ++ ret ++ int3 ++ int3 ++ int3 ++ lfence ++ call srso_safe_ret ++ int3 ++SYM_CODE_END(srso_safe_ret) ++SYM_FUNC_END(srso_untrain_ret) ++__EXPORT_THUNK(srso_untrain_ret) ++ ++SYM_FUNC_START(__x86_return_thunk) ++ ALTERNATIVE_2 "jmp __ret", "call srso_safe_ret", X86_FEATURE_SRSO, \ ++ "call srso_safe_ret_alias", X86_FEATURE_SRSO_ALIAS ++ int3 ++SYM_CODE_END(__x86_return_thunk) + EXPORT_SYMBOL(__x86_return_thunk) + + #endif /* CONFIG_RETHUNK */ +diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c +index 34a08f6a528e9..56d5ab70bfa1c 100644 +--- a/arch/x86/mm/init.c ++++ b/arch/x86/mm/init.c +@@ -27,6 +27,7 @@ + #include <asm/pti.h> + #include <asm/text-patching.h> + #include <asm/memtype.h> ++#include <asm/paravirt.h> + + /* + * We need to define the tracepoints somewhere, and tlb.c +@@ -822,9 +823,12 @@ void __init poking_init(void) + spinlock_t *ptl; + pte_t *ptep; + +- poking_mm = copy_init_mm(); ++ poking_mm = mm_alloc(); + BUG_ON(!poking_mm); + ++ /* Xen PV guests need the PGD to be pinned. */ ++ paravirt_arch_dup_mmap(NULL, poking_mm); ++ + /* + * Randomize the poking address, but make sure that the following page + * will be mapped at the same PMD. We need 2 pages, so find space for 3, +diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c +index b47b5111397a7..a1f974309b1cf 100644 +--- a/arch/x86/xen/smp_pv.c ++++ b/arch/x86/xen/smp_pv.c +@@ -30,6 +30,7 @@ + #include <asm/desc.h> + #include <asm/cpu.h> + #include <asm/io_apic.h> ++#include <asm/fpu/internal.h> + + #include <xen/interface/xen.h> + #include <xen/interface/vcpu.h> +@@ -63,6 +64,7 @@ static void cpu_bringup(void) + + cr4_init(); + cpu_init(); ++ fpu__init_cpu(); + touch_softlockup_watchdog(); + + /* PVH runs in ring 0 and allows us to do native syscalls. Yay! */ +diff --git a/arch/xtensa/include/asm/bugs.h b/arch/xtensa/include/asm/bugs.h +deleted file mode 100644 +index 69b29d1982494..0000000000000 +--- a/arch/xtensa/include/asm/bugs.h ++++ /dev/null +@@ -1,18 +0,0 @@ +-/* +- * include/asm-xtensa/bugs.h +- * +- * This is included by init/main.c to check for architecture-dependent bugs. +- * +- * Xtensa processors don't have any bugs. :) +- * +- * This file is subject to the terms and conditions of the GNU General +- * Public License. See the file "COPYING" in the main directory of +- * this archive for more details. +- */ +- +-#ifndef _XTENSA_BUGS_H +-#define _XTENSA_BUGS_H +- +-static void check_bugs(void) { } +- +-#endif /* _XTENSA_BUGS_H */ +diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c +index 450dca235a2f4..46430cf2401e7 100644 +--- a/drivers/base/cpu.c ++++ b/drivers/base/cpu.c +@@ -577,6 +577,18 @@ ssize_t __weak cpu_show_retbleed(struct device *dev, + return sysfs_emit(buf, "Not affected\n"); + } + ++ssize_t __weak cpu_show_gds(struct device *dev, ++ struct device_attribute *attr, char *buf) ++{ ++ return sysfs_emit(buf, "Not affected\n"); ++} ++ ++ssize_t __weak cpu_show_spec_rstack_overflow(struct device *dev, ++ struct device_attribute *attr, char *buf) ++{ ++ return sysfs_emit(buf, "Not affected\n"); ++} ++ + static DEVICE_ATTR(meltdown, 0444, cpu_show_meltdown, NULL); + static DEVICE_ATTR(spectre_v1, 0444, cpu_show_spectre_v1, NULL); + static DEVICE_ATTR(spectre_v2, 0444, cpu_show_spectre_v2, NULL); +@@ -588,6 +600,8 @@ static DEVICE_ATTR(itlb_multihit, 0444, cpu_show_itlb_multihit, NULL); + static DEVICE_ATTR(srbds, 0444, cpu_show_srbds, NULL); + static DEVICE_ATTR(mmio_stale_data, 0444, cpu_show_mmio_stale_data, NULL); + static DEVICE_ATTR(retbleed, 0444, cpu_show_retbleed, NULL); ++static DEVICE_ATTR(gather_data_sampling, 0444, cpu_show_gds, NULL); ++static DEVICE_ATTR(spec_rstack_overflow, 0444, cpu_show_spec_rstack_overflow, NULL); + + static struct attribute *cpu_root_vulnerabilities_attrs[] = { + &dev_attr_meltdown.attr, +@@ -601,6 +615,8 @@ static struct attribute *cpu_root_vulnerabilities_attrs[] = { + &dev_attr_srbds.attr, + &dev_attr_mmio_stale_data.attr, + &dev_attr_retbleed.attr, ++ &dev_attr_gather_data_sampling.attr, ++ &dev_attr_spec_rstack_overflow.attr, + NULL + }; + +diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c +index 63118b56c5289..5017033c705ae 100644 +--- a/drivers/net/xen-netback/netback.c ++++ b/drivers/net/xen-netback/netback.c +@@ -396,7 +396,7 @@ static void xenvif_get_requests(struct xenvif_queue *queue, + struct gnttab_map_grant_ref *gop = queue->tx_map_ops + *map_ops; + struct xen_netif_tx_request *txp = first; + +- nr_slots = shinfo->nr_frags + 1; ++ nr_slots = shinfo->nr_frags + frag_overflow + 1; + + copy_count(skb) = 0; + XENVIF_TX_CB(skb)->split_mask = 0; +@@ -462,8 +462,8 @@ static void xenvif_get_requests(struct xenvif_queue *queue, + } + } + +- for (shinfo->nr_frags = 0; shinfo->nr_frags < nr_slots; +- shinfo->nr_frags++, gop++) { ++ for (shinfo->nr_frags = 0; nr_slots > 0 && shinfo->nr_frags < MAX_SKB_FRAGS; ++ shinfo->nr_frags++, gop++, nr_slots--) { + index = pending_index(queue->pending_cons++); + pending_idx = queue->pending_ring[index]; + xenvif_tx_create_map_op(queue, pending_idx, txp, +@@ -476,12 +476,12 @@ static void xenvif_get_requests(struct xenvif_queue *queue, + txp++; + } + +- if (frag_overflow) { ++ if (nr_slots > 0) { + + shinfo = skb_shinfo(nskb); + frags = shinfo->frags; + +- for (shinfo->nr_frags = 0; shinfo->nr_frags < frag_overflow; ++ for (shinfo->nr_frags = 0; shinfo->nr_frags < nr_slots; + shinfo->nr_frags++, txp++, gop++) { + index = pending_index(queue->pending_cons++); + pending_idx = queue->pending_ring[index]; +@@ -492,6 +492,11 @@ static void xenvif_get_requests(struct xenvif_queue *queue, + } + + skb_shinfo(skb)->frag_list = nskb; ++ } else if (nskb) { ++ /* A frag_list skb was allocated but it is no longer needed ++ * because enough slots were converted to copy ops above. ++ */ ++ kfree_skb(nskb); + } + + (*copy_ops) = cop - queue->tx_copy_ops; +diff --git a/include/asm-generic/bugs.h b/include/asm-generic/bugs.h +deleted file mode 100644 +index 69021830f078d..0000000000000 +--- a/include/asm-generic/bugs.h ++++ /dev/null +@@ -1,11 +0,0 @@ +-/* SPDX-License-Identifier: GPL-2.0 */ +-#ifndef __ASM_GENERIC_BUGS_H +-#define __ASM_GENERIC_BUGS_H +-/* +- * This file is included by 'init/main.c' to check for +- * architecture-dependent bugs. +- */ +- +-static inline void check_bugs(void) { } +- +-#endif /* __ASM_GENERIC_BUGS_H */ +diff --git a/include/linux/cpu.h b/include/linux/cpu.h +index 6102a21a01d9a..d4c860de9a6a6 100644 +--- a/include/linux/cpu.h ++++ b/include/linux/cpu.h +@@ -70,6 +70,8 @@ extern ssize_t cpu_show_mmio_stale_data(struct device *dev, + char *buf); + extern ssize_t cpu_show_retbleed(struct device *dev, + struct device_attribute *attr, char *buf); ++extern ssize_t cpu_show_spec_rstack_overflow(struct device *dev, ++ struct device_attribute *attr, char *buf); + + extern __printf(4, 5) + struct device *cpu_device_create(struct device *parent, void *drvdata, +@@ -187,6 +189,12 @@ void arch_cpu_idle_enter(void); + void arch_cpu_idle_exit(void); + void arch_cpu_idle_dead(void); + ++#ifdef CONFIG_ARCH_HAS_CPU_FINALIZE_INIT ++void arch_cpu_finalize_init(void); ++#else ++static inline void arch_cpu_finalize_init(void) { } ++#endif ++ + int cpu_report_state(int cpu); + int cpu_check_up_prepare(int cpu); + void cpu_set_state_online(int cpu); +diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h +index d351f1b362ef9..d23977e9035d4 100644 +--- a/include/linux/sched/task.h ++++ b/include/linux/sched/task.h +@@ -61,6 +61,7 @@ extern void sched_dead(struct task_struct *p); + void __noreturn do_task_dead(void); + void __noreturn make_task_dead(int signr); + ++extern void mm_cache_init(void); + extern void proc_caches_init(void); + + extern void fork_init(void); +@@ -87,7 +88,6 @@ extern void exit_itimers(struct task_struct *); + extern pid_t kernel_clone(struct kernel_clone_args *kargs); + struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node); + struct task_struct *fork_idle(int); +-struct mm_struct *copy_init_mm(void); + extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags); + extern long kernel_wait4(pid_t, int __user *, int, struct rusage *); + int kernel_wait(pid_t pid, int *stat); +diff --git a/init/main.c b/init/main.c +index 649d9e4201a80..63737af8de51e 100644 +--- a/init/main.c ++++ b/init/main.c +@@ -96,7 +96,6 @@ + #include <linux/cache.h> + #include <linux/rodata_test.h> + #include <linux/jump_label.h> +-#include <linux/mem_encrypt.h> + #include <linux/kcsan.h> + #include <linux/init_syscalls.h> + #include <linux/stackdepot.h> +@@ -104,7 +103,6 @@ + #include <net/net_namespace.h> + + #include <asm/io.h> +-#include <asm/bugs.h> + #include <asm/setup.h> + #include <asm/sections.h> + #include <asm/cacheflush.h> +@@ -788,8 +786,6 @@ void __init __weak thread_stack_cache_init(void) + } + #endif + +-void __init __weak mem_encrypt_init(void) { } +- + void __init __weak poking_init(void) { } + + void __init __weak pgtable_cache_init(void) { } +@@ -859,6 +855,7 @@ static void __init mm_init(void) + init_espfix_bsp(); + /* Should be run after espfix64 is set up. */ + pti_init(); ++ mm_cache_init(); + } + + #ifdef CONFIG_HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET +@@ -991,7 +988,7 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void) + sort_main_extable(); + trap_init(); + mm_init(); +- ++ poking_init(); + ftrace_init(); + + /* trace_printk can be enabled here */ +@@ -1083,14 +1080,6 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void) + */ + locking_selftest(); + +- /* +- * This needs to be called before any devices perform DMA +- * operations that might use the SWIOTLB bounce buffers. It will +- * mark the bounce buffers as decrypted so that their usage will +- * not cause "plain-text" data to be decrypted when accessed. +- */ +- mem_encrypt_init(); +- + #ifdef CONFIG_BLK_DEV_INITRD + if (initrd_start && !initrd_below_start_ok && + page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) { +@@ -1107,6 +1096,9 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void) + late_time_init(); + sched_clock_init(); + calibrate_delay(); ++ ++ arch_cpu_finalize_init(); ++ + pid_idr_init(); + anon_vma_init(); + #ifdef CONFIG_X86 +@@ -1133,9 +1125,6 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void) + taskstats_init_early(); + delayacct_init(); + +- poking_init(); +- check_bugs(); +- + acpi_subsystem_init(); + arch_post_acpi_subsys_init(); + kcsan_init(); +diff --git a/kernel/fork.c b/kernel/fork.c +index 1906230a000e3..ace0717c71e27 100644 +--- a/kernel/fork.c ++++ b/kernel/fork.c +@@ -2522,11 +2522,6 @@ struct task_struct * __init fork_idle(int cpu) + return task; + } + +-struct mm_struct *copy_init_mm(void) +-{ +- return dup_mm(NULL, &init_mm); +-} +- + /* + * This is like kernel_clone(), but shaved down and tailored to just + * creating io_uring workers. It returns a created task, or an error pointer. +@@ -2921,10 +2916,27 @@ static void sighand_ctor(void *data) + init_waitqueue_head(&sighand->signalfd_wqh); + } + +-void __init proc_caches_init(void) ++void __init mm_cache_init(void) + { + unsigned int mm_size; + ++ /* ++ * The mm_cpumask is located at the end of mm_struct, and is ++ * dynamically sized based on the maximum CPU number this system ++ * can have, taking hotplug into account (nr_cpu_ids). ++ */ ++ mm_size = sizeof(struct mm_struct) + cpumask_size(); ++ ++ mm_cachep = kmem_cache_create_usercopy("mm_struct", ++ mm_size, ARCH_MIN_MMSTRUCT_ALIGN, ++ SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_ACCOUNT, ++ offsetof(struct mm_struct, saved_auxv), ++ sizeof_field(struct mm_struct, saved_auxv), ++ NULL); ++} ++ ++void __init proc_caches_init(void) ++{ + sighand_cachep = kmem_cache_create("sighand_cache", + sizeof(struct sighand_struct), 0, + SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_TYPESAFE_BY_RCU| +@@ -2942,19 +2954,6 @@ void __init proc_caches_init(void) + SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_ACCOUNT, + NULL); + +- /* +- * The mm_cpumask is located at the end of mm_struct, and is +- * dynamically sized based on the maximum CPU number this system +- * can have, taking hotplug into account (nr_cpu_ids). +- */ +- mm_size = sizeof(struct mm_struct) + cpumask_size(); +- +- mm_cachep = kmem_cache_create_usercopy("mm_struct", +- mm_size, ARCH_MIN_MMSTRUCT_ALIGN, +- SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_ACCOUNT, +- offsetof(struct mm_struct, saved_auxv), +- sizeof_field(struct mm_struct, saved_auxv), +- NULL); + vm_area_cachep = KMEM_CACHE(vm_area_struct, SLAB_PANIC|SLAB_ACCOUNT); + mmap_init(); + nsproxy_cache_init(); +diff --git a/tools/arch/x86/include/asm/cpufeatures.h b/tools/arch/x86/include/asm/cpufeatures.h +index bcaedfe60572f..861451839cf2f 100644 +--- a/tools/arch/x86/include/asm/cpufeatures.h ++++ b/tools/arch/x86/include/asm/cpufeatures.h +@@ -14,7 +14,7 @@ + * Defines x86 CPU feature bits + */ + #define NCAPINTS 20 /* N 32-bit words worth of info */ +-#define NBUGINTS 1 /* N 32-bit bug flags */ ++#define NBUGINTS 2 /* N 32-bit bug flags */ + + /* + * Note: If the comment begins with a quoted string, that string is used +diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c +index f62db0e006e9c..cf8ea35941253 100644 +--- a/tools/objtool/arch/x86/decode.c ++++ b/tools/objtool/arch/x86/decode.c +@@ -725,5 +725,8 @@ bool arch_is_retpoline(struct symbol *sym) + + bool arch_is_rethunk(struct symbol *sym) + { +- return !strcmp(sym->name, "__x86_return_thunk"); ++ return !strcmp(sym->name, "__x86_return_thunk") || ++ !strcmp(sym->name, "srso_untrain_ret") || ++ !strcmp(sym->name, "srso_safe_ret") || ++ !strcmp(sym->name, "__ret"); + } |