From 66ee3636eddcc82ab82b539d08b85fb5ac1dff9b Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sun, 4 Feb 2024 21:20:03 +0900 Subject: x86/kconfig: Select ARCH_WANT_FRAME_POINTERS again when UNWINDER_FRAME_POINTER=y It took me some time to understand the purpose of the tricky code at the end of arch/x86/Kconfig.debug. Without it, the following would be shown: WARNING: unmet direct dependencies detected for FRAME_POINTER because 81d387190039 ("x86/kconfig: Consolidate unwinders into multiple choice selection") removed 'select ARCH_WANT_FRAME_POINTERS'. The correct and more straightforward approach should have been to move it where 'select FRAME_POINTER' is located. Several architectures properly handle the conditional selection of ARCH_WANT_FRAME_POINTERS. For example, 'config UNWINDER_FRAME_POINTER' in arch/arm/Kconfig.debug. Fixes: 81d387190039 ("x86/kconfig: Consolidate unwinders into multiple choice selection") Signed-off-by: Masahiro Yamada Signed-off-by: Borislav Petkov (AMD) Acked-by: Josh Poimboeuf Link: https://lore.kernel.org/r/20240204122003.53795-1-masahiroy@kernel.org --- arch/x86/Kconfig.debug | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index c5d614d28a75..74777a97e394 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -248,6 +248,7 @@ config UNWINDER_ORC config UNWINDER_FRAME_POINTER bool "Frame pointer unwinder" + select ARCH_WANT_FRAME_POINTERS select FRAME_POINTER help This option enables the frame pointer unwinder for unwinding kernel @@ -271,7 +272,3 @@ config UNWINDER_GUESS overhead. endchoice - -config FRAME_POINTER - depends on !UNWINDER_ORC && !UNWINDER_GUESS - bool -- cgit v1.2.3-58-ga151 From 9d22c96316ac59ed38e80920c698fed38717b91b Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 17 May 2024 16:40:36 +0200 Subject: x86/topology: Handle bogus ACPI tables correctly The ACPI specification clearly states how the processors should be enumerated in the MADT: "To ensure that the boot processor is supported post initialization, two guidelines should be followed. The first is that OSPM should initialize processors in the order that they appear in the MADT. The second is that platform firmware should list the boot processor as the first processor entry in the MADT. ... Failure of OSPM implementations and platform firmware to abide by these guidelines can result in both unpredictable and non optimal platform operation." The kernel relies on that ordering to detect the real BSP on crash kernels which is important to avoid sending a INIT IPI to it as that would cause a full machine reset. On a Dell XPS 16 9640 the BIOS ignores this rule and enumerates the CPUs in the wrong order. As a consequence the kernel falsely detects a crash kernel and disables the corresponding CPU. Prevent this by checking the IA32_APICBASE MSR for the BSP bit on the boot CPU. If that bit is set, then the MADT based BSP detection can be safely ignored. If the kernel detects a mismatch between the BSP bit and the first enumerated MADT entry then emit a firmware bug message. This obviously also has to be taken into account when the boot APIC ID and the first enumerated APIC ID match. If the boot CPU does not have the BSP bit set in the APICBASE MSR then there is no way for the boot CPU to determine which of the CPUs is the real BSP. Sending an INIT to the real BSP would reset the machine so the only sane way to deal with that is to limit the number of CPUs to one and emit a corresponding warning message. Fixes: 5c5682b9f87a ("x86/cpu: Detect real BSP on crash kernels") Reported-by: Carsten Tolkmit Signed-off-by: Thomas Gleixner Tested-by: Carsten Tolkmit Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/87le48jycb.ffs@tglx Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218837 --- arch/x86/kernel/cpu/topology.c | 53 +++++++++++++++++++++++++++++++++++++++--- 1 file changed, 50 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/cpu/topology.c b/arch/x86/kernel/cpu/topology.c index d17c9b71eb4a..621a151ccf7d 100644 --- a/arch/x86/kernel/cpu/topology.c +++ b/arch/x86/kernel/cpu/topology.c @@ -128,6 +128,9 @@ static void topo_set_cpuids(unsigned int cpu, u32 apic_id, u32 acpi_id) static __init bool check_for_real_bsp(u32 apic_id) { + bool is_bsp = false, has_apic_base = boot_cpu_data.x86 >= 6; + u64 msr; + /* * There is no real good way to detect whether this a kdump() * kernel, but except on the Voyager SMP monstrosity which is not @@ -144,17 +147,61 @@ static __init bool check_for_real_bsp(u32 apic_id) if (topo_info.real_bsp_apic_id != BAD_APICID) return false; + /* + * Check whether the enumeration order is broken by evaluating the + * BSP bit in the APICBASE MSR. If the CPU does not have the + * APICBASE MSR then the BSP detection is not possible and the + * kernel must rely on the firmware enumeration order. + */ + if (has_apic_base) { + rdmsrl(MSR_IA32_APICBASE, msr); + is_bsp = !!(msr & MSR_IA32_APICBASE_BSP); + } + if (apic_id == topo_info.boot_cpu_apic_id) { - topo_info.real_bsp_apic_id = apic_id; - return false; + /* + * If the boot CPU has the APIC BSP bit set then the + * firmware enumeration is agreeing. If the CPU does not + * have the APICBASE MSR then the only choice is to trust + * the enumeration order. + */ + if (is_bsp || !has_apic_base) { + topo_info.real_bsp_apic_id = apic_id; + return false; + } + /* + * If the boot APIC is enumerated first, but the APICBASE + * MSR does not have the BSP bit set, then there is no way + * to discover the real BSP here. Assume a crash kernel and + * limit the number of CPUs to 1 as an INIT to the real BSP + * would reset the machine. + */ + pr_warn("Enumerated BSP APIC %x is not marked in APICBASE MSR\n", apic_id); + pr_warn("Assuming crash kernel. Limiting to one CPU to prevent machine INIT\n"); + set_nr_cpu_ids(1); + goto fwbug; } - pr_warn("Boot CPU APIC ID not the first enumerated APIC ID: %x > %x\n", + pr_warn("Boot CPU APIC ID not the first enumerated APIC ID: %x != %x\n", topo_info.boot_cpu_apic_id, apic_id); + + if (is_bsp) { + /* + * The boot CPU has the APIC BSP bit set. Use it and complain + * about the broken firmware enumeration. + */ + topo_info.real_bsp_apic_id = topo_info.boot_cpu_apic_id; + goto fwbug; + } + pr_warn("Crash kernel detected. Disabling real BSP to prevent machine INIT\n"); topo_info.real_bsp_apic_id = apic_id; return true; + +fwbug: + pr_warn(FW_BUG "APIC enumeration order not specification compliant\n"); + return false; } static unsigned int topo_unit_count(u32 lvlid, enum x86_topology_domains at_level, -- cgit v1.2.3-58-ga151 From 6d85a058cf4941b5b2713b879ef41430e6aa74f3 Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Mon, 20 May 2024 15:45:32 -0700 Subject: crypto: x86/aes-xts - switch to new Intel CPU model defines New CPU #defines encode vendor and family as well as model. Signed-off-by: Tony Luck Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Eric Biggers Acked-by: Herbert Xu Link: https://lore.kernel.org/r/20240520224620.9480-2-tony.luck@intel.com --- arch/x86/crypto/aesni-intel_glue.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c index 5b25d2a58aeb..ef031655b2d3 100644 --- a/arch/x86/crypto/aesni-intel_glue.c +++ b/arch/x86/crypto/aesni-intel_glue.c @@ -1223,14 +1223,14 @@ DEFINE_XTS_ALG(vaes_avx10_512, "xts-aes-vaes-avx10_512", 800); * implementation with ymm registers (256-bit vectors) will be used instead. */ static const struct x86_cpu_id zmm_exclusion_list[] = { - { .vendor = X86_VENDOR_INTEL, .family = 6, .model = INTEL_FAM6_SKYLAKE_X }, - { .vendor = X86_VENDOR_INTEL, .family = 6, .model = INTEL_FAM6_ICELAKE_X }, - { .vendor = X86_VENDOR_INTEL, .family = 6, .model = INTEL_FAM6_ICELAKE_D }, - { .vendor = X86_VENDOR_INTEL, .family = 6, .model = INTEL_FAM6_ICELAKE }, - { .vendor = X86_VENDOR_INTEL, .family = 6, .model = INTEL_FAM6_ICELAKE_L }, - { .vendor = X86_VENDOR_INTEL, .family = 6, .model = INTEL_FAM6_ICELAKE_NNPI }, - { .vendor = X86_VENDOR_INTEL, .family = 6, .model = INTEL_FAM6_TIGERLAKE_L }, - { .vendor = X86_VENDOR_INTEL, .family = 6, .model = INTEL_FAM6_TIGERLAKE }, + X86_MATCH_VFM(INTEL_SKYLAKE_X, 0), + X86_MATCH_VFM(INTEL_ICELAKE_X, 0), + X86_MATCH_VFM(INTEL_ICELAKE_D, 0), + X86_MATCH_VFM(INTEL_ICELAKE, 0), + X86_MATCH_VFM(INTEL_ICELAKE_L, 0), + X86_MATCH_VFM(INTEL_ICELAKE_NNPI, 0), + X86_MATCH_VFM(INTEL_TIGERLAKE_L, 0), + X86_MATCH_VFM(INTEL_TIGERLAKE, 0), /* Allow Rocket Lake and later, and Sapphire Rapids and later. */ /* Also allow AMD CPUs (starting with Zen 4, the first with AVX-512). */ {}, -- cgit v1.2.3-58-ga151 From 93022482b2948a9a7e9b5a2bb685f2e1cb4c3348 Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Mon, 20 May 2024 15:45:33 -0700 Subject: x86/cpu: Fix x86_match_cpu() to match just X86_VENDOR_INTEL Code in v6.9 arch/x86/kernel/smpboot.c was changed by commit 4db64279bc2b ("x86/cpu: Switch to new Intel CPU model defines") from: static const struct x86_cpu_id intel_cod_cpu[] = { X86_MATCH_INTEL_FAM6_MODEL(HASWELL_X, 0), /* COD */ X86_MATCH_INTEL_FAM6_MODEL(BROADWELL_X, 0), /* COD */ X86_MATCH_INTEL_FAM6_MODEL(ANY, 1), /* SNC */ <--- 443 {} }; static bool match_llc(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o) { const struct x86_cpu_id *id = x86_match_cpu(intel_cod_cpu); to: static const struct x86_cpu_id intel_cod_cpu[] = { X86_MATCH_VFM(INTEL_HASWELL_X, 0), /* COD */ X86_MATCH_VFM(INTEL_BROADWELL_X, 0), /* COD */ X86_MATCH_VFM(INTEL_ANY, 1), /* SNC */ {} }; static bool match_llc(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o) { const struct x86_cpu_id *id = x86_match_cpu(intel_cod_cpu); On an Intel CPU with SNC enabled this code previously matched the rule on line 443 to avoid printing messages about insane cache configuration. The new code did not match any rules. Expanding the macros for the intel_cod_cpu[] array shows that the old is equivalent to: static const struct x86_cpu_id intel_cod_cpu[] = { [0] = { .vendor = 0, .family = 6, .model = 0x3F, .steppings = 0, .feature = 0, .driver_data = 0 }, [1] = { .vendor = 0, .family = 6, .model = 0x4F, .steppings = 0, .feature = 0, .driver_data = 0 }, [2] = { .vendor = 0, .family = 6, .model = 0x00, .steppings = 0, .feature = 0, .driver_data = 1 }, [3] = { .vendor = 0, .family = 0, .model = 0x00, .steppings = 0, .feature = 0, .driver_data = 0 } } while the new code expands to: static const struct x86_cpu_id intel_cod_cpu[] = { [0] = { .vendor = 0, .family = 6, .model = 0x3F, .steppings = 0, .feature = 0, .driver_data = 0 }, [1] = { .vendor = 0, .family = 6, .model = 0x4F, .steppings = 0, .feature = 0, .driver_data = 0 }, [2] = { .vendor = 0, .family = 0, .model = 0x00, .steppings = 0, .feature = 0, .driver_data = 1 }, [3] = { .vendor = 0, .family = 0, .model = 0x00, .steppings = 0, .feature = 0, .driver_data = 0 } } Looking at the code for x86_match_cpu(): const struct x86_cpu_id *x86_match_cpu(const struct x86_cpu_id *match) { const struct x86_cpu_id *m; struct cpuinfo_x86 *c = &boot_cpu_data; for (m = match; m->vendor | m->family | m->model | m->steppings | m->feature; m++) { ... } return NULL; it is clear that there was no match because the ANY entry in the table (array index 2) is now the loop termination condition (all of vendor, family, model, steppings, and feature are zero). So this code was working before because the "ANY" check was looking for any Intel CPU in family 6. But fails now because the family is a wild card. So the root cause is that x86_match_cpu() has never been able to match on a rule with just X86_VENDOR_INTEL and all other fields set to wildcards. Add a new flags field to struct x86_cpu_id that has a bit set to indicate that this entry in the array is valid. Update X86_MATCH*() macros to set that bit. Change the end-marker check in x86_match_cpu() to just check the flags field for this bit. Backporter notes: The commit in Fixes is really the one that is broken: you can't have m->vendor as part of the loop termination conditional in x86_match_cpu() because it can happen - as it has happened above - that that whole conditional is 0 albeit vendor == 0 is a valid case - X86_VENDOR_INTEL is 0. However, the only case where the above happens is the SNC check added by 4db64279bc2b1 so you only need this fix if you have backported that other commit 4db64279bc2b ("x86/cpu: Switch to new Intel CPU model defines") Fixes: 644e9cbbe3fc ("Add driver auto probing for x86 features v4") Suggested-by: Thomas Gleixner Suggested-by: Borislav Petkov Signed-off-by: Tony Luck Signed-off-by: Borislav Petkov (AMD) Cc: # see above Link: https://lore.kernel.org/r/20240517144312.GBZkdtAOuJZCvxhFbJ@fat_crate.local --- arch/x86/include/asm/cpu_device_id.h | 5 +++++ arch/x86/kernel/cpu/match.c | 4 +--- include/linux/mod_devicetable.h | 2 ++ 3 files changed, 8 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/cpu_device_id.h b/arch/x86/include/asm/cpu_device_id.h index 970a232009c3..b6325ee30871 100644 --- a/arch/x86/include/asm/cpu_device_id.h +++ b/arch/x86/include/asm/cpu_device_id.h @@ -53,6 +53,9 @@ #define X86_CENTAUR_FAM6_C7_D 0xd #define X86_CENTAUR_FAM6_NANO 0xf +/* x86_cpu_id::flags */ +#define X86_CPU_ID_FLAG_ENTRY_VALID BIT(0) + #define X86_STEPPINGS(mins, maxs) GENMASK(maxs, mins) /** * X86_MATCH_VENDOR_FAM_MODEL_STEPPINGS_FEATURE - Base macro for CPU matching @@ -79,6 +82,7 @@ .model = _model, \ .steppings = _steppings, \ .feature = _feature, \ + .flags = X86_CPU_ID_FLAG_ENTRY_VALID, \ .driver_data = (unsigned long) _data \ } @@ -89,6 +93,7 @@ .model = _model, \ .steppings = _steppings, \ .feature = _feature, \ + .flags = X86_CPU_ID_FLAG_ENTRY_VALID, \ .driver_data = (unsigned long) _data \ } diff --git a/arch/x86/kernel/cpu/match.c b/arch/x86/kernel/cpu/match.c index 8651643bddae..8e7de733320a 100644 --- a/arch/x86/kernel/cpu/match.c +++ b/arch/x86/kernel/cpu/match.c @@ -38,9 +38,7 @@ const struct x86_cpu_id *x86_match_cpu(const struct x86_cpu_id *match) const struct x86_cpu_id *m; struct cpuinfo_x86 *c = &boot_cpu_data; - for (m = match; - m->vendor | m->family | m->model | m->steppings | m->feature; - m++) { + for (m = match; m->flags & X86_CPU_ID_FLAG_ENTRY_VALID; m++) { if (m->vendor != X86_VENDOR_ANY && c->x86_vendor != m->vendor) continue; if (m->family != X86_FAMILY_ANY && c->x86 != m->family) diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h index 7a9a07ea451b..4338b1b4ac44 100644 --- a/include/linux/mod_devicetable.h +++ b/include/linux/mod_devicetable.h @@ -690,6 +690,8 @@ struct x86_cpu_id { __u16 model; __u16 steppings; __u16 feature; /* bit index */ + /* Solely for kernel-internal use: DO NOT EXPORT to userspace! */ + __u16 flags; kernel_ulong_t driver_data; }; -- cgit v1.2.3-58-ga151