diff options
Diffstat (limited to 'debian/patches/bugfix/x86')
5 files changed, 0 insertions, 707 deletions
diff --git a/debian/patches/bugfix/x86/Documentation-hw-vuln-Add-documentation-for-RFDS.patch b/debian/patches/bugfix/x86/Documentation-hw-vuln-Add-documentation-for-RFDS.patch deleted file mode 100644 index 781be97097..0000000000 --- a/debian/patches/bugfix/x86/Documentation-hw-vuln-Add-documentation-for-RFDS.patch +++ /dev/null @@ -1,140 +0,0 @@ -From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> -Date: Mon, 11 Mar 2024 12:29:43 -0700 -Subject: Documentation/hw-vuln: Add documentation for RFDS -Origin: https://git.kernel.org/linus/4e42765d1be01111df0c0275bbaf1db1acef346e - -Add the documentation for transient execution vulnerability Register -File Data Sampling (RFDS) that affects Intel Atom CPUs. - -Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> -Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> -Reviewed-by: Thomas Gleixner <tglx@linutronix.de> -Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> ---- - Documentation/admin-guide/hw-vuln/index.rst | 1 + - .../hw-vuln/reg-file-data-sampling.rst | 104 ++++++++++++++++++ - 2 files changed, 105 insertions(+) - create mode 100644 Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst - -diff --git a/Documentation/admin-guide/hw-vuln/index.rst b/Documentation/admin-guide/hw-vuln/index.rst -index de99caabf65a..ff0b440ef2dc 100644 ---- a/Documentation/admin-guide/hw-vuln/index.rst -+++ b/Documentation/admin-guide/hw-vuln/index.rst -@@ -21,3 +21,4 @@ are configurable at compile, boot or run time. - cross-thread-rsb - srso - gather_data_sampling -+ reg-file-data-sampling -diff --git a/Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst b/Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst -new file mode 100644 -index 000000000000..0585d02b9a6c ---- /dev/null -+++ b/Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst -@@ -0,0 +1,104 @@ -+================================== -+Register File Data Sampling (RFDS) -+================================== -+ -+Register File Data Sampling (RFDS) is a microarchitectural vulnerability that -+only affects Intel Atom parts(also branded as E-cores). RFDS may allow -+a malicious actor to infer data values previously used in floating point -+registers, vector registers, or integer registers. RFDS does not provide the -+ability to choose which data is inferred. CVE-2023-28746 is assigned to RFDS. -+ -+Affected Processors -+=================== -+Below is the list of affected Intel processors [#f1]_: -+ -+ =================== ============ -+ Common name Family_Model -+ =================== ============ -+ ATOM_GOLDMONT 06_5CH -+ ATOM_GOLDMONT_D 06_5FH -+ ATOM_GOLDMONT_PLUS 06_7AH -+ ATOM_TREMONT_D 06_86H -+ ATOM_TREMONT 06_96H -+ ALDERLAKE 06_97H -+ ALDERLAKE_L 06_9AH -+ ATOM_TREMONT_L 06_9CH -+ RAPTORLAKE 06_B7H -+ RAPTORLAKE_P 06_BAH -+ ATOM_GRACEMONT 06_BEH -+ RAPTORLAKE_S 06_BFH -+ =================== ============ -+ -+As an exception to this table, Intel Xeon E family parts ALDERLAKE(06_97H) and -+RAPTORLAKE(06_B7H) codenamed Catlow are not affected. They are reported as -+vulnerable in Linux because they share the same family/model with an affected -+part. Unlike their affected counterparts, they do not enumerate RFDS_CLEAR or -+CPUID.HYBRID. This information could be used to distinguish between the -+affected and unaffected parts, but it is deemed not worth adding complexity as -+the reporting is fixed automatically when these parts enumerate RFDS_NO. -+ -+Mitigation -+========== -+Intel released a microcode update that enables software to clear sensitive -+information using the VERW instruction. Like MDS, RFDS deploys the same -+mitigation strategy to force the CPU to clear the affected buffers before an -+attacker can extract the secrets. This is achieved by using the otherwise -+unused and obsolete VERW instruction in combination with a microcode update. -+The microcode clears the affected CPU buffers when the VERW instruction is -+executed. -+ -+Mitigation points -+----------------- -+VERW is executed by the kernel before returning to user space, and by KVM -+before VMentry. None of the affected cores support SMT, so VERW is not required -+at C-state transitions. -+ -+New bits in IA32_ARCH_CAPABILITIES -+---------------------------------- -+Newer processors and microcode update on existing affected processors added new -+bits to IA32_ARCH_CAPABILITIES MSR. These bits can be used to enumerate -+vulnerability and mitigation capability: -+ -+- Bit 27 - RFDS_NO - When set, processor is not affected by RFDS. -+- Bit 28 - RFDS_CLEAR - When set, processor is affected by RFDS, and has the -+ microcode that clears the affected buffers on VERW execution. -+ -+Mitigation control on the kernel command line -+--------------------------------------------- -+The kernel command line allows to control RFDS mitigation at boot time with the -+parameter "reg_file_data_sampling=". The valid arguments are: -+ -+ ========== ================================================================= -+ on If the CPU is vulnerable, enable mitigation; CPU buffer clearing -+ on exit to userspace and before entering a VM. -+ off Disables mitigation. -+ ========== ================================================================= -+ -+Mitigation default is selected by CONFIG_MITIGATION_RFDS. -+ -+Mitigation status information -+----------------------------- -+The Linux kernel provides a sysfs interface to enumerate the current -+vulnerability status of the system: whether the system is vulnerable, and -+which mitigations are active. The relevant sysfs file is: -+ -+ /sys/devices/system/cpu/vulnerabilities/reg_file_data_sampling -+ -+The possible values in this file are: -+ -+ .. list-table:: -+ -+ * - 'Not affected' -+ - The processor is not vulnerable -+ * - 'Vulnerable' -+ - The processor is vulnerable, but no mitigation enabled -+ * - 'Vulnerable: No microcode' -+ - The processor is vulnerable but microcode is not updated. -+ * - 'Mitigation: Clear Register File' -+ - The processor is vulnerable and the CPU buffer clearing mitigation is -+ enabled. -+ -+References -+---------- -+.. [#f1] Affected Processors -+ https://www.intel.com/content/www/us/en/developer/topic-technology/software-security-guidance/processors-affected-consolidated-product-cpu-model.html --- -2.43.0 - diff --git a/debian/patches/bugfix/x86/KVM-x86-Export-RFDS_NO-and-RFDS_CLEAR-to-guests.patch b/debian/patches/bugfix/x86/KVM-x86-Export-RFDS_NO-and-RFDS_CLEAR-to-guests.patch deleted file mode 100644 index 13a5c96a49..0000000000 --- a/debian/patches/bugfix/x86/KVM-x86-Export-RFDS_NO-and-RFDS_CLEAR-to-guests.patch +++ /dev/null @@ -1,48 +0,0 @@ -From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> -Date: Mon, 11 Mar 2024 12:29:43 -0700 -Subject: KVM/x86: Export RFDS_NO and RFDS_CLEAR to guests -Origin: https://git.kernel.org/linus/2a0180129d726a4b953232175857d442651b55a0 - -Mitigation for RFDS requires RFDS_CLEAR capability which is enumerated -by MSR_IA32_ARCH_CAPABILITIES bit 27. If the host has it set, export it -to guests so that they can deploy the mitigation. - -RFDS_NO indicates that the system is not vulnerable to RFDS, export it -to guests so that they don't deploy the mitigation unnecessarily. When -the host is not affected by X86_BUG_RFDS, but has RFDS_NO=0, synthesize -RFDS_NO to the guest. - -Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> -Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> -Reviewed-by: Thomas Gleixner <tglx@linutronix.de> -Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> ---- - arch/x86/kvm/x86.c | 5 ++++- - 1 file changed, 4 insertions(+), 1 deletion(-) - -diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c -index 48a61d283406..68fdf3ba031a 100644 ---- a/arch/x86/kvm/x86.c -+++ b/arch/x86/kvm/x86.c -@@ -1623,7 +1623,8 @@ static bool kvm_is_immutable_feature_msr(u32 msr) - 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_GDS_NO) -+ ARCH_CAP_FB_CLEAR | ARCH_CAP_RRSBA | ARCH_CAP_PBRSB_NO | ARCH_CAP_GDS_NO | \ -+ ARCH_CAP_RFDS_NO | ARCH_CAP_RFDS_CLEAR) - - static u64 kvm_get_arch_capabilities(void) - { -@@ -1655,6 +1656,8 @@ static u64 kvm_get_arch_capabilities(void) - data |= ARCH_CAP_SSB_NO; - if (!boot_cpu_has_bug(X86_BUG_MDS)) - data |= ARCH_CAP_MDS_NO; -+ if (!boot_cpu_has_bug(X86_BUG_RFDS)) -+ data |= ARCH_CAP_RFDS_NO; - - if (!boot_cpu_has(X86_FEATURE_RTM)) { - /* --- -2.43.0 - diff --git a/debian/patches/bugfix/x86/platform-x86-p2sb-On-Goldmont-only-cache-P2SB-and-SP.patch b/debian/patches/bugfix/x86/platform-x86-p2sb-On-Goldmont-only-cache-P2SB-and-SP.patch deleted file mode 100644 index 50e5f8dc5d..0000000000 --- a/debian/patches/bugfix/x86/platform-x86-p2sb-On-Goldmont-only-cache-P2SB-and-SP.patch +++ /dev/null @@ -1,77 +0,0 @@ -From: Hans de Goede <hdegoede@redhat.com> -Date: Mon, 4 Mar 2024 14:43:55 +0100 -Subject: platform/x86: p2sb: On Goldmont only cache P2SB and SPI devfn BAR -Origin: https://git.kernel.org/linus/aec7d25b497ce4a8d044e9496de0aa433f7f8f06 -Bug-Debian: https://bugs.debian.org/1065320 - -On Goldmont p2sb_bar() only ever gets called for 2 devices, the actual P2SB -devfn 13,0 and the SPI controller which is part of the P2SB, devfn 13,2. - -But the current p2sb code tries to cache BAR0 info for all of -devfn 13,0 to 13,7 . This involves calling pci_scan_single_device() -for device 13 functions 0-7 and the hw does not seem to like -pci_scan_single_device() getting called for some of the other hidden -devices. E.g. on an ASUS VivoBook D540NV-GQ065T this leads to continuous -ACPI errors leading to high CPU usage. - -Fix this by only caching BAR0 info and thus only calling -pci_scan_single_device() for the P2SB and the SPI controller. - -Fixes: 5913320eb0b3 ("platform/x86: p2sb: Allow p2sb_bar() calls during PCI device probe") -Reported-by: Danil Rybakov <danilrybakov249@gmail.com> -Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218531 -Tested-by: Danil Rybakov <danilrybakov249@gmail.com> -Signed-off-by: Hans de Goede <hdegoede@redhat.com> -Link: https://lore.kernel.org/r/20240304134356.305375-2-hdegoede@redhat.com ---- - drivers/platform/x86/p2sb.c | 25 +++++++++---------------- - 1 file changed, 9 insertions(+), 16 deletions(-) - -diff --git a/drivers/platform/x86/p2sb.c b/drivers/platform/x86/p2sb.c -index 6bd14d0132db..3d66e1d4eb1f 100644 ---- a/drivers/platform/x86/p2sb.c -+++ b/drivers/platform/x86/p2sb.c -@@ -20,9 +20,11 @@ - #define P2SBC_HIDE BIT(8) - - #define P2SB_DEVFN_DEFAULT PCI_DEVFN(31, 1) -+#define P2SB_DEVFN_GOLDMONT PCI_DEVFN(13, 0) -+#define SPI_DEVFN_GOLDMONT PCI_DEVFN(13, 2) - - static const struct x86_cpu_id p2sb_cpu_ids[] = { -- X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT, PCI_DEVFN(13, 0)), -+ X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT, P2SB_DEVFN_GOLDMONT), - {} - }; - -@@ -98,21 +100,12 @@ static void p2sb_scan_and_cache_devfn(struct pci_bus *bus, unsigned int devfn) - - static int p2sb_scan_and_cache(struct pci_bus *bus, unsigned int devfn) - { -- unsigned int slot, fn; -- -- if (PCI_FUNC(devfn) == 0) { -- /* -- * When function number of the P2SB device is zero, scan it and -- * other function numbers, and if devices are available, cache -- * their BAR0s. -- */ -- slot = PCI_SLOT(devfn); -- for (fn = 0; fn < NR_P2SB_RES_CACHE; fn++) -- p2sb_scan_and_cache_devfn(bus, PCI_DEVFN(slot, fn)); -- } else { -- /* Scan the P2SB device and cache its BAR0 */ -- p2sb_scan_and_cache_devfn(bus, devfn); -- } -+ /* Scan the P2SB device and cache its BAR0 */ -+ p2sb_scan_and_cache_devfn(bus, devfn); -+ -+ /* On Goldmont p2sb_bar() also gets called for the SPI controller */ -+ if (devfn == P2SB_DEVFN_GOLDMONT) -+ p2sb_scan_and_cache_devfn(bus, SPI_DEVFN_GOLDMONT); - - if (!p2sb_valid_resource(&p2sb_resources[PCI_FUNC(devfn)].res)) - return -ENOENT; --- -2.43.0 - diff --git a/debian/patches/bugfix/x86/x86-mmio-Disable-KVM-mitigation-when-X86_FEATURE_CLE.patch b/debian/patches/bugfix/x86/x86-mmio-Disable-KVM-mitigation-when-X86_FEATURE_CLE.patch deleted file mode 100644 index 313064d2bc..0000000000 --- a/debian/patches/bugfix/x86/x86-mmio-Disable-KVM-mitigation-when-X86_FEATURE_CLE.patch +++ /dev/null @@ -1,58 +0,0 @@ -From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> -Date: Mon, 11 Mar 2024 12:29:43 -0700 -Subject: x86/mmio: Disable KVM mitigation when X86_FEATURE_CLEAR_CPU_BUF is - set -Origin: https://git.kernel.org/linus/e95df4ec0c0c9791941f112db699fae794b9862a - -Currently MMIO Stale Data mitigation for CPUs not affected by MDS/TAA is -to only deploy VERW at VMentry by enabling mmio_stale_data_clear static -branch. No mitigation is needed for kernel->user transitions. If such -CPUs are also affected by RFDS, its mitigation may set -X86_FEATURE_CLEAR_CPU_BUF to deploy VERW at kernel->user and VMentry. -This could result in duplicate VERW at VMentry. - -Fix this by disabling mmio_stale_data_clear static branch when -X86_FEATURE_CLEAR_CPU_BUF is enabled. - -Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> -Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> -Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com> ---- - arch/x86/kernel/cpu/bugs.c | 14 ++++++++++++-- - 1 file changed, 12 insertions(+), 2 deletions(-) - -diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c -index 48d049cd74e7..cd6ac89c1a0d 100644 ---- a/arch/x86/kernel/cpu/bugs.c -+++ b/arch/x86/kernel/cpu/bugs.c -@@ -422,6 +422,13 @@ static void __init mmio_select_mitigation(void) - if (boot_cpu_has_bug(X86_BUG_MDS) || (boot_cpu_has_bug(X86_BUG_TAA) && - boot_cpu_has(X86_FEATURE_RTM))) - setup_force_cpu_cap(X86_FEATURE_CLEAR_CPU_BUF); -+ -+ /* -+ * X86_FEATURE_CLEAR_CPU_BUF could be enabled by other VERW based -+ * mitigations, disable KVM-only mitigation in that case. -+ */ -+ if (boot_cpu_has(X86_FEATURE_CLEAR_CPU_BUF)) -+ static_branch_disable(&mmio_stale_data_clear); - else - static_branch_enable(&mmio_stale_data_clear); - -@@ -498,8 +505,11 @@ static void __init md_clear_update_mitigation(void) - taa_mitigation = TAA_MITIGATION_VERW; - taa_select_mitigation(); - } -- if (mmio_mitigation == MMIO_MITIGATION_OFF && -- boot_cpu_has_bug(X86_BUG_MMIO_STALE_DATA)) { -+ /* -+ * MMIO_MITIGATION_OFF is not checked here so that mmio_stale_data_clear -+ * gets updated correctly as per X86_FEATURE_CLEAR_CPU_BUF state. -+ */ -+ if (boot_cpu_has_bug(X86_BUG_MMIO_STALE_DATA)) { - mmio_mitigation = MMIO_MITIGATION_VERW; - mmio_select_mitigation(); - } --- -2.43.0 - diff --git a/debian/patches/bugfix/x86/x86-rfds-Mitigate-Register-File-Data-Sampling-RFDS.patch b/debian/patches/bugfix/x86/x86-rfds-Mitigate-Register-File-Data-Sampling-RFDS.patch deleted file mode 100644 index 21603126c5..0000000000 --- a/debian/patches/bugfix/x86/x86-rfds-Mitigate-Register-File-Data-Sampling-RFDS.patch +++ /dev/null @@ -1,384 +0,0 @@ -From: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> -Date: Mon, 11 Mar 2024 12:29:43 -0700 -Subject: x86/rfds: Mitigate Register File Data Sampling (RFDS) -Origin: https://git.kernel.org/linus/8076fcde016c9c0e0660543e67bff86cb48a7c9c - -RFDS is a CPU vulnerability that may allow userspace to infer kernel -stale data previously used in floating point registers, vector registers -and integer registers. RFDS only affects certain Intel Atom processors. - -Intel released a microcode update that uses VERW instruction to clear -the affected CPU buffers. Unlike MDS, none of the affected cores support -SMT. - -Add RFDS bug infrastructure and enable the VERW based mitigation by -default, that clears the affected buffers just before exiting to -userspace. Also add sysfs reporting and cmdline parameter -"reg_file_data_sampling" to control the mitigation. - -For details see: -Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst - -Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> -Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> -Reviewed-by: Thomas Gleixner <tglx@linutronix.de> -Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> ---- - .../ABI/testing/sysfs-devices-system-cpu | 1 + - .../admin-guide/kernel-parameters.txt | 21 +++++ - arch/x86/Kconfig | 11 +++ - arch/x86/include/asm/cpufeatures.h | 1 + - arch/x86/include/asm/msr-index.h | 8 ++ - arch/x86/kernel/cpu/bugs.c | 78 ++++++++++++++++++- - arch/x86/kernel/cpu/common.c | 38 ++++++++- - drivers/base/cpu.c | 3 + - include/linux/cpu.h | 2 + - 9 files changed, 157 insertions(+), 6 deletions(-) - -diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu -index a1db6db47505..710d47be11e0 100644 ---- a/Documentation/ABI/testing/sysfs-devices-system-cpu -+++ b/Documentation/ABI/testing/sysfs-devices-system-cpu -@@ -516,6 +516,7 @@ What: /sys/devices/system/cpu/vulnerabilities - /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/reg_file_data_sampling - /sys/devices/system/cpu/vulnerabilities/retbleed - /sys/devices/system/cpu/vulnerabilities/spec_store_bypass - /sys/devices/system/cpu/vulnerabilities/spectre_v1 -diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt -index 31b3a25680d0..73062d47a462 100644 ---- a/Documentation/admin-guide/kernel-parameters.txt -+++ b/Documentation/admin-guide/kernel-parameters.txt -@@ -1150,6 +1150,26 @@ - The filter can be disabled or changed to another - driver later using sysfs. - -+ reg_file_data_sampling= -+ [X86] Controls mitigation for Register File Data -+ Sampling (RFDS) vulnerability. RFDS is a CPU -+ vulnerability which may allow userspace to infer -+ kernel data values previously stored in floating point -+ registers, vector registers, or integer registers. -+ RFDS only affects Intel Atom processors. -+ -+ on: Turns ON the mitigation. -+ off: Turns OFF the mitigation. -+ -+ This parameter overrides the compile time default set -+ by CONFIG_MITIGATION_RFDS. Mitigation cannot be -+ disabled when other VERW based mitigations (like MDS) -+ are enabled. In order to disable RFDS mitigation all -+ VERW based mitigations need to be disabled. -+ -+ For details see: -+ Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst -+ - driver_async_probe= [KNL] - List of driver names to be probed asynchronously. * - matches with all driver names. If * is specified, the -@@ -3398,6 +3418,7 @@ - nospectre_bhb [ARM64] - nospectre_v1 [X86,PPC] - nospectre_v2 [X86,PPC,S390,ARM64] -+ reg_file_data_sampling=off [X86] - retbleed=off [X86] - spec_store_bypass_disable=off [X86,PPC] - spectre_v2_user=off [X86] -diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig -index 5edec175b9bf..637e337c332e 100644 ---- a/arch/x86/Kconfig -+++ b/arch/x86/Kconfig -@@ -2614,6 +2614,17 @@ config GDS_FORCE_MITIGATION - - If in doubt, say N. - -+config MITIGATION_RFDS -+ bool "RFDS Mitigation" -+ depends on CPU_SUP_INTEL -+ default y -+ help -+ Enable mitigation for Register File Data Sampling (RFDS) by default. -+ RFDS is a hardware vulnerability which affects Intel Atom CPUs. It -+ allows unprivileged speculative access to stale data previously -+ stored in floating point, vector and integer registers. -+ See also <file:Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst> -+ - endif - - config ARCH_HAS_ADD_PAGES -diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h -index 2b62cdd8dd12..8511aad59581 100644 ---- a/arch/x86/include/asm/cpufeatures.h -+++ b/arch/x86/include/asm/cpufeatures.h -@@ -503,4 +503,5 @@ - /* BUG word 2 */ - #define X86_BUG_SRSO X86_BUG(1*32 + 0) /* AMD SRSO bug */ - #define X86_BUG_DIV0 X86_BUG(1*32 + 1) /* AMD DIV0 speculation bug */ -+#define X86_BUG_RFDS X86_BUG(1*32 + 2) /* CPU is vulnerable to Register File Data Sampling */ - #endif /* _ASM_X86_CPUFEATURES_H */ -diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h -index f1bd7b91b3c6..d1b5edaf6c34 100644 ---- a/arch/x86/include/asm/msr-index.h -+++ b/arch/x86/include/asm/msr-index.h -@@ -165,6 +165,14 @@ - * CPU is not vulnerable to Gather - * Data Sampling (GDS). - */ -+#define ARCH_CAP_RFDS_NO BIT(27) /* -+ * Not susceptible to Register -+ * File Data Sampling. -+ */ -+#define ARCH_CAP_RFDS_CLEAR BIT(28) /* -+ * VERW clears CPU Register -+ * File. -+ */ - - #define ARCH_CAP_XAPIC_DISABLE BIT(21) /* - * IA32_XAPIC_DISABLE_STATUS MSR -diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c -index cd6ac89c1a0d..01ac18f56147 100644 ---- a/arch/x86/kernel/cpu/bugs.c -+++ b/arch/x86/kernel/cpu/bugs.c -@@ -480,6 +480,57 @@ static int __init mmio_stale_data_parse_cmdline(char *str) - } - early_param("mmio_stale_data", mmio_stale_data_parse_cmdline); - -+#undef pr_fmt -+#define pr_fmt(fmt) "Register File Data Sampling: " fmt -+ -+enum rfds_mitigations { -+ RFDS_MITIGATION_OFF, -+ RFDS_MITIGATION_VERW, -+ RFDS_MITIGATION_UCODE_NEEDED, -+}; -+ -+/* Default mitigation for Register File Data Sampling */ -+static enum rfds_mitigations rfds_mitigation __ro_after_init = -+ IS_ENABLED(CONFIG_MITIGATION_RFDS) ? RFDS_MITIGATION_VERW : RFDS_MITIGATION_OFF; -+ -+static const char * const rfds_strings[] = { -+ [RFDS_MITIGATION_OFF] = "Vulnerable", -+ [RFDS_MITIGATION_VERW] = "Mitigation: Clear Register File", -+ [RFDS_MITIGATION_UCODE_NEEDED] = "Vulnerable: No microcode", -+}; -+ -+static void __init rfds_select_mitigation(void) -+{ -+ if (!boot_cpu_has_bug(X86_BUG_RFDS) || cpu_mitigations_off()) { -+ rfds_mitigation = RFDS_MITIGATION_OFF; -+ return; -+ } -+ if (rfds_mitigation == RFDS_MITIGATION_OFF) -+ return; -+ -+ if (x86_read_arch_cap_msr() & ARCH_CAP_RFDS_CLEAR) -+ setup_force_cpu_cap(X86_FEATURE_CLEAR_CPU_BUF); -+ else -+ rfds_mitigation = RFDS_MITIGATION_UCODE_NEEDED; -+} -+ -+static __init int rfds_parse_cmdline(char *str) -+{ -+ if (!str) -+ return -EINVAL; -+ -+ if (!boot_cpu_has_bug(X86_BUG_RFDS)) -+ return 0; -+ -+ if (!strcmp(str, "off")) -+ rfds_mitigation = RFDS_MITIGATION_OFF; -+ else if (!strcmp(str, "on")) -+ rfds_mitigation = RFDS_MITIGATION_VERW; -+ -+ return 0; -+} -+early_param("reg_file_data_sampling", rfds_parse_cmdline); -+ - #undef pr_fmt - #define pr_fmt(fmt) "" fmt - -@@ -513,6 +564,11 @@ static void __init md_clear_update_mitigation(void) - mmio_mitigation = MMIO_MITIGATION_VERW; - mmio_select_mitigation(); - } -+ if (rfds_mitigation == RFDS_MITIGATION_OFF && -+ boot_cpu_has_bug(X86_BUG_RFDS)) { -+ rfds_mitigation = RFDS_MITIGATION_VERW; -+ rfds_select_mitigation(); -+ } - out: - if (boot_cpu_has_bug(X86_BUG_MDS)) - pr_info("MDS: %s\n", mds_strings[mds_mitigation]); -@@ -522,6 +578,8 @@ static void __init md_clear_update_mitigation(void) - pr_info("MMIO Stale Data: %s\n", mmio_strings[mmio_mitigation]); - else if (boot_cpu_has_bug(X86_BUG_MMIO_UNKNOWN)) - pr_info("MMIO Stale Data: Unknown: No mitigations\n"); -+ if (boot_cpu_has_bug(X86_BUG_RFDS)) -+ pr_info("Register File Data Sampling: %s\n", rfds_strings[rfds_mitigation]); - } - - static void __init md_clear_select_mitigation(void) -@@ -529,11 +587,12 @@ static void __init md_clear_select_mitigation(void) - mds_select_mitigation(); - taa_select_mitigation(); - mmio_select_mitigation(); -+ rfds_select_mitigation(); - - /* -- * As MDS, TAA and MMIO Stale Data mitigations are inter-related, update -- * and print their mitigation after MDS, TAA and MMIO Stale Data -- * mitigation selection is done. -+ * As these mitigations are inter-related and rely on VERW instruction -+ * to clear the microarchitural buffers, update and print their status -+ * after mitigation selection is done for each of these vulnerabilities. - */ - md_clear_update_mitigation(); - } -@@ -2622,6 +2681,11 @@ static ssize_t mmio_stale_data_show_state(char *buf) - sched_smt_active() ? "vulnerable" : "disabled"); - } - -+static ssize_t rfds_show_state(char *buf) -+{ -+ return sysfs_emit(buf, "%s\n", rfds_strings[rfds_mitigation]); -+} -+ - static char *stibp_state(void) - { - if (spectre_v2_in_eibrs_mode(spectre_v2_enabled) && -@@ -2781,6 +2845,9 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr - case X86_BUG_GDS: - return gds_show_state(buf); - -+ case X86_BUG_RFDS: -+ return rfds_show_state(buf); -+ - default: - break; - } -@@ -2855,4 +2922,9 @@ ssize_t cpu_show_gds(struct device *dev, struct device_attribute *attr, char *bu - { - return cpu_show_common(dev, attr, buf, X86_BUG_GDS); - } -+ -+ssize_t cpu_show_reg_file_data_sampling(struct device *dev, struct device_attribute *attr, char *buf) -+{ -+ return cpu_show_common(dev, attr, buf, X86_BUG_RFDS); -+} - #endif -diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c -index fbc4e60d027c..40d8c110bb32 100644 ---- a/arch/x86/kernel/cpu/common.c -+++ b/arch/x86/kernel/cpu/common.c -@@ -1267,6 +1267,8 @@ static const __initconst struct x86_cpu_id cpu_vuln_whitelist[] = { - #define SRSO BIT(5) - /* CPU is affected by GDS */ - #define GDS BIT(6) -+/* CPU is affected by Register File Data Sampling */ -+#define RFDS BIT(7) - - static const struct x86_cpu_id cpu_vuln_blacklist[] __initconst = { - VULNBL_INTEL_STEPPINGS(IVYBRIDGE, X86_STEPPING_ANY, SRBDS), -@@ -1294,9 +1296,18 @@ static const struct x86_cpu_id cpu_vuln_blacklist[] __initconst = { - 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 | 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_INTEL_STEPPINGS(ALDERLAKE, X86_STEPPING_ANY, RFDS), -+ VULNBL_INTEL_STEPPINGS(ALDERLAKE_L, X86_STEPPING_ANY, RFDS), -+ VULNBL_INTEL_STEPPINGS(RAPTORLAKE, X86_STEPPING_ANY, RFDS), -+ VULNBL_INTEL_STEPPINGS(RAPTORLAKE_P, X86_STEPPING_ANY, RFDS), -+ VULNBL_INTEL_STEPPINGS(RAPTORLAKE_S, X86_STEPPING_ANY, RFDS), -+ VULNBL_INTEL_STEPPINGS(ATOM_GRACEMONT, X86_STEPPING_ANY, RFDS), -+ VULNBL_INTEL_STEPPINGS(ATOM_TREMONT, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RFDS), -+ VULNBL_INTEL_STEPPINGS(ATOM_TREMONT_D, X86_STEPPING_ANY, MMIO | RFDS), -+ VULNBL_INTEL_STEPPINGS(ATOM_TREMONT_L, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RFDS), -+ VULNBL_INTEL_STEPPINGS(ATOM_GOLDMONT, X86_STEPPING_ANY, RFDS), -+ VULNBL_INTEL_STEPPINGS(ATOM_GOLDMONT_D, X86_STEPPING_ANY, RFDS), -+ VULNBL_INTEL_STEPPINGS(ATOM_GOLDMONT_PLUS, X86_STEPPING_ANY, RFDS), - - VULNBL_AMD(0x15, RETBLEED), - VULNBL_AMD(0x16, RETBLEED), -@@ -1330,6 +1341,24 @@ static bool arch_cap_mmio_immune(u64 ia32_cap) - ia32_cap & ARCH_CAP_SBDR_SSDP_NO); - } - -+static bool __init vulnerable_to_rfds(u64 ia32_cap) -+{ -+ /* The "immunity" bit trumps everything else: */ -+ if (ia32_cap & ARCH_CAP_RFDS_NO) -+ return false; -+ -+ /* -+ * VMMs set ARCH_CAP_RFDS_CLEAR for processors not in the blacklist to -+ * indicate that mitigation is needed because guest is running on a -+ * vulnerable hardware or may migrate to such hardware: -+ */ -+ if (ia32_cap & ARCH_CAP_RFDS_CLEAR) -+ return true; -+ -+ /* Only consult the blacklist when there is no enumeration: */ -+ return cpu_matches(cpu_vuln_blacklist, RFDS); -+} -+ - static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c) - { - u64 ia32_cap = x86_read_arch_cap_msr(); -@@ -1441,6 +1470,9 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c) - boot_cpu_has(X86_FEATURE_AVX)) - setup_force_cpu_bug(X86_BUG_GDS); - -+ if (vulnerable_to_rfds(ia32_cap)) -+ setup_force_cpu_bug(X86_BUG_RFDS); -+ - if (cpu_matches(cpu_vuln_whitelist, NO_MELTDOWN)) - return; - -diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c -index 47de0f140ba6..0b33e81f9c9b 100644 ---- a/drivers/base/cpu.c -+++ b/drivers/base/cpu.c -@@ -588,6 +588,7 @@ CPU_SHOW_VULN_FALLBACK(mmio_stale_data); - CPU_SHOW_VULN_FALLBACK(retbleed); - CPU_SHOW_VULN_FALLBACK(spec_rstack_overflow); - CPU_SHOW_VULN_FALLBACK(gds); -+CPU_SHOW_VULN_FALLBACK(reg_file_data_sampling); - - static DEVICE_ATTR(meltdown, 0444, cpu_show_meltdown, NULL); - static DEVICE_ATTR(spectre_v1, 0444, cpu_show_spectre_v1, NULL); -@@ -602,6 +603,7 @@ 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(spec_rstack_overflow, 0444, cpu_show_spec_rstack_overflow, NULL); - static DEVICE_ATTR(gather_data_sampling, 0444, cpu_show_gds, NULL); -+static DEVICE_ATTR(reg_file_data_sampling, 0444, cpu_show_reg_file_data_sampling, NULL); - - static struct attribute *cpu_root_vulnerabilities_attrs[] = { - &dev_attr_meltdown.attr, -@@ -617,6 +619,7 @@ static struct attribute *cpu_root_vulnerabilities_attrs[] = { - &dev_attr_retbleed.attr, - &dev_attr_spec_rstack_overflow.attr, - &dev_attr_gather_data_sampling.attr, -+ &dev_attr_reg_file_data_sampling.attr, - NULL - }; - -diff --git a/include/linux/cpu.h b/include/linux/cpu.h -index dcb89c987164..8654714421a0 100644 ---- a/include/linux/cpu.h -+++ b/include/linux/cpu.h -@@ -75,6 +75,8 @@ extern ssize_t cpu_show_spec_rstack_overflow(struct device *dev, - struct device_attribute *attr, char *buf); - extern ssize_t cpu_show_gds(struct device *dev, - struct device_attribute *attr, char *buf); -+extern ssize_t cpu_show_reg_file_data_sampling(struct device *dev, -+ struct device_attribute *attr, char *buf); - - extern __printf(4, 5) - struct device *cpu_device_create(struct device *parent, void *drvdata, --- -2.43.0 - |