From 8a01ec97dc066009dd89e43bfcf55644f2dd6d19 Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Mon, 9 Jan 2023 07:29:36 -0800 Subject: [PATCH] x86/mce: Mask out non-address bits from machine check bank Systems that support various memory encryption schemes (MKTME, TDX, SEV) use high order physical address bits to indicate which key should be used for a specific memory location. When a memory error is reported, some systems may report those key bits in the IA32_MCi_ADDR machine check MSR. The Intel SDM has a footnote for the contents of the address register that says: "Useful bits in this field depend on the address methodology in use when the register state is saved." AMD Processor Programming Reference has a more explicit description of the MCA_ADDR register: "For physical addresses, the most significant bit is given by Core::X86::Cpuid::LongModeInfo[PhysAddrSize]." Add a new #define MCI_ADDR_PHYSADDR for the mask of valid physical address bits within the machine check bank address register. Use this mask for recoverable machine check handling and in the EDAC driver to ignore any key bits that may be present. [ Tony: Based on independent fixes proposed by Fan Du and Isaku Yamahata ] Reported-by: Isaku Yamahata Reported-by: Fan Du Signed-off-by: Tony Luck Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Yazen Ghannam Link: https://lore.kernel.org/r/20230109152936.397862-1-tony.luck@intel.com --- arch/x86/include/asm/mce.h | 3 +++ arch/x86/kernel/cpu/mce/core.c | 14 +++++++++----- drivers/edac/skx_common.c | 2 +- 3 files changed, 13 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h index 6e986088817d..9646ed6e8c0b 100644 --- a/arch/x86/include/asm/mce.h +++ b/arch/x86/include/asm/mce.h @@ -88,6 +88,9 @@ #define MCI_MISC_ADDR_MEM 3 /* memory address */ #define MCI_MISC_ADDR_GENERIC 7 /* generic */ +/* MCi_ADDR register defines */ +#define MCI_ADDR_PHYSADDR GENMASK_ULL(boot_cpu_data.x86_phys_bits - 1, 0) + /* CTL2 register defines */ #define MCI_CTL2_CMCI_EN BIT_ULL(30) #define MCI_CTL2_CMCI_THRESHOLD_MASK 0x7fffULL diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c index 626a1c666252..7832a69d170e 100644 --- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -573,7 +573,7 @@ static int uc_decode_notifier(struct notifier_block *nb, unsigned long val, mce->severity != MCE_DEFERRED_SEVERITY) return NOTIFY_DONE; - pfn = mce->addr >> PAGE_SHIFT; + pfn = (mce->addr & MCI_ADDR_PHYSADDR) >> PAGE_SHIFT; if (!memory_failure(pfn, 0)) { set_mce_nospec(pfn); mce->kflags |= MCE_HANDLED_UC; @@ -1294,6 +1294,7 @@ static void kill_me_maybe(struct callback_head *cb) { struct task_struct *p = container_of(cb, struct task_struct, mce_kill_me); int flags = MF_ACTION_REQUIRED; + unsigned long pfn; int ret; p->mce_count = 0; @@ -1302,9 +1303,10 @@ static void kill_me_maybe(struct callback_head *cb) if (!p->mce_ripv) flags |= MF_MUST_KILL; - ret = memory_failure(p->mce_addr >> PAGE_SHIFT, flags); + pfn = (p->mce_addr & MCI_ADDR_PHYSADDR) >> PAGE_SHIFT; + ret = memory_failure(pfn, flags); if (!ret) { - set_mce_nospec(p->mce_addr >> PAGE_SHIFT); + set_mce_nospec(pfn); sync_core(); return; } @@ -1326,11 +1328,13 @@ static void kill_me_maybe(struct callback_head *cb) static void kill_me_never(struct callback_head *cb) { struct task_struct *p = container_of(cb, struct task_struct, mce_kill_me); + unsigned long pfn; p->mce_count = 0; pr_err("Kernel accessed poison in user space at %llx\n", p->mce_addr); - if (!memory_failure(p->mce_addr >> PAGE_SHIFT, 0)) - set_mce_nospec(p->mce_addr >> PAGE_SHIFT); + pfn = (p->mce_addr & MCI_ADDR_PHYSADDR) >> PAGE_SHIFT; + if (!memory_failure(pfn, 0)) + set_mce_nospec(pfn); } static void queue_task_work(struct mce *m, char *msg, void (*func)(struct callback_head *)) diff --git a/drivers/edac/skx_common.c b/drivers/edac/skx_common.c index f0f8e98f6efb..806986f03177 100644 --- a/drivers/edac/skx_common.c +++ b/drivers/edac/skx_common.c @@ -657,7 +657,7 @@ int skx_mce_check_error(struct notifier_block *nb, unsigned long val, memset(&res, 0, sizeof(res)); res.mce = mce; - res.addr = mce->addr; + res.addr = mce->addr & MCI_ADDR_PHYSADDR; /* Try driver decoder first */ if (!(driver_decode && driver_decode(&res))) { -- 2.34.1