From 201bc182ad6333468013f1af0719ffe125826b6a Mon Sep 17 00:00:00 2001 From: William Roche Date: Tue, 17 Mar 2026 10:38:10 +0000 Subject: x86/mce/amd: Check SMCA feature bit before accessing SMCA MSRs People do effort to inject MCEs into guests in order to simulate/test handling of hardware errors. The real use case behind it is testing the handling of SIGBUS which the memory failure code sends to the process. If that process is QEMU, instead of killing the whole guest, the MCE can be injected into the guest kernel so that latter can attempt proper handling and kill the user *process* in the guest, instead, which caused the MCE. The assumption being here that the whole injection flow can supply enough information that the guest kernel can pinpoint the right process. But that's a different topic... Regardless of virtualization or not, access to SMCA-specific registers like MCA_DESTAT should only be done after having checked the smca feature bit. And there are AMD machines like Bulldozer (the one before Zen1) which do support deferred errors but are not SMCA machines. Therefore, properly check the feature bit before accessing related MSRs. [ bp: Rewrite commit message. ] Fixes: 7cb735d7c0cb ("x86/mce: Unify AMD DFR handler with MCA Polling") Signed-off-by: William Roche Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Yazen Ghannam Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20260218163025.1316501-1-william.roche@oracle.com --- arch/x86/kernel/cpu/mce/amd.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c index da13c1e37f87..a030ee4cecc2 100644 --- a/arch/x86/kernel/cpu/mce/amd.c +++ b/arch/x86/kernel/cpu/mce/amd.c @@ -875,13 +875,18 @@ void amd_clear_bank(struct mce *m) { amd_reset_thr_limit(m->bank); - /* Clear MCA_DESTAT for all deferred errors even those logged in MCA_STATUS. */ - if (m->status & MCI_STATUS_DEFERRED) - mce_wrmsrq(MSR_AMD64_SMCA_MCx_DESTAT(m->bank), 0); + if (mce_flags.smca) { + /* + * Clear MCA_DESTAT for all deferred errors even those + * logged in MCA_STATUS. + */ + if (m->status & MCI_STATUS_DEFERRED) + mce_wrmsrq(MSR_AMD64_SMCA_MCx_DESTAT(m->bank), 0); - /* Don't clear MCA_STATUS if MCA_DESTAT was used exclusively. */ - if (m->kflags & MCE_CHECK_DFR_REGS) - return; + /* Don't clear MCA_STATUS if MCA_DESTAT was used exclusively. */ + if (m->kflags & MCE_CHECK_DFR_REGS) + return; + } mce_wrmsrq(mca_msr_reg(m->bank, MCA_STATUS), 0); } -- cgit v1.2.3 From 63f8b60151dc00895137bfadc987f258060ab264 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Fri, 20 Mar 2026 17:06:53 +0100 Subject: x86/entry/vdso: Fix path of included gettimeofday.c Commit in Fixes forgot to convert one include path to be relative to the kernel source directory after adding latter to flags-y. Fix it. [ bp: Rewrite commit message. ] Fixes: 693c819fedcd ("x86/entry/vdso: Refactor the vdso build") Signed-off-by: Vladimir Oltean Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/r/20260307174406.1808981-1-vladimir.oltean@nxp.com --- arch/x86/entry/vdso/common/vclock_gettime.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/entry/vdso/common/vclock_gettime.c b/arch/x86/entry/vdso/common/vclock_gettime.c index 027b7e88d753..57066f346b3f 100644 --- a/arch/x86/entry/vdso/common/vclock_gettime.c +++ b/arch/x86/entry/vdso/common/vclock_gettime.c @@ -13,7 +13,7 @@ #include #include -#include "../../../../lib/vdso/gettimeofday.c" +#include "lib/vdso/gettimeofday.c" int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz) { -- cgit v1.2.3 From 1f6aa5bbf1d0f81a8a2aafc16136e7dd9a609ff3 Mon Sep 17 00:00:00 2001 From: Kyle Meyer Date: Fri, 20 Mar 2026 12:19:20 -0500 Subject: x86/platform/uv: Handle deconfigured sockets When a socket is deconfigured, it's mapped to SOCK_EMPTY (0xffff). This causes a panic while allocating UV hub info structures. Fix this by using NUMA_NO_NODE, allowing UV hub info structures to be allocated on valid nodes. Fixes: 8a50c5851927 ("x86/platform/uv: UV support for sub-NUMA clustering") Signed-off-by: Kyle Meyer Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Steve Wahl Cc: stable@vger.kernel.org Link: https://patch.msgid.link/ab2BmGL0ehVkkjKk@hpe.com --- arch/x86/kernel/apic/x2apic_uv_x.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c index 15209f220e1f..42568ceec481 100644 --- a/arch/x86/kernel/apic/x2apic_uv_x.c +++ b/arch/x86/kernel/apic/x2apic_uv_x.c @@ -1708,8 +1708,22 @@ static void __init uv_system_init_hub(void) struct uv_hub_info_s *new_hub; /* Allocate & fill new per hub info list */ - new_hub = (bid == 0) ? &uv_hub_info_node0 - : kzalloc_node(bytes, GFP_KERNEL, uv_blade_to_node(bid)); + if (bid == 0) { + new_hub = &uv_hub_info_node0; + } else { + int nid; + + /* + * Deconfigured sockets are mapped to SOCK_EMPTY. Use + * NUMA_NO_NODE to allocate on a valid node. + */ + nid = uv_blade_to_node(bid); + if (nid == SOCK_EMPTY) + nid = NUMA_NO_NODE; + + new_hub = kzalloc_node(bytes, GFP_KERNEL, nid); + } + if (WARN_ON_ONCE(!new_hub)) { /* do not kfree() bid 0, which is statically allocated */ while (--bid > 0) -- cgit v1.2.3