From: ira.weiny@intel.com To: Dave Hansen <dave.hansen@linux.intel.com>, Dan Williams <dan.j.williams@intel.com> Cc: Ira Weiny <ira.weiny@intel.com>, Sean Christopherson <seanjc@google.com>, Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, Peter Zijlstra <peterz@infradead.org>, Andy Lutomirski <luto@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>, Fenghua Yu <fenghua.yu@intel.com>, Rick Edgecombe <rick.p.edgecombe@intel.com>, x86@kernel.org, linux-kernel@vger.kernel.org, nvdimm@lists.linux.dev, linux-mm@kvack.org Subject: [PATCH V7 06/18] x86/fault: Adjust WARN_ON for PKey fault Date: Tue, 3 Aug 2021 21:32:19 -0700 [thread overview] Message-ID: <20210804043231.2655537-7-ira.weiny@intel.com> (raw) In-Reply-To: <20210804043231.2655537-1-ira.weiny@intel.com> From: Ira Weiny <ira.weiny@intel.com> Previously if a Protection key fault occurred it indicated something very wrong because user page mappings are not supposed to be in the kernel address space. Now PKey faults may happen on kernel mappings if the feature is enabled. Remove the warning in the fault path and allow the oops to occur without extra debugging if PKS is enabled. Cc: Sean Christopherson <seanjc@google.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Ira Weiny <ira.weiny@intel.com> --- arch/x86/mm/fault.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index b2eefdefc108..e133c0ed72a0 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1141,11 +1141,15 @@ do_kern_addr_fault(struct pt_regs *regs, unsigned long hw_error_code, unsigned long address) { /* - * Protection keys exceptions only happen on user pages. We - * have no user pages in the kernel portion of the address - * space, so do not expect them here. + * X86_PF_PK (Protection key exceptions) may occur on kernel addresses + * when PKS (PKeys Supervisor) is enabled. + * + * However, if PKS is not enabled WARN if this exception is seen + * because there are no user pages in the kernel portion of the address + * space. */ - WARN_ON_ONCE(hw_error_code & X86_PF_PK); + WARN_ON_ONCE(!cpu_feature_enabled(X86_FEATURE_PKS) && + (hw_error_code & X86_PF_PK)); #ifdef CONFIG_X86_32 /* -- 2.28.0.rc0.12.gb6a658bd00c9
next prev parent reply other threads:[~2021-08-04 4:33 UTC|newest] Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-08-04 4:32 [PATCH V7 00/18] PKS/PMEM: Add Stray Write Protection ira.weiny 2021-08-04 4:32 ` [PATCH V7 01/18] x86/pkeys: Create pkeys_common.h ira.weiny 2021-08-04 4:32 ` [PATCH V7 02/18] x86/fpu: Refactor arch_set_user_pkey_access() ira.weiny 2021-11-25 14:23 ` Thomas Gleixner 2021-08-04 4:32 ` [PATCH V7 03/18] x86/pks: Add additional PKEY helper macros ira.weiny 2021-11-25 14:25 ` Thomas Gleixner 2021-11-25 16:58 ` Thomas Gleixner 2021-12-08 0:51 ` Ira Weiny 2021-12-08 15:11 ` Thomas Gleixner 2021-08-04 4:32 ` [PATCH V7 04/18] x86/pks: Add PKS defines and Kconfig options ira.weiny 2021-08-04 4:32 ` [PATCH V7 05/18] x86/pks: Add PKS setup code ira.weiny 2021-11-25 15:15 ` Thomas Gleixner 2021-11-26 3:11 ` taoyi.ty 2021-11-26 9:57 ` Thomas Gleixner 2021-11-26 11:03 ` Thomas Gleixner 2021-08-04 4:32 ` ira.weiny [this message] 2021-08-04 4:32 ` [PATCH V7 07/18] x86/pks: Preserve the PKRS MSR on context switch ira.weiny 2021-11-25 15:25 ` Thomas Gleixner 2021-08-04 4:32 ` [PATCH V7 08/18] x86/entry: Preserve PKRS MSR across exceptions ira.weiny 2021-11-13 0:50 ` Ira Weiny 2021-11-25 11:19 ` Thomas Gleixner 2021-12-03 1:13 ` Andy Lutomirski 2021-11-25 14:12 ` Thomas Gleixner 2021-12-07 1:54 ` Ira Weiny 2021-12-07 4:45 ` Ira Weiny 2021-12-08 0:21 ` Thomas Gleixner 2021-08-04 4:32 ` [PATCH V7 09/18] x86/pks: Add PKS kernel API ira.weiny 2021-08-04 4:32 ` [PATCH V7 10/18] x86/pks: Introduce pks_abandon_protections() ira.weiny 2021-08-04 4:32 ` [PATCH V7 11/18] x86/pks: Add PKS Test code ira.weiny 2021-08-04 4:32 ` [PATCH V7 12/18] x86/pks: Add PKS fault callbacks ira.weiny 2021-08-11 21:18 ` Edgecombe, Rick P 2021-08-17 3:21 ` Ira Weiny 2021-08-04 4:32 ` [PATCH V7 13/18] memremap_pages: Add access protection via supervisor Protection Keys (PKS) ira.weiny 2021-08-04 4:32 ` [PATCH V7 14/18] memremap_pages: Add memremap.pks_fault_mode ira.weiny 2021-08-04 4:57 ` Randy Dunlap 2021-08-07 19:32 ` Ira Weiny 2021-08-11 19:01 ` Edgecombe, Rick P 2021-08-17 3:12 ` Ira Weiny 2021-08-04 4:32 ` [PATCH V7 15/18] kmap: Add stray access protection for devmap pages ira.weiny 2021-08-04 4:32 ` [PATCH V7 16/18] dax: Stray access protection for dax_direct_access() ira.weiny 2021-08-04 4:32 ` [PATCH V7 17/18] nvdimm/pmem: Enable stray access protection ira.weiny 2021-08-04 4:32 ` [PATCH V7 18/18] devdax: " ira.weiny
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