Messages in this thread Patch in this message | | | From | ira.weiny@intel ... | Subject | [PATCH V8 26/44] x86/fault: Print PKS MSR on fault | Date | Thu, 27 Jan 2022 09:54:47 -0800 |
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From: Ira Weiny <ira.weiny@intel.com>
If a PKS fault occurs it will be easier to debug it if the PKS MSR value at the time of the fault is known.
Add pks_dump_fault_info() to dump the PKRS MSR on fault if enabled.
Suggested-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Ira Weiny <ira.weiny@intel.com>
--- Changes for V8 Split this into it's own patch. --- arch/x86/include/asm/pks.h | 2 ++ arch/x86/mm/fault.c | 3 +++ arch/x86/mm/pkeys.c | 11 +++++++++++ 3 files changed, 16 insertions(+)
diff --git a/arch/x86/include/asm/pks.h b/arch/x86/include/asm/pks.h index 82baa594cb3b..fc3c66f1bb04 100644 --- a/arch/x86/include/asm/pks.h +++ b/arch/x86/include/asm/pks.h @@ -8,6 +8,7 @@ void pks_setup(void); void pks_write_current(void); void pks_save_pt_regs(struct pt_regs *regs); void pks_restore_pt_regs(struct pt_regs *regs); +void pks_dump_fault_info(struct pt_regs *regs); #else /* !CONFIG_ARCH_ENABLE_SUPERVISOR_PKEYS */ @@ -15,6 +16,7 @@ static inline void pks_setup(void) { } static inline void pks_write_current(void) { } static inline void pks_save_pt_regs(struct pt_regs *regs) { } static inline void pks_restore_pt_regs(struct pt_regs *regs) { } +static inline void pks_dump_fault_info(struct pt_regs *regs) { } #endif /* CONFIG_ARCH_ENABLE_SUPERVISOR_PKEYS */ diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 030eb3e08550..697c06f08103 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -549,6 +549,9 @@ show_fault_oops(struct pt_regs *regs, unsigned long error_code, unsigned long ad (error_code & X86_PF_PK) ? "protection keys violation" : "permissions violation"); + if (error_code & X86_PF_PK) + pks_dump_fault_info(regs); + if (!(error_code & X86_PF_USER) && user_mode(regs)) { struct desc_ptr idt, gdt; u16 ldtr, tr; diff --git a/arch/x86/mm/pkeys.c b/arch/x86/mm/pkeys.c index 33b7f84ed33b..bdd700d5ad03 100644 --- a/arch/x86/mm/pkeys.c +++ b/arch/x86/mm/pkeys.c @@ -288,6 +288,17 @@ void pks_restore_pt_regs(struct pt_regs *regs) pks_write_pkrs(current->thread.pks_saved_pkrs); } +void pks_dump_fault_info(struct pt_regs *regs) +{ + struct pt_regs_auxiliary *aux_pt_regs; + + if (!cpu_feature_enabled(X86_FEATURE_PKS)) + return; + + aux_pt_regs = &to_extended_pt_regs(regs)->aux; + pr_alert("PKRS: 0x%x\n", aux_pt_regs->pks_thread_pkrs); +} + /* * PKS is independent of PKU and either or both may be supported on a CPU. * -- 2.31.1
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