diff --git a/arch/powerpc/include/asm/security_features.h b/arch/powerpc/include/asm/security_features.h new file mode 100644 index 000000000000..db00ad2c72c2 --- /dev/null +++ b/arch/powerpc/include/asm/security_features.h @@ -0,0 +1,65 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Security related feature bit definitions. + * + * Copyright 2018, Michael Ellerman, IBM Corporation. + */ + +#ifndef _ASM_POWERPC_SECURITY_FEATURES_H +#define _ASM_POWERPC_SECURITY_FEATURES_H + + +extern unsigned long powerpc_security_features; + +static inline void security_ftr_set(unsigned long feature) +{ + powerpc_security_features |= feature; +} + +static inline void security_ftr_clear(unsigned long feature) +{ + powerpc_security_features &= ~feature; +} + +static inline bool security_ftr_enabled(unsigned long feature) +{ + return !!(powerpc_security_features & feature); +} + + +// Features indicating support for Spectre/Meltdown mitigations + +// The L1-D cache can be flushed with ori r30,r30,0 +#define SEC_FTR_L1D_FLUSH_ORI30 0x0000000000000001ull + +// The L1-D cache can be flushed with mtspr 882,r0 (aka SPRN_TRIG2) +#define SEC_FTR_L1D_FLUSH_TRIG2 0x0000000000000002ull + +// ori r31,r31,0 acts as a speculation barrier +#define SEC_FTR_SPEC_BAR_ORI31 0x0000000000000004ull + +// Speculation past bctr is disabled +#define SEC_FTR_BCCTRL_SERIALISED 0x0000000000000008ull + +// Entries in L1-D are private to a SMT thread +#define SEC_FTR_L1D_THREAD_PRIV 0x0000000000000010ull + +// Indirect branch prediction cache disabled +#define SEC_FTR_COUNT_CACHE_DISABLED 0x0000000000000020ull + + +// Features indicating need for Spectre/Meltdown mitigations + +// The L1-D cache should be flushed on MSR[HV] 1->0 transition (hypervisor to guest) +#define SEC_FTR_L1D_FLUSH_HV 0x0000000000000040ull + +// The L1-D cache should be flushed on MSR[PR] 0->1 transition (kernel to userspace) +#define SEC_FTR_L1D_FLUSH_PR 0x0000000000000080ull + +// A speculation barrier should be used for bounds checks (Spectre variant 1) +#define SEC_FTR_BNDS_CHK_SPEC_BAR 0x0000000000000100ull + +// Firmware configuration indicates user favours security over performance +#define SEC_FTR_FAVOUR_SECURITY 0x0000000000000200ull + +#endif /* _ASM_POWERPC_SECURITY_FEATURES_H */ diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index ba336930d448..e9b0962743b8 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -40,7 +40,7 @@ obj-$(CONFIG_PPC64) += setup_64.o sys_ppc32.o \ obj-$(CONFIG_VDSO32) += vdso32/ obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o obj-$(CONFIG_PPC_BOOK3S_64) += cpu_setup_ppc970.o cpu_setup_pa6t.o -obj-$(CONFIG_PPC_BOOK3S_64) += cpu_setup_power.o +obj-$(CONFIG_PPC_BOOK3S_64) += cpu_setup_power.o security.o obj-$(CONFIG_PPC_BOOK3S_64) += mce.o mce_power.o obj64-$(CONFIG_RELOCATABLE) += reloc_64.o obj-$(CONFIG_PPC_BOOK3E_64) += exceptions-64e.o idle_book3e.o diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c new file mode 100644 index 000000000000..4ccba00d224c --- /dev/null +++ b/arch/powerpc/kernel/security.c @@ -0,0 +1,15 @@ +// SPDX-License-Identifier: GPL-2.0+ +// +// Security related flags and so on. +// +// Copyright 2018, Michael Ellerman, IBM Corporation. + +#include +#include + + +unsigned long powerpc_security_features __read_mostly = \ + SEC_FTR_L1D_FLUSH_HV | \ + SEC_FTR_L1D_FLUSH_PR | \ + SEC_FTR_BNDS_CHK_SPEC_BAR | \ + SEC_FTR_FAVOUR_SECURITY;