From 26e041208291bfdea1cb9e26bc94a0f9499efe15 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Tue, 11 Jul 2023 17:59:18 +0200 Subject: [PATCH] powerpc/kuap: Use MMU_FTR_KUAP on all and refactor disabling kuap All but book3s/64 use a static branch key for disabling kuap. book3s/64 uses an mmu feature. Refactor all targets to use MMU_FTR_KUAP like book3s/64. For PPC32 that implies updating mmu features fixups once KUAP has been initialised. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://msgid.link/6b3d7c977bad73378ea368bc6818e9c94ea95ab0.1689091022.git.christophe.leroy@csgroup.eu --- arch/powerpc/include/asm/book3s/32/kup.h | 9 --------- arch/powerpc/include/asm/book3s/64/kup.h | 5 ----- arch/powerpc/include/asm/kup.h | 11 +++++++++++ arch/powerpc/include/asm/nohash/32/kup-8xx.h | 9 --------- arch/powerpc/include/asm/nohash/kup-booke.h | 8 -------- arch/powerpc/kernel/cputable.c | 4 ++++ arch/powerpc/mm/book3s32/kuap.c | 5 +---- arch/powerpc/mm/init_32.c | 2 ++ arch/powerpc/mm/nohash/kup.c | 6 +----- 9 files changed, 19 insertions(+), 40 deletions(-) diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h index 0da0dea76c47..4ca6122ef0e1 100644 --- a/arch/powerpc/include/asm/book3s/32/kup.h +++ b/arch/powerpc/include/asm/book3s/32/kup.h @@ -9,10 +9,6 @@ #ifndef __ASSEMBLY__ -#include - -extern struct static_key_false disable_kuap_key; - #ifdef CONFIG_PPC_KUAP #include @@ -20,11 +16,6 @@ extern struct static_key_false disable_kuap_key; #define KUAP_NONE (~0UL) #define KUAP_ALL (~1UL) -static __always_inline bool kuap_is_disabled(void) -{ - return static_branch_unlikely(&disable_kuap_key); -} - static inline void kuap_lock_one(unsigned long addr) { mtsr(mfsr(addr) | SR_KS, addr); diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h index 72fc4263ed26..a014f4d9a2aa 100644 --- a/arch/powerpc/include/asm/book3s/64/kup.h +++ b/arch/powerpc/include/asm/book3s/64/kup.h @@ -230,11 +230,6 @@ static inline u64 current_thread_iamr(void) #ifdef CONFIG_PPC_KUAP -static __always_inline bool kuap_is_disabled(void) -{ - return !mmu_has_feature(MMU_FTR_KUAP); -} - static inline void kuap_user_restore(struct pt_regs *regs) { bool restore_amr = false, restore_iamr = false; diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h index 24cde16c4fbe..bab161b609c1 100644 --- a/arch/powerpc/include/asm/kup.h +++ b/arch/powerpc/include/asm/kup.h @@ -6,6 +6,12 @@ #define KUAP_WRITE 2 #define KUAP_READ_WRITE (KUAP_READ | KUAP_WRITE) +#ifndef __ASSEMBLY__ +#include + +static __always_inline bool kuap_is_disabled(void); +#endif + #ifdef CONFIG_PPC_BOOK3S_64 #include #endif @@ -41,6 +47,11 @@ void setup_kuep(bool disabled); #ifdef CONFIG_PPC_KUAP void setup_kuap(bool disabled); + +static __always_inline bool kuap_is_disabled(void) +{ + return !mmu_has_feature(MMU_FTR_KUAP); +} #else static inline void setup_kuap(bool disabled) { } diff --git a/arch/powerpc/include/asm/nohash/32/kup-8xx.h b/arch/powerpc/include/asm/nohash/32/kup-8xx.h index a372cd822887..d0601859c45a 100644 --- a/arch/powerpc/include/asm/nohash/32/kup-8xx.h +++ b/arch/powerpc/include/asm/nohash/32/kup-8xx.h @@ -9,17 +9,8 @@ #ifndef __ASSEMBLY__ -#include - #include -extern struct static_key_false disable_kuap_key; - -static __always_inline bool kuap_is_disabled(void) -{ - return static_branch_unlikely(&disable_kuap_key); -} - static inline void __kuap_save_and_lock(struct pt_regs *regs) { regs->kuap = mfspr(SPRN_MD_AP); diff --git a/arch/powerpc/include/asm/nohash/kup-booke.h b/arch/powerpc/include/asm/nohash/kup-booke.h index 71182cbe20c3..8e4734c8fef1 100644 --- a/arch/powerpc/include/asm/nohash/kup-booke.h +++ b/arch/powerpc/include/asm/nohash/kup-booke.h @@ -13,18 +13,10 @@ #else -#include #include #include -extern struct static_key_false disable_kuap_key; - -static __always_inline bool kuap_is_disabled(void) -{ - return static_branch_unlikely(&disable_kuap_key); -} - static inline void __kuap_lock(void) { mtspr(SPRN_PID, 0); diff --git a/arch/powerpc/kernel/cputable.c b/arch/powerpc/kernel/cputable.c index 8a32bffefa5b..e97a0fd0ae90 100644 --- a/arch/powerpc/kernel/cputable.c +++ b/arch/powerpc/kernel/cputable.c @@ -75,6 +75,10 @@ static struct cpu_spec * __init setup_cpu_spec(unsigned long offset, t->cpu_features |= old.cpu_features & CPU_FTR_PMAO_BUG; } + /* Set kuap ON at startup, will be disabled later if cmdline has 'nosmap' */ + if (IS_ENABLED(CONFIG_PPC_KUAP) && IS_ENABLED(CONFIG_PPC32)) + t->mmu_features |= MMU_FTR_KUAP; + *PTRRELOC(&cur_cpu_spec) = &the_cpu_spec; /* diff --git a/arch/powerpc/mm/book3s32/kuap.c b/arch/powerpc/mm/book3s32/kuap.c index 28676cabb005..24c1c686e6b9 100644 --- a/arch/powerpc/mm/book3s32/kuap.c +++ b/arch/powerpc/mm/book3s32/kuap.c @@ -3,9 +3,6 @@ #include #include -struct static_key_false disable_kuap_key; -EXPORT_SYMBOL(disable_kuap_key); - void kuap_lock_all_ool(void) { kuap_lock_all(); @@ -30,7 +27,7 @@ void setup_kuap(bool disabled) return; if (disabled) - static_branch_enable(&disable_kuap_key); + cur_cpu_spec->mmu_features &= ~MMU_FTR_KUAP; else pr_info("Activating Kernel Userspace Access Protection\n"); } diff --git a/arch/powerpc/mm/init_32.c b/arch/powerpc/mm/init_32.c index d4cc3749e621..d8adc452f431 100644 --- a/arch/powerpc/mm/init_32.c +++ b/arch/powerpc/mm/init_32.c @@ -126,6 +126,8 @@ void __init MMU_init(void) setup_kup(); + update_mmu_feature_fixups(MMU_FTR_KUAP); + /* Shortly after that, the entire linear mapping will be available */ memblock_set_current_limit(lowmem_end_addr); } diff --git a/arch/powerpc/mm/nohash/kup.c b/arch/powerpc/mm/nohash/kup.c index 552becf90e97..94ff82b9ae60 100644 --- a/arch/powerpc/mm/nohash/kup.c +++ b/arch/powerpc/mm/nohash/kup.c @@ -5,7 +5,6 @@ #include #include -#include #include #include @@ -13,16 +12,13 @@ #include #ifdef CONFIG_PPC_KUAP -struct static_key_false disable_kuap_key; -EXPORT_SYMBOL(disable_kuap_key); - void setup_kuap(bool disabled) { if (disabled) { if (IS_ENABLED(CONFIG_40x)) disable_kuep = true; if (smp_processor_id() == boot_cpuid) - static_branch_enable(&disable_kuap_key); + cur_cpu_spec->mmu_features &= ~MMU_FTR_KUAP; return; }