Store and restore the AMR, IAMR and UAMOR register state of the task before scheduling out and after scheduling in, respectively.
Signed-off-by: Ram Pai <linux...@us.ibm.com> --- arch/powerpc/include/asm/pkeys.h | 4 +++ arch/powerpc/include/asm/processor.h | 5 ++++ arch/powerpc/kernel/process.c | 10 ++++++++ arch/powerpc/mm/pkeys.c | 39 ++++++++++++++++++++++++++++++++++ 4 files changed, 58 insertions(+), 0 deletions(-) diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h index 7fd48a4..78c5362 100644 --- a/arch/powerpc/include/asm/pkeys.h +++ b/arch/powerpc/include/asm/pkeys.h @@ -143,5 +143,9 @@ static inline void pkey_mm_init(struct mm_struct *mm) mm_pkey_allocation_map(mm) = initial_allocation_mask; } +extern void thread_pkey_regs_save(struct thread_struct *thread); +extern void thread_pkey_regs_restore(struct thread_struct *new_thread, + struct thread_struct *old_thread); +extern void thread_pkey_regs_init(struct thread_struct *thread); extern void pkey_initialize(void); #endif /*_ASM_PPC64_PKEYS_H */ diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h index fab7ff8..de9d9ba 100644 --- a/arch/powerpc/include/asm/processor.h +++ b/arch/powerpc/include/asm/processor.h @@ -309,6 +309,11 @@ struct thread_struct { struct thread_vr_state ckvr_state; /* Checkpointed VR state */ unsigned long ckvrsave; /* Checkpointed VRSAVE */ #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ +#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS + unsigned long amr; + unsigned long iamr; + unsigned long uamor; +#endif #ifdef CONFIG_KVM_BOOK3S_32_HANDLER void* kvm_shadow_vcpu; /* KVM internal data */ #endif /* CONFIG_KVM_BOOK3S_32_HANDLER */ diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index a0c74bb..ba80002 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -42,6 +42,7 @@ #include <linux/hw_breakpoint.h> #include <linux/uaccess.h> #include <linux/elf-randomize.h> +#include <linux/pkeys.h> #include <asm/pgtable.h> #include <asm/io.h> @@ -1085,6 +1086,9 @@ static inline void save_sprs(struct thread_struct *t) t->tar = mfspr(SPRN_TAR); } #endif +#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS + thread_pkey_regs_save(t); +#endif } static inline void restore_sprs(struct thread_struct *old_thread, @@ -1120,6 +1124,9 @@ static inline void restore_sprs(struct thread_struct *old_thread, mtspr(SPRN_TAR, new_thread->tar); } #endif +#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS + thread_pkey_regs_restore(new_thread, old_thread); +#endif } #ifdef CONFIG_PPC_BOOK3S_64 @@ -1705,6 +1712,9 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp) current->thread.tm_tfiar = 0; current->thread.load_tm = 0; #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ +#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS + thread_pkey_regs_init(¤t->thread); +#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */ } EXPORT_SYMBOL(start_thread); diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c index 2282864..7cd1be4 100644 --- a/arch/powerpc/mm/pkeys.c +++ b/arch/powerpc/mm/pkeys.c @@ -149,3 +149,42 @@ int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey, init_amr(pkey, new_amr_bits); return 0; } + +void thread_pkey_regs_save(struct thread_struct *thread) +{ + if (!pkey_inited) + return; + + /* @TODO skip saving any registers if the thread + * has not used any keys yet. + */ + + thread->amr = read_amr(); + thread->iamr = read_iamr(); + thread->uamor = read_uamor(); +} + +void thread_pkey_regs_restore(struct thread_struct *new_thread, + struct thread_struct *old_thread) +{ + if (!pkey_inited) + return; + + /* @TODO just reset uamor to zero if the new_thread + * has not used any keys yet. + */ + + if (old_thread->amr != new_thread->amr) + write_amr(new_thread->amr); + if (old_thread->iamr != new_thread->iamr) + write_iamr(new_thread->iamr); + if (old_thread->uamor != new_thread->uamor) + write_uamor(new_thread->uamor); +} + +void thread_pkey_regs_init(struct thread_struct *thread) +{ + write_amr(0x0ul); + write_iamr(0x0ul); + write_uamor(0x0ul); +} -- 1.7.1