[RFC v4 05/17] powerpc: store and restore the pkey state across context switches
From: Ram Pai <hidden>
Date: 2017-06-27 10:12:39
Also in:
linux-arch, linux-mm, lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
Store and restore the AMR, IAMR and UMOR register state of the task before scheduling out and after scheduling in, respectively. Signed-off-by: Ram Pai <redacted> --- arch/powerpc/include/asm/processor.h | 5 +++++ arch/powerpc/kernel/process.c | 18 ++++++++++++++++++ 2 files changed, 23 insertions(+)
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index a2123f2..1f714df 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h@@ -310,6 +310,11 @@ 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 baae104..37d001a 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c@@ -1096,6 +1096,11 @@ static inline void save_sprs(struct thread_struct *t) t->tar = mfspr(SPRN_TAR); } #endif +#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS + t->amr = mfspr(SPRN_AMR); + t->iamr = mfspr(SPRN_IAMR); + t->uamor = mfspr(SPRN_UAMOR); +#endif } static inline void restore_sprs(struct thread_struct *old_thread,
@@ -1131,6 +1136,14 @@ static inline void restore_sprs(struct thread_struct *old_thread, mtspr(SPRN_TAR, new_thread->tar); } #endif +#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS + if (old_thread->amr != new_thread->amr) + mtspr(SPRN_AMR, new_thread->amr); + if (old_thread->iamr != new_thread->iamr) + mtspr(SPRN_IAMR, new_thread->iamr); + if (old_thread->uamor != new_thread->uamor) + mtspr(SPRN_UAMOR, new_thread->uamor); +#endif } struct task_struct *__switch_to(struct task_struct *prev,
@@ -1686,6 +1699,11 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp) current->thread.tm_texasr = 0; current->thread.tm_tfiar = 0; #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */ +#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS + current->thread.amr = 0x0ul; + current->thread.iamr = 0x0ul; + current->thread.uamor = 0x0ul; +#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */ } EXPORT_SYMBOL(start_thread);
--
1.8.3.1