From 0685f217afe8279a754490954b8dcc02cb763a5d Mon Sep 17 00:00:00 2001 From: Ram Pai Date: Thu, 18 Jan 2018 17:50:28 -0800 Subject: [PATCH] powerpc: cleanup AMR, IAMR when a key is allocated or freed Cleanup the bits corresponding to a key in the AMR, and IAMR register, when the key is newly allocated/activated or is freed. We dont want some residual bits cause the hardware enforce unintended behavior when the key is activated or freed. Reviewed-by: Thiago Jung Bauermann Signed-off-by: Ram Pai Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/pkeys.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h index 79b105d1ff73..5ed52ac39bab 100644 --- a/arch/powerpc/include/asm/pkeys.h +++ b/arch/powerpc/include/asm/pkeys.h @@ -58,6 +58,8 @@ static inline bool mm_pkey_is_allocated(struct mm_struct *mm, int pkey) __mm_pkey_is_allocated(mm, pkey)); } +extern void __arch_activate_pkey(int pkey); +extern void __arch_deactivate_pkey(int pkey); /* * Returns a positive, 5-bit key on success, or -1 on failure. * Relies on the mmap_sem to protect against concurrency in mm_pkey_alloc() and @@ -85,6 +87,12 @@ static inline int mm_pkey_alloc(struct mm_struct *mm) ret = ffz((u32)mm_pkey_allocation_map(mm)); __mm_pkey_allocated(mm, ret); + + /* + * Enable the key in the hardware + */ + if (ret > 0) + __arch_activate_pkey(ret); return ret; } @@ -96,6 +104,10 @@ static inline int mm_pkey_free(struct mm_struct *mm, int pkey) if (!mm_pkey_is_allocated(mm, pkey)) return -EINVAL; + /* + * Disable the key in the hardware + */ + __arch_deactivate_pkey(pkey); __mm_pkey_free(mm, pkey); return 0; -- GitLab