From: Fenghua Yu fenghua.yu@intel.com
Define a helper, update_pkey_val(), which will be used to support both Protection Key User (PKU) and the new Protection Key for Supervisor (PKS) in subsequent patches.
Co-developed-by: Ira Weiny ira.weiny@intel.com Signed-off-by: Ira Weiny ira.weiny@intel.com Signed-off-by: Fenghua Yu fenghua.yu@intel.com --- arch/x86/include/asm/pkeys.h | 2 ++ arch/x86/kernel/fpu/xstate.c | 22 ++++------------------ arch/x86/mm/pkeys.c | 21 +++++++++++++++++++++ 3 files changed, 27 insertions(+), 18 deletions(-)
diff --git a/arch/x86/include/asm/pkeys.h b/arch/x86/include/asm/pkeys.h index f9feba80894b..4526245b03e5 100644 --- a/arch/x86/include/asm/pkeys.h +++ b/arch/x86/include/asm/pkeys.h @@ -136,4 +136,6 @@ static inline int vma_pkey(struct vm_area_struct *vma) return (vma->vm_flags & vma_pkey_mask) >> VM_PKEY_SHIFT; }
+u32 update_pkey_val(u32 pk_reg, int pkey, unsigned int flags); + #endif /*_ASM_X86_PKEYS_H */ diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index b55cf3acd82a..725f10670d0a 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -990,9 +990,7 @@ const void *get_xsave_field_ptr(int xfeature_nr) int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, unsigned long init_val) { - u32 old_pkru; - int pkey_shift = (pkey * PKR_BITS_PER_PKEY); - u32 new_pkru_bits = 0; + u32 pkru;
/* * This check implies XSAVE support. OSPKE only gets @@ -1008,21 +1006,9 @@ int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, */ WARN_ON_ONCE(pkey >= arch_max_pkey());
- /* Set the bits we need in PKRU: */ - if (init_val & PKEY_DISABLE_ACCESS) - new_pkru_bits |= PKR_AD_BIT; - if (init_val & PKEY_DISABLE_WRITE) - new_pkru_bits |= PKR_WD_BIT; - - /* Shift the bits in to the correct place in PKRU for pkey: */ - new_pkru_bits <<= pkey_shift; - - /* Get old PKRU and mask off any old bits in place: */ - old_pkru = read_pkru(); - old_pkru &= ~((PKR_AD_BIT|PKR_WD_BIT) << pkey_shift); - - /* Write old part along with new part: */ - write_pkru(old_pkru | new_pkru_bits); + pkru = read_pkru(); + pkru = update_pkey_val(pkru, pkey, init_val); + write_pkru(pkru);
return 0; } diff --git a/arch/x86/mm/pkeys.c b/arch/x86/mm/pkeys.c index f5efb4007e74..3cf8f775f36d 100644 --- a/arch/x86/mm/pkeys.c +++ b/arch/x86/mm/pkeys.c @@ -208,3 +208,24 @@ static __init int setup_init_pkru(char *opt) return 1; } __setup("init_pkru=", setup_init_pkru); + +/* + * Update the pk_reg value and return it. + * + * Kernel users use the same flags as user space: + * PKEY_DISABLE_ACCESS + * PKEY_DISABLE_WRITE + */ +u32 update_pkey_val(u32 pk_reg, int pkey, unsigned int flags) +{ + int pkey_shift = pkey * PKR_BITS_PER_PKEY; + + pk_reg &= ~(((1 << PKR_BITS_PER_PKEY) - 1) << pkey_shift); + + if (flags & PKEY_DISABLE_ACCESS) + pk_reg |= PKR_AD_BIT << pkey_shift; + if (flags & PKEY_DISABLE_WRITE) + pk_reg |= PKR_WD_BIT << pkey_shift; + + return pk_reg; +}