This patch provides the implementation for arch_vma_access_permitted(). Returns true if the requested access is allowed by pkey associated with the vma.
Signed-off-by: Ram Pai linuxram@us.ibm.com --- arch/powerpc/include/asm/mmu_context.h | 5 +++- arch/powerpc/mm/pkeys.c | 34 ++++++++++++++++++++++++++++++++ 2 files changed, 38 insertions(+), 1 deletions(-)
diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h index 209f127..cd2bd73 100644 --- a/arch/powerpc/include/asm/mmu_context.h +++ b/arch/powerpc/include/asm/mmu_context.h @@ -186,6 +186,10 @@ static inline void arch_bprm_mm_init(struct mm_struct *mm, { }
+#ifdef CONFIG_PPC_MEM_KEYS +bool arch_vma_access_permitted(struct vm_area_struct *vma, bool write, + bool execute, bool foreign); +#else /* CONFIG_PPC_MEM_KEYS */ static inline bool arch_vma_access_permitted(struct vm_area_struct *vma, bool write, bool execute, bool foreign) { @@ -193,7 +197,6 @@ static inline bool arch_vma_access_permitted(struct vm_area_struct *vma, return true; }
-#ifndef CONFIG_PPC_MEM_KEYS #define pkey_mm_init(mm) #define thread_pkey_regs_save(thread) #define thread_pkey_regs_restore(new_thread, old_thread) diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c index 0e044ea..0701aa3 100644 --- a/arch/powerpc/mm/pkeys.c +++ b/arch/powerpc/mm/pkeys.c @@ -390,3 +390,37 @@ bool arch_pte_access_permitted(u64 pte, bool write, bool execute)
return pkey_access_permitted(pte_to_pkey_bits(pte), write, execute); } + +/* + * We only want to enforce protection keys on the current thread because we + * effectively have no access to AMR/IAMR for other threads or any way to tell + * which AMR/IAMR in a threaded process we could use. + * + * So do not enforce things if the VMA is not from the current mm, or if we are + * in a kernel thread. + */ +static inline bool vma_is_foreign(struct vm_area_struct *vma) +{ + if (!current->mm) + return true; + + /* if it is not our ->mm, it has to be foreign */ + if (current->mm != vma->vm_mm) + return true; + + return false; +} + +bool arch_vma_access_permitted(struct vm_area_struct *vma, bool write, + bool execute, bool foreign) +{ + if (static_branch_likely(&pkey_disabled)) + return true; + /* + * Do not enforce our key-permissions on a foreign vma. + */ + if (foreign || vma_is_foreign(vma)) + return true; + + return pkey_access_permitted(vma_pkey(vma), write, execute); +}