summaryrefslogtreecommitdiff
path: root/arch/powerpc
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/include/asm/mmu_context.h5
-rw-r--r--arch/powerpc/mm/pkeys.c34
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 209f12705fbb..cd2bd739c0df 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 5071778fdd20..4a885cc165e5 100644
--- a/arch/powerpc/mm/pkeys.c
+++ b/arch/powerpc/mm/pkeys.c
@@ -386,3 +386,37 @@ 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);
+}