#define thread_pkey_regs_save(thread)
#define thread_pkey_regs_restore(new_thread, old_thread)
#define thread_pkey_regs_init(thread)
+
+static inline int vma_pkey(struct vm_area_struct *vma)
+{
+ return 0;
+}
#endif /* CONFIG_PPC_MEM_KEYS */
#endif /* __KERNEL__ */
return (((u64)pkey << VM_PKEY_SHIFT) & ARCH_VM_PKEY_FLAGS);
}
+static inline int vma_pkey(struct vm_area_struct *vma)
+{
+ if (static_branch_likely(&pkey_disabled))
+ return 0;
+ return (vma->vm_flags & ARCH_VM_PKEY_FLAGS) >> VM_PKEY_SHIFT;
+}
+
#define arch_max_pkey() pkeys_total
#define pkey_alloc_mask(pkey) (0x1 << pkey)
return __execute_only_pkey(mm);
}
+extern int __arch_override_mprotect_pkey(struct vm_area_struct *vma,
+ int prot, int pkey);
static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma,
int prot, int pkey)
{
- return 0;
+ if (static_branch_likely(&pkey_disabled))
+ return 0;
+
+ /*
+ * Is this an mprotect_pkey() call? If so, never override the value that
+ * came from the user.
+ */
+ if (pkey != -1)
+ return pkey;
+
+ return __arch_override_mprotect_pkey(vma, prot, pkey);
}
extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
mm->context.execute_only_pkey = execute_only_pkey;
return execute_only_pkey;
}
+
+static inline bool vma_is_pkey_exec_only(struct vm_area_struct *vma)
+{
+ /* Do this check first since the vm_flags should be hot */
+ if ((vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC)) != VM_EXEC)
+ return false;
+
+ return (vma_pkey(vma) == vma->vm_mm->context.execute_only_pkey);
+}
+
+/*
+ * This should only be called for *plain* mprotect calls.
+ */
+int __arch_override_mprotect_pkey(struct vm_area_struct *vma, int prot,
+ int pkey)
+{
+ /*
+ * If the currently associated pkey is execute-only, but the requested
+ * protection requires read or write, move it back to the default pkey.
+ */
+ if (vma_is_pkey_exec_only(vma) && (prot & (PROT_READ | PROT_WRITE)))
+ return 0;
+
+ /*
+ * The requested protection is execute-only. Hence let's use an
+ * execute-only pkey.
+ */
+ if (prot == PROT_EXEC) {
+ pkey = execute_only_pkey(vma->vm_mm);
+ if (pkey > 0)
+ return pkey;
+ }
+
+ /* Nothing to override. */
+ return vma_pkey(vma);
+}