mm/core, x86/mm/pkeys: Add execute-only protection keys support

[cascardo/linux.git] / mm / mmap.c

diff --git a/mm/mmap.c b/mm/mmap.c
index 2f2415a..0175b7d 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -43,6 +43,7 @@
 #include <linux/printk.h>
 #include <linux/userfaultfd_k.h>
 #include <linux/moduleparam.h>
+#include <linux/pkeys.h>
 
 #include <asm/uaccess.h>
 #include <asm/cacheflush.h>
@@ -1270,6 +1271,7 @@ unsigned long do_mmap(struct file *file, unsigned long addr,
                        unsigned long pgoff, unsigned long *populate)
 {
        struct mm_struct *mm = current->mm;
+       int pkey = 0;
 
        *populate = 0;
 
@@ -1309,11 +1311,17 @@ unsigned long do_mmap(struct file *file, unsigned long addr,
        if (offset_in_page(addr))
                return addr;
 
+       if (prot == PROT_EXEC) {
+               pkey = execute_only_pkey(mm);
+               if (pkey < 0)
+                       pkey = 0;
+       }
+
        /* Do simple checking here so the lower-level routines won't have
         * to. we assume access permissions have been handled by the open
         * of the memory object, so we don't do any here.
         */
-       vm_flags |= calc_vm_prot_bits(prot) | calc_vm_flag_bits(flags) |
+       vm_flags |= calc_vm_prot_bits(prot, pkey) | calc_vm_flag_bits(flags) |
                        mm->def_flags | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
 
        if (flags & MAP_LOCKED)
@@ -3042,11 +3050,16 @@ static int special_mapping_fault(struct vm_area_struct *vma,
        pgoff_t pgoff;
        struct page **pages;
 
-       if (vma->vm_ops == &legacy_special_mapping_vmops)
+       if (vma->vm_ops == &legacy_special_mapping_vmops) {
                pages = vma->vm_private_data;
-       else
-               pages = ((struct vm_special_mapping *)vma->vm_private_data)->
-                       pages;
+       } else {
+               struct vm_special_mapping *sm = vma->vm_private_data;
+
+               if (sm->fault)
+                       return sm->fault(sm, vma, vmf);
+
+               pages = sm->pages;
+       }
 
        for (pgoff = vmf->pgoff; pgoff && *pages; ++pages)
                pgoff--;