riscv: set the permission of vdso_data to read-only

The original vdso_data page is empty, so the permission of the vdso_data
page can be the same with the vdso text page. After introducing the vDSO
common flow, the vdso_data is not empty and the permission should be
changed to read-only.

Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
This commit is contained in:
Vincent Chen 2020-06-09 22:14:49 +08:00 committed by Palmer Dabbelt
parent ad5d1122b8
commit 01f76386b0
No known key found for this signature in database
GPG Key ID: 2E1319F35FBB1889
1 changed files with 14 additions and 2 deletions

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@ -79,13 +79,22 @@ int arch_setup_additional_pages(struct linux_binprm *bprm,
*/
mm->context.vdso = (void *)vdso_base;
ret = install_special_mapping(mm, vdso_base, vdso_len,
ret =
install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
(VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC),
vdso_pagelist);
if (unlikely(ret)) {
mm->context.vdso = NULL;
goto end;
}
vdso_base += (vdso_pages << PAGE_SHIFT);
ret = install_special_mapping(mm, vdso_base, PAGE_SIZE,
(VM_READ | VM_MAYREAD), &vdso_pagelist[vdso_pages]);
if (unlikely(ret))
mm->context.vdso = NULL;
end:
up_write(&mm->mmap_sem);
return ret;
@ -95,5 +104,8 @@ const char *arch_vma_name(struct vm_area_struct *vma)
{
if (vma->vm_mm && (vma->vm_start == (long)vma->vm_mm->context.vdso))
return "[vdso]";
if (vma->vm_mm && (vma->vm_start ==
(long)vma->vm_mm->context.vdso + PAGE_SIZE))
return "[vdso_data]";
return NULL;
}