Unverified Commit 01f76386 authored by Vincent Chen's avatar Vincent Chen Committed by Palmer Dabbelt
Browse files

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: default avatarVincent Chen <vincent.chen@sifive.com>
Signed-off-by: default avatarPalmer Dabbelt <palmerdabbelt@google.com>
parent ad5d1122

arch/riscv/kernel/vdso.c

+14 −2
Original line number Diff line number Diff line
@@ -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))

	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;

}

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