Commit 7461a4f7 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/vdso: Use VDSO size in arch_setup_additional_pages() 



In arch_setup_additional_pages(), instead of using number of VDSO
pages and recalculate VDSO size, directly use the VDSO size.

As vdso_ready is set, vdso_pages can't be 0 so just remove the test.

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4edfa548c3885a430b765335dc720105716e273f.1601197618.git.christophe.leroy@csgroup.eu
parent 4fe0e3c1

arch/powerpc/kernel/vdso.c

+6 −12
Original line number Diff line number Diff line
@@ -126,7 +126,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 
{

	struct mm_struct *mm = current->mm;

	struct page **vdso_pagelist;

	unsigned long vdso_pages;

	unsigned long vdso_size;

	unsigned long vdso_base;

	int rc;
@@ -135,11 +135,11 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 


	if (is_32bit_task()) {

		vdso_pagelist = vdso32_pagelist;

		vdso_pages = vdso32_pages;

		vdso_size = &vdso32_end - &vdso32_start;

		vdso_base = VDSO32_MBASE;

	} else {

		vdso_pagelist = vdso64_pagelist;

		vdso_pages = vdso64_pages;

		vdso_size = &vdso64_end - &vdso64_start;

		/*

		 * On 64bit we don't have a preferred map address. This

		 * allows get_unmapped_area to find an area near other mmaps
@@ -150,13 +150,8 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 


	current->mm->context.vdso_base = 0;



	/* vDSO has a problem and was disabled, just don't "enable" it for the

	 * process

	 */

	if (vdso_pages == 0)

		return 0;

	/* Add a page to the vdso size for the data page */

	vdso_pages ++;

	vdso_size += PAGE_SIZE;



	/*

	 * pick a base address for the vDSO in process space. We try to put it
@@ -167,8 +162,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 
	if (mmap_write_lock_killable(mm))

		return -EINTR;

	vdso_base = get_unmapped_area(NULL, vdso_base,

				      (vdso_pages << PAGE_SHIFT) +

				      ((VDSO_ALIGNMENT - 1) & PAGE_MASK),

				      vdso_size + ((VDSO_ALIGNMENT - 1) & PAGE_MASK),

				      0, 0);

	if (IS_ERR_VALUE(vdso_base)) {

		rc = vdso_base;
@@ -195,7 +189,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) 
	 * It's fine to use that for setting breakpoints in the vDSO code

	 * pages though.

	 */

	rc = install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,

	rc = install_special_mapping(mm, vdso_base, vdso_size,

				     VM_READ|VM_EXEC|

				     VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,

				     vdso_pagelist);