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Subject[PATCH v1 08/30] powerpc/vdso: Use VDSO size in arch_setup_additional_pages()
Date
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: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/vdso.c | 18 ++++++------------
1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c
index a24f6a583fac..448ecaa27ac5 100644
--- a/arch/powerpc/kernel/vdso.c
+++ b/arch/powerpc/kernel/vdso.c
@@ -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);
--
2.25.0
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