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arm64: vdso: move to _install_special_mapping and remove arch_vma_name

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_install_special_mapping replaces install_special_mapping and removes
the need to detect special VMA in arch_vma_name.

This patch moves the vdso and compat vectors page code over to the new
API.

Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Will Deacon 2014-07-09 19:22:12 +01:00 committed by Catalin Marinas
parent 8715493852
commit 2fea7f6c98
1 changed files with 35 additions and 45 deletions
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80
arch/arm64/kernel/vdso.c
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@ -88,22 +88,29 @@ int aarch32_setup_vectors_page(struct linux_binprm *bprm, int uses_interp)
{ {
struct mm_struct *mm = current->mm; struct mm_struct *mm = current->mm;
unsigned long addr = AARCH32_VECTORS_BASE; unsigned long addr = AARCH32_VECTORS_BASE;
int ret; static struct vm_special_mapping spec = {
.name = "[vectors]",
.pages = vectors_page,
};
void *ret;
down_write(&mm->mmap_sem); down_write(&mm->mmap_sem);
current->mm->context.vdso = (void *)addr; current->mm->context.vdso = (void *)addr;
/* Map vectors page at the high address. */ /* Map vectors page at the high address. */
ret = install_special_mapping(mm, addr, PAGE_SIZE, ret = _install_special_mapping(mm, addr, PAGE_SIZE,
VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC, VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC,
vectors_page); &spec);
up_write(&mm->mmap_sem); up_write(&mm->mmap_sem);
return ret; return PTR_ERR_OR_ZERO(ret);
} }
#endif /* CONFIG_COMPAT */ #endif /* CONFIG_COMPAT */
static struct vm_special_mapping vdso_spec[2];
static int __init vdso_init(void) static int __init vdso_init(void)
{ {
int i; int i;
@ -130,6 +137,17 @@ static int __init vdso_init(void)
/* Grab the vDSO data page. */ /* Grab the vDSO data page. */
vdso_pagelist[i] = virt_to_page(vdso_data); vdso_pagelist[i] = virt_to_page(vdso_data);
/* Populate the special mapping structures */
vdso_spec[0] = (struct vm_special_mapping) {
.name = "[vdso]",
.pages = vdso_pagelist,
};
vdso_spec[1] = (struct vm_special_mapping) {
.name = "[vvar]",
.pages = vdso_pagelist + vdso_pages,
};
return 0; return 0;
} }
arch_initcall(vdso_init); arch_initcall(vdso_init);
@ -139,7 +157,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm,
{ {
struct mm_struct *mm = current->mm; struct mm_struct *mm = current->mm;
unsigned long vdso_base, vdso_text_len, vdso_mapping_len; unsigned long vdso_base, vdso_text_len, vdso_mapping_len;
int ret; void *ret;
vdso_text_len = vdso_pages << PAGE_SHIFT; vdso_text_len = vdso_pages << PAGE_SHIFT;
/* Be sure to map the data page */ /* Be sure to map the data page */
@ -148,23 +166,23 @@ int arch_setup_additional_pages(struct linux_binprm *bprm,
down_write(&mm->mmap_sem); down_write(&mm->mmap_sem);
vdso_base = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0); vdso_base = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0);
if (IS_ERR_VALUE(vdso_base)) { if (IS_ERR_VALUE(vdso_base)) {
ret = vdso_base; ret = ERR_PTR(vdso_base);
goto up_fail; goto up_fail;
} }
mm->context.vdso = (void *)vdso_base; mm->context.vdso = (void *)vdso_base;
ret = install_special_mapping(mm, vdso_base, vdso_text_len, ret = _install_special_mapping(mm, vdso_base, vdso_text_len,
VM_READ|VM_EXEC| VM_READ|VM_EXEC|
VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC, VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
vdso_pagelist); &vdso_spec[0]);
if (ret) if (IS_ERR(ret))
goto up_fail; goto up_fail;
vdso_base += vdso_text_len; vdso_base += vdso_text_len;
ret = install_special_mapping(mm, vdso_base, PAGE_SIZE, ret = _install_special_mapping(mm, vdso_base, PAGE_SIZE,
VM_READ|VM_MAYREAD, VM_READ|VM_MAYREAD,
vdso_pagelist + vdso_pages); &vdso_spec[1]);
if (ret) if (IS_ERR(ret))
goto up_fail; goto up_fail;
up_write(&mm->mmap_sem); up_write(&mm->mmap_sem);
@ -173,35 +191,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm,
up_fail: up_fail:
mm->context.vdso = NULL; mm->context.vdso = NULL;
up_write(&mm->mmap_sem); up_write(&mm->mmap_sem);
return ret; return PTR_ERR(ret);
}
const char *arch_vma_name(struct vm_area_struct *vma)
{
unsigned long vdso_text;
if (!vma->vm_mm)
return NULL;
vdso_text = (unsigned long)vma->vm_mm->context.vdso;
/*
* We can re-use the vdso pointer in mm_context_t for identifying
* the vectors page for compat applications. The vDSO will always
* sit above TASK_UNMAPPED_BASE and so we don't need to worry about
* it conflicting with the vectors base.
*/
if (vma->vm_start == vdso_text) {
#ifdef CONFIG_COMPAT
if (vma->vm_start == AARCH32_VECTORS_BASE)
return "[vectors]";
#endif
return "[vdso]";
} else if (vma->vm_start == (vdso_text + (vdso_pages << PAGE_SHIFT))) {
return "[vvar]";
}
return NULL;
} }
/* /*