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Diffstat (limited to 'arch/s390/kernel/vdso.c')
-rw-r--r--arch/s390/kernel/vdso.c91
1 files changed, 64 insertions, 27 deletions
diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c
index 10516ae3b55e..b89d19f6f2ab 100644
--- a/arch/s390/kernel/vdso.c
+++ b/arch/s390/kernel/vdso.c
@@ -50,6 +50,56 @@ static struct page **vdso64_pagelist;
*/
unsigned int __read_mostly vdso_enabled = 1;
+static int vdso_fault(const struct vm_special_mapping *sm,
+ struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+ struct page **vdso_pagelist;
+ unsigned long vdso_pages;
+
+ vdso_pagelist = vdso64_pagelist;
+ vdso_pages = vdso64_pages;
+#ifdef CONFIG_COMPAT
+ if (is_compat_task()) {
+ vdso_pagelist = vdso32_pagelist;
+ vdso_pages = vdso32_pages;
+ }
+#endif
+
+ if (vmf->pgoff >= vdso_pages)
+ return VM_FAULT_SIGBUS;
+
+ vmf->page = vdso_pagelist[vmf->pgoff];
+ get_page(vmf->page);
+ return 0;
+}
+
+static int vdso_mremap(const struct vm_special_mapping *sm,
+ struct vm_area_struct *vma)
+{
+ unsigned long vdso_pages;
+
+ vdso_pages = vdso64_pages;
+#ifdef CONFIG_COMPAT
+ if (is_compat_task())
+ vdso_pages = vdso32_pages;
+#endif
+
+ if ((vdso_pages << PAGE_SHIFT) != vma->vm_end - vma->vm_start)
+ return -EINVAL;
+
+ if (WARN_ON_ONCE(current->mm != vma->vm_mm))
+ return -EFAULT;
+
+ current->mm->context.vdso_base = vma->vm_start;
+ return 0;
+}
+
+static const struct vm_special_mapping vdso_mapping = {
+ .name = "[vdso]",
+ .fault = vdso_fault,
+ .mremap = vdso_mremap,
+};
+
static int __init vdso_setup(char *s)
{
unsigned long val;
@@ -181,7 +231,7 @@ static void vdso_init_cr5(void)
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
struct mm_struct *mm = current->mm;
- struct page **vdso_pagelist;
+ struct vm_area_struct *vma;
unsigned long vdso_pages;
unsigned long vdso_base;
int rc;
@@ -194,13 +244,10 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
if (!uses_interp)
return 0;
- vdso_pagelist = vdso64_pagelist;
vdso_pages = vdso64_pages;
#ifdef CONFIG_COMPAT
- if (is_compat_task()) {
- vdso_pagelist = vdso32_pagelist;
+ if (is_compat_task())
vdso_pages = vdso32_pages;
- }
#endif
/*
* vDSO has a problem and was disabled, just don't "enable" it for
@@ -209,8 +256,6 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
if (vdso_pages == 0)
return 0;
- current->mm->context.vdso_base = 0;
-
/*
* pick a base address for the vDSO in process space. We try to put
* it at vdso_base which is the "natural" base for it, but we might
@@ -225,13 +270,6 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
}
/*
- * Put vDSO base into mm struct. We need to do this before calling
- * install_special_mapping or the perf counter mmap tracking code
- * will fail to recognise it as a vDSO (since arch_vma_name fails).
- */
- current->mm->context.vdso_base = vdso_base;
-
- /*
* our vma flags don't have VM_WRITE so by default, the process
* isn't allowed to write those pages.
* gdb can break that with ptrace interface, and thus trigger COW
@@ -241,24 +279,23 @@ 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,
- VM_READ|VM_EXEC|
- VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
- vdso_pagelist);
- if (rc)
- current->mm->context.vdso_base = 0;
+ vma = _install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
+ VM_READ|VM_EXEC|
+ VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
+ &vdso_mapping);
+ if (IS_ERR(vma)) {
+ rc = PTR_ERR(vma);
+ goto out_up;
+ }
+
+ current->mm->context.vdso_base = vdso_base;
+ rc = 0;
+
out_up:
up_write(&mm->mmap_sem);
return rc;
}
-const char *arch_vma_name(struct vm_area_struct *vma)
-{
- if (vma->vm_mm && vma->vm_start == vma->vm_mm->context.vdso_base)
- return "[vdso]";
- return NULL;
-}
-
static int __init vdso_init(void)
{
int i;