[PATCH 2/2] mm: various cleanups in get_user_pages()
This patch contains various cleanups, including making sure vma is valid, and
the return value of follow_hugetlb_page() is validated.
Signed-off-by: Eugene Teo <[EMAIL PROTECTED]>
---
mm/memory.c | 26 ++
1 files changed, 18 insertions(+), 8 deletions(-)
diff --git a/mm/memory.c b/mm/memory.c
index 54f951b..49403a8 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1003,7 +1003,9 @@ int get_user_pages(struct task_struct *tsk, struct
mm_struct *mm,
unsigned int foll_flags;
vma = find_extend_vma(mm, start);
- if (!vma && in_gate_area(tsk, start)) {
+ if (!vma)
+ goto finish_or_fault;
+ if (in_gate_area(tsk, start)) {
unsigned long pg = start & PAGE_MASK;
struct vm_area_struct *gate_vma = get_gate_vma(tsk);
pgd_t *pgd;
@@ -1011,7 +1013,7 @@ int get_user_pages(struct task_struct *tsk, struct
mm_struct *mm,
pmd_t *pmd;
pte_t *pte;
if (write) /* user gate pages are read-only */
- return i ? : -EFAULT;
+ goto finish_or_fault;
if (pg > TASK_SIZE)
pgd = pgd_offset_k(pg);
else
@@ -1021,11 +1023,11 @@ int get_user_pages(struct task_struct *tsk, struct
mm_struct *mm,
BUG_ON(pud_none(*pud));
pmd = pmd_offset(pud, pg);
if (pmd_none(*pmd))
- return i ? : -EFAULT;
+ goto finish_or_fault;
pte = pte_offset_map(pmd, pg);
if (pte_none(*pte)) {
pte_unmap(pte);
- return i ? : -EFAULT;
+ goto finish_or_fault;
}
if (pages) {
struct page *page = vm_normal_page(gate_vma,
start, *pte);
@@ -1041,13 +1043,15 @@ int get_user_pages(struct task_struct *tsk, struct
mm_struct *mm,
continue;
}
- if (!vma || (vma->vm_flags & (VM_IO | VM_PFNMAP))
+ if ((vma->vm_flags & (VM_IO | VM_PFNMAP))
|| !(vm_flags & vma->vm_flags))
- return i ? : -EFAULT;
+ goto finish_or_fault;
if (is_vm_hugetlb_page(vma)) {
i = follow_hugetlb_page(mm, vma, pages, vmas,
, len, i, write);
+ if (i == -EFAULT)
+ goto finish_or_fault;
continue;
}
@@ -1080,9 +1084,9 @@ int get_user_pages(struct task_struct *tsk, struct
mm_struct *mm,
foll_flags & FOLL_WRITE);
if (ret & VM_FAULT_ERROR) {
if (ret & VM_FAULT_OOM)
- return i ? i : -ENOMEM;
+ goto finish_or_oom;
else if (ret & VM_FAULT_SIGBUS)
- return i ? i : -EFAULT;
+ goto finish_or_fault;
BUG();
}
if (ret & VM_FAULT_MAJOR)
@@ -1115,6 +1119,12 @@ int get_user_pages(struct task_struct *tsk, struct
mm_struct *mm,
}
}
return i;
+
+finish_or_oom:
+ return i ? : -ENOMEM;
+
+finish_or_fault:
+ return i ? : -EFAULT;
}
EXPORT_SYMBOL(get_user_pages);
--
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[PATCH 2/2] mm: various cleanups in get_user_pages()
This patch contains various cleanups, including making sure vma is valid, and
the return value of follow_hugetlb_page() is validated.
Signed-off-by: Eugene Teo [EMAIL PROTECTED]
---
mm/memory.c | 26 ++
1 files changed, 18 insertions(+), 8 deletions(-)
diff --git a/mm/memory.c b/mm/memory.c
index 54f951b..49403a8 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1003,7 +1003,9 @@ int get_user_pages(struct task_struct *tsk, struct
mm_struct *mm,
unsigned int foll_flags;
vma = find_extend_vma(mm, start);
- if (!vma in_gate_area(tsk, start)) {
+ if (!vma)
+ goto finish_or_fault;
+ if (in_gate_area(tsk, start)) {
unsigned long pg = start PAGE_MASK;
struct vm_area_struct *gate_vma = get_gate_vma(tsk);
pgd_t *pgd;
@@ -1011,7 +1013,7 @@ int get_user_pages(struct task_struct *tsk, struct
mm_struct *mm,
pmd_t *pmd;
pte_t *pte;
if (write) /* user gate pages are read-only */
- return i ? : -EFAULT;
+ goto finish_or_fault;
if (pg TASK_SIZE)
pgd = pgd_offset_k(pg);
else
@@ -1021,11 +1023,11 @@ int get_user_pages(struct task_struct *tsk, struct
mm_struct *mm,
BUG_ON(pud_none(*pud));
pmd = pmd_offset(pud, pg);
if (pmd_none(*pmd))
- return i ? : -EFAULT;
+ goto finish_or_fault;
pte = pte_offset_map(pmd, pg);
if (pte_none(*pte)) {
pte_unmap(pte);
- return i ? : -EFAULT;
+ goto finish_or_fault;
}
if (pages) {
struct page *page = vm_normal_page(gate_vma,
start, *pte);
@@ -1041,13 +1043,15 @@ int get_user_pages(struct task_struct *tsk, struct
mm_struct *mm,
continue;
}
- if (!vma || (vma-vm_flags (VM_IO | VM_PFNMAP))
+ if ((vma-vm_flags (VM_IO | VM_PFNMAP))
|| !(vm_flags vma-vm_flags))
- return i ? : -EFAULT;
+ goto finish_or_fault;
if (is_vm_hugetlb_page(vma)) {
i = follow_hugetlb_page(mm, vma, pages, vmas,
start, len, i, write);
+ if (i == -EFAULT)
+ goto finish_or_fault;
continue;
}
@@ -1080,9 +1084,9 @@ int get_user_pages(struct task_struct *tsk, struct
mm_struct *mm,
foll_flags FOLL_WRITE);
if (ret VM_FAULT_ERROR) {
if (ret VM_FAULT_OOM)
- return i ? i : -ENOMEM;
+ goto finish_or_oom;
else if (ret VM_FAULT_SIGBUS)
- return i ? i : -EFAULT;
+ goto finish_or_fault;
BUG();
}
if (ret VM_FAULT_MAJOR)
@@ -1115,6 +1119,12 @@ int get_user_pages(struct task_struct *tsk, struct
mm_struct *mm,
}
}
return i;
+
+finish_or_oom:
+ return i ? : -ENOMEM;
+
+finish_or_fault:
+ return i ? : -EFAULT;
}
EXPORT_SYMBOL(get_user_pages);
--
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the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
