[PATCH 1/3] mm: use long type for page counts in mm_populate() and get_user_pages()
From: Michel Lespinasse
Date: Wed Jan 30 2013 - 19:26:35 EST
Use long type for page counts in mm_populate() so as to avoid integer
overflow when running the following test code:
int main(void) {
void *p = mmap(NULL, 0x100000000000, PROT_READ,
MAP_PRIVATE | MAP_ANON, -1, 0);
printf("p: %p\n", p);
mlockall(MCL_CURRENT);
printf("done\n");
return 0;
}
Signed-off-by: Michel Lespinasse <walken@xxxxxxxxxx>
---
include/linux/hugetlb.h | 6 +++---
include/linux/mm.h | 14 +++++++-------
mm/hugetlb.c | 10 +++++-----
mm/memory.c | 14 +++++++-------
mm/mlock.c | 5 +++--
5 files changed, 25 insertions(+), 24 deletions(-)
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 0c80d3f57a5b..fc6ed17cfd17 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -43,9 +43,9 @@ int hugetlb_mempolicy_sysctl_handler(struct ctl_table *, int,
#endif
int copy_hugetlb_page_range(struct mm_struct *, struct mm_struct *, struct vm_area_struct *);
-int follow_hugetlb_page(struct mm_struct *, struct vm_area_struct *,
- struct page **, struct vm_area_struct **,
- unsigned long *, int *, int, unsigned int flags);
+long follow_hugetlb_page(struct mm_struct *, struct vm_area_struct *,
+ struct page **, struct vm_area_struct **,
+ unsigned long *, long *, long, unsigned int flags);
void unmap_hugepage_range(struct vm_area_struct *,
unsigned long, unsigned long, struct page *);
void __unmap_hugepage_range_final(struct mmu_gather *tlb,
diff --git a/include/linux/mm.h b/include/linux/mm.h
index a224430578f0..d5716094f191 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1040,13 +1040,13 @@ extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void *
extern int access_remote_vm(struct mm_struct *mm, unsigned long addr,
void *buf, int len, int write);
-int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
- unsigned long start, int len, unsigned int foll_flags,
- struct page **pages, struct vm_area_struct **vmas,
- int *nonblocking);
-int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
- unsigned long start, int nr_pages, int write, int force,
- struct page **pages, struct vm_area_struct **vmas);
+long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
+ unsigned long start, long len, unsigned int foll_flags,
+ struct page **pages, struct vm_area_struct **vmas,
+ int *nonblocking);
+long get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
+ unsigned long start, long nr_pages, int write, int force,
+ struct page **pages, struct vm_area_struct **vmas);
int get_user_pages_fast(unsigned long start, int nr_pages, int write,
struct page **pages);
struct kvec;
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 4f3ea0b1e57c..4ad07221ce60 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2924,14 +2924,14 @@ follow_huge_pud(struct mm_struct *mm, unsigned long address,
return NULL;
}
-int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
- struct page **pages, struct vm_area_struct **vmas,
- unsigned long *position, int *length, int i,
- unsigned int flags)
+long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
+ struct page **pages, struct vm_area_struct **vmas,
+ unsigned long *position, long *length, long i,
+ unsigned int flags)
{
unsigned long pfn_offset;
unsigned long vaddr = *position;
- int remainder = *length;
+ long remainder = *length;
struct hstate *h = hstate_vma(vma);
spin_lock(&mm->page_table_lock);
diff --git a/mm/memory.c b/mm/memory.c
index f56683208e7f..381b78c20d84 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1673,12 +1673,12 @@ static inline int stack_guard_page(struct vm_area_struct *vma, unsigned long add
* instead of __get_user_pages. __get_user_pages should be used only if
* you need some special @gup_flags.
*/
-int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
- unsigned long start, int nr_pages, unsigned int gup_flags,
- struct page **pages, struct vm_area_struct **vmas,
- int *nonblocking)
+long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
+ unsigned long start, long nr_pages, unsigned int gup_flags,
+ struct page **pages, struct vm_area_struct **vmas,
+ int *nonblocking)
{
- int i;
+ long i;
unsigned long vm_flags;
if (nr_pages <= 0)
@@ -1977,8 +1977,8 @@ int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm,
*
* See also get_user_pages_fast, for performance critical applications.
*/
-int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
- unsigned long start, int nr_pages, int write, int force,
+long get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
+ unsigned long start, long nr_pages, int write, int force,
struct page **pages, struct vm_area_struct **vmas)
{
int flags = FOLL_TOUCH;
diff --git a/mm/mlock.c b/mm/mlock.c
index b1647fbd6bce..e1fa9e4b0a66 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -160,7 +160,7 @@ long __mlock_vma_pages_range(struct vm_area_struct *vma,
{
struct mm_struct *mm = vma->vm_mm;
unsigned long addr = start;
- int nr_pages = (end - start) / PAGE_SIZE;
+ long nr_pages = (end - start) / PAGE_SIZE;
int gup_flags;
VM_BUG_ON(start & ~PAGE_MASK);
@@ -378,7 +378,7 @@ int __mm_populate(unsigned long start, unsigned long len, int ignore_errors)
unsigned long end, nstart, nend;
struct vm_area_struct *vma = NULL;
int locked = 0;
- int ret = 0;
+ long ret = 0;
VM_BUG_ON(start & ~PAGE_MASK);
VM_BUG_ON(len != PAGE_ALIGN(len));
@@ -421,6 +421,7 @@ int __mm_populate(unsigned long start, unsigned long len, int ignore_errors)
ret = __mlock_posix_error_return(ret);
break;
}
+ VM_BUG_ON(!ret);
nend = nstart + ret * PAGE_SIZE;
ret = 0;
}
--
1.8.1
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