On Thu, 11 Apr 2013 15:28:51 +0400 Pavel Emelyanov <xe...@parallels.com> wrote:
> A new clear-refs type will be added in the next patch, so prepare
> code for that.
>
> @@ -730,7 +733,7 @@ static ssize_t clear_refs_write(struct file *file, const
> char __user *buf,
> char buffer[PROC_NUMBUF];
> struct mm_struct *mm;
> struct vm_area_struct *vma;
> - int type;
> + enum clear_refs_types type;
> int rv;
>
> memset(buffer, 0, sizeof(buffer));
> @@ -738,10 +741,10 @@ static ssize_t clear_refs_write(struct file *file,
> const char __user *buf,
> count = sizeof(buffer) - 1;
> if (copy_from_user(buffer, buf, count))
> return -EFAULT;
> - rv = kstrtoint(strstrip(buffer), 10, &type);
> + rv = kstrtoint(strstrip(buffer), 10, (int *)&type);
This is naughty. The compiler is allowed to put the enum into storage
which is smaller (or, I guess, larger) than sizeof(int). I've seen one
compiler which puts such an enum into a 16-bit word.
--- a/fs/proc/task_mmu.c~clear_refs-sanitize-accepted-commands-declaration-fix
+++ a/fs/proc/task_mmu.c
@@ -734,6 +734,7 @@ static ssize_t clear_refs_write(struct f
struct mm_struct *mm;
struct vm_area_struct *vma;
enum clear_refs_types type;
+ int itype;
int rv;
memset(buffer, 0, sizeof(buffer));
@@ -741,9 +742,10 @@ static ssize_t clear_refs_write(struct f
count = sizeof(buffer) - 1;
if (copy_from_user(buffer, buf, count))
return -EFAULT;
- rv = kstrtoint(strstrip(buffer), 10, (int *)&type);
+ rv = kstrtoint(strstrip(buffer), 10, &itype);
if (rv < 0)
return rv;
+ type = (enum clear_refs_types)itype;
if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
return -EINVAL;
task = get_proc_task(file_inode(file));
_
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
