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-rw-r--r--fs/proc/generic.c47
1 files changed, 23 insertions, 24 deletions
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index b638fb500743..72b431d0a0a4 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -54,6 +54,18 @@ proc_file_read(struct file *file, char __user *buf, size_t nbytes,
ssize_t n, count;
char *start;
struct proc_dir_entry * dp;
+ unsigned long long pos;
+
+ /*
+ * Gaah, please just use "seq_file" instead. The legacy /proc
+ * interfaces cut loff_t down to off_t for reads, and ignore
+ * the offset entirely for writes..
+ */
+ pos = *ppos;
+ if (pos > MAX_NON_LFS)
+ return 0;
+ if (nbytes > MAX_NON_LFS - pos)
+ nbytes = MAX_NON_LFS - pos;
dp = PDE(inode);
if (!(page = (char*) __get_free_page(GFP_KERNEL)))
@@ -202,30 +214,17 @@ proc_file_write(struct file *file, const char __user *buffer,
static loff_t
proc_file_lseek(struct file *file, loff_t offset, int orig)
{
- lock_kernel();
-
- switch (orig) {
- case 0:
- if (offset < 0)
- goto out;
- file->f_pos = offset;
- unlock_kernel();
- return(file->f_pos);
- case 1:
- if (offset + file->f_pos < 0)
- goto out;
- file->f_pos += offset;
- unlock_kernel();
- return(file->f_pos);
- case 2:
- goto out;
- default:
- goto out;
- }
-
-out:
- unlock_kernel();
- return -EINVAL;
+ loff_t retval = -EINVAL;
+ switch (orig) {
+ case 1:
+ offset += file->f_pos;
+ /* fallthrough */
+ case 0:
+ if (offset < 0 || offset > MAX_NON_LFS)
+ break;
+ file->f_pos = retval = offset;
+ }
+ return retval;
}
static int proc_notify_change(struct dentry *dentry, struct iattr *iattr)

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