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authorLinus Torvalds <torvalds@g5.osdl.org>2005-12-30 08:39:10 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2005-12-30 08:39:10 -0800
commit8b90db0df7187a01fb7177f1f812123138f562cf (patch)
tree8d7029403cc50d822bc22085202bfdbf6110203b
parent40c37213a081990b1d3778f57630f97df75a7ec1 (diff)
Insanity avoidance in /proc
The old /proc interfaces were never updated to use loff_t, and are just generally broken. Now, we should be using the seq_file interface for all of the proc files, but converting the legacy functions is more work than most people care for and has little upside.. But at least we can make the non-LFS rules explicit, rather than just insanely wrapping the offset or something. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-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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