diff options
| -rw-r--r-- | fs/proc/generic.c | 47 |
1 files changed, 23 insertions, 24 deletions
diff --git a/fs/proc/generic.c b/fs/proc/generic.c index b638fb50074340..72b431d0a0a412 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) |