Messages in this thread |  | | | From | OGAWA Hirofumi <> | | Subject | Re: [PATCH 6/6] vfs: introduce FMODE_NEG_OFFSET for allowing negative f_pos | | Date | Sat, 16 Jan 2010 21:54:39 +0900 |
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Wu Fengguang <fengguang.wu@intel.com> writes:
> +static int > +__negative_fpos_check(struct file *file, loff_t pos, size_t count) > +{ > + /* > + * pos or pos+count is negative here, check overflow. > + * too big "count" will be caught in rw_verify_area(). > + */ > + if ((pos < 0) && (pos + count < pos)) > + return -EOVERFLOW; > + if (file->f_mode & FMODE_NEG_OFFSET) > + return 0; > + return -EINVAL; > +} > + > /* > * rw_verify_area doesn't like huge counts. We limit > * them to something that fits in "int" so that others > @@ -222,8 +236,11 @@ int rw_verify_area(int read_write, struc > if (unlikely((ssize_t) count < 0)) > return retval; > pos = *ppos; > - if (unlikely((pos < 0) || (loff_t) (pos + count) < 0)) > - return retval; > + if (unlikely((pos < 0) || (loff_t) (pos + count) < 0)) { > + retval = __negative_fpos_check(file, pos, count); > + if (retval) > + return retval; > + } > > if (unlikely(inode->i_flock && mandatory_lock(inode))) { > retval = locks_mandatory_area(
Um... How do lseek() work? It sounds like to violate error code range. -- OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
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