From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754221Ab3JHC5q (ORCPT ); Mon, 7 Oct 2013 22:57:46 -0400 Received: from smtp.outflux.net ([198.145.64.163]:53826 "EHLO smtp.outflux.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752045Ab3JHC5U (ORCPT ); Mon, 7 Oct 2013 22:57:20 -0400 From: Kees Cook To: akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org, Tetsuo Handa , joe@perches.com, keescook@chromium.org Subject: [PATCH 1/3] seq_file: Introduce seq_setwidth() and seq_pad() Date: Mon, 7 Oct 2013 19:56:49 -0700 Message-Id: <1381201011-4230-1-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 1.7.9.5 X-HELO: www.outflux.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tetsuo Handa There are several users who want to know bytes written by seq_*() for alignment purpose. Currently they are using %n format for knowing it because seq_*() returns 0 on success. This patch introduces seq_setwidth() and seq_pad() for allowing them to align without using %n format. Signed-off-by: Tetsuo Handa Acked-by: Kees Cook --- fs/seq_file.c | 15 +++++++++++++++ include/linux/seq_file.h | 15 +++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/fs/seq_file.c b/fs/seq_file.c index 3135c25..40e471e 100644 --- a/fs/seq_file.c +++ b/fs/seq_file.c @@ -764,6 +764,21 @@ int seq_write(struct seq_file *seq, const void *data, size_t len) } EXPORT_SYMBOL(seq_write); +/** + * seq_pad - write padding spaces to buffer + * @m: seq_file identifying the buffer to which data should be written + * @c: the byte to append after padding if non-zero + */ +void seq_pad(struct seq_file *m, char c) +{ + int size = m->pad_until - m->count; + if (size > 0) + seq_printf(m, "%*s", size, ""); + if (c) + seq_putc(m, c); +} +EXPORT_SYMBOL(seq_pad); + struct list_head *seq_list_start(struct list_head *head, loff_t pos) { struct list_head *lh; diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h index 4e32edc..52e0097 100644 --- a/include/linux/seq_file.h +++ b/include/linux/seq_file.h @@ -20,6 +20,7 @@ struct seq_file { size_t size; size_t from; size_t count; + size_t pad_until; loff_t index; loff_t read_pos; u64 version; @@ -79,6 +80,20 @@ static inline void seq_commit(struct seq_file *m, int num) } } +/** + * seq_setwidth - set padding width + * @m: the seq_file handle + * @size: the max number of bytes to pad. + * + * Call seq_setwidth() for setting max width, then call seq_printf() etc. and + * finally call seq_pad() to pad the remaining bytes. + */ +static inline void seq_setwidth(struct seq_file *m, size_t size) +{ + m->pad_until = m->count + size; +} +void seq_pad(struct seq_file *m, char c); + char *mangle_path(char *s, const char *p, const char *esc); int seq_open(struct file *, const struct seq_operations *); ssize_t seq_read(struct file *, char __user *, size_t, loff_t *); -- 1.7.9.5