From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Thu, 02 Dec 2021 11:50:36 +0100 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by lore.white.stw.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1msjfg-0003e7-8Y for lore@lore.pengutronix.de; Thu, 02 Dec 2021 11:50:36 +0100 Received: from bombadil.infradead.org ([2607:7c80:54:e::133]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1msjff-0001a5-CF for lore@pengutronix.de; Thu, 02 Dec 2021 11:50:36 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=ABpSHHhO5a8GLDPpypxBqTP9rbsi5FyPBlzNtgs9Bbk=; b=00X9nKjTkBHRms OiOBbjqjWUb7FJX78UXJutE7JlAvpW5zNjhxEvgmP5rsz7LXl6u67K5029z1XPoWuxJkMrzDRZttq 7/MCVu4P1aWc9nd+I4PZ1OueIev9TnYghCGRaLY/btynNLdYCkdQ7wWDi47CJC8ihLIhtTB0YtzCk FPW/F2XfcEJR1Ju82776Q9016oEz1ecM72yd32RMO4dnnjkPwzC3/c1E7gd4/xIyhAMgL90PCZZKG IaWc0Dnxy43rffqLng3f4zihP9aAEG/O43GM4DhxAy2CzLO/BewuhiY/qGKM4NVydTVUGOufZRya5 PSoXi/3GA/cD0ajfClRQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1msjdw-00Bsct-Qo; Thu, 02 Dec 2021 10:48:48 +0000 Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1msjdr-00BsaR-DY for barebox@lists.infradead.org; Thu, 02 Dec 2021 10:48:44 +0000 Received: from dude02.hi.pengutronix.de ([2001:67c:670:100:1d::28]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1msjdn-0001Mj-Nu; Thu, 02 Dec 2021 11:48:39 +0100 Received: from has by dude02.hi.pengutronix.de with local (Exim 4.94.2) (envelope-from ) id 1msjdn-00GPxF-95; Thu, 02 Dec 2021 11:48:39 +0100 From: Holger Assmann To: barebox@lists.infradead.org Date: Thu, 2 Dec 2021 11:48:37 +0100 Message-Id: <20211202104837.3912925-1-h.assmann@pengutronix.de> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211202_024843_480014_03DE765B X-CRM114-Status: GOOD ( 14.92 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: afa@pengutronix.de, Holger Assmann Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:e::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.ext.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-4.9 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: [PATCH] fs: jffs2: fix error when reading blocks with offset X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.ext.pengutronix.de) This bug resulted in a panic when trying to read a file partially with an offset, e.g. when starting Linux. In such a case a header is loaded by a separate call of jffs2_read(), which then copies only the first n bytes out of the respective block. When the remaining data of the block is then subsequently going to to be read the system deviates in its behaviour from that under Linux by not calling jffs2_read_inode_range() in a 4k-alignment, but with an offset. jffs2_read_inode_range() originates from the Linux jffs2 driver. When being called with an offset it still reads 4096 bytes of data and eventually returns fragments of two consecutive blocks. jffs2_read() then reads this result whilst again applying the offset, therefore returning faulty data. We fix that problem by calling jffs2_get_block() without an offset and therefore reading the whole block. The offset is then applied when we actually perform memcpy with the returned buffer. This fix might also increase the performance since the respective block is likely to be cached from the previous call. Signed-off-by: Holger Assmann --- fs/jffs2/fs.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/jffs2/fs.c b/fs/jffs2/fs.c index 1a2b443792..3d4cb98c97 100644 --- a/fs/jffs2/fs.c +++ b/fs/jffs2/fs.c @@ -74,6 +74,9 @@ static int jffs2_get_block(struct jffs2_file *jf, unsigned int pos) struct jffs2_inode_info *f = JFFS2_INODE_INFO(jf->inode); int ret; + /* pos always has to be 4096 bytes aligned here */ + WARN_ON(pos % 4096 != 0); + if (pos != jf->offset) { ret = jffs2_read_inode_range(c, f, jf->buf, pos, JFFS2_BLOCK_SIZE); @@ -98,13 +101,14 @@ static int jffs2_read(struct device_d *_dev, FILE *f, void *buf, /* Read till end of current block */ ofs = f->pos % JFFS2_BLOCK_SIZE; if (ofs) { - ret = jffs2_get_block(jf, pos); + ret = jffs2_get_block(jf, f->pos - ofs); /* Align down block */ if (ret) return ret; now = min(size, JFFS2_BLOCK_SIZE - ofs); - memcpy(buf, jf->buf + ofs, now); + /* Complete block has been read, re-apply ofset now */ + memcpy(buf, jf->buf + ofs, now); size -= now; pos += now; buf += now; -- 2.30.2 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox