From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755613Ab3AHLjF (ORCPT ); Tue, 8 Jan 2013 06:39:05 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:27951 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754587Ab3AHLjE (ORCPT ); Tue, 8 Jan 2013 06:39:04 -0500 Date: Tue, 8 Jan 2013 14:38:51 +0300 From: Dan Carpenter To: Tomoya MORINAGA Cc: Arnd Bergmann , Greg Kroah-Hartman , linux-kernel@vger.kernel.org Subject: Re: add Packet hub driver for Topcliff Platform controller hub Message-ID: <20130108113851.GP7302@mwanda> References: <20130107090210.GA20716@elgon.mountain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: ucsinet22.oracle.com [156.151.31.94] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 08, 2013 at 07:30:34PM +0900, Tomoya MORINAGA wrote: > Hi Dan, > > On Mon, Jan 7, 2013 at 6:02 PM, Dan Carpenter wrote: > > The patch cf4ece53460c: "add Packet hub driver for Topcliff Platform > > controller hub" from Sep 1, 2010, leads to the following warning: > > drivers/misc/pch_phub.c:596 pch_phub_bin_write() > > error: buffer overflow 'buf' 4096 <= 15359 > > > > Sorry my question is about an old patch. Smatch complains because we > > only pass a PAGE_SIZE buffer to sysfs files so the test for > > "if (count > PCH_PHUB_OROM_SIZE) {" makes it think we are overflowing. > > In fact, count is never more than 4096 so there is no overflow, but I > > also think that it means only the first 4096 bytes of the firmware gets > > updated. > > > > drivers/misc/pch_phub.c > > 560 static ssize_t pch_phub_bin_write(struct file *filp, struct kobject *kobj, > > 561 struct bin_attribute *attr, > > 562 char *buf, loff_t off, size_t count) > > 563 { > > 564 int err; > > 565 unsigned int addr_offset; > > 566 int ret; > > 567 ssize_t rom_size; > > 568 struct pch_phub_reg *chip = > > 569 dev_get_drvdata(container_of(kobj, struct device, kobj)); > > 570 > > 571 ret = mutex_lock_interruptible(&pch_phub_mutex); > > 572 if (ret) > > 573 return -ERESTARTSYS; > > 574 > > 575 if (off > PCH_PHUB_OROM_SIZE) { > > 576 addr_offset = 0; > > 577 goto return_ok; > > 578 } > > 579 if (count > PCH_PHUB_OROM_SIZE) { > > ^^^^^^^^^^^^^^^^^^ > > This is 15359. > > > > 580 addr_offset = 0; > > 581 goto return_ok; > > 582 } > > 583 > > 584 chip->pch_phub_extrom_base_address = pci_map_rom(chip->pdev, &rom_size); > > 585 if (!chip->pch_phub_extrom_base_address) { > > 586 err = -ENOMEM; > > 587 goto exrom_map_err; > > 588 } > > 589 > > 590 for (addr_offset = 0; addr_offset < count; addr_offset++) { > > 591 if (PCH_PHUB_OROM_SIZE < off + addr_offset) > > 592 goto return_ok; > > 593 > > 594 ret = pch_phub_write_serial_rom(chip, > > 595 chip->pch_opt_rom_start_address + addr_offset + off, > > 596 buf[addr_offset]); > > ^^^^^^^^^^^^^^^^ > > Smatch complains because "buf" is only 4096 bytes. > > > > I can understand your saying. > > You mean just delete the following condition ? > > 579 if (count > PCH_PHUB_OROM_SIZE) { > What I'm saying is that sysfs files can only be 4096 bytes (larger on some arches with a larger PAGE_SIZE) and your firmware is larger than that. It won't work. regards, dan carpenter > Thanks. > > -- > ROHM Co., Ltd. > tomoya