From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752488AbcFTDal (ORCPT ); Sun, 19 Jun 2016 23:30:41 -0400 Received: from mailout3.samsung.com ([203.254.224.33]:45832 "EHLO mailout3.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752416AbcFTDa2 (ORCPT ); Sun, 19 Jun 2016 23:30:28 -0400 X-AuditID: cbfee68e-f79266d000001428-3c-576763524f36 From: Seung-Woo Kim To: "'Jaehoon Chung'" , ulf.hansson@linaro.org, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org Cc: sw0312.kim@samsung.com References: <1465358840-22826-1-git-send-email-sw0312.kim@samsung.com> <1466140609-5773-1-git-send-email-sw0312.kim@samsung.com> <57675635.20808@samsung.com> In-reply-to: <57675635.20808@samsung.com> Subject: RE: [PATCH v2] mmc: dw_mmc: remove UBSAN warning in dw_mci_setup_bus() Date: Mon, 20 Jun 2016 12:30:26 +0900 Message-id: <000401d1caa4$16809d70$4381d850$@samsung.com> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7bit X-Mailer: Microsoft Outlook 14.0 Thread-index: AQLIqjc85rBdfXLimZriFYrM+1DVewIywaCyAUbB/3QCyFRM+Z3R5Ahg Content-language: ko X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrCIsWRmVeSWpSXmKPExsWyRsSkQDcoOT3cYPUeVosbv9pYLS7vmsNm ceR/P6PFjMkv2SyOrw13YPW4c20Pm0ffllWMHp83yQUwR3HZpKTmZJalFunbJXBlHJ3bxVRw QrVib9t1lgbGVrkuRk4OCQETicVH/7BC2GISF+6tZ+ti5OIQEljBKHHyz3JmmKLTa+5BJWYx Skzb08AM4XxglNh49AwLSBWbgI7E/iW/wUaJCNRLbPp9ihHEZhaQkti2FGbsV0aJWZM2soMk OAU0JZYfeAJmCwv4S8xftwHMZhFQlTh36AlYM6+ApURLyxRmCFtQ4sfkeywQQ7Uk1u88zgRh y0tsXvMW6lQFiR1nXzNCHOEmMWn2O6gaEYl9L94xghwhIXCMXWLDj09sEMsEJL5NPgQ0lAMo ISux6QDUHEmJgytusEwAOhfJ6llIVs9CsnoWkhULGFlWMYqmFiQXFCelFxnpFSfmFpfmpesl 5+duYgRG5ul/z/p2MN48YH2IUYCDUYmH1+JsWrgQa2JZcWXuIUZToIsmMkuJJucD4z+vJN7Q 2MzIwtTE1NjI3NJMSZw3QepnsJBAemJJanZqakFqUXxRaU5q8SFGJg5OqQbGzk/9q13qXGRr L6rqzP54NDn7gdSvjtdca86dfjn5Lfebbzcu1LC3rxXIrt+Y17Ayn2Vip5zz9KNH5Sc/uJv7 lK/pT9Ml4Z3u2+dc4G3Zmbt4yvlVIS9Wi/rW37cs2d0QLzLt4lyBK80TrqY/4D5wZcmc6S/y ulb9erD5jW/lSh0lhg8hk6dxNiqxFGckGmoxFxUnAgAa58MTxwIAAA== X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFmpkleLIzCtJLcpLzFFi42I5/e+xoG5gcnq4welbNhY3frWxWlzeNYfN 4sj/fkaLGZNfslkcXxvuwOpx59oeNo++LasYPT5vkgtgjmpgtMlITUxJLVJIzUvOT8nMS7dV 8g6Od443NTMw1DW0tDBXUshLzE21VXLxCdB1y8wBWqmkUJaYUwoUCkgsLlbSt8M0ITTETdcC pjFC1zckCK7HyAANJKxhzDg6t4up4IRqxd626ywNjK1yXYycHBICJhKn19xjg7DFJC7cWw9k c3EICcxilJi2p4EZwvnAKLHx6BkWkCo2AR2J/Ut+s4LYIgL1Ept+n2IEsZkFpCS2LYXp/soo MWvSRnaQBKeApsTyA0/AbGEBf4n56zaA2SwCqhLnDj0Ba+YVsJRoaZnCDGELSvyYfI8FYqiW xPqdx5kgbHmJzWveMkOcqiCx4+xrRogj3CQmzX4HVSMise/FO8YJjEKzkIyahWTULCSjZiFp WcDIsopRIrUguaA4KT3XMC+1XK84Mbe4NC9dLzk/dxMjOPqfSe1gPLjL/RCjAAejEg+vgEN6 uBBrYllxZe4hRgkOZiUR3p54oBBvSmJlVWpRfnxRaU5q8SFGU6BnJzJLiSbnAxNTXkm8obGJ mZGlkbmhhZGxuZI47+P/68KEBNITS1KzU1MLUotg+pg4OKUaGC+trt4gnHzTZsrZ6j8R/5TP 64p+4n7jezHaNTtnjmbekbw5ocsZfaSO9eizmpi7HTg8oWDuxu0Tm8VCNj9LrpsmtWxBp5l1 9brdq/ovnzqxTf7Wj90L5Vb9Wm/Xv8x+082U8++WBfVnRgflPNBozE3tPGlz0TPIY0vx8cfb VhucP93evmnBG1UlluKMREMt5qLiRAC0c6vdFAMAAA== DLP-Filter: Pass X-MTR: 20000000000000000@CPGS X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Jaehoon, > -----Original Message----- > From: Jaehoon Chung [mailto:jh80.chung@samsung.com] > Sent: Monday, June 20, 2016 11:34 AM > To: Seung-Woo Kim; ulf.hansson@linaro.org; linux-mmc@vger.kernel.org; linux-kernel@vger.kernel.org > Subject: Re: [PATCH v2] mmc: dw_mmc: remove UBSAN warning in dw_mci_setup_bus() > > Hi SeungWoo, > > On 06/17/2016 02:16 PM, Seung-Woo Kim wrote: > > This patch removes following UBSAN warnings in dw_mci_setup_bus(). > > > > UBSAN: Undefined behaviour in drivers/mmc/host/dw_mmc.c:1102:14 > > shift exponent 250 is too large for 32-bit type 'unsigned int' > > Call trace: > > [] dump_backtrace+0x0/0x380 > > [] show_stack+0x14/0x20 > > [] dump_stack+0xe0/0x120 > > [] ubsan_epilogue+0x18/0x68 > > [] __ubsan_handle_shift_out_of_bounds+0x18c/0x1bc > > [] dw_mci_setup_bus+0x3a0/0x438 > > [...] > > > > UBSAN: Undefined behaviour in drivers/mmc/host/dw_mmc.c:1132:27 > > shift exponent 250 is too large for 32-bit type 'unsigned int' > > Call trace: > > [] dump_backtrace+0x0/0x380 > > [] show_stack+0x14/0x20 > > [] dump_stack+0xe0/0x120 > > [] ubsan_epilogue+0x18/0x68 > > [] __ubsan_handle_shift_out_of_bounds+0x18c/0x1bc > > [] dw_mci_setup_bus+0x384/0x438 > > [...] > > > > The warnings are caused because of shift with more than 31 on 32 > > bit variable, so this patch fixes to keep both clock and divider > > instead of shift. > > > > Signed-off-by: Seung-Woo Kim > > --- > > drivers/mmc/host/dw_mmc.c | 8 +++++--- > > drivers/mmc/host/dw_mmc.h | 8 +++++--- > > 2 files changed, 10 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c > > index 2cc6123..d05c8cc 100644 > > --- a/drivers/mmc/host/dw_mmc.c > > +++ b/drivers/mmc/host/dw_mmc.c > > @@ -1099,7 +1099,8 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot, bool force_clkinit) > > > > div = (host->bus_hz != clock) ? DIV_ROUND_UP(div, 2) : 0; > > > > - if ((clock << div) != slot->__clk_old || force_clkinit) > > + if (clock != slot->__clk_old || div != slot->__div_old || > > + force_clkinit) > > I have realized why we put this condition..after checking your below codes. > This was patch to avoid the spamming for CONFIG_MMC_CLKGATE.. > but CONFIG_MMC_CLKAGET didn't use anymore.. I think we can remove this condition. > > How about? There is no CONFIG_MMC_CLKAGET, but message is still printed. So without the condition check, there will be too much log. If you will just remove below print, then I agree about removing the condition and __clk_old, instead of my patch. Thanks, - Seung-Woo Kim > > Best Regards, > Jaehoon Chung > > > dev_info(&slot->mmc->class_dev, > > "Bus speed (slot %d) = %dHz (slot req %dHz, actual %dHZ div = %d)\n", > > slot->id, host->bus_hz, clock, > > @@ -1128,8 +1129,9 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot, bool force_clkinit) > > /* inform CIU */ > > mci_send_cmd(slot, sdmmc_cmd_bits, 0); > > > > - /* keep the clock with reflecting clock dividor */ > > - slot->__clk_old = clock << div; > > + /* keep the clock and clock divider */ > > + slot->__clk_old = clock; > > + slot->__div_old = div; > > } > > > > host->current_speed = clock; > > diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h > > index 1e8d838..fdfc3f5 100644 > > --- a/drivers/mmc/host/dw_mmc.h > > +++ b/drivers/mmc/host/dw_mmc.h > > @@ -245,9 +245,10 @@ extern int dw_mci_resume(struct dw_mci *host); > > * @queue_node: List node for placing this node in the @queue list of > > * &struct dw_mci. > > * @clock: Clock rate configured by set_ios(). Protected by host->lock. > > - * @__clk_old: The last updated clock with reflecting clock divider. > > - * Keeping track of this helps us to avoid spamming the console > > - * with CONFIG_MMC_CLKGATE. > > + * @__clk_old: The last updated clock. > > + * @__div_old: The last updated clock divider. > > + * Keeping track of clock and clock divider helps us to avoid spamming > > + * the console with CONFIG_MMC_CLKGATE. > > * @flags: Random state bits associated with the slot. > > * @id: Number of this slot. > > * @sdio_id: Number of this slot in the SDIO interrupt registers. > > @@ -263,6 +264,7 @@ struct dw_mci_slot { > > > > unsigned int clock; > > unsigned int __clk_old; > > + unsigned int __div_old; > > > > unsigned long flags; > > #define DW_MMC_CARD_PRESENT 0 > >