[cip-dev] [PATCH 4.4-cip 15/23] mmc: dw_mmc: remove UBSAN warning in dw_mci_setup_bus()
From: Ben Hutchings <hidden>
Date: 2016-12-09 00:36:43
Subsystem:
multimedia card (mmc), secure digital (sd) and sdio subsystem, synopsys designware mmc/sd/sdio driver, the rest · Maintainers:
Ulf Hansson, Jaehoon Chung, Shawn Lin, Linus Torvalds
From: Seung-Woo Kim <sw0312.kim@samsung.com> commit 65257a0deed5aee66b4e3708944f0be62a64cabc upstream. 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: [<ffffff90080908a8>] dump_backtrace+0x0/0x380 [<ffffff9008090c3c>] show_stack+0x14/0x20 [<ffffff90087457b8>] dump_stack+0xe0/0x120 [<ffffff90087b1360>] ubsan_epilogue+0x18/0x68 [<ffffff90087b1a94>] __ubsan_handle_shift_out_of_bounds+0x18c/0x1bc [<ffffff9008d89cb8>] 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: [<ffffff90080908a8>] dump_backtrace+0x0/0x380 [<ffffff9008090c3c>] show_stack+0x14/0x20 [<ffffff90087457b8>] dump_stack+0xe0/0x120 [<ffffff90087b1360>] ubsan_epilogue+0x18/0x68 [<ffffff90087b1a94>] __ubsan_handle_shift_out_of_bounds+0x18c/0x1bc [<ffffff9008d89c9c>] dw_mci_setup_bus+0x384/0x438 [...] The warnings are caused because of bit shift which is used to filter spamming message for CONFIG_MMC_CLKGATE, but the config is already removed. So this patch just removes the shift. Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com> Signed-off-by: Ulf Hansson <redacted> Signed-off-by: Ben Hutchings <redacted> --- drivers/mmc/host/dw_mmc.c | 14 +++++--------- drivers/mmc/host/dw_mmc.h | 4 ---- 2 files changed, 5 insertions(+), 13 deletions(-)
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index fb204ee6ff89..0b38014ad315 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c@@ -1102,12 +1102,11 @@ 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) - 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, - div ? ((host->bus_hz / div) >> 1) : - host->bus_hz, div); + 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, + div ? ((host->bus_hz / div) >> 1) : + host->bus_hz, div); /* disable clock */ mci_writel(host, CLKENA, 0);
@@ -1130,9 +1129,6 @@ 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; } host->current_speed = clock;
diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
index f695b58f0613..18fb8f5aaa34 100644
--- a/drivers/mmc/host/dw_mmc.h
+++ b/drivers/mmc/host/dw_mmc.h@@ -242,9 +242,6 @@ 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. * @flags: Random state bits associated with the slot. * @id: Number of this slot. * @sdio_id: Number of this slot in the SDIO interrupt registers.
@@ -259,7 +256,6 @@ struct dw_mci_slot { struct list_head queue_node; unsigned int clock; - unsigned int __clk_old; unsigned long flags; #define DW_MMC_CARD_PRESENT 0
--
2.10.2
--
Ben Hutchings
Software Developer, Codethink Ltd.