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mmc: dw_mmc: remove UBSAN warning in dw_mci_setup_bus()

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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 <ulf.hansson@linaro.org>
This commit is contained in:
Seung-Woo Kim 2016-06-20 13:09:45 +09:00 committed by Ulf Hansson
parent 46d179525a
commit 65257a0dee
2 changed files with 5 additions and 13 deletions
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14
drivers/mmc/host/dw_mmc.c
View file

@ -1100,12 +1100,11 @@ 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);
@ -1128,9 +1127,6 @@ 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;

4
drivers/mmc/host/dw_mmc.h
View file

@ -245,9 +245,6 @@ 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.
@ -262,7 +259,6 @@ 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