Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1424659 > unrolled thread

[PATCH v2] mmc: dw_mmc: remove UBSAN warning in dw_mci_setup_bus()

Started bySeung-Woo Kim <sw0312.kim@samsung.com>
First post2016-06-17 07:20 +0200
Last post2016-06-22 03:30 +0200
Articles 6 — 2 participants

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  [PATCH v2] mmc: dw_mmc: remove UBSAN warning in dw_mci_setup_bus() Seung-Woo Kim <sw0312.kim@samsung.com> - 2016-06-17 07:20 +0200
    Re: [PATCH v2] mmc: dw_mmc: remove UBSAN warning in dw_mci_setup_bus() Jaehoon Chung <jh80.chung@samsung.com> - 2016-06-20 05:10 +0200
      RE: [PATCH v2] mmc: dw_mmc: remove UBSAN warning in dw_mci_setup_bus() Seung-Woo Kim <sw0312.kim@samsung.com> - 2016-06-20 05:40 +0200
        RE: [PATCH v2] mmc: dw_mmc: remove UBSAN warning in dw_mci_setup_bus() Seung-Woo Kim <sw0312.kim@samsung.com> - 2016-06-20 05:50 +0200
    [PATCH v3] mmc: dw_mmc: remove UBSAN warning in dw_mci_setup_bus() Seung-Woo Kim <sw0312.kim@samsung.com> - 2016-06-20 06:10 +0200
      Re: [PATCH v3] mmc: dw_mmc: remove UBSAN warning in dw_mci_setup_bus() Jaehoon Chung <jh80.chung@samsung.com> - 2016-06-22 03:30 +0200

#1424659 — [PATCH v2] mmc: dw_mmc: remove UBSAN warning in dw_mci_setup_bus()

FromSeung-Woo Kim <sw0312.kim@samsung.com>
Date2016-06-17 07:20 +0200
Subject[PATCH v2] mmc: dw_mmc: remove UBSAN warning in dw_mci_setup_bus()
Message-ID<rKUme-2iZ-3@gated-at.bofh.it>
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 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 <sw0312.kim@samsung.com>
---
 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)
 			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
-- 
1.7.4.1

[toc] | [next] | [standalone]

#1426157

FromJaehoon Chung <jh80.chung@samsung.com>
Date2016-06-20 05:10 +0200
Message-ID<rLXL4-2L5-15@gated-at.bofh.it>
In reply to#1424659
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:
>   [<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 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 <sw0312.kim@samsung.com>
> ---
>  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?

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
>

[toc] | [prev] | [next] | [standalone]

#1426167

FromSeung-Woo Kim <sw0312.kim@samsung.com>
Date2016-06-20 05:40 +0200
Message-ID<rLYe5-2UC-1@gated-at.bofh.it>
In reply to#1426157
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:
> >   [<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 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 <sw0312.kim@samsung.com>
> > ---
> >  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
> >

[toc] | [prev] | [next] | [standalone]

#1426170

FromSeung-Woo Kim <sw0312.kim@samsung.com>
Date2016-06-20 05:50 +0200
Message-ID<rLYnL-2XU-1@gated-at.bofh.it>
In reply to#1426167
Hi,

> -----Original Message-----
> From: Seung-Woo Kim [mailto:sw0312.kim@samsung.com]
> Sent: Monday, June 20, 2016 12:30 PM
> To: 'Jaehoon Chung'; ulf.hansson@linaro.org; linux-mmc@vger.kernel.org; linux-kernel@vger.kernel.org
> Cc: sw0312.kim@samsung.com
> Subject: RE: [PATCH v2] mmc: dw_mmc: remove UBSAN warning in dw_mci_setup_bus()
> 
> 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:
> > >   [<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 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 <sw0312.kim@samsung.com>
> > > ---
> > >  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.

I tested again after removing the condition check, it prints same log and there
is not too much log. Let's just remove the condition and __clk_old.

Regards,
- Seung-Woo Kim

> 
> 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
> > >
>

[toc] | [prev] | [next] | [standalone]

#1426179 — [PATCH v3] mmc: dw_mmc: remove UBSAN warning in dw_mci_setup_bus()

FromSeung-Woo Kim <sw0312.kim@samsung.com>
Date2016-06-20 06:10 +0200
Subject[PATCH v3] mmc: dw_mmc: remove UBSAN warning in dw_mci_setup_bus()
Message-ID<rLYH8-3lv-7@gated-at.bofh.it>
In reply to#1424659
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>
---
 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 2cc6123..bada11e 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1099,12 +1099,11 @@ 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);
@@ -1127,9 +1126,6 @@ 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 1e8d838..5961037 100644
--- a/drivers/mmc/host/dw_mmc.h
+++ b/drivers/mmc/host/dw_mmc.h
@@ -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
-- 
1.7.9.5

[toc] | [prev] | [next] | [standalone]

#1428319 — Re: [PATCH v3] mmc: dw_mmc: remove UBSAN warning in dw_mci_setup_bus()

FromJaehoon Chung <jh80.chung@samsung.com>
Date2016-06-22 03:30 +0200
SubjectRe: [PATCH v3] mmc: dw_mmc: remove UBSAN warning in dw_mci_setup_bus()
Message-ID<rMF9n-57L-15@gated-at.bofh.it>
In reply to#1426179
Hi Seung-Woo,

On 06/20/2016 01:09 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:
>   [<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>

Applied this patch on my repository.
Thanks!

Best Regards,
Jaehoon Chung

> ---
>  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 2cc6123..bada11e 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -1099,12 +1099,11 @@ 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);
> @@ -1127,9 +1126,6 @@ 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 1e8d838..5961037 100644
> --- a/drivers/mmc/host/dw_mmc.h
> +++ b/drivers/mmc/host/dw_mmc.h
> @@ -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
>

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web