[PATCH v2 0/3] usb: chipidea: An USB DMA fix + cleanups for Tegra

[PATCH v2 0/3] usb: chipidea: An USB DMA fix + cleanups for Tegra

[Michał Mirosław]

This series contains a fix for a DMA buffer overflow in Tegra USB driver
followed by a cleanup of the DMA bounce buffer code and another cleanup
to make probe() consistently use dev_err_probe() for error printk()s.

v2: reworded the commit message in patch #1

Michał Mirosław (3):
  usb: chipidea: Fix DMA overwrite for Tegra
  usb: chipidea: Simplify Tegra DMA alignment code
  usb: chipidea: tegra: Consistently use dev_err_probe()

 drivers/usb/chipidea/ci_hdrc_tegra.c | 16 ++++------
 drivers/usb/chipidea/host.c          | 48 ++++++++++++----------------
 2 files changed, 27 insertions(+), 37 deletions(-)

-- 
2.39.2

[PATCH v2 1/3] usb: chipidea: Fix DMA overwrite for Tegra

[Michał Mirosław]

Tegra USB controllers seem to issue DMA in full 32-bit words only and thus
may overwrite unevenly-sized buffers.  One such occurrence is detected by
SLUB when receiving a reply to a 1-byte buffer (below).  Fix this by
allocating a bounce buffer also for buffers with sizes not a multiple of 4.

=============================================================================
BUG kmalloc-64 (Tainted: G    B             ): kmalloc Redzone overwritten
-----------------------------------------------------------------------------

0x8555cd02-0x8555cd03 @offset=3330. First byte 0x0 instead of 0xcc
Allocated in usb_get_status+0x2b/0xac age=1 cpu=3 pid=41
 __kmem_cache_alloc_node+0x12f/0x1e4
 __kmalloc+0x33/0x8c
 usb_get_status+0x2b/0xac
 hub_probe+0x5e9/0xcec
 usb_probe_interface+0xbf/0x21c
 really_probe+0xa5/0x2c4
 __driver_probe_device+0x75/0x174
 driver_probe_device+0x31/0x94
 __device_attach_driver+0x65/0xc0
 bus_for_each_drv+0x4b/0x74
 __device_attach+0x69/0x120
 bus_probe_device+0x65/0x6c
 device_add+0x48b/0x5f8
 usb_set_configuration+0x37b/0x6b4
 usb_generic_driver_probe+0x37/0x68
 usb_probe_device+0x35/0xb4
Slab 0xbf622b80 objects=21 used=18 fp=0x8555cdc0 flags=0x800(slab|zone=0)
Object 0x8555cd00 @offset=3328 fp=0x00000000

Redzone  8555ccc0: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
Redzone  8555ccd0: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
Redzone  8555cce0: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
Redzone  8555ccf0: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
Object   8555cd00: 01 00 00 00 cc cc cc cc cc cc cc cc cc cc cc cc  ................
Object   8555cd10: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
Object   8555cd20: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
Object   8555cd30: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
Redzone  8555cd40: cc cc cc cc                                      ....
Padding  8555cd74: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a              ZZZZZZZZZZZZ
CPU: 3 PID: 41 Comm: kworker/3:1 Tainted: G    B              6.6.0-rc1mq-00118-g59786f827ea1 #1115
Hardware name: NVIDIA Tegra SoC (Flattened Device Tree)
Workqueue: usb_hub_wq hub_event
[<8010ca28>] (unwind_backtrace) from [<801090a5>] (show_stack+0x11/0x14)
[<801090a5>] (show_stack) from [<805da2fb>] (dump_stack_lvl+0x4d/0x7c)
[<805da2fb>] (dump_stack_lvl) from [<8026464f>] (check_bytes_and_report+0xb3/0xe4)
[<8026464f>] (check_bytes_and_report) from [<802648e1>] (check_object+0x261/0x290)
[<802648e1>] (check_object) from [<802671b1>] (free_to_partial_list+0x105/0x3f8)
[<802671b1>] (free_to_partial_list) from [<80268613>] (__kmem_cache_free+0x103/0x128)
[<80268613>] (__kmem_cache_free) from [<80425a67>] (usb_get_status+0x73/0xac)
[<80425a67>] (usb_get_status) from [<80421b31>] (hub_probe+0x5e9/0xcec)
[<80421b31>] (hub_probe) from [<80428bbb>] (usb_probe_interface+0xbf/0x21c)
[<80428bbb>] (usb_probe_interface) from [<803ee13d>] (really_probe+0xa5/0x2c4)
[<803ee13d>] (really_probe) from [<803ee3d1>] (__driver_probe_device+0x75/0x174)
[<803ee3d1>] (__driver_probe_device) from [<803ee501>] (driver_probe_device+0x31/0x94)
usb 1-1: device descriptor read/8, error -71

Fixes: fc53d5279094 ("usb: chipidea: tegra: Support host mode")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
---
 drivers/usb/chipidea/host.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/chipidea/host.c b/drivers/usb/chipidea/host.c
index 08af26b762a2..abddd39d1ff1 100644
--- a/drivers/usb/chipidea/host.c
+++ b/drivers/usb/chipidea/host.c
@@ -411,12 +411,13 @@ static int ci_hdrc_alloc_dma_aligned_buffer(struct urb *urb, gfp_t mem_flags)
 	const unsigned int ci_hdrc_usb_dma_align = 32;
 	size_t kmalloc_size;
 
-	if (urb->num_sgs || urb->sg || urb->transfer_buffer_length == 0 ||
-	    !((uintptr_t)urb->transfer_buffer & (ci_hdrc_usb_dma_align - 1)))
+	if (urb->num_sgs || urb->sg || urb->transfer_buffer_length == 0)
+		return 0;
+	if (!((uintptr_t)urb->transfer_buffer & (ci_hdrc_usb_dma_align - 1)) && !(urb->transfer_buffer_length & 3))
 		return 0;
 
 	/* Allocate a buffer with enough padding for alignment */
-	kmalloc_size = urb->transfer_buffer_length +
+	kmalloc_size = ALIGN(urb->transfer_buffer_length, 4) +
 		       sizeof(struct ci_hdrc_dma_aligned_buffer) +
 		       ci_hdrc_usb_dma_align - 1;
 
-- 
2.39.2

[PATCH v2 2/3] usb: chipidea: Simplify Tegra DMA alignment code

[Michał Mirosław]

The USB host on Tegra3 works with 32-bit alignment. Previous code tried
to align the buffer, but it did align the wrapper struct instead, so
the buffer was at a constant offset of 8 bytes (two pointers) from
expected alignment.  Since kmalloc() guarantees at least 8-byte
alignment already, the alignment-extending is removed.

Fixes: fc53d5279094 ("usb: chipidea: tegra: Support host mode")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
---
 drivers/usb/chipidea/host.c | 45 +++++++++++++++----------------------
 1 file changed, 18 insertions(+), 27 deletions(-)

diff --git a/drivers/usb/chipidea/host.c b/drivers/usb/chipidea/host.c
index abddd39d1ff1..0cce19208370 100644
--- a/drivers/usb/chipidea/host.c
+++ b/drivers/usb/chipidea/host.c
@@ -30,8 +30,7 @@ struct ehci_ci_priv {
 };
 
 struct ci_hdrc_dma_aligned_buffer {
-	void *kmalloc_ptr;
-	void *old_xfer_buffer;
+	void *original_buffer;
 	u8 data[];
 };
 
@@ -380,60 +379,52 @@ static int ci_ehci_bus_suspend(struct usb_hcd *hcd)
 	return 0;
 }
 
-static void ci_hdrc_free_dma_aligned_buffer(struct urb *urb)
+static void ci_hdrc_free_dma_aligned_buffer(struct urb *urb, bool copy_back)
 {
 	struct ci_hdrc_dma_aligned_buffer *temp;
-	size_t length;
 
 	if (!(urb->transfer_flags & URB_ALIGNED_TEMP_BUFFER))
 		return;
+	urb->transfer_flags &= ~URB_ALIGNED_TEMP_BUFFER;
 
 	temp = container_of(urb->transfer_buffer,
 			    struct ci_hdrc_dma_aligned_buffer, data);
+	urb->transfer_buffer = temp->original_buffer;
+
+	if (copy_back && usb_urb_dir_in(urb)) {
+		size_t length;
 
-	if (usb_urb_dir_in(urb)) {
 		if (usb_pipeisoc(urb->pipe))
 			length = urb->transfer_buffer_length;
 		else
 			length = urb->actual_length;
 
-		memcpy(temp->old_xfer_buffer, temp->data, length);
+		memcpy(temp->original_buffer, temp->data, length);
 	}
-	urb->transfer_buffer = temp->old_xfer_buffer;
-	kfree(temp->kmalloc_ptr);
 
-	urb->transfer_flags &= ~URB_ALIGNED_TEMP_BUFFER;
+	kfree(temp);
 }
 
 static int ci_hdrc_alloc_dma_aligned_buffer(struct urb *urb, gfp_t mem_flags)
 {
-	struct ci_hdrc_dma_aligned_buffer *temp, *kmalloc_ptr;
-	const unsigned int ci_hdrc_usb_dma_align = 32;
-	size_t kmalloc_size;
+	struct ci_hdrc_dma_aligned_buffer *temp;
 
 	if (urb->num_sgs || urb->sg || urb->transfer_buffer_length == 0)
 		return 0;
-	if (!((uintptr_t)urb->transfer_buffer & (ci_hdrc_usb_dma_align - 1)) && !(urb->transfer_buffer_length & 3))
+	if (IS_ALIGNED((uintptr_t)urb->transfer_buffer, 4)
+	    && IS_ALIGNED(urb->transfer_buffer_length, 4))
 		return 0;
 
-	/* Allocate a buffer with enough padding for alignment */
-	kmalloc_size = ALIGN(urb->transfer_buffer_length, 4) +
-		       sizeof(struct ci_hdrc_dma_aligned_buffer) +
-		       ci_hdrc_usb_dma_align - 1;
-
-	kmalloc_ptr = kmalloc(kmalloc_size, mem_flags);
-	if (!kmalloc_ptr)
+	temp = kmalloc(sizeof(*temp) + ALIGN(urb->transfer_buffer_length, 4), mem_flags);
+	if (!temp)
 		return -ENOMEM;
 
-	/* Position our struct dma_aligned_buffer such that data is aligned */
-	temp = PTR_ALIGN(kmalloc_ptr + 1, ci_hdrc_usb_dma_align) - 1;
-	temp->kmalloc_ptr = kmalloc_ptr;
-	temp->old_xfer_buffer = urb->transfer_buffer;
 	if (usb_urb_dir_out(urb))
 		memcpy(temp->data, urb->transfer_buffer,
 		       urb->transfer_buffer_length);
+
+	temp->original_buffer = urb->transfer_buffer;
 	urb->transfer_buffer = temp->data;
-
 	urb->transfer_flags |= URB_ALIGNED_TEMP_BUFFER;
 
 	return 0;
@@ -450,7 +441,7 @@ static int ci_hdrc_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
 
 	ret = usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
 	if (ret)
-		ci_hdrc_free_dma_aligned_buffer(urb);
+		ci_hdrc_free_dma_aligned_buffer(urb, false);
 
 	return ret;
 }
@@ -458,7 +449,7 @@ static int ci_hdrc_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
 static void ci_hdrc_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
 {
 	usb_hcd_unmap_urb_for_dma(hcd, urb);
-	ci_hdrc_free_dma_aligned_buffer(urb);
+	ci_hdrc_free_dma_aligned_buffer(urb, true);
 }
 
 #ifdef CONFIG_PM_SLEEP
-- 
2.39.2

[PATCH v2 3/3] usb: chipidea: tegra: Consistently use dev_err_probe()

[Michał Mirosław]

Convert all error exits from probe() to dev_err_probe().

Acked-by: Peter Chen <peter.chen@kernel.org>
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
---
 drivers/usb/chipidea/ci_hdrc_tegra.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/chipidea/ci_hdrc_tegra.c b/drivers/usb/chipidea/ci_hdrc_tegra.c
index 8e78bf643e25..2cc305803217 100644
--- a/drivers/usb/chipidea/ci_hdrc_tegra.c
+++ b/drivers/usb/chipidea/ci_hdrc_tegra.c
@@ -293,14 +293,12 @@ static int tegra_usb_probe(struct platform_device *pdev)
 	usb->phy = devm_usb_get_phy_by_phandle(&pdev->dev, "nvidia,phy", 0);
 	if (IS_ERR(usb->phy))
 		return dev_err_probe(&pdev->dev, PTR_ERR(usb->phy),
-				     "failed to get PHY\n");
+				     "failed to get PHY");
 
 	usb->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(usb->clk)) {
-		err = PTR_ERR(usb->clk);
-		dev_err(&pdev->dev, "failed to get clock: %d\n", err);
-		return err;
-	}
+	if (IS_ERR(usb->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(usb->clk),
+				     "failed to get clock");
 
 	err = devm_tegra_core_dev_init_opp_table_common(&pdev->dev);
 	if (err)
@@ -316,7 +314,7 @@ static int tegra_usb_probe(struct platform_device *pdev)
 
 	err = tegra_usb_reset_controller(&pdev->dev);
 	if (err) {
-		dev_err(&pdev->dev, "failed to reset controller: %d\n", err);
+		dev_err_probe(&pdev->dev, err, "failed to reset controller");
 		goto fail_power_off;
 	}
 
@@ -347,8 +345,8 @@ static int tegra_usb_probe(struct platform_device *pdev)
 	usb->dev = ci_hdrc_add_device(&pdev->dev, pdev->resource,
 				      pdev->num_resources, &usb->data);
 	if (IS_ERR(usb->dev)) {
-		err = PTR_ERR(usb->dev);
-		dev_err(&pdev->dev, "failed to add HDRC device: %d\n", err);
+		err = dev_err_probe(&pdev->dev, PTR_ERR(usb->dev),
+				    "failed to add HDRC device");
 		goto phy_shutdown;
 	}
 
-- 
2.39.2

Re: [PATCH v2 1/3] usb: chipidea: Fix DMA overwrite for Tegra

[Thierry Reding]

[-- Attachment #1: Type: text/plain, Size: 3779 bytes --]

On Thu, Sep 28, 2023 at 11:06:03PM +0200, Michał Mirosław wrote:
> Tegra USB controllers seem to issue DMA in full 32-bit words only and thus
> may overwrite unevenly-sized buffers.  One such occurrence is detected by
> SLUB when receiving a reply to a 1-byte buffer (below).  Fix this by
> allocating a bounce buffer also for buffers with sizes not a multiple of 4.
> 
> =============================================================================
> BUG kmalloc-64 (Tainted: G    B             ): kmalloc Redzone overwritten
> -----------------------------------------------------------------------------
> 
> 0x8555cd02-0x8555cd03 @offset=3330. First byte 0x0 instead of 0xcc
> Allocated in usb_get_status+0x2b/0xac age=1 cpu=3 pid=41
>  __kmem_cache_alloc_node+0x12f/0x1e4
>  __kmalloc+0x33/0x8c
>  usb_get_status+0x2b/0xac
>  hub_probe+0x5e9/0xcec
>  usb_probe_interface+0xbf/0x21c
>  really_probe+0xa5/0x2c4
>  __driver_probe_device+0x75/0x174
>  driver_probe_device+0x31/0x94
>  __device_attach_driver+0x65/0xc0
>  bus_for_each_drv+0x4b/0x74
>  __device_attach+0x69/0x120
>  bus_probe_device+0x65/0x6c
>  device_add+0x48b/0x5f8
>  usb_set_configuration+0x37b/0x6b4
>  usb_generic_driver_probe+0x37/0x68
>  usb_probe_device+0x35/0xb4
> Slab 0xbf622b80 objects=21 used=18 fp=0x8555cdc0 flags=0x800(slab|zone=0)
> Object 0x8555cd00 @offset=3328 fp=0x00000000
> 
> Redzone  8555ccc0: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
> Redzone  8555ccd0: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
> Redzone  8555cce0: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
> Redzone  8555ccf0: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
> Object   8555cd00: 01 00 00 00 cc cc cc cc cc cc cc cc cc cc cc cc  ................
> Object   8555cd10: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
> Object   8555cd20: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
> Object   8555cd30: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
> Redzone  8555cd40: cc cc cc cc                                      ....
> Padding  8555cd74: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a              ZZZZZZZZZZZZ
> CPU: 3 PID: 41 Comm: kworker/3:1 Tainted: G    B              6.6.0-rc1mq-00118-g59786f827ea1 #1115
> Hardware name: NVIDIA Tegra SoC (Flattened Device Tree)
> Workqueue: usb_hub_wq hub_event
> [<8010ca28>] (unwind_backtrace) from [<801090a5>] (show_stack+0x11/0x14)
> [<801090a5>] (show_stack) from [<805da2fb>] (dump_stack_lvl+0x4d/0x7c)
> [<805da2fb>] (dump_stack_lvl) from [<8026464f>] (check_bytes_and_report+0xb3/0xe4)
> [<8026464f>] (check_bytes_and_report) from [<802648e1>] (check_object+0x261/0x290)
> [<802648e1>] (check_object) from [<802671b1>] (free_to_partial_list+0x105/0x3f8)
> [<802671b1>] (free_to_partial_list) from [<80268613>] (__kmem_cache_free+0x103/0x128)
> [<80268613>] (__kmem_cache_free) from [<80425a67>] (usb_get_status+0x73/0xac)
> [<80425a67>] (usb_get_status) from [<80421b31>] (hub_probe+0x5e9/0xcec)
> [<80421b31>] (hub_probe) from [<80428bbb>] (usb_probe_interface+0xbf/0x21c)
> [<80428bbb>] (usb_probe_interface) from [<803ee13d>] (really_probe+0xa5/0x2c4)
> [<803ee13d>] (really_probe) from [<803ee3d1>] (__driver_probe_device+0x75/0x174)
> [<803ee3d1>] (__driver_probe_device) from [<803ee501>] (driver_probe_device+0x31/0x94)
> usb 1-1: device descriptor read/8, error -71
> 
> Fixes: fc53d5279094 ("usb: chipidea: tegra: Support host mode")
> Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
> ---
>  drivers/usb/chipidea/host.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)

Acked-by: Thierry Reding <treding@nvidia.com>

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]

Re: [PATCH v2 2/3] usb: chipidea: Simplify Tegra DMA alignment code

[Thierry Reding]

[-- Attachment #1: Type: text/plain, Size: 4695 bytes --]

On Thu, Sep 28, 2023 at 11:06:03PM +0200, Michał Mirosław wrote:
> The USB host on Tegra3 works with 32-bit alignment. Previous code tried
> to align the buffer, but it did align the wrapper struct instead, so
> the buffer was at a constant offset of 8 bytes (two pointers) from
> expected alignment.  Since kmalloc() guarantees at least 8-byte
> alignment already, the alignment-extending is removed.
> 
> Fixes: fc53d5279094 ("usb: chipidea: tegra: Support host mode")
> Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
> ---
>  drivers/usb/chipidea/host.c | 45 +++++++++++++++----------------------
>  1 file changed, 18 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/usb/chipidea/host.c b/drivers/usb/chipidea/host.c
> index abddd39d1ff1..0cce19208370 100644
> --- a/drivers/usb/chipidea/host.c
> +++ b/drivers/usb/chipidea/host.c
> @@ -30,8 +30,7 @@ struct ehci_ci_priv {
>  };
>  
>  struct ci_hdrc_dma_aligned_buffer {
> -	void *kmalloc_ptr;
> -	void *old_xfer_buffer;
> +	void *original_buffer;
>  	u8 data[];
>  };
>  
> @@ -380,60 +379,52 @@ static int ci_ehci_bus_suspend(struct usb_hcd *hcd)
>  	return 0;
>  }
>  
> -static void ci_hdrc_free_dma_aligned_buffer(struct urb *urb)
> +static void ci_hdrc_free_dma_aligned_buffer(struct urb *urb, bool copy_back)
>  {
>  	struct ci_hdrc_dma_aligned_buffer *temp;
> -	size_t length;
>  
>  	if (!(urb->transfer_flags & URB_ALIGNED_TEMP_BUFFER))
>  		return;
> +	urb->transfer_flags &= ~URB_ALIGNED_TEMP_BUFFER;

This threw me off a bit until I realized it was already there
previously, just in a different place. Is there a particular reason why
this is moved?

Regardless, this looks fine, so:

Acked-by: Thierry Reding <treding@nvidia.com>

>  
>  	temp = container_of(urb->transfer_buffer,
>  			    struct ci_hdrc_dma_aligned_buffer, data);
> +	urb->transfer_buffer = temp->original_buffer;
> +
> +	if (copy_back && usb_urb_dir_in(urb)) {
> +		size_t length;
>  
> -	if (usb_urb_dir_in(urb)) {
>  		if (usb_pipeisoc(urb->pipe))
>  			length = urb->transfer_buffer_length;
>  		else
>  			length = urb->actual_length;
>  
> -		memcpy(temp->old_xfer_buffer, temp->data, length);
> +		memcpy(temp->original_buffer, temp->data, length);
>  	}
> -	urb->transfer_buffer = temp->old_xfer_buffer;
> -	kfree(temp->kmalloc_ptr);
>  
> -	urb->transfer_flags &= ~URB_ALIGNED_TEMP_BUFFER;
> +	kfree(temp);
>  }
>  
>  static int ci_hdrc_alloc_dma_aligned_buffer(struct urb *urb, gfp_t mem_flags)
>  {
> -	struct ci_hdrc_dma_aligned_buffer *temp, *kmalloc_ptr;
> -	const unsigned int ci_hdrc_usb_dma_align = 32;
> -	size_t kmalloc_size;
> +	struct ci_hdrc_dma_aligned_buffer *temp;
>  
>  	if (urb->num_sgs || urb->sg || urb->transfer_buffer_length == 0)
>  		return 0;
> -	if (!((uintptr_t)urb->transfer_buffer & (ci_hdrc_usb_dma_align - 1)) && !(urb->transfer_buffer_length & 3))
> +	if (IS_ALIGNED((uintptr_t)urb->transfer_buffer, 4)
> +	    && IS_ALIGNED(urb->transfer_buffer_length, 4))
>  		return 0;
>  
> -	/* Allocate a buffer with enough padding for alignment */
> -	kmalloc_size = ALIGN(urb->transfer_buffer_length, 4) +
> -		       sizeof(struct ci_hdrc_dma_aligned_buffer) +
> -		       ci_hdrc_usb_dma_align - 1;
> -
> -	kmalloc_ptr = kmalloc(kmalloc_size, mem_flags);
> -	if (!kmalloc_ptr)
> +	temp = kmalloc(sizeof(*temp) + ALIGN(urb->transfer_buffer_length, 4), mem_flags);
> +	if (!temp)
>  		return -ENOMEM;
>  
> -	/* Position our struct dma_aligned_buffer such that data is aligned */
> -	temp = PTR_ALIGN(kmalloc_ptr + 1, ci_hdrc_usb_dma_align) - 1;
> -	temp->kmalloc_ptr = kmalloc_ptr;
> -	temp->old_xfer_buffer = urb->transfer_buffer;
>  	if (usb_urb_dir_out(urb))
>  		memcpy(temp->data, urb->transfer_buffer,
>  		       urb->transfer_buffer_length);
> +
> +	temp->original_buffer = urb->transfer_buffer;
>  	urb->transfer_buffer = temp->data;
> -
>  	urb->transfer_flags |= URB_ALIGNED_TEMP_BUFFER;
>  
>  	return 0;
> @@ -450,7 +441,7 @@ static int ci_hdrc_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
>  
>  	ret = usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
>  	if (ret)
> -		ci_hdrc_free_dma_aligned_buffer(urb);
> +		ci_hdrc_free_dma_aligned_buffer(urb, false);
>  
>  	return ret;
>  }
> @@ -458,7 +449,7 @@ static int ci_hdrc_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
>  static void ci_hdrc_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
>  {
>  	usb_hcd_unmap_urb_for_dma(hcd, urb);
> -	ci_hdrc_free_dma_aligned_buffer(urb);
> +	ci_hdrc_free_dma_aligned_buffer(urb, true);
>  }
>  
>  #ifdef CONFIG_PM_SLEEP
> -- 
> 2.39.2
> 

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Re: [PATCH v2 3/3] usb: chipidea: tegra: Consistently use dev_err_probe()

[Thierry Reding]

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On Thu, Sep 28, 2023 at 11:06:04PM +0200, Michał Mirosław wrote:
> Convert all error exits from probe() to dev_err_probe().
> 
> Acked-by: Peter Chen <peter.chen@kernel.org>
> Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
> ---
>  drivers/usb/chipidea/ci_hdrc_tegra.c | 16 +++++++---------
>  1 file changed, 7 insertions(+), 9 deletions(-)

Acked-by: Thierry Reding <treding@nvidia.com>

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Re: [PATCH v2 1/3] usb: chipidea: Fix DMA overwrite for Tegra

[Peter Chen]

On 23-09-28 23:06:03, Michał Mirosław wrote:
> Tegra USB controllers seem to issue DMA in full 32-bit words only and thus
> may overwrite unevenly-sized buffers.  One such occurrence is detected by
> SLUB when receiving a reply to a 1-byte buffer (below).  Fix this by
> allocating a bounce buffer also for buffers with sizes not a multiple of 4.
> 
> =============================================================================
> BUG kmalloc-64 (Tainted: G    B             ): kmalloc Redzone overwritten
> -----------------------------------------------------------------------------
> 
> 0x8555cd02-0x8555cd03 @offset=3330. First byte 0x0 instead of 0xcc
> Allocated in usb_get_status+0x2b/0xac age=1 cpu=3 pid=41
>  __kmem_cache_alloc_node+0x12f/0x1e4
>  __kmalloc+0x33/0x8c
>  usb_get_status+0x2b/0xac
>  hub_probe+0x5e9/0xcec
>  usb_probe_interface+0xbf/0x21c
>  really_probe+0xa5/0x2c4
>  __driver_probe_device+0x75/0x174
>  driver_probe_device+0x31/0x94
>  __device_attach_driver+0x65/0xc0
>  bus_for_each_drv+0x4b/0x74
>  __device_attach+0x69/0x120
>  bus_probe_device+0x65/0x6c
>  device_add+0x48b/0x5f8
>  usb_set_configuration+0x37b/0x6b4
>  usb_generic_driver_probe+0x37/0x68
>  usb_probe_device+0x35/0xb4
> Slab 0xbf622b80 objects=21 used=18 fp=0x8555cdc0 flags=0x800(slab|zone=0)
> Object 0x8555cd00 @offset=3328 fp=0x00000000
> 
> Redzone  8555ccc0: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
> Redzone  8555ccd0: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
> Redzone  8555cce0: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
> Redzone  8555ccf0: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
> Object   8555cd00: 01 00 00 00 cc cc cc cc cc cc cc cc cc cc cc cc  ................
> Object   8555cd10: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
> Object   8555cd20: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
> Object   8555cd30: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
> Redzone  8555cd40: cc cc cc cc                                      ....
> Padding  8555cd74: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a              ZZZZZZZZZZZZ
> CPU: 3 PID: 41 Comm: kworker/3:1 Tainted: G    B              6.6.0-rc1mq-00118-g59786f827ea1 #1115
> Hardware name: NVIDIA Tegra SoC (Flattened Device Tree)
> Workqueue: usb_hub_wq hub_event
> [<8010ca28>] (unwind_backtrace) from [<801090a5>] (show_stack+0x11/0x14)
> [<801090a5>] (show_stack) from [<805da2fb>] (dump_stack_lvl+0x4d/0x7c)
> [<805da2fb>] (dump_stack_lvl) from [<8026464f>] (check_bytes_and_report+0xb3/0xe4)
> [<8026464f>] (check_bytes_and_report) from [<802648e1>] (check_object+0x261/0x290)
> [<802648e1>] (check_object) from [<802671b1>] (free_to_partial_list+0x105/0x3f8)
> [<802671b1>] (free_to_partial_list) from [<80268613>] (__kmem_cache_free+0x103/0x128)
> [<80268613>] (__kmem_cache_free) from [<80425a67>] (usb_get_status+0x73/0xac)
> [<80425a67>] (usb_get_status) from [<80421b31>] (hub_probe+0x5e9/0xcec)
> [<80421b31>] (hub_probe) from [<80428bbb>] (usb_probe_interface+0xbf/0x21c)
> [<80428bbb>] (usb_probe_interface) from [<803ee13d>] (really_probe+0xa5/0x2c4)
> [<803ee13d>] (really_probe) from [<803ee3d1>] (__driver_probe_device+0x75/0x174)
> [<803ee3d1>] (__driver_probe_device) from [<803ee501>] (driver_probe_device+0x31/0x94)
> usb 1-1: device descriptor read/8, error -71
> 
> Fixes: fc53d5279094 ("usb: chipidea: tegra: Support host mode")
> Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>

Acked-by: Peter Chen <peter.chen@kernel.org>
> ---
>  drivers/usb/chipidea/host.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/chipidea/host.c b/drivers/usb/chipidea/host.c
> index 08af26b762a2..abddd39d1ff1 100644
> --- a/drivers/usb/chipidea/host.c
> +++ b/drivers/usb/chipidea/host.c
> @@ -411,12 +411,13 @@ static int ci_hdrc_alloc_dma_aligned_buffer(struct urb *urb, gfp_t mem_flags)
>  	const unsigned int ci_hdrc_usb_dma_align = 32;
>  	size_t kmalloc_size;
>  
> -	if (urb->num_sgs || urb->sg || urb->transfer_buffer_length == 0 ||
> -	    !((uintptr_t)urb->transfer_buffer & (ci_hdrc_usb_dma_align - 1)))
> +	if (urb->num_sgs || urb->sg || urb->transfer_buffer_length == 0)
> +		return 0;
> +	if (!((uintptr_t)urb->transfer_buffer & (ci_hdrc_usb_dma_align - 1)) && !(urb->transfer_buffer_length & 3))
>  		return 0;
>  
>  	/* Allocate a buffer with enough padding for alignment */
> -	kmalloc_size = urb->transfer_buffer_length +
> +	kmalloc_size = ALIGN(urb->transfer_buffer_length, 4) +
>  		       sizeof(struct ci_hdrc_dma_aligned_buffer) +
>  		       ci_hdrc_usb_dma_align - 1;
>  
> -- 
> 2.39.2
> 

-- 

Thanks,
Peter Chen

Re: [PATCH v2 2/3] usb: chipidea: Simplify Tegra DMA alignment code

[Peter Chen]

On 23-10-11 23:53:28, Thierry Reding wrote:
> On Thu, Sep 28, 2023 at 11:06:03PM +0200, Michał Mirosław wrote:
> > The USB host on Tegra3 works with 32-bit alignment. Previous code tried
> > to align the buffer, but it did align the wrapper struct instead, so
> > the buffer was at a constant offset of 8 bytes (two pointers) from
> > expected alignment.  Since kmalloc() guarantees at least 8-byte
> > alignment already, the alignment-extending is removed.
> > 
> > Fixes: fc53d5279094 ("usb: chipidea: tegra: Support host mode")
> > Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
> > ---
> >  drivers/usb/chipidea/host.c | 45 +++++++++++++++----------------------
> >  1 file changed, 18 insertions(+), 27 deletions(-)
> > 
> > diff --git a/drivers/usb/chipidea/host.c b/drivers/usb/chipidea/host.c
> > index abddd39d1ff1..0cce19208370 100644
> > --- a/drivers/usb/chipidea/host.c
> > +++ b/drivers/usb/chipidea/host.c
> > @@ -30,8 +30,7 @@ struct ehci_ci_priv {
> >  };
> >  
> >  struct ci_hdrc_dma_aligned_buffer {
> > -	void *kmalloc_ptr;
> > -	void *old_xfer_buffer;
> > +	void *original_buffer;
> >  	u8 data[];
> >  };
> >  
> > @@ -380,60 +379,52 @@ static int ci_ehci_bus_suspend(struct usb_hcd *hcd)
> >  	return 0;
> >  }
> >  
> > -static void ci_hdrc_free_dma_aligned_buffer(struct urb *urb)
> > +static void ci_hdrc_free_dma_aligned_buffer(struct urb *urb, bool copy_back)
> >  {
> >  	struct ci_hdrc_dma_aligned_buffer *temp;
> > -	size_t length;
> >  
> >  	if (!(urb->transfer_flags & URB_ALIGNED_TEMP_BUFFER))
> >  		return;
> > +	urb->transfer_flags &= ~URB_ALIGNED_TEMP_BUFFER;
> 
> This threw me off a bit until I realized it was already there
> previously, just in a different place. Is there a particular reason why
> this is moved?
> 
> Regardless, this looks fine, so:
> 
> Acked-by: Thierry Reding <treding@nvidia.com>

Acked-by: Peter Chen <peter.chen@kernel.org>

-- 

Thanks,
Peter Chen

Re: [PATCH v2 2/3] usb: chipidea: Simplify Tegra DMA alignment code

[Michał Mirosław]

On Wed, Oct 11, 2023 at 11:53:28PM +0200, Thierry Reding wrote:
> On Thu, Sep 28, 2023 at 11:06:03PM +0200, Michał Mirosław wrote:
> > The USB host on Tegra3 works with 32-bit alignment. Previous code tried
> > to align the buffer, but it did align the wrapper struct instead, so
> > the buffer was at a constant offset of 8 bytes (two pointers) from
> > expected alignment.  Since kmalloc() guarantees at least 8-byte
> > alignment already, the alignment-extending is removed.
> > 
> > Fixes: fc53d5279094 ("usb: chipidea: tegra: Support host mode")
> > Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
> > ---
> >  drivers/usb/chipidea/host.c | 45 +++++++++++++++----------------------
> >  1 file changed, 18 insertions(+), 27 deletions(-)
> > 
> > diff --git a/drivers/usb/chipidea/host.c b/drivers/usb/chipidea/host.c
> > index abddd39d1ff1..0cce19208370 100644
> > --- a/drivers/usb/chipidea/host.c
> > +++ b/drivers/usb/chipidea/host.c
> > @@ -30,8 +30,7 @@ struct ehci_ci_priv {
> >  };
> >  
> >  struct ci_hdrc_dma_aligned_buffer {
> > -	void *kmalloc_ptr;
> > -	void *old_xfer_buffer;
> > +	void *original_buffer;
> >  	u8 data[];
> >  };
> >  
> > @@ -380,60 +379,52 @@ static int ci_ehci_bus_suspend(struct usb_hcd *hcd)
> >  	return 0;
> >  }
> >  
> > -static void ci_hdrc_free_dma_aligned_buffer(struct urb *urb)
> > +static void ci_hdrc_free_dma_aligned_buffer(struct urb *urb, bool copy_back)
> >  {
> >  	struct ci_hdrc_dma_aligned_buffer *temp;
> > -	size_t length;
> >  
> >  	if (!(urb->transfer_flags & URB_ALIGNED_TEMP_BUFFER))
> >  		return;
> > +	urb->transfer_flags &= ~URB_ALIGNED_TEMP_BUFFER;
> 
> This threw me off a bit until I realized it was already there
> previously, just in a different place. Is there a particular reason why
> this is moved?

I figured that it is easier to understand if the test and clear of the
URB_ALIGNED_TEMP_BUFFER bit is in a single place. Seeing it again, I
think it could be replaced with __test_and_clear_bit() in a future commit.

Best Regards
Michał Mirosław