Re: [PATCH] i2c: mux: demux-pinctrl: Annotate struct i2c_demux_pinctrl_priv with __counted_by

2023-09-24 Thread Wolfram Sang 
On Fri, Sep 22, 2023 at 10:49:59AM -0700, Kees Cook wrote:
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
> 
> As found with Coccinelle[1], add __counted_by for struct 
> i2c_demux_pinctrl_priv.
> Additionally, since the element count member must be set before accessing
> the annotated flexible array member, move its initialization earlier.
> 
> [1] 
> https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: Wolfram Sang 
> Cc: Peter Rosin 
> Cc: linux-...@vger.kernel.org
> Signed-off-by: Kees Cook 

Fixed a blank line and applied to for-next, thanks!



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Re: [PATCH] i2c: mux: demux-pinctrl: Annotate struct i2c_demux_pinctrl_priv with __counted_by

2023-09-23 Thread Gustavo A. R. Silva 




On 9/22/23 11:49, Kees Cook wrote:

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct i2c_demux_pinctrl_priv.
Additionally, since the element count member must be set before accessing
the annotated flexible array member, move its initialization earlier.

[1] 
https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Wolfram Sang 
Cc: Peter Rosin 
Cc: linux-...@vger.kernel.org
Signed-off-by: Kees Cook 


Reviewed-by: Gustavo A. R. Silva 

Thanks
--
Gustavo


---
  drivers/i2c/muxes/i2c-demux-pinctrl.c | 6 +++---
  1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/muxes/i2c-demux-pinctrl.c 
b/drivers/i2c/muxes/i2c-demux-pinctrl.c
index a3a122fae71e..5e15d8777229 100644
--- a/drivers/i2c/muxes/i2c-demux-pinctrl.c
+++ b/drivers/i2c/muxes/i2c-demux-pinctrl.c
@@ -32,7 +32,7 @@ struct i2c_demux_pinctrl_priv {
const char *bus_name;
struct i2c_adapter cur_adap;
struct i2c_algorithm algo;
-   struct i2c_demux_pinctrl_chan chan[];
+   struct i2c_demux_pinctrl_chan chan[] __counted_by(num_chan);
  };
  
  static int i2c_demux_master_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)

@@ -226,6 +226,8 @@ static int i2c_demux_pinctrl_probe(struct platform_device 
*pdev)
if (!priv || !props)
return -ENOMEM;
  
+	priv->num_chan = num_chan;

+
err = of_property_read_string(np, "i2c-bus-name", >bus_name);
if (err)
return err;
@@ -248,8 +250,6 @@ static int i2c_demux_pinctrl_probe(struct platform_device 
*pdev)
of_changeset_init(>chan[i].chgset);
of_changeset_update_property(>chan[i].chgset, adap_np, 
[i]);
}
-
-   priv->num_chan = num_chan;
priv->dev = >dev;
  
  	platform_set_drvdata(pdev, priv);

[PATCH] i2c: mux: demux-pinctrl: Annotate struct i2c_demux_pinctrl_priv with __counted_by

2023-09-22 Thread Kees Cook 
Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct i2c_demux_pinctrl_priv.
Additionally, since the element count member must be set before accessing
the annotated flexible array member, move its initialization earlier.

[1] 
https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Wolfram Sang 
Cc: Peter Rosin 
Cc: linux-...@vger.kernel.org
Signed-off-by: Kees Cook 
---
 drivers/i2c/muxes/i2c-demux-pinctrl.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/muxes/i2c-demux-pinctrl.c 
b/drivers/i2c/muxes/i2c-demux-pinctrl.c
index a3a122fae71e..5e15d8777229 100644
--- a/drivers/i2c/muxes/i2c-demux-pinctrl.c
+++ b/drivers/i2c/muxes/i2c-demux-pinctrl.c
@@ -32,7 +32,7 @@ struct i2c_demux_pinctrl_priv {
const char *bus_name;
struct i2c_adapter cur_adap;
struct i2c_algorithm algo;
-   struct i2c_demux_pinctrl_chan chan[];
+   struct i2c_demux_pinctrl_chan chan[] __counted_by(num_chan);
 };
 
 static int i2c_demux_master_xfer(struct i2c_adapter *adap, struct i2c_msg 
msgs[], int num)
@@ -226,6 +226,8 @@ static int i2c_demux_pinctrl_probe(struct platform_device 
*pdev)
if (!priv || !props)
return -ENOMEM;
 
+   priv->num_chan = num_chan;
+
err = of_property_read_string(np, "i2c-bus-name", >bus_name);
if (err)
return err;
@@ -248,8 +250,6 @@ static int i2c_demux_pinctrl_probe(struct platform_device 
*pdev)
of_changeset_init(>chan[i].chgset);
of_changeset_update_property(>chan[i].chgset, adap_np, 
[i]);
}
-
-   priv->num_chan = num_chan;
priv->dev = >dev;
 
platform_set_drvdata(pdev, priv);
-- 
2.34.1