lkml.org 
[lkml]   [2023]   [Sep]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] i2c: mux: demux-pinctrl: Annotate struct i2c_demux_pinctrl_priv with __counted_by
Date
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 <wsa+renesas@sang-engineering.com>
Cc: Peter Rosin <peda@axentia.se>
Cc: linux-i2c@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
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", &priv->bus_name);
if (err)
return err;
@@ -248,8 +250,6 @@ static int i2c_demux_pinctrl_probe(struct platform_device *pdev)
of_changeset_init(&priv->chan[i].chgset);
of_changeset_update_property(&priv->chan[i].chgset, adap_np, &props[i]);
}
-
- priv->num_chan = num_chan;
priv->dev = &pdev->dev;

platform_set_drvdata(pdev, priv);
--
2.34.1
\
 
 \ /
  Last update: 2023-09-22 19:51    [W:0.101 / U:0.800 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site