Convert mux_control_ops to a flexible array member at the end of the mux_chip struct and add the __counted_by() compiler attribute to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE.
Use struct_size() to calculate the number of bytes to allocate for a new mux chip and to remove the following Coccinelle/coccicheck warning: WARNING: Use struct_size Use size_add() to safely add any extra bytes. Compile-tested only. Link: https://github.com/KSPP/linux/issues/83 Signed-off-by: Thorsten Blum <thorsten.b...@linux.dev> --- drivers/mux/core.c | 7 +++---- include/linux/mux/driver.h | 4 ++-- 2 files changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/mux/core.c b/drivers/mux/core.c index 02be4ba37257..a3840fe0995f 100644 --- a/drivers/mux/core.c +++ b/drivers/mux/core.c @@ -98,13 +98,12 @@ struct mux_chip *mux_chip_alloc(struct device *dev, if (WARN_ON(!dev || !controllers)) return ERR_PTR(-EINVAL); - mux_chip = kzalloc(sizeof(*mux_chip) + - controllers * sizeof(*mux_chip->mux) + - sizeof_priv, GFP_KERNEL); + mux_chip = kzalloc(size_add(struct_size(mux_chip, mux, controllers), + sizeof_priv), + GFP_KERNEL); if (!mux_chip) return ERR_PTR(-ENOMEM); - mux_chip->mux = (struct mux_control *)(mux_chip + 1); mux_chip->dev.class = &mux_class; mux_chip->dev.type = &mux_type; mux_chip->dev.parent = dev; diff --git a/include/linux/mux/driver.h b/include/linux/mux/driver.h index 18824064f8c0..e58e59354e23 100644 --- a/include/linux/mux/driver.h +++ b/include/linux/mux/driver.h @@ -56,18 +56,18 @@ struct mux_control { /** * struct mux_chip - Represents a chip holding mux controllers. * @controllers: Number of mux controllers handled by the chip. - * @mux: Array of mux controllers that are handled. * @dev: Device structure. * @id: Used to identify the device internally. * @ops: Mux controller operations. + * @mux: Array of mux controllers that are handled. */ struct mux_chip { unsigned int controllers; - struct mux_control *mux; struct device dev; int id; const struct mux_control_ops *ops; + struct mux_control mux[] __counted_by(controllers); }; #define to_mux_chip(x) container_of((x), struct mux_chip, dev) -- 2.48.1
