* [PATCHv2] hsi: hsi_core: use kzalloc_flex
@ 2026-03-17 19:58 Rosen Penev
2026-03-18 11:50 ` Sebastian Reichel
0 siblings, 1 reply; 2+ messages in thread
From: Rosen Penev @ 2026-03-17 19:58 UTC (permalink / raw)
To: linux-kernel
Cc: Sebastian Reichel, Kees Cook, Gustavo A. R. Silva,
open list:KERNEL HARDENING (not covered by other areas):Keyword:b__counted_by(_le|_be)?b
Simplifies allocations by using a flexible array member in this struct.
Add __counted_by to get extra runtime analysis.
Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
v2: remove wrong null check
drivers/hsi/hsi_core.c | 38 +++++++++++++++-----------------------
include/linux/hsi/hsi.h | 2 +-
2 files changed, 16 insertions(+), 24 deletions(-)
diff --git a/drivers/hsi/hsi_core.c b/drivers/hsi/hsi_core.c
index 7cb2dcb30fdb..001bcadf4b8e 100644
--- a/drivers/hsi/hsi_core.c
+++ b/drivers/hsi/hsi_core.c
@@ -342,13 +342,11 @@ static void hsi_controller_release(struct device *dev)
{
struct hsi_controller *hsi = to_hsi_controller(dev);
- kfree(hsi->port);
kfree(hsi);
}
static void hsi_port_release(struct device *dev)
{
- kfree(to_hsi_port(dev));
}
/**
@@ -446,7 +444,7 @@ void hsi_put_controller(struct hsi_controller *hsi)
return;
for (i = 0; i < hsi->num_ports; i++)
- if (hsi->port && hsi->port[i])
+ if (hsi->port[i])
put_device(&hsi->port[i]->device);
put_device(&hsi->device);
}
@@ -462,39 +460,33 @@ EXPORT_SYMBOL_GPL(hsi_put_controller);
struct hsi_controller *hsi_alloc_controller(unsigned int n_ports, gfp_t flags)
{
struct hsi_controller *hsi;
- struct hsi_port **port;
unsigned int i;
if (!n_ports)
return NULL;
- hsi = kzalloc_obj(*hsi, flags);
+ hsi = kzalloc_flex(*hsi, port, n_ports, flags);
if (!hsi)
return NULL;
- port = kzalloc_objs(*port, n_ports, flags);
- if (!port) {
- kfree(hsi);
- return NULL;
- }
+
hsi->num_ports = n_ports;
- hsi->port = port;
hsi->device.release = hsi_controller_release;
device_initialize(&hsi->device);
for (i = 0; i < n_ports; i++) {
- port[i] = kzalloc_obj(**port, flags);
- if (port[i] == NULL)
+ hsi->port[i] = kzalloc_obj(**hsi->port, flags);
+ if (hsi->port[i] == NULL)
goto out;
- port[i]->num = i;
- port[i]->async = hsi_dummy_msg;
- port[i]->setup = hsi_dummy_cl;
- port[i]->flush = hsi_dummy_cl;
- port[i]->start_tx = hsi_dummy_cl;
- port[i]->stop_tx = hsi_dummy_cl;
- port[i]->release = hsi_dummy_cl;
- mutex_init(&port[i]->lock);
- BLOCKING_INIT_NOTIFIER_HEAD(&port[i]->n_head);
- dev_set_name(&port[i]->device, "port%d", i);
+ hsi->port[i]->num = i;
+ hsi->port[i]->async = hsi_dummy_msg;
+ hsi->port[i]->setup = hsi_dummy_cl;
+ hsi->port[i]->flush = hsi_dummy_cl;
+ hsi->port[i]->start_tx = hsi_dummy_cl;
+ hsi->port[i]->stop_tx = hsi_dummy_cl;
+ hsi->port[i]->release = hsi_dummy_cl;
+ mutex_init(&hsi->port[i]->lock);
+ BLOCKING_INIT_NOTIFIER_HEAD(&hsi->port[i]->n_head);
+ dev_set_name(&hsi->port[i]->device, "port%d", i);
hsi->port[i]->device.release = hsi_port_release;
device_initialize(&hsi->port[i]->device);
}
diff --git a/include/linux/hsi/hsi.h b/include/linux/hsi/hsi.h
index 6ca92bff02c6..ea6bef9b6012 100644
--- a/include/linux/hsi/hsi.h
+++ b/include/linux/hsi/hsi.h
@@ -271,7 +271,7 @@ struct hsi_controller {
struct module *owner;
unsigned int id;
unsigned int num_ports;
- struct hsi_port **port;
+ struct hsi_port *port[] __counted_by(num_ports);
};
#define to_hsi_controller(dev) container_of(dev, struct hsi_controller, device)
--
2.53.0
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCHv2] hsi: hsi_core: use kzalloc_flex
2026-03-17 19:58 [PATCHv2] hsi: hsi_core: use kzalloc_flex Rosen Penev
@ 2026-03-18 11:50 ` Sebastian Reichel
0 siblings, 0 replies; 2+ messages in thread
From: Sebastian Reichel @ 2026-03-18 11:50 UTC (permalink / raw)
To: Rosen Penev; +Cc: linux-kernel, Kees Cook, Gustavo A. R. Silva, linux-hardening
[-- Attachment #1: Type: text/plain, Size: 3933 bytes --]
Hi,
On Tue, Mar 17, 2026 at 12:58:19PM -0700, Rosen Penev wrote:
> Simplifies allocations by using a flexible array member in this struct.
>
> Add __counted_by to get extra runtime analysis.
>
> Signed-off-by: Rosen Penev <rosenp@gmail.com>
> ---
> v2: remove wrong null check
> drivers/hsi/hsi_core.c | 38 +++++++++++++++-----------------------
> include/linux/hsi/hsi.h | 2 +-
> 2 files changed, 16 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/hsi/hsi_core.c b/drivers/hsi/hsi_core.c
> index 7cb2dcb30fdb..001bcadf4b8e 100644
> --- a/drivers/hsi/hsi_core.c
> +++ b/drivers/hsi/hsi_core.c
> @@ -342,13 +342,11 @@ static void hsi_controller_release(struct device *dev)
> {
> struct hsi_controller *hsi = to_hsi_controller(dev);
>
> - kfree(hsi->port);
> kfree(hsi);
> }
>
> static void hsi_port_release(struct device *dev)
> {
> - kfree(to_hsi_port(dev));
Why is this free being removed? This is freeing hsi->port[i], which
still has an extra allocation after your patch.
FWIW - it should be possible to further simplify things (in a
potential follow-up patch) that also drops this extra
allocation/free by simply embedding an array of 'struct hsi_port'
instead of a pointer array in 'struct hsi_controller'.
Greetings,
-- Sebastian
> }
>
> /**
> @@ -446,7 +444,7 @@ void hsi_put_controller(struct hsi_controller *hsi)
> return;
>
> for (i = 0; i < hsi->num_ports; i++)
> - if (hsi->port && hsi->port[i])
> + if (hsi->port[i])
> put_device(&hsi->port[i]->device);
> put_device(&hsi->device);
> }
> @@ -462,39 +460,33 @@ EXPORT_SYMBOL_GPL(hsi_put_controller);
> struct hsi_controller *hsi_alloc_controller(unsigned int n_ports, gfp_t flags)
> {
> struct hsi_controller *hsi;
> - struct hsi_port **port;
> unsigned int i;
>
> if (!n_ports)
> return NULL;
>
> - hsi = kzalloc_obj(*hsi, flags);
> + hsi = kzalloc_flex(*hsi, port, n_ports, flags);
> if (!hsi)
> return NULL;
> - port = kzalloc_objs(*port, n_ports, flags);
> - if (!port) {
> - kfree(hsi);
> - return NULL;
> - }
> +
> hsi->num_ports = n_ports;
> - hsi->port = port;
> hsi->device.release = hsi_controller_release;
> device_initialize(&hsi->device);
>
> for (i = 0; i < n_ports; i++) {
> - port[i] = kzalloc_obj(**port, flags);
> - if (port[i] == NULL)
> + hsi->port[i] = kzalloc_obj(**hsi->port, flags);
> + if (hsi->port[i] == NULL)
> goto out;
> - port[i]->num = i;
> - port[i]->async = hsi_dummy_msg;
> - port[i]->setup = hsi_dummy_cl;
> - port[i]->flush = hsi_dummy_cl;
> - port[i]->start_tx = hsi_dummy_cl;
> - port[i]->stop_tx = hsi_dummy_cl;
> - port[i]->release = hsi_dummy_cl;
> - mutex_init(&port[i]->lock);
> - BLOCKING_INIT_NOTIFIER_HEAD(&port[i]->n_head);
> - dev_set_name(&port[i]->device, "port%d", i);
> + hsi->port[i]->num = i;
> + hsi->port[i]->async = hsi_dummy_msg;
> + hsi->port[i]->setup = hsi_dummy_cl;
> + hsi->port[i]->flush = hsi_dummy_cl;
> + hsi->port[i]->start_tx = hsi_dummy_cl;
> + hsi->port[i]->stop_tx = hsi_dummy_cl;
> + hsi->port[i]->release = hsi_dummy_cl;
> + mutex_init(&hsi->port[i]->lock);
> + BLOCKING_INIT_NOTIFIER_HEAD(&hsi->port[i]->n_head);
> + dev_set_name(&hsi->port[i]->device, "port%d", i);
> hsi->port[i]->device.release = hsi_port_release;
> device_initialize(&hsi->port[i]->device);
> }
> diff --git a/include/linux/hsi/hsi.h b/include/linux/hsi/hsi.h
> index 6ca92bff02c6..ea6bef9b6012 100644
> --- a/include/linux/hsi/hsi.h
> +++ b/include/linux/hsi/hsi.h
> @@ -271,7 +271,7 @@ struct hsi_controller {
> struct module *owner;
> unsigned int id;
> unsigned int num_ports;
> - struct hsi_port **port;
> + struct hsi_port *port[] __counted_by(num_ports);
> };
>
> #define to_hsi_controller(dev) container_of(dev, struct hsi_controller, device)
> --
> 2.53.0
>
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