[PATCH] powerpc: Fix PS3 allmodconfig warning

From: Geoff Levand
Date: Sat Mar 23 2024 - 21:24:10 EST


The struct ps3_notification_device in the ps3_probe_thread routine
is too large to be on the stack, causing a warning for an
allmodconfig build with clang.

Change the struct ps3_notification_device from a variable on the stack
to a dynamically allocated variable.

Reported-by: Arnd Bergmann <arnd@xxxxxxxxxx>
Signed-off-by: Geoff Levand <geoff@xxxxxxxxxxxxx>

diff --git a/arch/powerpc/platforms/ps3/device-init.c b/arch/powerpc/platforms/ps3/device-init.c
index 878bc160246e..03292869e6a1 100644
--- a/arch/powerpc/platforms/ps3/device-init.c
+++ b/arch/powerpc/platforms/ps3/device-init.c
@@ -770,49 +770,51 @@ static struct task_struct *probe_task;

static int ps3_probe_thread(void *data)
{
- struct ps3_notification_device dev;
+ struct {
+ struct ps3_notification_device dev;
+ u8 buf[512];
+ } *local;
+ struct ps3_notify_cmd *notify_cmd;
+ struct ps3_notify_event *notify_event;
int res;
unsigned int irq;
u64 lpar;
- void *buf;
- struct ps3_notify_cmd *notify_cmd;
- struct ps3_notify_event *notify_event;

pr_debug(" -> %s:%u: kthread started\n", __func__, __LINE__);

- buf = kzalloc(512, GFP_KERNEL);
- if (!buf)
+ local = kzalloc(sizeof(local), GFP_KERNEL);
+ if (!local)
return -ENOMEM;

- lpar = ps3_mm_phys_to_lpar(__pa(buf));
- notify_cmd = buf;
- notify_event = buf;
+ lpar = ps3_mm_phys_to_lpar(__pa(&local->buf));
+ notify_cmd = (struct ps3_notify_cmd *)&local->buf;
+ notify_event = (struct ps3_notify_event *)&local->buf;

/* dummy system bus device */
- dev.sbd.bus_id = (u64)data;
- dev.sbd.dev_id = PS3_NOTIFICATION_DEV_ID;
- dev.sbd.interrupt_id = PS3_NOTIFICATION_INTERRUPT_ID;
+ local->dev.sbd.bus_id = (u64)data;
+ local->dev.sbd.dev_id = PS3_NOTIFICATION_DEV_ID;
+ local->dev.sbd.interrupt_id = PS3_NOTIFICATION_INTERRUPT_ID;

- res = lv1_open_device(dev.sbd.bus_id, dev.sbd.dev_id, 0);
+ res = lv1_open_device(local->dev.sbd.bus_id, local->dev.sbd.dev_id, 0);
if (res) {
pr_err("%s:%u: lv1_open_device failed %s\n", __func__,
__LINE__, ps3_result(res));
goto fail_free;
}

- res = ps3_sb_event_receive_port_setup(&dev.sbd, PS3_BINDING_CPU_ANY,
- &irq);
+ res = ps3_sb_event_receive_port_setup(&local->dev.sbd,
+ PS3_BINDING_CPU_ANY, &irq);
if (res) {
pr_err("%s:%u: ps3_sb_event_receive_port_setup failed %d\n",
__func__, __LINE__, res);
goto fail_close_device;
}

- spin_lock_init(&dev.lock);
- rcuwait_init(&dev.wait);
+ spin_lock_init(&local->dev.lock);
+ rcuwait_init(&local->dev.wait);

res = request_irq(irq, ps3_notification_interrupt, 0,
- "ps3_notification", &dev);
+ "ps3_notification", &local->dev);
if (res) {
pr_err("%s:%u: request_irq failed %d\n", __func__, __LINE__,
res);
@@ -823,7 +825,7 @@ static int ps3_probe_thread(void *data)
notify_cmd->operation_code = 0; /* must be zero */
notify_cmd->event_mask = 1UL << notify_region_probe;

- res = ps3_notification_read_write(&dev, lpar, 1);
+ res = ps3_notification_read_write(&local->dev, lpar, 1);
if (res)
goto fail_free_irq;

@@ -834,36 +836,37 @@ static int ps3_probe_thread(void *data)

memset(notify_event, 0, sizeof(*notify_event));

- res = ps3_notification_read_write(&dev, lpar, 0);
+ res = ps3_notification_read_write(&local->dev, lpar, 0);
if (res)
break;

pr_debug("%s:%u: notify event type 0x%llx bus id %llu dev id %llu"
" type %llu port %llu\n", __func__, __LINE__,
- notify_event->event_type, notify_event->bus_id,
- notify_event->dev_id, notify_event->dev_type,
- notify_event->dev_port);
+ notify_event->event_type, notify_event->bus_id,
+ notify_event->dev_id, notify_event->dev_type,
+ notify_event->dev_port);

if (notify_event->event_type != notify_region_probe ||
- notify_event->bus_id != dev.sbd.bus_id) {
+ notify_event->bus_id != local->dev.sbd.bus_id) {
pr_warn("%s:%u: bad notify_event: event %llu, dev_id %llu, dev_type %llu\n",
__func__, __LINE__, notify_event->event_type,
notify_event->dev_id, notify_event->dev_type);
continue;
}

- ps3_find_and_add_device(dev.sbd.bus_id, notify_event->dev_id);
+ ps3_find_and_add_device(local->dev.sbd.bus_id,
+ notify_event->dev_id);

} while (!kthread_should_stop());

fail_free_irq:
- free_irq(irq, &dev);
+ free_irq(irq, &local->dev);
fail_sb_event_receive_port_destroy:
- ps3_sb_event_receive_port_destroy(&dev.sbd, irq);
+ ps3_sb_event_receive_port_destroy(&local->dev.sbd, irq);
fail_close_device:
- lv1_close_device(dev.sbd.bus_id, dev.sbd.dev_id);
+ lv1_close_device(local->dev.sbd.bus_id, local->dev.sbd.dev_id);
fail_free:
- kfree(buf);
+ kfree(local);

probe_task = NULL;