forked from Minki/linux
927633a6d2
In stm_heartbeat_init(): return value gets reset after the first
iteration by stm_source_register_device(), so allocation failures
after that will, after a clean up, return success. Fix that.
Fixes: 1192918530 ("stm class: Add heartbeat stm source device")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hui <john.wanghui@huawei.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lore.kernel.org/r/20210115195917.3184-2-alexander.shishkin@linux.intel.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
121 lines
2.8 KiB
C
121 lines
2.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Simple heartbeat STM source driver
|
|
* Copyright (c) 2016, Intel Corporation.
|
|
*
|
|
* Heartbeat STM source will send repetitive messages over STM devices to a
|
|
* trace host.
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/hrtimer.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/stm.h>
|
|
|
|
#define STM_HEARTBEAT_MAX 32
|
|
|
|
static int nr_devs = 4;
|
|
static int interval_ms = 10;
|
|
|
|
module_param(nr_devs, int, 0400);
|
|
module_param(interval_ms, int, 0600);
|
|
|
|
static struct stm_heartbeat {
|
|
struct stm_source_data data;
|
|
struct hrtimer hrtimer;
|
|
unsigned int active;
|
|
} stm_heartbeat[STM_HEARTBEAT_MAX];
|
|
|
|
static const char str[] = "heartbeat stm source driver is here to serve you";
|
|
|
|
static enum hrtimer_restart stm_heartbeat_hrtimer_handler(struct hrtimer *hr)
|
|
{
|
|
struct stm_heartbeat *heartbeat = container_of(hr, struct stm_heartbeat,
|
|
hrtimer);
|
|
|
|
stm_source_write(&heartbeat->data, 0, str, sizeof str);
|
|
if (heartbeat->active)
|
|
hrtimer_forward_now(hr, ms_to_ktime(interval_ms));
|
|
|
|
return heartbeat->active ? HRTIMER_RESTART : HRTIMER_NORESTART;
|
|
}
|
|
|
|
static int stm_heartbeat_link(struct stm_source_data *data)
|
|
{
|
|
struct stm_heartbeat *heartbeat =
|
|
container_of(data, struct stm_heartbeat, data);
|
|
|
|
heartbeat->active = 1;
|
|
hrtimer_start(&heartbeat->hrtimer, ms_to_ktime(interval_ms),
|
|
HRTIMER_MODE_ABS);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void stm_heartbeat_unlink(struct stm_source_data *data)
|
|
{
|
|
struct stm_heartbeat *heartbeat =
|
|
container_of(data, struct stm_heartbeat, data);
|
|
|
|
heartbeat->active = 0;
|
|
hrtimer_cancel(&heartbeat->hrtimer);
|
|
}
|
|
|
|
static int stm_heartbeat_init(void)
|
|
{
|
|
int i, ret;
|
|
|
|
if (nr_devs < 0 || nr_devs > STM_HEARTBEAT_MAX)
|
|
return -EINVAL;
|
|
|
|
for (i = 0; i < nr_devs; i++) {
|
|
stm_heartbeat[i].data.name =
|
|
kasprintf(GFP_KERNEL, "heartbeat.%d", i);
|
|
if (!stm_heartbeat[i].data.name) {
|
|
ret = -ENOMEM;
|
|
goto fail_unregister;
|
|
}
|
|
|
|
stm_heartbeat[i].data.nr_chans = 1;
|
|
stm_heartbeat[i].data.link = stm_heartbeat_link;
|
|
stm_heartbeat[i].data.unlink = stm_heartbeat_unlink;
|
|
hrtimer_init(&stm_heartbeat[i].hrtimer, CLOCK_MONOTONIC,
|
|
HRTIMER_MODE_ABS);
|
|
stm_heartbeat[i].hrtimer.function =
|
|
stm_heartbeat_hrtimer_handler;
|
|
|
|
ret = stm_source_register_device(NULL, &stm_heartbeat[i].data);
|
|
if (ret)
|
|
goto fail_free;
|
|
}
|
|
|
|
return 0;
|
|
|
|
fail_unregister:
|
|
for (i--; i >= 0; i--) {
|
|
stm_source_unregister_device(&stm_heartbeat[i].data);
|
|
fail_free:
|
|
kfree(stm_heartbeat[i].data.name);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void stm_heartbeat_exit(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < nr_devs; i++) {
|
|
stm_source_unregister_device(&stm_heartbeat[i].data);
|
|
kfree(stm_heartbeat[i].data.name);
|
|
}
|
|
}
|
|
|
|
module_init(stm_heartbeat_init);
|
|
module_exit(stm_heartbeat_exit);
|
|
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_DESCRIPTION("stm_heartbeat driver");
|
|
MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>");
|