linux/arch/s390/appldata/appldata_os.c
Gustavo A. R. Silva 28ccce5f50 s390/appldata: use struct_size() helper
Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.

This code was detected with the help of Coccinelle and, audited and
fixed manually.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Message-Id: <20200617212930.GA11728@embeddedor>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2020-06-29 16:32:34 +02:00

212 lines
5.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Data gathering module for Linux-VM Monitor Stream, Stage 1.
* Collects misc. OS related data (CPU utilization, running processes).
*
* Copyright IBM Corp. 2003, 2006
*
* Author: Gerald Schaefer <gerald.schaefer@de.ibm.com>
*/
#define KMSG_COMPONENT "appldata"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/kernel_stat.h>
#include <linux/netdevice.h>
#include <linux/sched.h>
#include <linux/sched/loadavg.h>
#include <linux/sched/stat.h>
#include <asm/appldata.h>
#include <asm/smp.h>
#include "appldata.h"
/*
* OS data
*
* This is accessed as binary data by z/VM. If changes to it can't be avoided,
* the structure version (product ID, see appldata_base.c) needs to be changed
* as well and all documentation and z/VM applications using it must be
* updated.
*/
struct appldata_os_per_cpu {
u32 per_cpu_user; /* timer ticks spent in user mode */
u32 per_cpu_nice; /* ... spent with modified priority */
u32 per_cpu_system; /* ... spent in kernel mode */
u32 per_cpu_idle; /* ... spent in idle mode */
/* New in 2.6 */
u32 per_cpu_irq; /* ... spent in interrupts */
u32 per_cpu_softirq; /* ... spent in softirqs */
u32 per_cpu_iowait; /* ... spent while waiting for I/O */
/* New in modification level 01 */
u32 per_cpu_steal; /* ... stolen by hypervisor */
u32 cpu_id; /* number of this CPU */
} __attribute__((packed));
struct appldata_os_data {
u64 timestamp;
u32 sync_count_1; /* after VM collected the record data, */
u32 sync_count_2; /* sync_count_1 and sync_count_2 should be the
same. If not, the record has been updated on
the Linux side while VM was collecting the
(possibly corrupt) data */
u32 nr_cpus; /* number of (virtual) CPUs */
u32 per_cpu_size; /* size of the per-cpu data struct */
u32 cpu_offset; /* offset of the first per-cpu data struct */
u32 nr_running; /* number of runnable threads */
u32 nr_threads; /* number of threads */
u32 avenrun[3]; /* average nr. of running processes during */
/* the last 1, 5 and 15 minutes */
/* New in 2.6 */
u32 nr_iowait; /* number of blocked threads
(waiting for I/O) */
/* per cpu data */
struct appldata_os_per_cpu os_cpu[];
} __attribute__((packed));
static struct appldata_os_data *appldata_os_data;
static struct appldata_ops ops = {
.name = "os",
.record_nr = APPLDATA_RECORD_OS_ID,
.owner = THIS_MODULE,
.mod_lvl = {0xF0, 0xF1}, /* EBCDIC "01" */
};
/*
* appldata_get_os_data()
*
* gather OS data
*/
static void appldata_get_os_data(void *data)
{
int i, j, rc;
struct appldata_os_data *os_data;
unsigned int new_size;
os_data = data;
os_data->sync_count_1++;
os_data->nr_threads = nr_threads;
os_data->nr_running = nr_running();
os_data->nr_iowait = nr_iowait();
os_data->avenrun[0] = avenrun[0] + (FIXED_1/200);
os_data->avenrun[1] = avenrun[1] + (FIXED_1/200);
os_data->avenrun[2] = avenrun[2] + (FIXED_1/200);
j = 0;
for_each_online_cpu(i) {
os_data->os_cpu[j].per_cpu_user =
nsecs_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_USER]);
os_data->os_cpu[j].per_cpu_nice =
nsecs_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_NICE]);
os_data->os_cpu[j].per_cpu_system =
nsecs_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM]);
os_data->os_cpu[j].per_cpu_idle =
nsecs_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_IDLE]);
os_data->os_cpu[j].per_cpu_irq =
nsecs_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_IRQ]);
os_data->os_cpu[j].per_cpu_softirq =
nsecs_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ]);
os_data->os_cpu[j].per_cpu_iowait =
nsecs_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_IOWAIT]);
os_data->os_cpu[j].per_cpu_steal =
nsecs_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_STEAL]);
os_data->os_cpu[j].cpu_id = i;
j++;
}
os_data->nr_cpus = j;
new_size = struct_size(os_data, os_cpu, os_data->nr_cpus);
if (ops.size != new_size) {
if (ops.active) {
rc = appldata_diag(APPLDATA_RECORD_OS_ID,
APPLDATA_START_INTERVAL_REC,
(unsigned long) ops.data, new_size,
ops.mod_lvl);
if (rc != 0)
pr_err("Starting a new OS data collection "
"failed with rc=%d\n", rc);
rc = appldata_diag(APPLDATA_RECORD_OS_ID,
APPLDATA_STOP_REC,
(unsigned long) ops.data, ops.size,
ops.mod_lvl);
if (rc != 0)
pr_err("Stopping a faulty OS data "
"collection failed with rc=%d\n", rc);
}
ops.size = new_size;
}
os_data->timestamp = get_tod_clock();
os_data->sync_count_2++;
}
/*
* appldata_os_init()
*
* init data, register ops
*/
static int __init appldata_os_init(void)
{
int rc, max_size;
max_size = struct_size(appldata_os_data, os_cpu, num_possible_cpus());
if (max_size > APPLDATA_MAX_REC_SIZE) {
pr_err("Maximum OS record size %i exceeds the maximum "
"record size %i\n", max_size, APPLDATA_MAX_REC_SIZE);
rc = -ENOMEM;
goto out;
}
appldata_os_data = kzalloc(max_size, GFP_KERNEL | GFP_DMA);
if (appldata_os_data == NULL) {
rc = -ENOMEM;
goto out;
}
appldata_os_data->per_cpu_size = sizeof(struct appldata_os_per_cpu);
appldata_os_data->cpu_offset = offsetof(struct appldata_os_data,
os_cpu);
ops.data = appldata_os_data;
ops.callback = &appldata_get_os_data;
rc = appldata_register_ops(&ops);
if (rc != 0)
kfree(appldata_os_data);
out:
return rc;
}
/*
* appldata_os_exit()
*
* unregister ops
*/
static void __exit appldata_os_exit(void)
{
appldata_unregister_ops(&ops);
kfree(appldata_os_data);
}
module_init(appldata_os_init);
module_exit(appldata_os_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Gerald Schaefer");
MODULE_DESCRIPTION("Linux-VM Monitor Stream, OS statistics");