linux_dsm_epyc7002/arch/s390/kernel/diag.c
Philipp Rudo 8ebf6da9db s390/ftrace: fix potential crashes when switching tracers
Switching tracers include instruction patching. To prevent that a
instruction is patched while it's read the instruction patching is done
in stop_machine 'context'. This also means that any function called
during stop_machine must not be traced. Thus add 'notrace' to all
functions called within stop_machine.

Fixes: 1ec2772e0c ("s390/diag: add a statistic for diagnose calls")
Fixes: 38f2c691a4 ("s390: improve wait logic of stop_machine")
Fixes: 4ecf0a43e7 ("processor: get rid of cpu_relax_yield")
Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-04-22 16:20:55 +02:00

223 lines
5.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Implementation of s390 diagnose codes
*
* Copyright IBM Corp. 2007
* Author(s): Michael Holzheu <holzheu@de.ibm.com>
*/
#include <linux/export.h>
#include <linux/init.h>
#include <linux/cpu.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>
#include <asm/diag.h>
#include <asm/trace/diag.h>
#include <asm/sections.h>
struct diag_stat {
unsigned int counter[NR_DIAG_STAT];
};
static DEFINE_PER_CPU(struct diag_stat, diag_stat);
struct diag_desc {
int code;
char *name;
};
static const struct diag_desc diag_map[NR_DIAG_STAT] = {
[DIAG_STAT_X008] = { .code = 0x008, .name = "Console Function" },
[DIAG_STAT_X00C] = { .code = 0x00c, .name = "Pseudo Timer" },
[DIAG_STAT_X010] = { .code = 0x010, .name = "Release Pages" },
[DIAG_STAT_X014] = { .code = 0x014, .name = "Spool File Services" },
[DIAG_STAT_X044] = { .code = 0x044, .name = "Voluntary Timeslice End" },
[DIAG_STAT_X064] = { .code = 0x064, .name = "NSS Manipulation" },
[DIAG_STAT_X09C] = { .code = 0x09c, .name = "Relinquish Timeslice" },
[DIAG_STAT_X0DC] = { .code = 0x0dc, .name = "Appldata Control" },
[DIAG_STAT_X204] = { .code = 0x204, .name = "Logical-CPU Utilization" },
[DIAG_STAT_X210] = { .code = 0x210, .name = "Device Information" },
[DIAG_STAT_X224] = { .code = 0x224, .name = "EBCDIC-Name Table" },
[DIAG_STAT_X250] = { .code = 0x250, .name = "Block I/O" },
[DIAG_STAT_X258] = { .code = 0x258, .name = "Page-Reference Services" },
[DIAG_STAT_X26C] = { .code = 0x26c, .name = "Certain System Information" },
[DIAG_STAT_X288] = { .code = 0x288, .name = "Time Bomb" },
[DIAG_STAT_X2C4] = { .code = 0x2c4, .name = "FTP Services" },
[DIAG_STAT_X2FC] = { .code = 0x2fc, .name = "Guest Performance Data" },
[DIAG_STAT_X304] = { .code = 0x304, .name = "Partition-Resource Service" },
[DIAG_STAT_X308] = { .code = 0x308, .name = "List-Directed IPL" },
[DIAG_STAT_X318] = { .code = 0x318, .name = "CP Name and Version Codes" },
[DIAG_STAT_X500] = { .code = 0x500, .name = "Virtio Service" },
};
struct diag_ops __bootdata_preserved(diag_dma_ops);
struct diag210 *__bootdata_preserved(__diag210_tmp_dma);
static int show_diag_stat(struct seq_file *m, void *v)
{
struct diag_stat *stat;
unsigned long n = (unsigned long) v - 1;
int cpu, prec, tmp;
get_online_cpus();
if (n == 0) {
seq_puts(m, " ");
for_each_online_cpu(cpu) {
prec = 10;
for (tmp = 10; cpu >= tmp; tmp *= 10)
prec--;
seq_printf(m, "%*s%d", prec, "CPU", cpu);
}
seq_putc(m, '\n');
} else if (n <= NR_DIAG_STAT) {
seq_printf(m, "diag %03x:", diag_map[n-1].code);
for_each_online_cpu(cpu) {
stat = &per_cpu(diag_stat, cpu);
seq_printf(m, " %10u", stat->counter[n-1]);
}
seq_printf(m, " %s\n", diag_map[n-1].name);
}
put_online_cpus();
return 0;
}
static void *show_diag_stat_start(struct seq_file *m, loff_t *pos)
{
return *pos <= NR_DIAG_STAT ? (void *)((unsigned long) *pos + 1) : NULL;
}
static void *show_diag_stat_next(struct seq_file *m, void *v, loff_t *pos)
{
++*pos;
return show_diag_stat_start(m, pos);
}
static void show_diag_stat_stop(struct seq_file *m, void *v)
{
}
static const struct seq_operations show_diag_stat_sops = {
.start = show_diag_stat_start,
.next = show_diag_stat_next,
.stop = show_diag_stat_stop,
.show = show_diag_stat,
};
static int show_diag_stat_open(struct inode *inode, struct file *file)
{
return seq_open(file, &show_diag_stat_sops);
}
static const struct file_operations show_diag_stat_fops = {
.open = show_diag_stat_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static int __init show_diag_stat_init(void)
{
debugfs_create_file("diag_stat", 0400, NULL, NULL,
&show_diag_stat_fops);
return 0;
}
device_initcall(show_diag_stat_init);
void diag_stat_inc(enum diag_stat_enum nr)
{
this_cpu_inc(diag_stat.counter[nr]);
trace_s390_diagnose(diag_map[nr].code);
}
EXPORT_SYMBOL(diag_stat_inc);
void notrace diag_stat_inc_norecursion(enum diag_stat_enum nr)
{
this_cpu_inc(diag_stat.counter[nr]);
trace_s390_diagnose_norecursion(diag_map[nr].code);
}
EXPORT_SYMBOL(diag_stat_inc_norecursion);
/*
* Diagnose 14: Input spool file manipulation
*/
int diag14(unsigned long rx, unsigned long ry1, unsigned long subcode)
{
diag_stat_inc(DIAG_STAT_X014);
return diag_dma_ops.diag14(rx, ry1, subcode);
}
EXPORT_SYMBOL(diag14);
static inline int __diag204(unsigned long *subcode, unsigned long size, void *addr)
{
register unsigned long _subcode asm("0") = *subcode;
register unsigned long _size asm("1") = size;
asm volatile(
" diag %2,%0,0x204\n"
"0: nopr %%r7\n"
EX_TABLE(0b,0b)
: "+d" (_subcode), "+d" (_size) : "d" (addr) : "memory");
*subcode = _subcode;
return _size;
}
int diag204(unsigned long subcode, unsigned long size, void *addr)
{
diag_stat_inc(DIAG_STAT_X204);
size = __diag204(&subcode, size, addr);
if (subcode)
return -1;
return size;
}
EXPORT_SYMBOL(diag204);
/*
* Diagnose 210: Get information about a virtual device
*/
int diag210(struct diag210 *addr)
{
static DEFINE_SPINLOCK(diag210_lock);
unsigned long flags;
int ccode;
spin_lock_irqsave(&diag210_lock, flags);
*__diag210_tmp_dma = *addr;
diag_stat_inc(DIAG_STAT_X210);
ccode = diag_dma_ops.diag210(__diag210_tmp_dma);
*addr = *__diag210_tmp_dma;
spin_unlock_irqrestore(&diag210_lock, flags);
return ccode;
}
EXPORT_SYMBOL(diag210);
int diag224(void *ptr)
{
int rc = -EOPNOTSUPP;
diag_stat_inc(DIAG_STAT_X224);
asm volatile(
" diag %1,%2,0x224\n"
"0: lhi %0,0x0\n"
"1:\n"
EX_TABLE(0b,1b)
: "+d" (rc) :"d" (0), "d" (ptr) : "memory");
return rc;
}
EXPORT_SYMBOL(diag224);
/*
* Diagnose 26C: Access Certain System Information
*/
int diag26c(void *req, void *resp, enum diag26c_sc subcode)
{
diag_stat_inc(DIAG_STAT_X26C);
return diag_dma_ops.diag26c(req, resp, subcode);
}
EXPORT_SYMBOL(diag26c);