github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-09-24 06:24:02 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

s390/traps: Add exception statistics

Browse Source 
Add a new debugfs file which displays the number of exceptions (program
checks) per CPU. This is helpful for debugging purposes.

The statistics are typically available at
/sys/kernel/debug/s390/exceptions.

[ hca@linux.ibm.com: Forward ported code, changed file location ]

Suggested-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This commit is contained in:
Sven Schnelle 2026-06-17 14:33:50 +02:00 committed by Vasily Gorbik
parent debfa8d0a7
commit a7325d0d77
1 changed files with 40 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

41
arch/s390/kernel/traps.c
View File

@ -9,7 +9,9 @@
* Copyright (C) 1991, 1992 Linus Torvalds
*/
#include <linux/capability.h>
#include <linux/cpufeature.h>
#include <linux/debugfs.h>
#include <linux/kprobes.h>
#include <linux/kdebug.h>
#include <linux/randomize_kstack.h>
@ -33,6 +35,12 @@
#include <asm/fault.h>
#include "entry.h"
struct pgm_stat {
unsigned int count[128];
};
static DEFINE_PER_CPU_SHARED_ALIGNED(struct pgm_stat, pgm_stat);
static inline void __user *get_trap_ip(struct pt_regs *regs)
{
unsigned long address;
@ -332,6 +340,7 @@ void noinstr __do_pgm_check(struct pt_regs *regs)
struct lowcore *lc = get_lowcore();
bool percpu_needs_fixup;
irqentry_state_t state;
struct pgm_stat *stat;
unsigned int trapnr;
union teid teid;
@ -339,6 +348,10 @@ void noinstr __do_pgm_check(struct pt_regs *regs)
regs->int_code = lc->pgm_int_code;
regs->int_parm_long = teid.val;
regs->monitor_code = lc->monitor_code;
trapnr = regs->int_code & PGM_INT_CODE_MASK;
stat = this_cpu_ptr(&pgm_stat);
stat->count[trapnr]++;
/*
* In case of a guest fault, short-circuit the fault handler and return.
* This way the sie64a() function will return 0; fault address and
@ -383,7 +396,6 @@ void noinstr __do_pgm_check(struct pt_regs *regs)
if (!irqs_disabled_flags(regs->psw.mask))
trace_hardirqs_on();
__arch_local_irq_ssm(regs->psw.mask & ~PSW_MASK_PER);
trapnr = regs->int_code & PGM_INT_CODE_MASK;
if (trapnr)
pgm_check_table[trapnr](regs);
out:
@ -393,6 +405,33 @@ void noinstr __do_pgm_check(struct pt_regs *regs)
percpu_exit(regs, percpu_needs_fixup);
}
static int pgm_check_stat_show(struct seq_file *p, void *v)
{
int i, cpu;
cpus_read_lock();
seq_puts(p, " ");
for_each_online_cpu(cpu)
seq_printf(p, "CPU%-8d", cpu);
seq_putc(p, '\n');
for (i = 0; i < 128; i++) {
seq_printf(p, "%02x: ", i);
for_each_online_cpu(cpu)
seq_printf(p, "%10u ", per_cpu(pgm_stat, cpu).count[i]);
seq_putc(p, '\n');
}
cpus_read_unlock();
return 0;
}
DEFINE_SHOW_ATTRIBUTE(pgm_check_stat);
static int __init debugfs_pgm_check_init(void)
{
debugfs_create_file("exceptions", 0400, arch_debugfs_dir, NULL, &pgm_check_stat_fops);
return 0;
}
late_initcall(debugfs_pgm_check_init);
/*
* The program check table contains exactly 128 (0x00-0x7f) entries. Each
* line defines the function to be called corresponding to the program check