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freebsd-nq/module/spl/spl-debug.c
Brian Behlendorf 377e12f14a Rate limit debugging stack traces 
There have been issues in the past where excessive debug logging
to the console has resulted in significant performance impacts.
In the vast majority of these cases only a few stack traces are
required to diagnose the issue.  Therefore, stack traces dumped to
the console will now we limited to 5 every 60s.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Closes #374
2014-07-22 09:47:24 -07:00

1266 lines
36 KiB
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/*****************************************************************************\
* Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
* Copyright (C) 2007 The Regents of the University of California.
* Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
* Written by Brian Behlendorf <behlendorf1@llnl.gov>.
* UCRL-CODE-235197
*
* This file is part of the SPL, Solaris Porting Layer.
* For details, see <http://zfsonlinux.org/>.
*
* The SPL is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* The SPL is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with the SPL. If not, see <http://www.gnu.org/licenses/>.
*****************************************************************************
* Solaris Porting Layer (SPL) Debug Implementation.
\*****************************************************************************/
#include <linux/kmod.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/ctype.h>
#include <linux/kthread.h>
#include <linux/hardirq.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/proc_compat.h>
#include <linux/file_compat.h>
#include <linux/swap.h>
#include <linux/ratelimit.h>
#include <sys/sysmacros.h>
#include <sys/thread.h>
#include <spl-debug.h>
#include <spl-trace.h>
#include <spl-ctl.h>
#ifdef SS_DEBUG_SUBSYS
#undef SS_DEBUG_SUBSYS
#endif
#define SS_DEBUG_SUBSYS SS_DEBUG
/* Debug log support enabled */
#ifdef DEBUG_LOG
unsigned long spl_debug_subsys = ~0;
EXPORT_SYMBOL(spl_debug_subsys);
module_param(spl_debug_subsys, ulong, 0644);
MODULE_PARM_DESC(spl_debug_subsys, "Subsystem debugging level mask.");
unsigned long spl_debug_mask = SD_CANTMASK;
EXPORT_SYMBOL(spl_debug_mask);
module_param(spl_debug_mask, ulong, 0644);
MODULE_PARM_DESC(spl_debug_mask, "Debugging level mask.");
unsigned long spl_debug_printk = SD_CANTMASK;
EXPORT_SYMBOL(spl_debug_printk);
module_param(spl_debug_printk, ulong, 0644);
MODULE_PARM_DESC(spl_debug_printk, "Console printk level mask.");
int spl_debug_mb = -1;
EXPORT_SYMBOL(spl_debug_mb);
module_param(spl_debug_mb, int, 0644);
MODULE_PARM_DESC(spl_debug_mb, "Total debug buffer size.");
unsigned int spl_debug_binary = 1;
EXPORT_SYMBOL(spl_debug_binary);
unsigned int spl_debug_catastrophe;
EXPORT_SYMBOL(spl_debug_catastrophe);
unsigned int spl_debug_panic_on_bug = 0;
EXPORT_SYMBOL(spl_debug_panic_on_bug);
module_param(spl_debug_panic_on_bug, uint, 0644);
MODULE_PARM_DESC(spl_debug_panic_on_bug, "Panic on BUG");
static char spl_debug_file_name[PATH_MAX];
char spl_debug_file_path[PATH_MAX] = "/tmp/spl-log";
unsigned int spl_console_ratelimit = 1;
EXPORT_SYMBOL(spl_console_ratelimit);
long spl_console_max_delay;
EXPORT_SYMBOL(spl_console_max_delay);
long spl_console_min_delay;
EXPORT_SYMBOL(spl_console_min_delay);
unsigned int spl_console_backoff = SPL_DEFAULT_BACKOFF;
EXPORT_SYMBOL(spl_console_backoff);
unsigned int spl_debug_stack;
EXPORT_SYMBOL(spl_debug_stack);
static int spl_panic_in_progress;
union trace_data_union (*trace_data[TCD_TYPE_MAX])[NR_CPUS] __cacheline_aligned;
char *trace_console_buffers[NR_CPUS][3];
struct rw_semaphore trace_sem;
atomic_t trace_tage_allocated = ATOMIC_INIT(0);
static int spl_debug_dump_all_pages(dumplog_priv_t *dp, char *);
static void trace_fini(void);
/* Memory percentage breakdown by type */
static unsigned int pages_factor[TCD_TYPE_MAX] = {
80, /* 80% pages for TCD_TYPE_PROC */
10, /* 10% pages for TCD_TYPE_SOFTIRQ */
10 /* 10% pages for TCD_TYPE_IRQ */
};
const char *
spl_debug_subsys2str(int subsys)
{
switch (subsys) {
default:
return NULL;
case SS_UNDEFINED:
return "undefined";
case SS_ATOMIC:
return "atomic";
case SS_KOBJ:
return "kobj";
case SS_VNODE:
return "vnode";
case SS_TIME:
return "time";
case SS_RWLOCK:
return "rwlock";
case SS_THREAD:
return "thread";
case SS_CONDVAR:
return "condvar";
case SS_MUTEX:
return "mutex";
case SS_RNG:
return "rng";
case SS_TASKQ:
return "taskq";
case SS_KMEM:
return "kmem";
case SS_DEBUG:
return "debug";
case SS_GENERIC:
return "generic";
case SS_PROC:
return "proc";
case SS_MODULE:
return "module";
case SS_CRED:
return "cred";
case SS_KSTAT:
return "kstat";
case SS_XDR:
return "xdr";
case SS_TSD:
return "tsd";
case SS_ZLIB:
return "zlib";
case SS_USER1:
return "user1";
case SS_USER2:
return "user2";
case SS_USER3:
return "user3";
case SS_USER4:
return "user4";
case SS_USER5:
return "user5";
case SS_USER6:
return "user6";
case SS_USER7:
return "user7";
case SS_USER8:
return "user8";
}
}
const char *
spl_debug_dbg2str(int debug)
{
switch (debug) {
default:
return NULL;
case SD_TRACE:
return "trace";
case SD_INFO:
return "info";
case SD_WARNING:
return "warning";
case SD_ERROR:
return "error";
case SD_EMERG:
return "emerg";
case SD_CONSOLE:
return "console";
case SD_IOCTL:
return "ioctl";
case SD_DPRINTF:
return "dprintf";
case SD_OTHER:
return "other";
}
}
int
spl_debug_mask2str(char *str, int size, unsigned long mask, int is_subsys)
{
const char *(*fn)(int bit) = is_subsys ? spl_debug_subsys2str :
spl_debug_dbg2str;
const char *token;
int i, bit, len = 0;
if (mask == 0) { /* "0" */
if (size > 0)
str[0] = '0';
len = 1;
} else { /* space-separated tokens */
for (i = 0; i < 32; i++) {
bit = 1 << i;
if ((mask & bit) == 0)
continue;
token = fn(bit);
if (token == NULL) /* unused bit */
continue;
if (len > 0) { /* separator? */
if (len < size)
str[len] = ' ';
len++;
}
while (*token != 0) {
if (len < size)
str[len] = *token;
token++;
len++;
}
}
}
/* terminate 'str' */
if (len < size)
str[len] = 0;
else
str[size - 1] = 0;
return len;
}
static int
spl_debug_token2mask(int *mask, const char *str, int len, int is_subsys)
{
const char *(*fn)(int bit) = is_subsys ? spl_debug_subsys2str :
spl_debug_dbg2str;
const char *token;
int i, j, bit;
/* match against known tokens */
for (i = 0; i < 32; i++) {
bit = 1 << i;
token = fn(bit);
if (token == NULL) /* unused? */
continue;
/* strcasecmp */
for (j = 0; ; j++) {
if (j == len) { /* end of token */
if (token[j] == 0) {
*mask = bit;
return 0;
}
break;
}
if (token[j] == 0)
break;
if (str[j] == token[j])
continue;
if (str[j] < 'A' || 'Z' < str[j])
break;
if (str[j] - 'A' + 'a' != token[j])
break;
}
}
return -EINVAL; /* no match */
}
int
spl_debug_str2mask(unsigned long *mask, const char *str, int is_subsys)
{
char op = 0;
int m = 0, matched, n, t;
/* Allow a number for backwards compatibility */
for (n = strlen(str); n > 0; n--)
if (!isspace(str[n-1]))
break;
matched = n;
if ((t = sscanf(str, "%i%n", &m, &matched)) >= 1 && matched == n) {
*mask = m;
return 0;
}
/* <str> must be a list of debug tokens or numbers separated by
* whitespace and optionally an operator ('+' or '-'). If an operator
* appears first in <str>, '*mask' is used as the starting point
* (relative), otherwise 0 is used (absolute). An operator applies to
* all following tokens up to the next operator. */
matched = 0;
while (*str != 0) {
while (isspace(*str)) /* skip whitespace */
str++;
if (*str == 0)
break;
if (*str == '+' || *str == '-') {
op = *str++;
/* op on first token == relative */
if (!matched)
m = *mask;
while (isspace(*str)) /* skip whitespace */
str++;
if (*str == 0) /* trailing op */
return -EINVAL;
}
/* find token length */
for (n = 0; str[n] != 0 && !isspace(str[n]); n++);
/* match token */
if (spl_debug_token2mask(&t, str, n, is_subsys) != 0)
return -EINVAL;
matched = 1;
if (op == '-')
m &= ~t;
else
m |= t;
str += n;
}
if (!matched)
return -EINVAL;
*mask = m;
return 0;
}
static void
spl_debug_dumplog_internal(dumplog_priv_t *dp)
{
void *journal_info;
journal_info = current->journal_info;
current->journal_info = NULL;
snprintf(spl_debug_file_name, sizeof(spl_debug_file_path) - 1,
"%s.%ld.%ld", spl_debug_file_path,
get_seconds(), (long)dp->dp_pid);
printk("SPL: Dumping log to %s\n", spl_debug_file_name);
spl_debug_dump_all_pages(dp, spl_debug_file_name);
current->journal_info = journal_info;
}
static int
spl_debug_dumplog_thread(void *arg)
{
dumplog_priv_t *dp = (dumplog_priv_t *)arg;
spl_debug_dumplog_internal(dp);
atomic_set(&dp->dp_done, 1);
wake_up(&dp->dp_waitq);
complete_and_exit(NULL, 0);
return 0; /* Unreachable */
}
/* When flag is set do not use a new thread for the debug dump */
int
spl_debug_dumplog(int flags)
{
struct task_struct *tsk;
dumplog_priv_t dp;
init_waitqueue_head(&dp.dp_waitq);
dp.dp_pid = current->pid;
dp.dp_flags = flags;
atomic_set(&dp.dp_done, 0);
if (dp.dp_flags & DL_NOTHREAD) {
spl_debug_dumplog_internal(&dp);
} else {
tsk = spl_kthread_create(spl_debug_dumplog_thread,(void *)&dp,"spl_debug");
if (tsk == NULL)
return -ENOMEM;
wake_up_process(tsk);
wait_event(dp.dp_waitq, atomic_read(&dp.dp_done));
}
return 0;
}
EXPORT_SYMBOL(spl_debug_dumplog);
static char *
trace_get_console_buffer(void)
{
int cpu = get_cpu();
int idx;
if (in_irq()) {
idx = 0;
} else if (in_softirq()) {
idx = 1;
} else {
idx = 2;
}
return trace_console_buffers[cpu][idx];
}
static void
trace_put_console_buffer(char *buffer)
{
put_cpu();
}
static int
trace_lock_tcd(struct trace_cpu_data *tcd)
{
__ASSERT(tcd->tcd_type < TCD_TYPE_MAX);
spin_lock_irqsave(&tcd->tcd_lock, tcd->tcd_lock_flags);
return 1;
}
static void
trace_unlock_tcd(struct trace_cpu_data *tcd)
{
__ASSERT(tcd->tcd_type < TCD_TYPE_MAX);
spin_unlock_irqrestore(&tcd->tcd_lock, tcd->tcd_lock_flags);
}
static struct trace_cpu_data *
trace_get_tcd(void)
{
int cpu;
struct trace_cpu_data *tcd;
cpu = get_cpu();
if (in_irq())
tcd = &(*trace_data[TCD_TYPE_IRQ])[cpu].tcd;
else if (in_softirq())
tcd = &(*trace_data[TCD_TYPE_SOFTIRQ])[cpu].tcd;
else
tcd = &(*trace_data[TCD_TYPE_PROC])[cpu].tcd;
trace_lock_tcd(tcd);
return tcd;
}
static void
trace_put_tcd (struct trace_cpu_data *tcd)
{
trace_unlock_tcd(tcd);
put_cpu();
}
static void
trace_set_debug_header(struct spl_debug_header *header, int subsys,
int mask, const int line, unsigned long stack)
{
struct timeval tv;
do_gettimeofday(&tv);
header->ph_subsys = subsys;
header->ph_mask = mask;
header->ph_cpu_id = smp_processor_id();
header->ph_sec = (__u32)tv.tv_sec;
header->ph_usec = tv.tv_usec;
header->ph_stack = stack;
header->ph_pid = current->pid;
header->ph_line_num = line;
return;
}
static void
trace_print_to_console(struct spl_debug_header *hdr, int mask, const char *buf,
int len, const char *file, const char *fn)
{
char *prefix = "SPL", *ptype = NULL;
if ((mask & SD_EMERG) != 0) {
prefix = "SPLError";
ptype = KERN_EMERG;
} else if ((mask & SD_ERROR) != 0) {
prefix = "SPLError";
ptype = KERN_ERR;
} else if ((mask & SD_WARNING) != 0) {
prefix = "SPL";
ptype = KERN_WARNING;
} else if ((mask & (SD_CONSOLE | spl_debug_printk)) != 0) {
prefix = "SPL";
ptype = KERN_INFO;
}
if ((mask & SD_CONSOLE) != 0) {
printk("%s%s: %.*s", ptype, prefix, len, buf);
} else {
printk("%s%s: %d:%d:(%s:%d:%s()) %.*s", ptype, prefix,
hdr->ph_pid, hdr->ph_stack, file,
hdr->ph_line_num, fn, len, buf);
}
return;
}
static int
trace_max_debug_mb(void)
{
return MAX(512, ((totalram_pages >> (20 - PAGE_SHIFT)) * 80) / 100);
}
static struct trace_page *
tage_alloc(int gfp)
{
struct page *page;
struct trace_page *tage;
page = alloc_pages(gfp | __GFP_NOWARN, 0);
if (page == NULL)
return NULL;
tage = kmalloc(sizeof(*tage), gfp);
if (tage == NULL) {
__free_pages(page, 0);
return NULL;
}
tage->page = page;
atomic_inc(&trace_tage_allocated);
return tage;
}
static void
tage_free(struct trace_page *tage)
{
__ASSERT(tage != NULL);
__ASSERT(tage->page != NULL);
__free_pages(tage->page, 0);
kfree(tage);
atomic_dec(&trace_tage_allocated);
}
static struct trace_page *
tage_from_list(struct list_head *list)
{
return list_entry(list, struct trace_page, linkage);
}
static void
tage_to_tail(struct trace_page *tage, struct list_head *queue)
{
__ASSERT(tage != NULL);
__ASSERT(queue != NULL);
list_move_tail(&tage->linkage, queue);
}
/* try to return a page that has 'len' bytes left at the end */
static struct trace_page *
trace_get_tage_try(struct trace_cpu_data *tcd, unsigned long len)
{
struct trace_page *tage;
if (tcd->tcd_cur_pages > 0) {
__ASSERT(!list_empty(&tcd->tcd_pages));
tage = tage_from_list(tcd->tcd_pages.prev);
if (tage->used + len <= PAGE_SIZE)
return tage;
}
if (tcd->tcd_cur_pages < tcd->tcd_max_pages) {
if (tcd->tcd_cur_stock_pages > 0) {
tage = tage_from_list(tcd->tcd_stock_pages.prev);
tcd->tcd_cur_stock_pages--;
list_del_init(&tage->linkage);
} else {
tage = tage_alloc(GFP_ATOMIC);
if (tage == NULL) {
printk(KERN_WARNING
"failure to allocate a tage (%ld)\n",
tcd->tcd_cur_pages);
return NULL;
}
}
tage->used = 0;
tage->cpu = smp_processor_id();
tage->type = tcd->tcd_type;
list_add_tail(&tage->linkage, &tcd->tcd_pages);
tcd->tcd_cur_pages++;
return tage;
}
return NULL;
}
/* return a page that has 'len' bytes left at the end */
static struct trace_page *
trace_get_tage(struct trace_cpu_data *tcd, unsigned long len)
{
struct trace_page *tage;
__ASSERT(len <= PAGE_SIZE);
tage = trace_get_tage_try(tcd, len);
if (tage)
return tage;
if (tcd->tcd_cur_pages > 0) {
tage = tage_from_list(tcd->tcd_pages.next);
tage->used = 0;
tage_to_tail(tage, &tcd->tcd_pages);
}
return tage;
}
int
spl_debug_msg(void *arg, int subsys, int mask, const char *file,
const char *fn, const int line, const char *format, ...)
{
spl_debug_limit_state_t *cdls = arg;
struct trace_cpu_data *tcd = NULL;
struct spl_debug_header header = { 0, };
struct trace_page *tage;
/* string_buf is used only if tcd != NULL, and is always set then */
char *string_buf = NULL;
char *debug_buf;
int known_size;
int needed = 85; /* average message length */
int max_nob;
va_list ap;
int i;
if (subsys == 0)
subsys = SS_DEBUG_SUBSYS;
if (mask == 0)
mask = SD_EMERG;
if (strchr(file, '/'))
file = strrchr(file, '/') + 1;
tcd = trace_get_tcd();
trace_set_debug_header(&header, subsys, mask, line, 0);
if (tcd == NULL)
goto console;
if (tcd->tcd_shutting_down) {
trace_put_tcd(tcd);
tcd = NULL;
goto console;
}
known_size = strlen(file) + 1;
if (fn)
known_size += strlen(fn) + 1;
if (spl_debug_binary)
known_size += sizeof(header);
/* '2' used because vsnprintf returns real size required for output
* _without_ terminating NULL. */
for (i = 0; i < 2; i++) {
tage = trace_get_tage(tcd, needed + known_size + 1);
if (tage == NULL) {
if (needed + known_size > PAGE_SIZE)
mask |= SD_ERROR;
trace_put_tcd(tcd);
tcd = NULL;
goto console;
}
string_buf = (char *)page_address(tage->page) +
tage->used + known_size;
max_nob = PAGE_SIZE - tage->used - known_size;
if (max_nob <= 0) {
printk(KERN_EMERG "negative max_nob: %i\n", max_nob);
mask |= SD_ERROR;
trace_put_tcd(tcd);
tcd = NULL;
goto console;
}
needed = 0;
if (format) {
va_start(ap, format);
needed += vsnprintf(string_buf, max_nob, format, ap);
va_end(ap);
}
if (needed < max_nob)
break;
}
header.ph_len = known_size + needed;
debug_buf = (char *)page_address(tage->page) + tage->used;
if (spl_debug_binary) {
memcpy(debug_buf, &header, sizeof(header));
tage->used += sizeof(header);
debug_buf += sizeof(header);
}
strcpy(debug_buf, file);
tage->used += strlen(file) + 1;
debug_buf += strlen(file) + 1;
if (fn) {
strcpy(debug_buf, fn);
tage->used += strlen(fn) + 1;
debug_buf += strlen(fn) + 1;
}
__ASSERT(debug_buf == string_buf);
tage->used += needed;
__ASSERT (tage->used <= PAGE_SIZE);
console:
if ((mask & spl_debug_printk) == 0) {
/* no console output requested */
if (tcd != NULL)
trace_put_tcd(tcd);
return 1;
}
if (cdls != NULL) {
if (spl_console_ratelimit && cdls->cdls_next != 0 &&
!time_before(cdls->cdls_next, jiffies)) {
/* skipping a console message */
cdls->cdls_count++;
if (tcd != NULL)
trace_put_tcd(tcd);
return 1;
}
if (time_before(cdls->cdls_next + spl_console_max_delay +
(10 * HZ), jiffies)) {
/* last timeout was a long time ago */
cdls->cdls_delay /= spl_console_backoff * 4;
} else {
cdls->cdls_delay *= spl_console_backoff;
if (cdls->cdls_delay < spl_console_min_delay)
cdls->cdls_delay = spl_console_min_delay;
else if (cdls->cdls_delay > spl_console_max_delay)
cdls->cdls_delay = spl_console_max_delay;
}
/* ensure cdls_next is never zero after it's been seen */
cdls->cdls_next = (jiffies + cdls->cdls_delay) | 1;
}
if (tcd != NULL) {
trace_print_to_console(&header, mask, string_buf, needed, file, fn);
trace_put_tcd(tcd);
} else {
string_buf = trace_get_console_buffer();
needed = 0;
if (format != NULL) {
va_start(ap, format);
needed += vsnprintf(string_buf,
TRACE_CONSOLE_BUFFER_SIZE, format, ap);
va_end(ap);
}
trace_print_to_console(&header, mask,
string_buf, needed, file, fn);
trace_put_console_buffer(string_buf);
}
if (cdls != NULL && cdls->cdls_count != 0) {
string_buf = trace_get_console_buffer();
needed = snprintf(string_buf, TRACE_CONSOLE_BUFFER_SIZE,
"Skipped %d previous similar message%s\n",
cdls->cdls_count, (cdls->cdls_count > 1) ? "s" : "");
trace_print_to_console(&header, mask,
string_buf, needed, file, fn);
trace_put_console_buffer(string_buf);
cdls->cdls_count = 0;
}
return 0;
}
EXPORT_SYMBOL(spl_debug_msg);
/* Do the collect_pages job on a single CPU: assumes that all other
* CPUs have been stopped during a panic. If this isn't true for
* some arch, this will have to be implemented separately in each arch.
*/
static void
collect_pages_from_single_cpu(struct page_collection *pc)
{
struct trace_cpu_data *tcd;
int i, j;
tcd_for_each(tcd, i, j) {
list_splice_init(&tcd->tcd_pages, &pc->pc_pages);
tcd->tcd_cur_pages = 0;
}
}
static void
collect_pages_on_all_cpus(struct page_collection *pc)
{
struct trace_cpu_data *tcd;
int i, cpu;
spin_lock(&pc->pc_lock);
for_each_possible_cpu(cpu) {
tcd_for_each_type_lock(tcd, i, cpu) {
list_splice_init(&tcd->tcd_pages, &pc->pc_pages);
tcd->tcd_cur_pages = 0;
}
}
spin_unlock(&pc->pc_lock);
}
static void
collect_pages(dumplog_priv_t *dp, struct page_collection *pc)
{
INIT_LIST_HEAD(&pc->pc_pages);
if (spl_panic_in_progress || dp->dp_flags & DL_SINGLE_CPU)
collect_pages_from_single_cpu(pc);
else
collect_pages_on_all_cpus(pc);
}
static void
put_pages_back_on_all_cpus(struct page_collection *pc)
{
struct trace_cpu_data *tcd;
struct list_head *cur_head;
struct trace_page *tage;
struct trace_page *tmp;
int i, cpu;
spin_lock(&pc->pc_lock);
for_each_possible_cpu(cpu) {
tcd_for_each_type_lock(tcd, i, cpu) {
cur_head = tcd->tcd_pages.next;
list_for_each_entry_safe(tage, tmp, &pc->pc_pages,
linkage) {
if (tage->cpu != cpu || tage->type != i)
continue;
tage_to_tail(tage, cur_head);
tcd->tcd_cur_pages++;
}
}
}
spin_unlock(&pc->pc_lock);
}
static void
put_pages_back(struct page_collection *pc)
{
if (!spl_panic_in_progress)
put_pages_back_on_all_cpus(pc);
}
static int
spl_debug_dump_all_pages(dumplog_priv_t *dp, char *filename)
{
struct page_collection pc;
struct file *filp;
struct trace_page *tage;
struct trace_page *tmp;
mm_segment_t oldfs;
int rc = 0;
down_write(&trace_sem);
filp = spl_filp_open(filename, O_CREAT|O_EXCL|O_WRONLY|O_LARGEFILE,
0600, &rc);
if (filp == NULL) {
if (rc != -EEXIST)
printk(KERN_ERR "SPL: Can't open %s for dump: %d\n",
filename, rc);
goto out;
}
spin_lock_init(&pc.pc_lock);
collect_pages(dp, &pc);
if (list_empty(&pc.pc_pages)) {
rc = 0;
goto close;
}
oldfs = get_fs();
set_fs(get_ds());
list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
rc = spl_filp_write(filp, page_address(tage->page),
tage->used, spl_filp_poff(filp));
if (rc != (int)tage->used) {
printk(KERN_WARNING "SPL: Wanted to write %u "
"but wrote %d\n", tage->used, rc);
put_pages_back(&pc);
__ASSERT(list_empty(&pc.pc_pages));
break;
}
list_del(&tage->linkage);
tage_free(tage);
}
set_fs(oldfs);
rc = spl_filp_fsync(filp, 1);
if (rc)
printk(KERN_ERR "SPL: Unable to sync: %d\n", rc);
close:
spl_filp_close(filp);
out:
up_write(&trace_sem);
return rc;
}
static void
spl_debug_flush_pages(void)
{
dumplog_priv_t dp;
struct page_collection pc;
struct trace_page *tage;
struct trace_page *tmp;
spin_lock_init(&pc.pc_lock);
init_waitqueue_head(&dp.dp_waitq);
dp.dp_pid = current->pid;
dp.dp_flags = 0;
atomic_set(&dp.dp_done, 0);
collect_pages(&dp, &pc);
list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
list_del(&tage->linkage);
tage_free(tage);
}
}
unsigned long
spl_debug_set_mask(unsigned long mask) {
spl_debug_mask = mask;
return 0;
}
EXPORT_SYMBOL(spl_debug_set_mask);
unsigned long
spl_debug_get_mask(void) {
return spl_debug_mask;
}
EXPORT_SYMBOL(spl_debug_get_mask);
unsigned long
spl_debug_set_subsys(unsigned long subsys) {
spl_debug_subsys = subsys;
return 0;
}
EXPORT_SYMBOL(spl_debug_set_subsys);
unsigned long
spl_debug_get_subsys(void) {
return spl_debug_subsys;
}
EXPORT_SYMBOL(spl_debug_get_subsys);
int
spl_debug_set_mb(int mb)
{
int i, j, pages;
int limit = trace_max_debug_mb();
struct trace_cpu_data *tcd;
if (mb < num_possible_cpus()) {
printk(KERN_ERR "SPL: Refusing to set debug buffer size to "
"%dMB - lower limit is %d\n", mb, num_possible_cpus());
return -EINVAL;
}
if (mb > limit) {
printk(KERN_ERR "SPL: Refusing to set debug buffer size to "
"%dMB - upper limit is %d\n", mb, limit);
return -EINVAL;
}
mb /= num_possible_cpus();
pages = mb << (20 - PAGE_SHIFT);
down_write(&trace_sem);
tcd_for_each(tcd, i, j)
tcd->tcd_max_pages = (pages * tcd->tcd_pages_factor) / 100;
up_write(&trace_sem);
return 0;
}
EXPORT_SYMBOL(spl_debug_set_mb);
int
spl_debug_get_mb(void)
{
int i, j;
struct trace_cpu_data *tcd;
int total_pages = 0;
down_read(&trace_sem);
tcd_for_each(tcd, i, j)
total_pages += tcd->tcd_max_pages;
up_read(&trace_sem);
return (total_pages >> (20 - PAGE_SHIFT)) + 1;
}
EXPORT_SYMBOL(spl_debug_get_mb);
/*
* Limit the number of stack traces dumped to not more than 5 every
* 60 seconds to prevent denial-of-service attacks from debug code.
*/
DEFINE_RATELIMIT_STATE(dumpstack_ratelimit_state, 60 * HZ, 5);
void
spl_debug_dumpstack(struct task_struct *tsk)
{
if (__ratelimit(&dumpstack_ratelimit_state)) {
if (tsk == NULL)
tsk = current;
printk("SPL: Showing stack for process %d\n", tsk->pid);
dump_stack();
}
}
EXPORT_SYMBOL(spl_debug_dumpstack);
void spl_debug_bug(char *file, const char *func, const int line, int flags)
{
spl_debug_catastrophe = 1;
spl_debug_msg(NULL, 0, SD_EMERG, file, func, line, "SPL PANIC\n");
if (in_interrupt())
panic("SPL PANIC in interrupt.\n");
if (in_atomic() || irqs_disabled())
flags |= DL_NOTHREAD;
/* Ensure all debug pages and dumped by current cpu */
if (spl_debug_panic_on_bug)
spl_panic_in_progress = 1;
spl_debug_dumpstack(NULL);
if (spl_debug_panic_on_bug) {
spl_debug_dumplog(flags);
panic("SPL PANIC");
}
set_task_state(current, TASK_UNINTERRUPTIBLE);
while (1)
schedule();
}
EXPORT_SYMBOL(spl_debug_bug);
int
spl_debug_clear_buffer(void)
{
spl_debug_flush_pages();
return 0;
}
EXPORT_SYMBOL(spl_debug_clear_buffer);
int
spl_debug_mark_buffer(char *text)
{
SDEBUG(SD_WARNING, "*************************************\n");
SDEBUG(SD_WARNING, "DEBUG MARKER: %s\n", text);
SDEBUG(SD_WARNING, "*************************************\n");
return 0;
}
EXPORT_SYMBOL(spl_debug_mark_buffer);
static int
trace_init(int max_pages)
{
struct trace_cpu_data *tcd;
int i, j;
init_rwsem(&trace_sem);
/* initialize trace_data */
memset(trace_data, 0, sizeof(trace_data));
for (i = 0; i < TCD_TYPE_MAX; i++) {
trace_data[i] = kmalloc(sizeof(union trace_data_union) *
NR_CPUS, GFP_KERNEL);
if (trace_data[i] == NULL)
goto out;
}
tcd_for_each(tcd, i, j) {
spin_lock_init(&tcd->tcd_lock);
tcd->tcd_pages_factor = pages_factor[i];
tcd->tcd_type = i;
tcd->tcd_cpu = j;
INIT_LIST_HEAD(&tcd->tcd_pages);
INIT_LIST_HEAD(&tcd->tcd_stock_pages);
tcd->tcd_cur_pages = 0;
tcd->tcd_cur_stock_pages = 0;
tcd->tcd_max_pages = (max_pages * pages_factor[i]) / 100;
tcd->tcd_shutting_down = 0;
}
for (i = 0; i < num_possible_cpus(); i++) {
for (j = 0; j < 3; j++) {
trace_console_buffers[i][j] =
kmalloc(TRACE_CONSOLE_BUFFER_SIZE,
GFP_KERNEL);
if (trace_console_buffers[i][j] == NULL)
goto out;
}
}
return 0;
out:
trace_fini();
printk(KERN_ERR "SPL: Insufficient memory for debug logs\n");
return -ENOMEM;
}
int
spl_debug_init(void)
{
int rc, max = spl_debug_mb;
spl_console_max_delay = SPL_DEFAULT_MAX_DELAY;
spl_console_min_delay = SPL_DEFAULT_MIN_DELAY;
/* If spl_debug_mb is set to an invalid value or uninitialized
* then just make the total buffers smp_num_cpus TCD_MAX_PAGES */
if (max > (totalram_pages >> (20 - 2 - PAGE_SHIFT)) / 5 ||
max >= 512 || max < 0) {
max = TCD_MAX_PAGES;
} else {
max = (max / num_online_cpus()) << (20 - PAGE_SHIFT);
}
rc = trace_init(max);
if (rc)
return rc;
return rc;
}
static void
trace_cleanup_on_all_cpus(void)
{
struct trace_cpu_data *tcd;
struct trace_page *tage;
struct trace_page *tmp;
int i, cpu;
for_each_possible_cpu(cpu) {
tcd_for_each_type_lock(tcd, i, cpu) {
tcd->tcd_shutting_down = 1;
list_for_each_entry_safe(tage, tmp, &tcd->tcd_pages,
linkage) {
list_del(&tage->linkage);
tage_free(tage);
}
tcd->tcd_cur_pages = 0;
}
}
}
static void
trace_fini(void)
{
int i, j;
trace_cleanup_on_all_cpus();
for (i = 0; i < num_possible_cpus(); i++) {
for (j = 0; j < 3; j++) {
if (trace_console_buffers[i][j] != NULL) {
kfree(trace_console_buffers[i][j]);
trace_console_buffers[i][j] = NULL;
}
}
}
for (i = 0; i < TCD_TYPE_MAX && trace_data[i] != NULL; i++) {
kfree(trace_data[i]);
trace_data[i] = NULL;
}
}
void
spl_debug_fini(void)
{
trace_fini();
}
#endif /* DEBUG_LOG */
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