/*
* Copyright (c) 2020 Red Hat, Inc.
*
* This program 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.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* $Id: //eng/vdo-releases/aluminum/src/c++/vdo/kernel/logger.c#4 $
*/
#include "logger.h"
#include <linux/delay.h>
#include <linux/hardirq.h>
#include <linux/module.h>
#include "errors.h"
#include "threadDevice.h"
static const int DEFAULT_PRIORITY = LOG_INFO;
typedef struct {
const char *name;
const int priority;
} PRIORITY_NAMES;
static const PRIORITY_NAMES PRIORITIES[] = {
{ "ALERT", LOG_ALERT },
{ "CRIT", LOG_CRIT },
{ "CRITICAL", LOG_CRIT },
{ "DEBUG", LOG_DEBUG },
{ "EMERG", LOG_EMERG },
{ "EMERGENCY", LOG_EMERG },
{ "ERR", LOG_ERR },
{ "ERROR", LOG_ERR },
{ "INFO", LOG_INFO },
{ "NOTICE", LOG_NOTICE },
{ "PANIC", LOG_EMERG },
{ "WARN", LOG_WARNING },
{ "WARNING", LOG_WARNING },
{ NULL, -1 },
};
enum {
PRIORITY_COUNT = 8
};
static const char *PRIORITY_STRINGS[] = {
"EMERGENCY",
"ALERT",
"CRITICAL",
"ERROR",
"WARN",
"NOTICE",
"INFO",
"DEBUG",
};
static int logLevel = LOG_INFO;
/**********************************************************************/
int stringToPriority(const char *string)
{
for (int i = 0; PRIORITIES[i].name != NULL; i++) {
if (strcasecmp(string, PRIORITIES[i].name) == 0) {
return PRIORITIES[i].priority;
}
}
return DEFAULT_PRIORITY;
}
/**********************************************************************/
int getLogLevel(void)
{
return logLevel;
}
/**********************************************************************/
void setLogLevel(int newLogLevel)
{
logLevel = newLogLevel;
}
/**********************************************************************/
const char *priorityToString(int priority)
{
if ((priority < 0) || (priority >= PRIORITY_COUNT)) {
return "unknown";
}
return PRIORITY_STRINGS[priority];
}
/**********************************************************************/
static const char *priorityToLogLevel(int priority)
{
switch (priority) {
case LOG_EMERG:
case LOG_ALERT:
case LOG_CRIT:
return KERN_CRIT;
case LOG_ERR:
return KERN_ERR;
case LOG_WARNING:
return KERN_WARNING;
case LOG_NOTICE:
return KERN_NOTICE;
case LOG_INFO:
return KERN_INFO;
case LOG_DEBUG:
return KERN_DEBUG;
default:
return "";
}
}
/**********************************************************************/
static const char *getCurrentInterruptType(void)
{
if (in_nmi()) {
return "NMI";
}
if (in_irq()) {
return "HI";
}
if (in_softirq()) {
return "SI";
}
return "INTR";
}
/**
* Emit a log message to the kernel log in a format suited to the current
* thread context. Context info formats:
*
* interrupt: kvdo[NMI]: blah
* thread w/dev id: kvdo12:myprog: blah
* kvdo thread: kvdo12:foobarQ: blah
* other thread: kvdo: myprog: blah
*
* Fields: module name, interrupt level, process name, device ID.
*
* @param level A string describing the logging level
* @param moduleName The name of the module doing the logging
* @param prefix The prefix of the log message
* @param vaf1 The first message format descriptor
* @param vaf2 The second message format descriptor
**/
static void emitLogMessage(const char *level,
const char *moduleName,
const char *prefix,
const struct va_format *vaf1,
const struct va_format *vaf2)
{
if (in_interrupt()) {
printk("%s%s[%s]: %s%pV%pV\n",
level, moduleName, getCurrentInterruptType(),
prefix, vaf1, vaf2);
return;
}
// Not at interrupt level; we have a process we can look at, and
// might have a device ID.
int deviceInstance = getThreadDeviceID();
if (deviceInstance != -1) {
printk("%s%s%u:%s: %s%pV%pV\n",
level, moduleName, deviceInstance, current->comm,
prefix, vaf1, vaf2);
return;
}
if (((current->flags & PF_KTHREAD) != 0)
&& (strncmp(moduleName, current->comm, strlen(moduleName)) == 0)) {
/*
* It's a kernel thread starting with "kvdo" (or whatever). Assume it's
* ours and that its name is sufficient.
*/
printk("%s%s: %s%pV%pV\n",
level, current->comm,
prefix, vaf1, vaf2);
return;
}
// Identify the module and the process.
printk("%s%s: %s: %s%pV%pV\n",
level, moduleName, current->comm,
prefix, vaf1, vaf2);
}
/**********************************************************************/
void logMessagePack(int priority,
const char *prefix,
const char *fmt1,
va_list args1,
const char *fmt2,
va_list args2)
{
if (priority > getLogLevel()) {
return;
}
/*
* The kernel's printk has some magic for indirection to a secondary
* va_list. It wants us to supply a pointer to the va_list.
*
* However, va_list varies across platforms and can be an array
* type, which makes passing it around as an argument kind of
* tricky, due to the automatic conversion to a pointer. This makes
* taking the address of the argument a dicey thing; if we use "&a"
* it works fine for non-array types, but for array types we get the
* address of a pointer. Functions like va_copy and sprintf don't
* care as they get "va_list" values passed and are written to do
* the right thing, but printk explicitly wants the address of the
* va_list.
*
* So, we copy the va_list values to ensure that "&" consistently
* works the way we want.
*/
va_list args1Copy;
va_copy(args1Copy, args1);
va_list args2Copy;
va_copy(args2Copy, args2);
struct va_format vaf1 = {
.fmt = (fmt1 != NULL) ? fmt1 : "",
.va = &args1Copy,
};
struct va_format vaf2 = {
.fmt = (fmt2 != NULL) ? fmt2 : "",
.va = &args2Copy,
};
if (prefix == NULL) {
prefix = "";
}
emitLogMessage(priorityToLogLevel(priority), THIS_MODULE->name,
prefix, &vaf1, &vaf2);
va_end(args1Copy);
va_end(args2Copy);
}
/**********************************************************************/
void logEmbeddedMessage(int priority,
const char *prefix,
const char *fmt1,
va_list args1,
const char *fmt2,
...)
{
va_list ap;
va_start(ap, fmt2);
logMessagePack(priority, prefix, fmt1, args1, fmt2, ap);
va_end(ap);
}
#pragma GCC diagnostic push
/*
* GCC (version 8.1.1 20180502 (Red Hat 8.1.1-1)) on Fedora 28 seems
* to think that this function should get a printf format
* attribute. But we have no second format string, and no additional
* arguments at the call site, and GCC also gets unhappy trying to
* analyze the format and values when there are none. So we'll just
* shut it up.
*/
#pragma GCC diagnostic ignored "-Wsuggest-attribute=format"
/**
* Log a message.
*
* This helper function exists solely to create a valid va_list with
* no useful info. It does the real work of vLogMessage, which wants a
* second va_list object to pass down.
*
* @param priority The syslog priority value for the message.
* @param format The format of the message (a printf style format)
* @param args The variadic argument list of format parameters.
**/
static void vLogMessageHelper(int priority,
const char *format,
va_list args,
...)
{
va_list dummy;
va_start(dummy, args);
logMessagePack(priority, NULL, format, args, NULL, dummy);
va_end(dummy);
}
#pragma GCC diagnostic pop
/*****************************************************************************/
void vLogMessage(int priority, const char *format, va_list args)
{
vLogMessageHelper(priority, format, args);
}
/**********************************************************************/
void logMessage(int priority, const char *format, ...)
{
va_list args;
va_start(args, format);
vLogMessage(priority, format, args);
va_end(args);
}
/**********************************************************************/
__attribute__((format(printf, 2, 3)))
static void logAtLevel(int priority, const char *format, ...)
{
va_list args;
va_start(args, format);
vLogMessage(priority, format, args);
va_end(args);
}
/**********************************************************************/
void logDebug(const char *format, ...)
{
va_list args;
va_start(args, format);
vLogMessage(LOG_DEBUG, format, args);
va_end(args);
}
/**********************************************************************/
void logInfo(const char *format, ...)
{
va_list args;
va_start(args, format);
vLogMessage(LOG_INFO, format, args);
va_end(args);
}
/**********************************************************************/
void logNotice(const char *format, ...)
{
va_list args;
va_start(args, format);
vLogMessage(LOG_NOTICE, format, args);
va_end(args);
}
/**********************************************************************/
void logWarning(const char *format, ...)
{
va_list args;
va_start(args, format);
vLogMessage(LOG_WARNING, format, args);
va_end(args);
}
/**********************************************************************/
void logError(const char *format, ...)
{
va_list args;
va_start(args, format);
vLogMessage(LOG_ERR, format, args);
va_end(args);
}
/**********************************************************************/
void vLogError(const char *format, va_list args)
{
vLogMessage(LOG_ERR, format, args);
}
/**********************************************************************/
void logBacktrace(int priority)
{
logAtLevel(priority, "[backtrace]");
if (priority > logLevel) {
return;
}
dump_stack();
}
/**********************************************************************/
int vLogWithStringError(int priority,
int errnum,
const char *format,
va_list args)
{
char errbuf[ERRBUF_SIZE] = "";
logEmbeddedMessage(priority, NULL, format, args, ": %s (%d)",
stringError(errnum, errbuf, sizeof(errbuf)),
errnum);
return errnum;
}
/**********************************************************************/
int logWithStringError(int priority, int errnum, const char *format, ...)
{
va_list args;
va_start(args, format);
vLogWithStringError(priority, errnum, format, args);
va_end(args);
return errnum;
}
/**********************************************************************/
int logErrorWithStringError(int errnum, const char *format, ...)
{
va_list args;
va_start(args, format);
vLogWithStringError(LOG_ERR, errnum, format, args);
va_end(args);
return errnum;
}
/**********************************************************************/
int vLogErrorWithStringError(int errnum, const char *format, va_list args)
{
vLogWithStringError(LOG_ERR, errnum, format, args);
return errnum;
}
/**********************************************************************/
int logWarningWithStringError(int errnum, const char *format, ...)
{
va_list args;
va_start(args, format);
vLogWithStringError(LOG_WARNING, errnum, format, args);
va_end(args);
return errnum;
}
/**********************************************************************/
int logDebugWithStringError(int errnum, const char *format, ...)
{
va_list args;
va_start(args, format);
vLogWithStringError(LOG_DEBUG, errnum, format, args);
va_end(args);
return errnum;
}
/**********************************************************************/
int logInfoWithStringError(int errnum, const char *format, ...)
{
va_list args;
va_start(args, format);
vLogWithStringError(LOG_INFO, errnum, format, args);
va_end(args);
return errnum;
}
/**********************************************************************/
int logNoticeWithStringError(int errnum, const char *format, ...)
{
va_list args;
va_start(args, format);
vLogWithStringError(LOG_NOTICE, errnum, format, args);
va_end(args);
return errnum;
}
/**********************************************************************/
int logFatalWithStringError(int errnum, const char *format, ...)
{
va_list args;
va_start(args, format);
vLogWithStringError(LOG_CRIT, errnum, format, args);
va_end(args);
return errnum;
}
/**********************************************************************/
int logUnrecoverable(int errnum, const char *format, ...)
{
if ((errnum == UDS_SUCCESS || errnum == UDS_QUEUED) || (errnum == 0)) {
return errnum;
}
va_list args;
va_start(args, format);
vLogWithStringError(LOG_CRIT, errnum, format, args);
va_end(args);
return makeUnrecoverable(errnum);
}
/**********************************************************************/
void logFatal(const char *format, ...)
{
va_list args;
va_start(args, format);
vLogMessage(LOG_CRIT, format, args);
va_end(args);
}
/**********************************************************************/
void pauseForLogger(void)
{
// Hopefully, a few milliseconds of sleep will be large enough
// for the kernel log buffer to be flushed.
msleep(4);
}