Current File : //usr/share/systemtap/runtime/linux/io.c
/* -*- linux-c -*-
* I/O for printing warnings, errors and debug messages
* Copyright (C) 2005-2009 Red Hat Inc.
*
* This file is part of systemtap, and is free software. You can
* redistribute it and/or modify it under the terms of the GNU General
* Public License (GPL); either version 2, or (at your option) any
* later version.
*/
#ifndef _STAPLINUX_IO_C_
#define _STAPLINUX_IO_C_
/** @file io.c
* @brief I/O for printing warnings, errors and debug messages.
*/
/** @addtogroup io I/O
* @{
*/
#define WARN_STRING "WARNING: "
#define ERR_STRING "ERROR: "
#if (STP_LOG_BUF_LEN < 10) /* sizeof(WARN_STRING) */
#error "STP_LOG_BUF_LEN is too short"
#endif
enum code { INFO=0, WARN, ERROR, DBUG };
static void _stp_vlog (enum code type, const char *func, int line, const char *fmt, va_list args)
__attribute ((format (printf, 4, 0)));
static void _stp_vlog (enum code type, const char *func, int line, const char *fmt, va_list args)
{
int num;
char *buf = per_cpu_ptr(Stp_lbuf, get_cpu());
int start = 0;
if (type == DBUG) {
start = _stp_snprintf(buf, STP_LOG_BUF_LEN, "%s:%d: ", func, line);
} else if (type == WARN) {
/* This strcpy() is OK, since we know STP_LOG_BUF_LEN
* is > sizeof(WARN_STRING). */
strcpy (buf, WARN_STRING);
start = sizeof(WARN_STRING) - 1;
} else if (type == ERROR) {
/* This strcpy() is OK, since we know STP_LOG_BUF_LEN
* is > sizeof(ERR_STRING) (which is < sizeof(WARN_STRING). */
strcpy (buf, ERR_STRING);
start = sizeof(ERR_STRING) - 1;
}
num = vscnprintf (buf + start, STP_LOG_BUF_LEN - start - 1, fmt, args);
if (num + start) {
if (buf[num + start - 1] != '\n') {
buf[num + start] = '\n';
num++;
buf[num + start] = '\0';
}
#ifdef STAP_DEBUG_PRINTK
if (type == DBUG) printk (KERN_DEBUG "%s", buf);
else if (type == WARN) printk (KERN_WARNING "%s", buf);
else if (type == ERROR) printk (KERN_ERR "%s", buf);
else printk (KERN_INFO "%s", buf);
#else
if (type != DBUG) {
_stp_ctl_send(STP_OOB_DATA, buf, start + num + 1);
} else {
_stp_print(buf);
_stp_print_flush();
}
#endif
}
put_cpu();
}
/** Prints warning.
* This function sends a warning message immediately to staprun. It
* will also be sent over the bulk transport (relayfs) if it is
* being used. If the last character is not a newline, then one
* is added.
* @param fmt A variable number of args.
*/
static void _stp_warn (const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
_stp_vlog (WARN, NULL, 0, fmt, args);
va_end(args);
}
/** Exits and unloads the module.
* This function sends a signal to staprun to tell it to
* unload the module and exit. The module will not be
* unloaded until after the current probe returns.
* @note Be careful to not treat this like the Linux exit()
* call. You should probably call return immediately after
* calling _stp_exit().
*/
static void _stp_exit (void)
{
/* Just set the flag since this is possibly called from
kprobe context. A timer will come along and call
_stp_request_exit() for us. */
_stp_exit_flag = 1;
}
/** Prints error message and exits.
* This function sends an error message immediately to staprun. It
* will also be sent over the bulk transport (relayfs) if it is
* being used. If the last character is not a newline, then one
* is added.
*
* After the error message is displayed, the module will transition
* to exiting-state (as if ^C was pressed) and will eventually unload.
* @param fmt A variable number of args.
* @sa _stp_exit().
*
* NB: this function should not be used from script-accessible tapset
* functions. Those should simply set CONTEXT->last_error, so that
* script-level try/catch blocks can handle them. This is for random
* runtime internal matters that a script didn't invoke and can't
* expect to handle.
*/
static void _stp_error (const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
_stp_vlog (ERROR, NULL, 0, fmt, args);
va_end(args);
_stp_exit();
}
/** Prints error message.
* This function sends an error message immediately to staprun. It
* will also be sent over the bulk transport (relayfs) if it is
* being used. If the last character is not a newline, then one
* is added.
*
* @param fmt A variable number of args.
* @sa _stp_error
*/
static void _stp_softerror (const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
_stp_vlog (ERROR, NULL, 0, fmt, args);
va_end(args);
}
static void _stp_dbug (const char *func, int line, const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
_stp_vlog (DBUG, func, line, fmt, args);
va_end(args);
}
/** @} */
#endif /* _STAPLINUX_IO_C_ */
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