// context-symbols tapset
// Copyright (C) 2005-2008, 2011 Red Hat Inc.
// Copyright (C) 2006 Intel Corporation.
//
// 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.
// <tapsetdescription>
// Context functions provide additional information about where an event occurred. These functions can 
//provide information such as a backtrace to where the event occurred and the current register values for the 
//processor.
// </tapsetdescription>

/**
 *  sfunction print_stack - Print out kernel stack from string
 *  @stk: String with list of hexadecimal addresses
 *
 *  Description: This function performs a symbolic lookup of the addresses
 *  in the given  string,
 *  which is assumed to be the result of a prior call to 
 *  backtrace().
 * 
 *  Print one line per address, including the address, the
 *  name  of the function containing the address, and an estimate of
 *  its position within that function.  Return nothing.
 */
function print_stack(stk:string) %{ /* pragma:symbols */
	char *ptr = STAP_ARG_stk;
	char *tok = strsep(&ptr, " ");
	while (tok && *tok) {
		_stp_print_addr (simple_strtol(tok, NULL, 16),
				 _STP_SYM_FULL, NULL);
		tok = strsep(&ptr, " ");
	}
%}

/**
 * sfunction sprint_stack - Return stack for kernel addresses from string
 * @stk: String with list of hexadecimal (kernel) addresses
 *
 * Perform a symbolic lookup of the addresses in the given string,
 * which is assumed to be the result of a prior call to backtrace().
 *
 * Returns a simple backtrace from the given hex string. One line per
 * address. Includes the symbol name (or hex address if symbol
 * couldn't be resolved) and module name (if found). Includes the
 * offset from the start of the function if found, otherwise the
 * offset will be added to the module (if found, between
 * brackets). Returns the backtrace as string (each line terminated by
 * a newline character).  Note that the returned stack will be
 * truncated to MAXSTRINGLEN, to print fuller and richer stacks use
 * print_stack.
 */
function sprint_stack:string(stk:string) %{ /* pure */ /* pragma:symbols */
	char *ptr = STAP_ARG_stk;
	char *tok = strsep(&ptr, " ");
	char *str = STAP_RETVALUE;
	size_t len = MAXSTRINGLEN - 1;
	while (tok && *tok && len > 0) {
		int s = _stp_snprint_addr(str, len,
					  simple_strtol(tok, NULL, 16),
					  _STP_SYM_SIMPLE, NULL);
		len -= s;
		str += s;
		tok = strsep(&ptr, " ");
	}

        str--;
        if (len > 0)
                str[0] = '\0';
        else
                STAP_RETVALUE[MAXSTRINGLEN - 1] = '\0';
%}

/**
 * sfunction probefunc - Return the probe point's function name, if known
 *
 * Description: This function returns the name of the function being probed.
 * It will do this based on the probe point string as returned by pp().
 * Please note: this function is deprecated, please use symname() and/or
 * usymname(). This function might return a function name based on the
 * current address if the probe point context couldn't be parsed.
 */
function probefunc:string () %{ /* pure */ /* pragma:symbols */
	char *ptr, *start;

	STAP_RETVALUE[0] = '\0';
	start = strstr(CONTEXT->probe_point, "function(\"");
	ptr = start + 10; 
	if (!start) {
		start = strstr(CONTEXT->probe_point, "inline(\"");
		ptr = start + 8;
	}

	if (start) {
		int len = MAXSTRINGLEN;
		char *dst = STAP_RETVALUE;
		while (*ptr != '@' && *ptr != '"' && --len > 0 && *ptr)
			*dst++ = *ptr++;
		*dst = 0;

	} else {
		struct pt_regs *regs;
		int user_mode;
		user_mode = c->probe_flags & _STP_PROBE_STATE_USER_MODE;
		regs = user_mode ? CONTEXT->uregs : CONTEXT->kregs;
		if (regs) {
			_stp_snprint_addr(STAP_RETVALUE, MAXSTRINGLEN,
					  REG_IP(regs), _STP_SYM_SYMBOL,
					  (user_mode ? current : NULL));
		}
	}
%}

/**
 * sfunction probemod - Return the probe point's kernel module name
 * 
 * Description: This function returns the name of the kernel module
 * containing the probe point, if known.
 */
function probemod:string () %{ /* pure */
	char *ptr, *start;

	start = strstr(CONTEXT->probe_point, "module(\"");
	ptr = start + 8;

	if (start) {
		int len = MAXSTRINGLEN;
		char *dst = STAP_RETVALUE;
		while (*ptr != '"' && --len && *ptr)
			*dst++ = *ptr++;
		*dst = 0;
	} else if (CONTEXT->kregs
		   && ! (CONTEXT->probe_flags & _STP_PROBE_STATE_USER_MODE)) {
		struct _stp_module *m;
		m = _stp_kmod_sec_lookup (REG_IP(CONTEXT->kregs), NULL);
		if (m && m->name)
			strlcpy (STAP_RETVALUE, m->name, MAXSTRINGLEN);
		else
			strlcpy (STAP_RETVALUE, "<unknown>", MAXSTRINGLEN);
	} else
		strlcpy (STAP_RETVALUE, "<unknown>", MAXSTRINGLEN);
%}

/**
 * sfunction modname - Return the kernel module name loaded at the address
 * @addr: The address to map to a kernel module name
 *
 * Description: Returns the module name associated with the given
 * address if known. If not known it will return the string "<unknown>".
 * If the address was not in a kernel module, but in the kernel itself,
 * then the string "kernel" will be returned.
 */
function modname:string (addr: long) %{ /* pure */
	struct _stp_module *m;
#ifdef STAPCONF_MODULE_TEXT_ADDRESS
	struct module *ko;
#endif
	m = _stp_kmod_sec_lookup (STAP_ARG_addr, NULL);
	if (m && m->name)
	  {
	    strlcpy (STAP_RETVALUE, m->name, MAXSTRINGLEN);
	    return;
	  }

#ifdef STAPCONF_MODULE_TEXT_ADDRESS
	preempt_disable();
	ko = __module_text_address (STAP_ARG_addr);
	if (ko && ko->name)
	  {
	    strlcpy (STAP_RETVALUE, ko->name, MAXSTRINGLEN);
	    preempt_enable_no_resched();
	    return;
	  }
	preempt_enable_no_resched();
#endif
	strlcpy (STAP_RETVALUE, "<unknown>", MAXSTRINGLEN);
%}

/**
 * sfunction symname - Return the kernel symbol associated with the given address
 * @addr: The address to translate
 *
 * Description: Returns the (function) symbol name associated with the
 * given address if known. If not known it will return the hex string
 * representation of addr.
 */
function symname:string (addr: long) %{ /* pure */ /* pragma:symbols */
	 _stp_snprint_addr(STAP_RETVALUE, MAXSTRINGLEN, STAP_ARG_addr,
			   _STP_SYM_SYMBOL, NULL);
%}

/**
 * sfunction symdata - Return the kernel symbol and module offset for the address
 * @addr: The address to translate
 *
 * Description: Returns the (function) symbol name associated with the
 * given address if known, the offset from the start and size of the
 * symbol, plus module name (between brackets). If symbol is unknown,
 * but module is known, the offset inside the module, plus the size of
 * the module is added.  If any element is not known it will be
 * omitted and if the symbol name is unknown it will return the hex
 * string for the given address.
 */
function symdata:string (addr: long) %{ /* pure */ /* pragma:symbols */
	_stp_snprint_addr(STAP_RETVALUE, MAXSTRINGLEN, STAP_ARG_addr,
			  _STP_SYM_DATA, NULL);
%}