GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: lib/libc/gmon/mcount.c Lines: 0 45 0.0 %
Date: 2017-11-13 Branches: 0 18 0.0 %

Line Branch Exec Source
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/*	$OpenBSD: mcount.c,v 1.15 2015/01/16 16:48:51 deraadt Exp $ */
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/*-
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 * Copyright (c) 1983, 1992, 1993
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 *	The Regents of the University of California.  All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    notice, this list of conditions and the following disclaimer in the
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 *    documentation and/or other materials provided with the distribution.
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 * 3. Neither the name of the University nor the names of its contributors
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 *    may be used to endorse or promote products derived from this software
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 *    without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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 * SUCH DAMAGE.
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 */
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#include <sys/types.h>
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#include <sys/gmon.h>
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/*
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 * mcount is called on entry to each function compiled with the profiling
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 * switch set.  _mcount(), which is declared in a machine-dependent way
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 * with _MCOUNT_DECL, does the actual work and is either inlined into a
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 * C routine or called by an assembly stub.  In any case, this magic is
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 * taken care of by the MCOUNT definition in <machine/profile.h>.
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 *
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 * _mcount updates data structures that represent traversals of the
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 * program's call graph edges.  frompc and selfpc are the return
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 * address and function address that represents the given call graph edge.
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 */
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_MCOUNT_DECL(u_long frompc, u_long selfpc) __used;
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/* _mcount; may be static, inline, etc */
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_MCOUNT_DECL(u_long frompc, u_long selfpc)
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{
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	u_short *frompcindex;
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	struct tostruct *top, *prevtop;
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	struct gmonparam *p;
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	long toindex;
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#ifdef _KERNEL
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	int s;
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	/*
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	 * Do not profile execution if memory for the current CPU
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	 * desciptor and profiling buffers has not yet been allocated
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	 * or if the CPU we are running on has not yet set its trap
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	 * handler.
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	 */
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	if (gmoninit == 0)
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		return;
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	if ((p = curcpu()->ci_gmon) == NULL)
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		return;
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#else
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	p = &_gmonparam;
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#endif
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	/*
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	 * check that we are profiling
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	 * and that we aren't recursively invoked.
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	 */
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	if (p->state != GMON_PROF_ON)
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		return;
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#ifdef _KERNEL
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	MCOUNT_ENTER;
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#else
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	p->state = GMON_PROF_BUSY;
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#endif
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	/*
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	 * check that frompcindex is a reasonable pc value.
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	 * for example:	signal catchers get called from the stack,
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	 *		not from text space.  too bad.
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	 */
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	frompc -= p->lowpc;
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	if (frompc > p->textsize)
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		goto done;
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#if (HASHFRACTION & (HASHFRACTION - 1)) == 0
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	if (p->hashfraction == HASHFRACTION)
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		frompcindex =
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		    &p->froms[frompc / (HASHFRACTION * sizeof(*p->froms))];
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	else
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#endif
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		frompcindex =
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		    &p->froms[frompc / (p->hashfraction * sizeof(*p->froms))];
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	toindex = *frompcindex;
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	if (toindex == 0) {
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		/*
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		 *	first time traversing this arc
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		 */
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		toindex = ++p->tos[0].link;
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		if (toindex >= p->tolimit)
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			/* halt further profiling */
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			goto overflow;
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		*frompcindex = toindex;
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		top = &p->tos[toindex];
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		top->selfpc = selfpc;
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		top->count = 1;
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		top->link = 0;
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		goto done;
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	}
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	top = &p->tos[toindex];
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	if (top->selfpc == selfpc) {
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		/*
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		 * arc at front of chain; usual case.
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		 */
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		top->count++;
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		goto done;
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	}
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	/*
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	 * have to go looking down chain for it.
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	 * top points to what we are looking at,
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	 * prevtop points to previous top.
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	 * we know it is not at the head of the chain.
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	 */
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	for (; /* goto done */; ) {
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		if (top->link == 0) {
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			/*
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			 * top is end of the chain and none of the chain
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			 * had top->selfpc == selfpc.
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			 * so we allocate a new tostruct
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			 * and link it to the head of the chain.
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			 */
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			toindex = ++p->tos[0].link;
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			if (toindex >= p->tolimit)
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				goto overflow;
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			top = &p->tos[toindex];
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			top->selfpc = selfpc;
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			top->count = 1;
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			top->link = *frompcindex;
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			*frompcindex = toindex;
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			goto done;
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		}
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		/*
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		 * otherwise, check the next arc on the chain.
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		 */
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		prevtop = top;
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		top = &p->tos[top->link];
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		if (top->selfpc == selfpc) {
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			/*
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			 * there it is.
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			 * increment its count
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			 * move it to the head of the chain.
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			 */
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			top->count++;
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			toindex = prevtop->link;
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			prevtop->link = top->link;
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			top->link = *frompcindex;
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			*frompcindex = toindex;
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			goto done;
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		}
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	}
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done:
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#ifdef _KERNEL
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	MCOUNT_EXIT;
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#else
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	p->state = GMON_PROF_ON;
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#endif
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	return;
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overflow:
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	p->state = GMON_PROF_ERROR;
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#ifdef _KERNEL
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	MCOUNT_EXIT;
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#endif
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	return;
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}
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/*
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 * Actual definition of mcount function.  Defined in <machine/profile.h>,
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 * which is included by <sys/gmon.h>.
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 */
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MCOUNT