Net2/usr/src/sys/kern/subr_mcount.c
/*
* Copyright (c) 1982, 1986 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)subr_mcount.c 7.10 (Berkeley) 5/7/91
*/
#ifdef GPROF
#include "gprof.h"
#include "param.h"
#include "systm.h"
#include "malloc.h"
/*
* Froms is actually a bunch of unsigned shorts indexing tos
*/
int profiling = 3;
u_short *froms;
struct tostruct *tos = 0;
long tolimit = 0;
char *s_lowpc = (char *)KERNBASE;
extern char etext;
char *s_highpc = &etext;
u_long s_textsize = 0;
int ssiz;
u_short *sbuf;
u_short *kcount;
kmstartup()
{
u_long fromssize, tossize;
/*
* Round lowpc and highpc to multiples of the density we're using
* so the rest of the scaling (here and in gprof) stays in ints.
*/
s_lowpc = (char *)
ROUNDDOWN((unsigned)s_lowpc, HISTFRACTION*sizeof (HISTCOUNTER));
s_highpc = (char *)
ROUNDUP((unsigned)s_highpc, HISTFRACTION*sizeof (HISTCOUNTER));
s_textsize = s_highpc - s_lowpc;
printf("Profiling kernel, s_textsize=%d [%x..%x]\n",
s_textsize, s_lowpc, s_highpc);
ssiz = (s_textsize / HISTFRACTION) + sizeof (struct phdr);
sbuf = (u_short *)malloc(ssiz, M_GPROF, M_WAITOK);
if (sbuf == 0) {
printf("No space for monitor buffer(s)\n");
return;
}
bzero(sbuf, ssiz);
fromssize = s_textsize / HASHFRACTION;
froms = (u_short *)malloc(fromssize, M_GPROF, M_NOWAIT);
if (froms == 0) {
printf("No space for monitor buffer(s)\n");
free(sbuf, M_GPROF);
sbuf = 0;
return;
}
bzero(froms, fromssize);
tolimit = s_textsize * ARCDENSITY / 100;
if (tolimit < MINARCS)
tolimit = MINARCS;
else if (tolimit > (0xffff - 1))
tolimit = 0xffff - 1;
tossize = tolimit * sizeof (struct tostruct);
tos = (struct tostruct *)malloc(tossize, M_GPROF, M_WAITOK);
if (tos == 0) {
printf("No space for monitor buffer(s)\n");
free(sbuf, M_GPROF), sbuf = 0;
free(froms, M_GPROF), froms = 0;
return;
}
bzero(tos, tossize);
tos[0].link = 0;
((struct phdr *)sbuf)->lpc = s_lowpc;
((struct phdr *)sbuf)->hpc = s_highpc;
((struct phdr *)sbuf)->ncnt = ssiz;
kcount = (u_short *)(((int)sbuf) + sizeof (struct phdr));
}
/*
* This routine is massaged so that it may be jsb'ed to on vax.
*/
asm(".text");
asm("#the beginning of mcount()");
asm(".data");
mcount()
{
register char *selfpc; /* r11 => r5 */
register u_short *frompcindex; /* r10 => r4 */
register struct tostruct *top; /* r9 => r3 */
register struct tostruct *prevtop; /* r8 => r2 */
register long toindex; /* r7 => r1 */
static int s;
asm(" .text"); /* make sure we're in text space */
/*
* Check that we are profiling.
*/
if (profiling)
goto out;
/*
* Find the return address for mcount,
* and the return address for mcount's caller.
*/
#ifdef lint
selfpc = (char *)0;
frompcindex = 0;
#else
; /* avoid label botch */
#ifdef __GNUC__
#if defined(vax)
Fix Me!!
#endif
#if defined(tahoe)
Fix Me!!
#endif
#if defined(hp300)
/*
* selfpc = pc pushed by mcount jsr,
* frompcindex = pc pushed by jsr into self.
* In GCC the caller's stack frame has already been built so we
* have to chase a6 to find caller's raddr. This assumes that all
* routines we are profiling were built with GCC and that all
* profiled routines use link/unlk.
*/
asm("movl a6@(4),%0" : "=r" (selfpc));
asm("movl a6@(0)@(4),%0" : "=r" (frompcindex));
#endif
#else
#if defined(vax)
asm(" movl (sp), r11"); /* selfpc = ... (jsb frame) */
asm(" movl 16(fp), r10"); /* frompcindex = (calls frame) */
#endif
#if defined(tahoe)
asm(" movl -8(fp),r12"); /* selfpc = callf frame */
asm(" movl (fp),r11");
asm(" movl -8(r11),r11"); /* frompcindex = 1 callf frame back */
#endif
#if defined(hp300)
Fix Me!!
#endif
#endif /* not __GNUC__ */
#endif /* not lint */
/*
* Insure that we cannot be recursively invoked.
* this requires that splhigh() and splx() below
* do NOT call mcount!
*/
#if defined(hp300)
asm("movw sr,%0" : "=g" (s));
asm("movw #0x2700,sr");
#else
s = splhigh();
#endif
/*
* Check that frompcindex is a reasonable pc value.
* For example: signal catchers get called from the stack,
* not from text space. too bad.
*/
frompcindex = (u_short *)((long)frompcindex - (long)s_lowpc);
if ((u_long)frompcindex > s_textsize)
goto done;
frompcindex =
&froms[((long)frompcindex) / (HASHFRACTION * sizeof (*froms))];
toindex = *frompcindex;
if (toindex == 0) {
/*
* First time traversing this arc
*/
toindex = ++tos[0].link;
if (toindex >= tolimit)
goto overflow;
*frompcindex = toindex;
top = &tos[toindex];
top->selfpc = selfpc;
top->count = 1;
top->link = 0;
goto done;
}
top = &tos[toindex];
if (top->selfpc == selfpc) {
/*
* Arc at front of chain; usual case.
*/
top->count++;
goto done;
}
/*
* Have to go looking down chain for it.
* Top points to what we are looking at,
* prevtop points to previous top.
* We know it is not at the head of the chain.
*/
for (; /* goto done */; ) {
if (top->link == 0) {
/*
* Top is end of the chain and none of the chain
* had top->selfpc == selfpc.
* So we allocate a new tostruct
* and link it to the head of the chain.
*/
toindex = ++tos[0].link;
if (toindex >= tolimit)
goto overflow;
top = &tos[toindex];
top->selfpc = selfpc;
top->count = 1;
top->link = *frompcindex;
*frompcindex = toindex;
goto done;
}
/*
* Otherwise, check the next arc on the chain.
*/
prevtop = top;
top = &tos[top->link];
if (top->selfpc == selfpc) {
/*
* There it is, increment its count and
* move it to the head of the chain.
*/
top->count++;
toindex = prevtop->link;
prevtop->link = top->link;
top->link = *frompcindex;
*frompcindex = toindex;
goto done;
}
}
done:
#if defined(hp300)
asm("movw %0,sr" : : "g" (s));
#else
splx(s);
#endif
/* and fall through */
out:
#if defined(vax)
asm(" rsb");
#endif
return;
overflow:
profiling = 3;
printf("mcount: tos overflow\n");
goto out;
}
asm(".text");
asm("#the end of mcount()");
asm(".data");
#endif