Add support for GCC's --test-coverage --profile-arcs options. Add code to call the functions listed in the .ctors section, these are used to string the per .o file counter blocks into a linked list. Add empty __bb_fork_func() to cope with GCC magic gandling of exec*() named functions. To add support for other platforms should be trivial, but involves determining the exact data-types gcc uses on that platform.
581 lines
17 KiB
C
581 lines
17 KiB
C
/*-
|
|
* Copyright (c) 1982, 1986, 1993
|
|
* The 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_prof.c 8.3 (Berkeley) 9/23/93
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/sysproto.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/lock.h>
|
|
#include <sys/mutex.h>
|
|
#include <sys/proc.h>
|
|
#include <sys/resourcevar.h>
|
|
#include <sys/sysctl.h>
|
|
|
|
#include <machine/cpu.h>
|
|
|
|
#ifdef GPROF
|
|
#include <sys/malloc.h>
|
|
#include <sys/gmon.h>
|
|
#undef MCOUNT
|
|
|
|
static MALLOC_DEFINE(M_GPROF, "gprof", "kernel profiling buffer");
|
|
|
|
static void kmstartup(void *);
|
|
SYSINIT(kmem, SI_SUB_KPROF, SI_ORDER_FIRST, kmstartup, NULL)
|
|
|
|
struct gmonparam _gmonparam = { GMON_PROF_OFF };
|
|
|
|
#ifdef GUPROF
|
|
#include <machine/asmacros.h>
|
|
|
|
void
|
|
nullfunc_loop_profiled()
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < CALIB_SCALE; i++)
|
|
nullfunc_profiled();
|
|
}
|
|
|
|
#define nullfunc_loop_profiled_end nullfunc_profiled /* XXX */
|
|
|
|
void
|
|
nullfunc_profiled()
|
|
{
|
|
}
|
|
#endif /* GUPROF */
|
|
|
|
/*
|
|
* Update the histograms to support extending the text region arbitrarily.
|
|
* This is done slightly naively (no sparse regions), so will waste slight
|
|
* amounts of memory, but will overall work nicely enough to allow profiling
|
|
* of KLDs.
|
|
*/
|
|
void
|
|
kmupetext(uintfptr_t nhighpc)
|
|
{
|
|
struct gmonparam np; /* slightly large */
|
|
struct gmonparam *p = &_gmonparam;
|
|
char *cp;
|
|
|
|
GIANT_REQUIRED;
|
|
bcopy(p, &np, sizeof(*p));
|
|
np.highpc = ROUNDUP(nhighpc, HISTFRACTION * sizeof(HISTCOUNTER));
|
|
if (np.highpc <= p->highpc)
|
|
return;
|
|
np.textsize = np.highpc - p->lowpc;
|
|
np.kcountsize = np.textsize / HISTFRACTION;
|
|
np.hashfraction = HASHFRACTION;
|
|
np.fromssize = np.textsize / HASHFRACTION;
|
|
np.tolimit = np.textsize * ARCDENSITY / 100;
|
|
if (np.tolimit < MINARCS)
|
|
np.tolimit = MINARCS;
|
|
else if (np.tolimit > MAXARCS)
|
|
np.tolimit = MAXARCS;
|
|
np.tossize = np.tolimit * sizeof(struct tostruct);
|
|
cp = malloc(np.kcountsize + np.fromssize + np.tossize,
|
|
M_GPROF, M_WAITOK);
|
|
/*
|
|
* Check for something else extending highpc while we slept.
|
|
*/
|
|
if (np.highpc <= p->highpc) {
|
|
free(cp, M_GPROF);
|
|
return;
|
|
}
|
|
np.tos = (struct tostruct *)cp;
|
|
cp += np.tossize;
|
|
np.kcount = (HISTCOUNTER *)cp;
|
|
cp += np.kcountsize;
|
|
np.froms = (u_short *)cp;
|
|
#ifdef GUPROF
|
|
/* Reinitialize pointers to overhead counters. */
|
|
np.cputime_count = &KCOUNT(&np, PC_TO_I(&np, cputime));
|
|
np.mcount_count = &KCOUNT(&np, PC_TO_I(&np, mcount));
|
|
np.mexitcount_count = &KCOUNT(&np, PC_TO_I(&np, mexitcount));
|
|
#endif
|
|
critical_enter();
|
|
bcopy(p->tos, np.tos, p->tossize);
|
|
bzero((char *)np.tos + p->tossize, np.tossize - p->tossize);
|
|
bcopy(p->kcount, np.kcount, p->kcountsize);
|
|
bzero((char *)np.kcount + p->kcountsize, np.kcountsize -
|
|
p->kcountsize);
|
|
bcopy(p->froms, np.froms, p->fromssize);
|
|
bzero((char *)np.froms + p->fromssize, np.fromssize - p->fromssize);
|
|
cp = (char *)p->tos;
|
|
bcopy(&np, p, sizeof(*p));
|
|
critical_exit();
|
|
free(cp, M_GPROF);
|
|
}
|
|
|
|
static void
|
|
kmstartup(dummy)
|
|
void *dummy;
|
|
{
|
|
char *cp;
|
|
struct gmonparam *p = &_gmonparam;
|
|
#ifdef GUPROF
|
|
int cputime_overhead;
|
|
int empty_loop_time;
|
|
int i;
|
|
int mcount_overhead;
|
|
int mexitcount_overhead;
|
|
int nullfunc_loop_overhead;
|
|
int nullfunc_loop_profiled_time;
|
|
uintfptr_t tmp_addr;
|
|
#endif
|
|
|
|
tcov_init();
|
|
/*
|
|
* 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.
|
|
*/
|
|
p->lowpc = ROUNDDOWN((u_long)btext, HISTFRACTION * sizeof(HISTCOUNTER));
|
|
p->highpc = ROUNDUP((u_long)etext, HISTFRACTION * sizeof(HISTCOUNTER));
|
|
p->textsize = p->highpc - p->lowpc;
|
|
printf("Profiling kernel, textsize=%lu [%x..%x]\n",
|
|
p->textsize, p->lowpc, p->highpc);
|
|
p->kcountsize = p->textsize / HISTFRACTION;
|
|
p->hashfraction = HASHFRACTION;
|
|
p->fromssize = p->textsize / HASHFRACTION;
|
|
p->tolimit = p->textsize * ARCDENSITY / 100;
|
|
if (p->tolimit < MINARCS)
|
|
p->tolimit = MINARCS;
|
|
else if (p->tolimit > MAXARCS)
|
|
p->tolimit = MAXARCS;
|
|
p->tossize = p->tolimit * sizeof(struct tostruct);
|
|
cp = (char *)malloc(p->kcountsize + p->fromssize + p->tossize,
|
|
M_GPROF, M_WAITOK | M_ZERO);
|
|
p->tos = (struct tostruct *)cp;
|
|
cp += p->tossize;
|
|
p->kcount = (HISTCOUNTER *)cp;
|
|
cp += p->kcountsize;
|
|
p->froms = (u_short *)cp;
|
|
|
|
#ifdef GUPROF
|
|
/* Initialize pointers to overhead counters. */
|
|
p->cputime_count = &KCOUNT(p, PC_TO_I(p, cputime));
|
|
p->mcount_count = &KCOUNT(p, PC_TO_I(p, mcount));
|
|
p->mexitcount_count = &KCOUNT(p, PC_TO_I(p, mexitcount));
|
|
|
|
/*
|
|
* Disable interrupts to avoid interference while we calibrate
|
|
* things.
|
|
*/
|
|
critical_enter();
|
|
|
|
/*
|
|
* Determine overheads.
|
|
* XXX this needs to be repeated for each useful timer/counter.
|
|
*/
|
|
cputime_overhead = 0;
|
|
startguprof(p);
|
|
for (i = 0; i < CALIB_SCALE; i++)
|
|
cputime_overhead += cputime();
|
|
|
|
empty_loop();
|
|
startguprof(p);
|
|
empty_loop();
|
|
empty_loop_time = cputime();
|
|
|
|
nullfunc_loop_profiled();
|
|
|
|
/*
|
|
* Start profiling. There won't be any normal function calls since
|
|
* interrupts are disabled, but we will call the profiling routines
|
|
* directly to determine their overheads.
|
|
*/
|
|
p->state = GMON_PROF_HIRES;
|
|
|
|
startguprof(p);
|
|
nullfunc_loop_profiled();
|
|
|
|
startguprof(p);
|
|
for (i = 0; i < CALIB_SCALE; i++)
|
|
#if defined(__i386__) && __GNUC__ >= 2
|
|
__asm("pushl %0; call __mcount; popl %%ecx"
|
|
:
|
|
: "i" (profil)
|
|
: "ax", "bx", "cx", "dx", "memory");
|
|
#elif defined(lint)
|
|
#else
|
|
#error
|
|
#endif
|
|
mcount_overhead = KCOUNT(p, PC_TO_I(p, profil));
|
|
|
|
startguprof(p);
|
|
for (i = 0; i < CALIB_SCALE; i++)
|
|
#if defined(__i386__) && __GNUC__ >= 2
|
|
__asm("call " __XSTRING(HIDENAME(mexitcount)) "; 1:"
|
|
: : : "ax", "bx", "cx", "dx", "memory");
|
|
__asm("movl $1b,%0" : "=rm" (tmp_addr));
|
|
#elif defined(lint)
|
|
#else
|
|
#error
|
|
#endif
|
|
mexitcount_overhead = KCOUNT(p, PC_TO_I(p, tmp_addr));
|
|
|
|
p->state = GMON_PROF_OFF;
|
|
stopguprof(p);
|
|
|
|
critical_exit();
|
|
|
|
nullfunc_loop_profiled_time = 0;
|
|
for (tmp_addr = (uintfptr_t)nullfunc_loop_profiled;
|
|
tmp_addr < (uintfptr_t)nullfunc_loop_profiled_end;
|
|
tmp_addr += HISTFRACTION * sizeof(HISTCOUNTER))
|
|
nullfunc_loop_profiled_time += KCOUNT(p, PC_TO_I(p, tmp_addr));
|
|
#define CALIB_DOSCALE(count) (((count) + CALIB_SCALE / 3) / CALIB_SCALE)
|
|
#define c2n(count, freq) ((int)((count) * 1000000000LL / freq))
|
|
printf("cputime %d, empty_loop %d, nullfunc_loop_profiled %d, mcount %d, mexitcount %d\n",
|
|
CALIB_DOSCALE(c2n(cputime_overhead, p->profrate)),
|
|
CALIB_DOSCALE(c2n(empty_loop_time, p->profrate)),
|
|
CALIB_DOSCALE(c2n(nullfunc_loop_profiled_time, p->profrate)),
|
|
CALIB_DOSCALE(c2n(mcount_overhead, p->profrate)),
|
|
CALIB_DOSCALE(c2n(mexitcount_overhead, p->profrate)));
|
|
cputime_overhead -= empty_loop_time;
|
|
mcount_overhead -= empty_loop_time;
|
|
mexitcount_overhead -= empty_loop_time;
|
|
|
|
/*-
|
|
* Profiling overheads are determined by the times between the
|
|
* following events:
|
|
* MC1: mcount() is called
|
|
* MC2: cputime() (called from mcount()) latches the timer
|
|
* MC3: mcount() completes
|
|
* ME1: mexitcount() is called
|
|
* ME2: cputime() (called from mexitcount()) latches the timer
|
|
* ME3: mexitcount() completes.
|
|
* The times between the events vary slightly depending on instruction
|
|
* combination and cache misses, etc. Attempt to determine the
|
|
* minimum times. These can be subtracted from the profiling times
|
|
* without much risk of reducing the profiling times below what they
|
|
* would be when profiling is not configured. Abbreviate:
|
|
* ab = minimum time between MC1 and MC3
|
|
* a = minumum time between MC1 and MC2
|
|
* b = minimum time between MC2 and MC3
|
|
* cd = minimum time between ME1 and ME3
|
|
* c = minimum time between ME1 and ME2
|
|
* d = minimum time between ME2 and ME3.
|
|
* These satisfy the relations:
|
|
* ab <= mcount_overhead (just measured)
|
|
* a + b <= ab
|
|
* cd <= mexitcount_overhead (just measured)
|
|
* c + d <= cd
|
|
* a + d <= nullfunc_loop_profiled_time (just measured)
|
|
* a >= 0, b >= 0, c >= 0, d >= 0.
|
|
* Assume that ab and cd are equal to the minimums.
|
|
*/
|
|
p->cputime_overhead = CALIB_DOSCALE(cputime_overhead);
|
|
p->mcount_overhead = CALIB_DOSCALE(mcount_overhead - cputime_overhead);
|
|
p->mexitcount_overhead = CALIB_DOSCALE(mexitcount_overhead
|
|
- cputime_overhead);
|
|
nullfunc_loop_overhead = nullfunc_loop_profiled_time - empty_loop_time;
|
|
p->mexitcount_post_overhead = CALIB_DOSCALE((mcount_overhead
|
|
- nullfunc_loop_overhead)
|
|
/ 4);
|
|
p->mexitcount_pre_overhead = p->mexitcount_overhead
|
|
+ p->cputime_overhead
|
|
- p->mexitcount_post_overhead;
|
|
p->mcount_pre_overhead = CALIB_DOSCALE(nullfunc_loop_overhead)
|
|
- p->mexitcount_post_overhead;
|
|
p->mcount_post_overhead = p->mcount_overhead
|
|
+ p->cputime_overhead
|
|
- p->mcount_pre_overhead;
|
|
printf(
|
|
"Profiling overheads: mcount: %d+%d, %d+%d; mexitcount: %d+%d, %d+%d nsec\n",
|
|
c2n(p->cputime_overhead, p->profrate),
|
|
c2n(p->mcount_overhead, p->profrate),
|
|
c2n(p->mcount_pre_overhead, p->profrate),
|
|
c2n(p->mcount_post_overhead, p->profrate),
|
|
c2n(p->cputime_overhead, p->profrate),
|
|
c2n(p->mexitcount_overhead, p->profrate),
|
|
c2n(p->mexitcount_pre_overhead, p->profrate),
|
|
c2n(p->mexitcount_post_overhead, p->profrate));
|
|
printf(
|
|
"Profiling overheads: mcount: %d+%d, %d+%d; mexitcount: %d+%d, %d+%d cycles\n",
|
|
p->cputime_overhead, p->mcount_overhead,
|
|
p->mcount_pre_overhead, p->mcount_post_overhead,
|
|
p->cputime_overhead, p->mexitcount_overhead,
|
|
p->mexitcount_pre_overhead, p->mexitcount_post_overhead);
|
|
#endif /* GUPROF */
|
|
}
|
|
|
|
/*
|
|
* Return kernel profiling information.
|
|
*/
|
|
static int
|
|
sysctl_kern_prof(SYSCTL_HANDLER_ARGS)
|
|
{
|
|
int *name = (int *) arg1;
|
|
u_int namelen = arg2;
|
|
struct gmonparam *gp = &_gmonparam;
|
|
int error;
|
|
int state;
|
|
|
|
/* all sysctl names at this level are terminal */
|
|
if (namelen != 1)
|
|
return (ENOTDIR); /* overloaded */
|
|
|
|
switch (name[0]) {
|
|
case GPROF_STATE:
|
|
state = gp->state;
|
|
error = sysctl_handle_int(oidp, &state, 0, req);
|
|
if (error)
|
|
return (error);
|
|
if (!req->newptr)
|
|
return (0);
|
|
if (state == GMON_PROF_OFF) {
|
|
gp->state = state;
|
|
stopprofclock(&proc0);
|
|
stopguprof(gp);
|
|
} else if (state == GMON_PROF_ON) {
|
|
gp->state = GMON_PROF_OFF;
|
|
stopguprof(gp);
|
|
gp->profrate = profhz;
|
|
startprofclock(&proc0);
|
|
gp->state = state;
|
|
#ifdef GUPROF
|
|
} else if (state == GMON_PROF_HIRES) {
|
|
gp->state = GMON_PROF_OFF;
|
|
stopprofclock(&proc0);
|
|
startguprof(gp);
|
|
gp->state = state;
|
|
#endif
|
|
} else if (state != gp->state)
|
|
return (EINVAL);
|
|
return (0);
|
|
case GPROF_COUNT:
|
|
return (sysctl_handle_opaque(oidp,
|
|
gp->kcount, gp->kcountsize, req));
|
|
case GPROF_FROMS:
|
|
return (sysctl_handle_opaque(oidp,
|
|
gp->froms, gp->fromssize, req));
|
|
case GPROF_TOS:
|
|
return (sysctl_handle_opaque(oidp,
|
|
gp->tos, gp->tossize, req));
|
|
case GPROF_GMONPARAM:
|
|
return (sysctl_handle_opaque(oidp, gp, sizeof *gp, req));
|
|
default:
|
|
return (EOPNOTSUPP);
|
|
}
|
|
/* NOTREACHED */
|
|
}
|
|
|
|
SYSCTL_NODE(_kern, KERN_PROF, prof, CTLFLAG_RW, sysctl_kern_prof, "");
|
|
#endif /* GPROF */
|
|
|
|
/*
|
|
* Profiling system call.
|
|
*
|
|
* The scale factor is a fixed point number with 16 bits of fraction, so that
|
|
* 1.0 is represented as 0x10000. A scale factor of 0 turns off profiling.
|
|
*/
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct profil_args {
|
|
caddr_t samples;
|
|
size_t size;
|
|
size_t offset;
|
|
u_int scale;
|
|
};
|
|
#endif
|
|
/*
|
|
* MPSAFE
|
|
*/
|
|
/* ARGSUSED */
|
|
int
|
|
profil(td, uap)
|
|
struct thread *td;
|
|
register struct profil_args *uap;
|
|
{
|
|
register struct uprof *upp;
|
|
int s;
|
|
int error = 0;
|
|
|
|
mtx_lock(&Giant);
|
|
|
|
if (uap->scale > (1 << 16)) {
|
|
error = EINVAL;
|
|
goto done2;
|
|
}
|
|
if (uap->scale == 0) {
|
|
stopprofclock(td->td_proc);
|
|
goto done2;
|
|
}
|
|
upp = &td->td_proc->p_stats->p_prof;
|
|
|
|
/* Block profile interrupts while changing state. */
|
|
s = splstatclock();
|
|
upp->pr_off = uap->offset;
|
|
upp->pr_scale = uap->scale;
|
|
upp->pr_base = uap->samples;
|
|
upp->pr_size = uap->size;
|
|
startprofclock(td->td_proc);
|
|
splx(s);
|
|
|
|
done2:
|
|
mtx_unlock(&Giant);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Scale is a fixed-point number with the binary point 16 bits
|
|
* into the value, and is <= 1.0. pc is at most 32 bits, so the
|
|
* intermediate result is at most 48 bits.
|
|
*/
|
|
#define PC_TO_INDEX(pc, prof) \
|
|
((int)(((u_quad_t)((pc) - (prof)->pr_off) * \
|
|
(u_quad_t)((prof)->pr_scale)) >> 16) & ~1)
|
|
|
|
/*
|
|
* Collect user-level profiling statistics; called on a profiling tick,
|
|
* when a process is running in user-mode. This routine may be called
|
|
* from an interrupt context. We try to update the user profiling buffers
|
|
* cheaply with fuswintr() and suswintr(). If that fails, we revert to
|
|
* an AST that will vector us to trap() with a context in which copyin
|
|
* and copyout will work. Trap will then call addupc_task().
|
|
*
|
|
* Note that we may (rarely) not get around to the AST soon enough, and
|
|
* lose profile ticks when the next tick overwrites this one, but in this
|
|
* case the system is overloaded and the profile is probably already
|
|
* inaccurate.
|
|
*/
|
|
void
|
|
addupc_intr(ke, pc, ticks)
|
|
register struct kse *ke;
|
|
register uintptr_t pc;
|
|
u_int ticks;
|
|
{
|
|
register struct uprof *prof;
|
|
register caddr_t addr;
|
|
register u_int i;
|
|
register int v;
|
|
|
|
if (ticks == 0)
|
|
return;
|
|
prof = &ke->ke_proc->p_stats->p_prof;
|
|
if (pc < prof->pr_off ||
|
|
(i = PC_TO_INDEX(pc, prof)) >= prof->pr_size)
|
|
return; /* out of range; ignore */
|
|
|
|
addr = prof->pr_base + i;
|
|
if ((v = fuswintr(addr)) == -1 || suswintr(addr, v + ticks) == -1) {
|
|
mtx_lock_spin(&sched_lock);
|
|
prof->pr_addr = pc;
|
|
prof->pr_ticks = ticks;
|
|
ke->ke_flags |= KEF_OWEUPC | KEF_ASTPENDING ;
|
|
mtx_unlock_spin(&sched_lock);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Much like before, but we can afford to take faults here. If the
|
|
* update fails, we simply turn off profiling.
|
|
*/
|
|
void
|
|
addupc_task(ke, pc, ticks)
|
|
register struct kse *ke;
|
|
register uintptr_t pc;
|
|
u_int ticks;
|
|
{
|
|
struct proc *p = ke->ke_proc;
|
|
register struct uprof *prof;
|
|
register caddr_t addr;
|
|
register u_int i;
|
|
u_short v;
|
|
|
|
if (ticks == 0)
|
|
return;
|
|
|
|
prof = &p->p_stats->p_prof;
|
|
if (pc < prof->pr_off ||
|
|
(i = PC_TO_INDEX(pc, prof)) >= prof->pr_size)
|
|
return;
|
|
|
|
addr = prof->pr_base + i;
|
|
if (copyin(addr, &v, sizeof(v)) == 0) {
|
|
v += ticks;
|
|
if (copyout(&v, addr, sizeof(v)) == 0)
|
|
return;
|
|
}
|
|
stopprofclock(p);
|
|
}
|
|
|
|
#if defined(__i386__) && __GNUC__ >= 2
|
|
/*
|
|
* Support for "--test-coverage --profile-arcs" in GCC.
|
|
*
|
|
* We need to call all the functions in the .ctor section, in order
|
|
* to get all the counter-arrays strung into a list.
|
|
*
|
|
* XXX: the .ctors call __bb_init_func which is located in over in
|
|
* XXX: i386/i386/support.s for historical reasons. There is probably
|
|
* XXX: no reason for that to be assembler anymore, but doing it right
|
|
* XXX: in MI C code requires one to reverse-engineer the type-selection
|
|
* XXX: inside GCC. Have fun.
|
|
*
|
|
* XXX: Worrisome perspective: Calling the .ctors may make C++ in the
|
|
* XXX: kernel feasible. Don't.
|
|
*/
|
|
typedef void (*ctor_t)(void);
|
|
extern ctor_t _start_ctors, _stop_ctors;
|
|
|
|
static void
|
|
tcov_init(void *foo __unused)
|
|
{
|
|
ctor_t *p, q;
|
|
|
|
for (p = &_start_ctors; p < &_stop_ctors; p++) {
|
|
q = *p;
|
|
q();
|
|
}
|
|
}
|
|
|
|
SYSINIT(kmem, SI_SUB_KPROF, SI_ORDER_SECOND, tcov_init, NULL)
|
|
|
|
/*
|
|
* GCC contains magic to recognize calls to for instance execve() and
|
|
* puts in calls to this function to preserve the profile counters.
|
|
* XXX: Put zinging punchline here.
|
|
*/
|
|
void __bb_fork_func(void);
|
|
void
|
|
__bb_fork_func(void)
|
|
{
|
|
}
|
|
|
|
#endif
|
|
|