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/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* 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. 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.
*/
#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>
/*
* 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
/* ARGSUSED */
int
sys_profil(struct thread *td, struct profil_args *uap)
{
struct uprof *upp;
struct proc *p;
if (uap->scale > (1 << 16))
return (EINVAL);
p = td->td_proc;
if (uap->scale == 0) {
PROC_LOCK(p);
stopprofclock(p);
PROC_UNLOCK(p);
return (0);
}
PROC_LOCK(p);
upp = &td->td_proc->p_stats->p_prof;
PROC_PROFLOCK(p);
upp->pr_off = uap->offset;
upp->pr_scale = uap->scale;
upp->pr_base = uap->samples;
upp->pr_size = uap->size;
PROC_PROFUNLOCK(p);
startprofclock(p);
PROC_UNLOCK(p);
return (0);
}
/*
* 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 perform the update with 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(struct thread *td, uintfptr_t pc, u_int ticks)
{
struct uprof *prof;
if (ticks == 0)
return;
prof = &td->td_proc->p_stats->p_prof;
PROC_PROFLOCK(td->td_proc);
if (pc < prof->pr_off || PC_TO_INDEX(pc, prof) >= prof->pr_size) {
PROC_PROFUNLOCK(td->td_proc);
return; /* out of range; ignore */
}
PROC_PROFUNLOCK(td->td_proc);
td->td_profil_addr = pc;
td->td_profil_ticks = ticks;
td->td_pflags |= TDP_OWEUPC;
ast_sched(td, TDA_OWEUPC);
}
/*
* Actually update the profiling statistics. If the update fails, we
* simply turn off profiling.
*/
void
addupc_task(struct thread *td, uintfptr_t pc, u_int ticks)
{
struct proc *p = td->td_proc;
struct uprof *prof;
caddr_t addr;
u_int i;
u_short v;
int stop = 0;
if (ticks == 0)
return;
PROC_LOCK(p);
if (!(p->p_flag & P_PROFIL)) {
PROC_UNLOCK(p);
return;
}
p->p_profthreads++;
prof = &p->p_stats->p_prof;
PROC_PROFLOCK(p);
if (pc < prof->pr_off ||
(i = PC_TO_INDEX(pc, prof)) >= prof->pr_size) {
PROC_PROFUNLOCK(p);
goto out;
}
addr = prof->pr_base + i;
PROC_PROFUNLOCK(p);
PROC_UNLOCK(p);
if (copyin(addr, &v, sizeof(v)) == 0) {
v += ticks;
if (copyout(&v, addr, sizeof(v)) == 0) {
PROC_LOCK(p);
goto out;
}
}
stop = 1;
PROC_LOCK(p);
out:
if (--p->p_profthreads == 0) {
if (p->p_flag & P_STOPPROF) {
wakeup(&p->p_profthreads);
p->p_flag &= ~P_STOPPROF;
stop = 0;
}
}
if (stop)
stopprofclock(p);
PROC_UNLOCK(p);
}
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