freebsd-dev/sys/compat/linux/linux_emul.c
Attilio Rao 54366c0bd7 - For kernel compiled only with KDTRACE_HOOKS and not any lock debugging
option, unbreak the lock tracing release semantic by embedding
  calls to LOCKSTAT_PROFILE_RELEASE_LOCK() direclty in the inlined
  version of the releasing functions for mutex, rwlock and sxlock.
  Failing to do so skips the lockstat_probe_func invokation for
  unlocking.
- As part of the LOCKSTAT support is inlined in mutex operation, for
  kernel compiled without lock debugging options, potentially every
  consumer must be compiled including opt_kdtrace.h.
  Fix this by moving KDTRACE_HOOKS into opt_global.h and remove the
  dependency by opt_kdtrace.h for all files, as now only KDTRACE_FRAMES
  is linked there and it is only used as a compile-time stub [0].

[0] immediately shows some new bug as DTRACE-derived support for debug
in sfxge is broken and it was never really tested.  As it was not
including correctly opt_kdtrace.h before it was never enabled so it
was kept broken for a while.  Fix this by using a protection stub,
leaving sfxge driver authors the responsibility for fixing it
appropriately [1].

Sponsored by:	EMC / Isilon storage division
Discussed with:	rstone
[0] Reported by:	rstone
[1] Discussed with:	philip
2013-11-25 07:38:45 +00:00

474 lines
13 KiB
C

/*-
* Copyright (c) 2006 Roman Divacky
* 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
* in this position and unchanged.
* 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. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_compat.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/imgact.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/sdt.h>
#include <sys/sx.h>
#include <sys/proc.h>
#include <sys/syscallsubr.h>
#include <sys/sysent.h>
#include <sys/sysproto.h>
#include <sys/unistd.h>
#ifdef COMPAT_LINUX32
#include <machine/../linux32/linux.h>
#include <machine/../linux32/linux32_proto.h>
#else
#include <machine/../linux/linux.h>
#include <machine/../linux/linux_proto.h>
#endif
#include <compat/linux/linux_dtrace.h>
#include <compat/linux/linux_emul.h>
#include <compat/linux/linux_futex.h>
#include <compat/linux/linux_misc.h>
/**
* Special DTrace provider for the linuxulator.
*
* In this file we define the provider for the entire linuxulator. All
* modules (= files of the linuxulator) use it.
*
* We define a different name depending on the emulated bitsize, see
* ../../<ARCH>/linux{,32}/linux.h, e.g.:
* native bitsize = linuxulator
* amd64, 32bit emulation = linuxulator32
*/
LIN_SDT_PROVIDER_DEFINE(LINUX_DTRACE);
/**
* Special DTrace module "locks", it covers some linuxulator internal
* locks.
*/
LIN_SDT_PROBE_DEFINE1(locks, emul_lock, locked, "struct mtx *");
LIN_SDT_PROBE_DEFINE1(locks, emul_lock, unlock, "struct mtx *");
LIN_SDT_PROBE_DEFINE1(locks, emul_shared_rlock, locked, "struct sx *");
LIN_SDT_PROBE_DEFINE1(locks, emul_shared_rlock, unlock, "struct sx *");
LIN_SDT_PROBE_DEFINE1(locks, emul_shared_wlock, locked, "struct sx *");
LIN_SDT_PROBE_DEFINE1(locks, emul_shared_wlock, unlock, "struct sx *");
/**
* DTrace probes in this module.
*/
LIN_SDT_PROBE_DEFINE2(emul, em_find, entry, "struct proc *", "int");
LIN_SDT_PROBE_DEFINE0(emul, em_find, return);
LIN_SDT_PROBE_DEFINE3(emul, proc_init, entry, "struct thread *", "pid_t",
"int");
LIN_SDT_PROBE_DEFINE0(emul, proc_init, create_thread);
LIN_SDT_PROBE_DEFINE0(emul, proc_init, fork);
LIN_SDT_PROBE_DEFINE0(emul, proc_init, exec);
LIN_SDT_PROBE_DEFINE0(emul, proc_init, return);
LIN_SDT_PROBE_DEFINE1(emul, proc_exit, entry, "struct proc *");
LIN_SDT_PROBE_DEFINE0(emul, proc_exit, futex_failed);
LIN_SDT_PROBE_DEFINE3(emul, proc_exit, reparent, "pid_t", "pid_t",
"struct proc *");
LIN_SDT_PROBE_DEFINE1(emul, proc_exit, child_clear_tid_error, "int");
LIN_SDT_PROBE_DEFINE0(emul, proc_exit, return);
LIN_SDT_PROBE_DEFINE2(emul, proc_exec, entry, "struct proc *",
"struct image_params *");
LIN_SDT_PROBE_DEFINE0(emul, proc_exec, return);
LIN_SDT_PROBE_DEFINE0(emul, linux_schedtail, entry);
LIN_SDT_PROBE_DEFINE1(emul, linux_schedtail, copyout_error, "int");
LIN_SDT_PROBE_DEFINE0(emul, linux_schedtail, return);
LIN_SDT_PROBE_DEFINE1(emul, linux_set_tid_address, entry, "int *");
LIN_SDT_PROBE_DEFINE0(emul, linux_set_tid_address, return);
LIN_SDT_PROBE_DEFINE2(emul, linux_kill_threads, entry, "struct thread *",
"int");
LIN_SDT_PROBE_DEFINE1(emul, linux_kill_threads, kill, "pid_t");
LIN_SDT_PROBE_DEFINE0(emul, linux_kill_threads, return);
struct sx emul_shared_lock;
struct mtx emul_lock;
/* this returns locked reference to the emuldata entry (if found) */
struct linux_emuldata *
em_find(struct proc *p, int locked)
{
struct linux_emuldata *em;
LIN_SDT_PROBE2(emul, em_find, entry, p, locked);
if (locked == EMUL_DOLOCK)
EMUL_LOCK(&emul_lock);
em = p->p_emuldata;
if (em == NULL && locked == EMUL_DOLOCK)
EMUL_UNLOCK(&emul_lock);
LIN_SDT_PROBE1(emul, em_find, return, em);
return (em);
}
int
linux_proc_init(struct thread *td, pid_t child, int flags)
{
struct linux_emuldata *em, *p_em;
struct proc *p;
LIN_SDT_PROBE3(emul, proc_init, entry, td, child, flags);
if (child != 0) {
/* fork or create a thread */
em = malloc(sizeof *em, M_LINUX, M_WAITOK | M_ZERO);
em->pid = child;
em->pdeath_signal = 0;
em->flags = 0;
em->robust_futexes = NULL;
if (flags & LINUX_CLONE_THREAD) {
/* handled later in the code */
LIN_SDT_PROBE0(emul, proc_init, create_thread);
} else {
struct linux_emuldata_shared *s;
LIN_SDT_PROBE0(emul, proc_init, fork);
s = malloc(sizeof *s, M_LINUX, M_WAITOK | M_ZERO);
s->refs = 1;
s->group_pid = child;
LIST_INIT(&s->threads);
em->shared = s;
}
} else {
/* exec */
LIN_SDT_PROBE0(emul, proc_init, exec);
/* lookup the old one */
em = em_find(td->td_proc, EMUL_DOLOCK);
KASSERT(em != NULL, ("proc_init: emuldata not found in exec case.\n"));
}
em->child_clear_tid = NULL;
em->child_set_tid = NULL;
/*
* allocate the shared struct only in clone()/fork cases in the case
* of clone() td = calling proc and child = pid of the newly created
* proc
*/
if (child != 0) {
if (flags & LINUX_CLONE_THREAD) {
/* lookup the parent */
/*
* we dont have to lock the p_em because
* its waiting for us in linux_clone so
* there is no chance of it changing the
* p_em->shared address
*/
p_em = em_find(td->td_proc, EMUL_DONTLOCK);
KASSERT(p_em != NULL, ("proc_init: parent emuldata not found for CLONE_THREAD\n"));
em->shared = p_em->shared;
EMUL_SHARED_WLOCK(&emul_shared_lock);
em->shared->refs++;
EMUL_SHARED_WUNLOCK(&emul_shared_lock);
} else {
/*
* handled earlier to avoid malloc(M_WAITOK) with
* rwlock held
*/
}
EMUL_SHARED_WLOCK(&emul_shared_lock);
LIST_INSERT_HEAD(&em->shared->threads, em, threads);
EMUL_SHARED_WUNLOCK(&emul_shared_lock);
p = pfind(child);
KASSERT(p != NULL, ("process not found in proc_init\n"));
p->p_emuldata = em;
PROC_UNLOCK(p);
} else
EMUL_UNLOCK(&emul_lock);
LIN_SDT_PROBE0(emul, proc_init, return);
return (0);
}
void
linux_proc_exit(void *arg __unused, struct proc *p)
{
struct linux_emuldata *em;
int error, shared_flags, shared_xstat;
struct thread *td = FIRST_THREAD_IN_PROC(p);
int *child_clear_tid;
struct proc *q, *nq;
if (__predict_true(p->p_sysent != &elf_linux_sysvec))
return;
LIN_SDT_PROBE1(emul, proc_exit, entry, p);
release_futexes(p);
/* find the emuldata */
em = em_find(p, EMUL_DOLOCK);
KASSERT(em != NULL, ("proc_exit: emuldata not found.\n"));
/* reparent all procs that are not a thread leader to initproc */
if (em->shared->group_pid != p->p_pid) {
LIN_SDT_PROBE3(emul, proc_exit, reparent,
em->shared->group_pid, p->p_pid, p);
child_clear_tid = em->child_clear_tid;
EMUL_UNLOCK(&emul_lock);
sx_xlock(&proctree_lock);
wakeup(initproc);
PROC_LOCK(p);
proc_reparent(p, initproc);
p->p_sigparent = SIGCHLD;
PROC_UNLOCK(p);
sx_xunlock(&proctree_lock);
} else {
child_clear_tid = em->child_clear_tid;
EMUL_UNLOCK(&emul_lock);
}
EMUL_SHARED_WLOCK(&emul_shared_lock);
shared_flags = em->shared->flags;
shared_xstat = em->shared->xstat;
LIST_REMOVE(em, threads);
em->shared->refs--;
if (em->shared->refs == 0) {
EMUL_SHARED_WUNLOCK(&emul_shared_lock);
free(em->shared, M_LINUX);
} else
EMUL_SHARED_WUNLOCK(&emul_shared_lock);
if ((shared_flags & EMUL_SHARED_HASXSTAT) != 0)
p->p_xstat = shared_xstat;
if (child_clear_tid != NULL) {
struct linux_sys_futex_args cup;
int null = 0;
error = copyout(&null, child_clear_tid, sizeof(null));
if (error) {
LIN_SDT_PROBE1(emul, proc_exit,
child_clear_tid_error, error);
free(em, M_LINUX);
LIN_SDT_PROBE0(emul, proc_exit, return);
return;
}
/* futexes stuff */
cup.uaddr = child_clear_tid;
cup.op = LINUX_FUTEX_WAKE;
cup.val = 0x7fffffff; /* Awake everyone */
cup.timeout = NULL;
cup.uaddr2 = NULL;
cup.val3 = 0;
error = linux_sys_futex(FIRST_THREAD_IN_PROC(p), &cup);
/*
* this cannot happen at the moment and if this happens it
* probably means there is a user space bug
*/
if (error) {
LIN_SDT_PROBE0(emul, proc_exit, futex_failed);
printf(LMSG("futex stuff in proc_exit failed.\n"));
}
}
/* clean the stuff up */
free(em, M_LINUX);
/* this is a little weird but rewritten from exit1() */
sx_xlock(&proctree_lock);
q = LIST_FIRST(&p->p_children);
for (; q != NULL; q = nq) {
nq = LIST_NEXT(q, p_sibling);
if (q->p_flag & P_WEXIT)
continue;
if (__predict_false(q->p_sysent != &elf_linux_sysvec))
continue;
em = em_find(q, EMUL_DOLOCK);
KASSERT(em != NULL, ("linux_reparent: emuldata not found: %i\n", q->p_pid));
PROC_LOCK(q);
if ((q->p_flag & P_WEXIT) == 0 && em->pdeath_signal != 0) {
kern_psignal(q, em->pdeath_signal);
}
PROC_UNLOCK(q);
EMUL_UNLOCK(&emul_lock);
}
sx_xunlock(&proctree_lock);
LIN_SDT_PROBE0(emul, proc_exit, return);
}
/*
* This is used in a case of transition from FreeBSD binary execing to linux binary
* in this case we create linux emuldata proc entry with the pid of the currently running
* process.
*/
void
linux_proc_exec(void *arg __unused, struct proc *p, struct image_params *imgp)
{
if (__predict_false(imgp->sysent == &elf_linux_sysvec)) {
LIN_SDT_PROBE2(emul, proc_exec, entry, p, imgp);
}
if (__predict_false(imgp->sysent == &elf_linux_sysvec
&& p->p_sysent != &elf_linux_sysvec))
linux_proc_init(FIRST_THREAD_IN_PROC(p), p->p_pid, 0);
if (__predict_false((p->p_sysent->sv_flags & SV_ABI_MASK) ==
SV_ABI_LINUX))
/* Kill threads regardless of imgp->sysent value */
linux_kill_threads(FIRST_THREAD_IN_PROC(p), SIGKILL);
if (__predict_false(imgp->sysent != &elf_linux_sysvec
&& p->p_sysent == &elf_linux_sysvec)) {
struct linux_emuldata *em;
/*
* XXX:There's a race because here we assign p->p_emuldata NULL
* but the process is still counted as linux one for a short
* time so some other process might reference it and try to
* access its p->p_emuldata and panicing on a NULL reference.
*/
em = em_find(p, EMUL_DONTLOCK);
KASSERT(em != NULL, ("proc_exec: emuldata not found.\n"));
EMUL_SHARED_WLOCK(&emul_shared_lock);
LIST_REMOVE(em, threads);
PROC_LOCK(p);
p->p_emuldata = NULL;
PROC_UNLOCK(p);
em->shared->refs--;
if (em->shared->refs == 0) {
EMUL_SHARED_WUNLOCK(&emul_shared_lock);
free(em->shared, M_LINUX);
} else
EMUL_SHARED_WUNLOCK(&emul_shared_lock);
free(em, M_LINUX);
}
if (__predict_false(imgp->sysent == &elf_linux_sysvec)) {
LIN_SDT_PROBE0(emul, proc_exec, return);
}
}
void
linux_schedtail(struct thread *td)
{
struct linux_emuldata *em;
struct proc *p;
int error = 0;
int *child_set_tid;
p = td->td_proc;
LIN_SDT_PROBE1(emul, linux_schedtail, entry, p);
/* find the emuldata */
em = em_find(p, EMUL_DOLOCK);
KASSERT(em != NULL, ("linux_schedtail: emuldata not found.\n"));
child_set_tid = em->child_set_tid;
EMUL_UNLOCK(&emul_lock);
if (child_set_tid != NULL) {
error = copyout(&p->p_pid, (int *)child_set_tid,
sizeof(p->p_pid));
if (error != 0) {
LIN_SDT_PROBE1(emul, linux_schedtail, copyout_error,
error);
}
}
LIN_SDT_PROBE0(emul, linux_schedtail, return);
return;
}
int
linux_set_tid_address(struct thread *td, struct linux_set_tid_address_args *args)
{
struct linux_emuldata *em;
LIN_SDT_PROBE1(emul, linux_set_tid_address, entry, args->tidptr);
/* find the emuldata */
em = em_find(td->td_proc, EMUL_DOLOCK);
KASSERT(em != NULL, ("set_tid_address: emuldata not found.\n"));
em->child_clear_tid = args->tidptr;
td->td_retval[0] = td->td_proc->p_pid;
EMUL_UNLOCK(&emul_lock);
LIN_SDT_PROBE0(emul, linux_set_tid_address, return);
return 0;
}
void
linux_kill_threads(struct thread *td, int sig)
{
struct linux_emuldata *em, *td_em, *tmp_em;
struct proc *sp;
LIN_SDT_PROBE2(emul, linux_kill_threads, entry, td, sig);
td_em = em_find(td->td_proc, EMUL_DONTLOCK);
KASSERT(td_em != NULL, ("linux_kill_threads: emuldata not found.\n"));
EMUL_SHARED_RLOCK(&emul_shared_lock);
LIST_FOREACH_SAFE(em, &td_em->shared->threads, threads, tmp_em) {
if (em->pid == td_em->pid)
continue;
sp = pfind(em->pid);
if ((sp->p_flag & P_WEXIT) == 0)
kern_psignal(sp, sig);
PROC_UNLOCK(sp);
LIN_SDT_PROBE1(emul, linux_kill_threads, kill, em->pid);
}
EMUL_SHARED_RUNLOCK(&emul_shared_lock);
LIN_SDT_PROBE0(emul, linux_kill_threads, return);
}