1 files changed, 145 insertions, 261 deletions
diff --git a/sys/compat/linux/linux_emul.c b/sys/compat/linux/linux_emul.c
index 61156ba..887f72e 100644
--- a/sys/compat/linux/linux_emul.c
+++ b/sys/compat/linux/linux_emul.c
@@ -1,5 +1,6 @@
 /*-
  * Copyright (c) 2006 Roman Divacky
+ * Copyright (c) 2013 Dmitry Chagin
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -36,6 +37,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/systm.h>
 #include <sys/imgact.h>
 #include <sys/kernel.h>
+#include <sys/ktr.h>
 #include <sys/lock.h>
 #include <sys/malloc.h>
 #include <sys/mutex.h>
@@ -59,6 +61,7 @@ __FBSDID("$FreeBSD$");
 #include <compat/linux/linux_emul.h>
 #include <compat/linux/linux_futex.h>
 #include <compat/linux/linux_misc.h>
+#include <compat/linux/linux_util.h>
 
 /**
  * Special DTrace provider for the linuxulator.
@@ -74,33 +77,21 @@ __FBSDID("$FreeBSD$");
 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_DEFINE1(emul, em_find, entry, "struct thread *");
 LIN_SDT_PROBE_DEFINE0(emul, em_find, return);
-LIN_SDT_PROBE_DEFINE3(emul, proc_init, entry, "struct thread *", "pid_t",
-    "int");
+LIN_SDT_PROBE_DEFINE3(emul, proc_init, entry, "struct thread *",
+    "struct thread *", "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_DEFINE1(emul, linux_thread_detach, entry, "struct thread *");
+LIN_SDT_PROBE_DEFINE0(emul, linux_thread_detach, futex_failed);
+LIN_SDT_PROBE_DEFINE1(emul, linux_thread_detach, child_clear_tid_error, "int");
+LIN_SDT_PROBE_DEFINE0(emul, linux_thread_detach, return);
 LIN_SDT_PROBE_DEFINE2(emul, proc_exec, entry, "struct proc *",
     "struct image_params *");
 LIN_SDT_PROBE_DEFINE0(emul, proc_exec, return);
@@ -109,284 +100,208 @@ 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) */
+/*
+ * This returns reference to the emuldata entry (if found)
+ *
+ * Hold PROC_LOCK when referencing emuldata from other threads.
+ */
 struct linux_emuldata *
-em_find(struct proc *p, int locked)
+em_find(struct thread *td)
 {
 	struct linux_emuldata *em;
 
-	LIN_SDT_PROBE2(emul, em_find, entry, p, locked);
+	LIN_SDT_PROBE1(emul, em_find, entry, td);
 
-	if (locked == EMUL_DOLOCK)
-		EMUL_LOCK(&emul_lock);
-
-	em = p->p_emuldata;
-
-	if (em == NULL && locked == EMUL_DOLOCK)
-		EMUL_UNLOCK(&emul_lock);
+	em = td->td_emuldata;
 
 	LIN_SDT_PROBE1(emul, em_find, return, em);
+
 	return (em);
 }
 
-int
-linux_proc_init(struct thread *td, pid_t child, int flags)
+void
+linux_proc_init(struct thread *td, struct thread *newtd, int flags)
 {
-	struct linux_emuldata *em, *p_em;
-	struct proc *p;
+	struct linux_emuldata *em;
 
-	LIN_SDT_PROBE3(emul, proc_init, entry, td, child, flags);
+	LIN_SDT_PROBE3(emul, proc_init, entry, td, newtd, flags);
 
-	if (child != 0) {
-		/* fork or create a thread */
-		em = malloc(sizeof *em, M_LINUX, M_WAITOK | M_ZERO);
-		em->pid = child;
+	if (newtd != NULL) {
+		/* non-exec call */
+		em = malloc(sizeof(*em), M_TEMP, M_WAITOK | M_ZERO);
 		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;
 
+			em->em_tid = newtd->td_tid;
+		} else {
 			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;
+			em->em_tid = newtd->td_proc->p_pid;
 		}
+		newtd->td_emuldata = em;
 	} else {
 		/* exec */
 		LIN_SDT_PROBE0(emul, proc_init, exec);
 
 		/* lookup the old one */
-		em = em_find(td->td_proc, EMUL_DOLOCK);
+		em = em_find(td);
 		KASSERT(em != NULL, ("proc_init: emuldata not found in exec case.\n"));
+
+		em->em_tid = td->td_proc->p_pid;
 	}
 
 	em->child_clear_tid = NULL;
 	em->child_set_tid = NULL;
 
+	LIN_SDT_PROBE0(emul, proc_init, return);
+}
+
+void 
+linux_proc_exit(void *arg __unused, struct proc *p)
+{
+	struct thread *td = curthread;
+
+	if (__predict_false(SV_CURPROC_ABI() != SV_ABI_LINUX)) {
+		LIN_SDT_PROBE1(emul, proc_exit, entry, p);
+		(p->p_sysent->sv_thread_detach)(td);
+	}
+}
+
+int 
+linux_common_execve(struct thread *td, struct image_args *eargs)
+{
+	struct linux_emuldata *em;
+	struct proc *p;
+	int error;
+
+	p = td->td_proc;
+
 	/*
-	 * 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
+	 * Unlike FreeBSD abort all other threads before
+	 * proceeding exec.
 	 */
-	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
-			 */
-		}
+	PROC_LOCK(p);
+	/* See exit1() comments. */
+	thread_suspend_check(0);
+	while (p->p_flag & P_HADTHREADS) {
+		if (!thread_single(p, SINGLE_EXIT))
+			break;
+		thread_suspend_check(0);
+	}
+	PROC_UNLOCK(p);
 
-		EMUL_SHARED_WLOCK(&emul_shared_lock);
-		LIST_INSERT_HEAD(&em->shared->threads, em, threads);
-		EMUL_SHARED_WUNLOCK(&emul_shared_lock);
+	error = kern_execve(td, eargs, NULL);
+	if (error != 0)
+		return (error);
 
-		p = pfind(child);
-		KASSERT(p != NULL, ("process not found in proc_init\n"));
-		p->p_emuldata = em;
+	/*
+	 * In a case of transition from Linux binary execing to
+	 * FreeBSD binary we destroy linux emuldata thread entry.
+	 */
+	if (SV_CURPROC_ABI() != SV_ABI_LINUX) {
+		PROC_LOCK(p);
+		em = em_find(td);
+		KASSERT(em != NULL, ("proc_exec: emuldata not found.\n"));
+		td->td_emuldata = NULL;
 		PROC_UNLOCK(p);
-	} else
-		EMUL_UNLOCK(&emul_lock);
 
-	LIN_SDT_PROBE0(emul, proc_init, return);
+		free(em, M_TEMP);
+	}
 	return (0);
 }
 
-void
-linux_proc_exit(void *arg __unused, struct proc *p)
+void 
+linux_proc_exec(void *arg __unused, struct proc *p, struct image_params *imgp)
 {
-	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;
+	struct thread *td = curthread;
 
-	LIN_SDT_PROBE1(emul, proc_exit, entry, p);
-
-	release_futexes(p);
+	/*
+	 * In a case of execing to linux binary we create linux
+	 * emuldata thread entry.
+	 */
+	if (__predict_false((imgp->sysent->sv_flags & SV_ABI_MASK) ==
+	    SV_ABI_LINUX)) {
+		LIN_SDT_PROBE2(emul, proc_exec, entry, p, imgp);
+		if (SV_PROC_ABI(p) == SV_ABI_LINUX)
+			linux_proc_init(td, NULL, 0);
+		else
+			linux_proc_init(td, td, 0);
 
-	/* find the emuldata */
-	em = em_find(p, EMUL_DOLOCK);
+		LIN_SDT_PROBE0(emul, proc_exec, return);
+	}
+}
 
-	KASSERT(em != NULL, ("proc_exit: emuldata not found.\n"));
+void
+linux_thread_detach(struct thread *td)
+{
+	struct linux_sys_futex_args cup;
+	struct linux_emuldata *em;
+	int *child_clear_tid;
+	int null = 0;
+	int error;
 
-	/* 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);
+	LIN_SDT_PROBE1(emul, linux_thread_detach, entry, td);
 
-		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);	
-	}
+	em = em_find(td);
+	KASSERT(em != NULL, ("thread_detach: emuldata not found.\n"));
 
-	EMUL_SHARED_WLOCK(&emul_shared_lock);
-	shared_flags = em->shared->flags;
-	shared_xstat = em->shared->xstat;
-	LIST_REMOVE(em, threads);
+	LINUX_CTR1(exit, "thread detach(%d)", em->em_tid);
 
-	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);
+	release_futexes(td, em);
 
-	if ((shared_flags & EMUL_SHARED_HASXSTAT) != 0)
-		p->p_xstat = shared_xstat;
+	child_clear_tid = em->child_clear_tid;
 
 	if (child_clear_tid != NULL) {
-		struct linux_sys_futex_args cup;
-		int null = 0;
 
+		LINUX_CTR2(exit, "thread detach(%d) %p",
+		    em->em_tid, child_clear_tid);
+	
 		error = copyout(&null, child_clear_tid, sizeof(null));
 		if (error) {
-			LIN_SDT_PROBE1(emul, proc_exit,
+			LIN_SDT_PROBE1(emul, linux_thread_detach,
 			    child_clear_tid_error, error);
 
-			free(em, M_LINUX);
-
-			LIN_SDT_PROBE0(emul, proc_exit, return);
+			LIN_SDT_PROBE0(emul, linux_thread_detach, 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);
+		error = linux_sys_futex(td, &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);
+			LIN_SDT_PROBE0(emul, linux_thread_detach, futex_failed);
+			printf(LMSG("futex stuff in thread_detach failed.\n"));
 		}
-		PROC_UNLOCK(q);
-		EMUL_UNLOCK(&emul_lock);
 	}
-	sx_xunlock(&proctree_lock);
 
-	LIN_SDT_PROBE0(emul, proc_exit, return);
+	LIN_SDT_PROBE0(emul, linux_thread_detach, 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)
+void
+linux_thread_dtor(void *arg __unused, struct thread *td)
 {
-	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);
+	struct linux_emuldata *em;
 
-		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);
+	em = em_find(td);
+	if (em == NULL)
+		return;
+	td->td_emuldata = NULL;
 
-		free(em, M_LINUX);
-	}
+	LINUX_CTR1(exit, "thread dtor(%d)", em->em_tid);
 
-	if (__predict_false(imgp->sysent == &elf_linux_sysvec)) {
-		LIN_SDT_PROBE0(emul, proc_exec, return);
-	}
+	free(em, M_TEMP);
 }
 
 void
@@ -397,30 +312,28 @@ linux_schedtail(struct thread *td)
 	int error = 0;
 	int *child_set_tid;
 
-	p = td->td_proc;
-
-	LIN_SDT_PROBE1(emul, linux_schedtail, entry, p);
+	LIN_SDT_PROBE1(emul, linux_schedtail, entry, td);
 
-	/* find the emuldata */
-	em = em_find(p, EMUL_DOLOCK);
+	p = td->td_proc;
 
+	em = em_find(td);
 	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));
+		error = copyout(&em->em_tid, (int *)child_set_tid,
+		    sizeof(em->em_tid));
+		LINUX_CTR4(clone, "schedtail(%d) %p stored %d error %d",
+		    td->td_tid, child_set_tid, em->em_tid, error);
 
 		if (error != 0) {
 			LIN_SDT_PROBE1(emul, linux_schedtail, copyout_error,
 			    error);
 		}
-	}
+	} else
+		LINUX_CTR1(clone, "schedtail(%d)", em->em_tid);
 
 	LIN_SDT_PROBE0(emul, linux_schedtail, return);
-
-	return;
 }
 
 int
@@ -430,45 +343,16 @@ linux_set_tid_address(struct thread *td, struct linux_set_tid_address_args *args
 
 	LIN_SDT_PROBE1(emul, linux_set_tid_address, entry, args->tidptr);
 
-	/* find the emuldata */
-	em = em_find(td->td_proc, EMUL_DOLOCK);
-
+	em = em_find(td);
 	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);
+	td->td_retval[0] = em->em_tid;
 
-	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);
+	LINUX_CTR3(set_tid_address, "tidptr(%d) %p, returns %d",
+	    em->em_tid, args->tidptr, td->td_retval[0]);
 
-	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);
+	LIN_SDT_PROBE0(emul, linux_set_tid_address, return);
+	return (0);
 }