- make arc4random*() functions thread safe. Use a custom spinlock function

instead of the generic pthread macros since free(3) uses __arc4_getbyte()
when freeing small sized allocations and the generic pthread macros call
malloc(3).
- eliminate passing pointers to a static variable with global scope (rs)
for additional code clarity and reduction.
- shlib minor bumps for libc and libpthread due to new functions.
From andreas@ with some bits from me. okay tedu@ marc@ w/some spot
checking from millert@

8 files changed, 125 insertions, 48 deletions

diff --git a/lib/libc/crypt/arc4random.c b/lib/libc/crypt/arc4random.c
index 35d79530022..8604548f3fc 100644
--- a/lib/libc/crypt/arc4random.c
+++ b/lib/libc/crypt/arc4random.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: arc4random.c,v 1.16 2007/02/12 19:58:47 otto Exp $	*/
+/*	$OpenBSD: arc4random.c,v 1.17 2008/01/01 00:43:39 kurt Exp $	*/
 
 /*
  * Copyright (c) 1996, David Mazieres <dm@uun.org>
@@ -40,6 +40,7 @@
 #include <sys/param.h>
 #include <sys/time.h>
 #include <sys/sysctl.h>
+#include "thread_private.h"
 
 #ifdef __GNUC__
 #define inline __inline
@@ -58,43 +59,48 @@ static struct arc4_stream rs;
 static pid_t arc4_stir_pid;
 static int arc4_count;
 
-static inline u_int8_t arc4_getbyte(struct arc4_stream *);
+static inline u_int8_t arc4_getbyte(void);
 
 static inline void
-arc4_init(struct arc4_stream *as)
+arc4_init(void)
 {
 	int     n;
 
 	for (n = 0; n < 256; n++)
-		as->s[n] = n;
-	as->i = 0;
-	as->j = 0;
+		rs.s[n] = n;
+	rs.i = 0;
+	rs.j = 0;
 }
 
 static inline void
-arc4_addrandom(struct arc4_stream *as, u_char *dat, int datlen)
+arc4_addrandom(u_char *dat, int datlen)
 {
 	int     n;
 	u_int8_t si;
 
-	as->i--;
+	rs.i--;
 	for (n = 0; n < 256; n++) {
-		as->i = (as->i + 1);
-		si = as->s[as->i];
-		as->j = (as->j + si + dat[n % datlen]);
-		as->s[as->i] = as->s[as->j];
-		as->s[as->j] = si;
+		rs.i = (rs.i + 1);
+		si = rs.s[rs.i];
+		rs.j = (rs.j + si + dat[n % datlen]);
+		rs.s[rs.i] = rs.s[rs.j];
+		rs.s[rs.j] = si;
 	}
-	as->j = as->i;
+	rs.j = rs.i;
 }
 
 static void
-arc4_stir(struct arc4_stream *as)
+arc4_stir(void)
 {
 	int     i, mib[2];
 	size_t	len;
 	u_char rnd[128];
 
+	if (!rs_initialized) {
+		arc4_init();
+		rs_initialized = 1;
+	}
+
 	mib[0] = CTL_KERN;
 	mib[1] = KERN_ARND;
 
@@ -102,75 +108,84 @@ arc4_stir(struct arc4_stream *as)
 	sysctl(mib, 2, rnd, &len, NULL, 0);
 
 	arc4_stir_pid = getpid();
-	arc4_addrandom(as, rnd, sizeof(rnd));
+	arc4_addrandom(rnd, sizeof(rnd));
 
 	/*
 	 * Discard early keystream, as per recommendations in:
 	 * http://www.wisdom.weizmann.ac.il/~itsik/RC4/Papers/Rc4_ksa.ps
 	 */
 	for (i = 0; i < 256; i++)
-		(void)arc4_getbyte(as);
+		(void)arc4_getbyte();
 	arc4_count = 1600000;
 }
 
 static inline u_int8_t
-arc4_getbyte(struct arc4_stream *as)
+arc4_getbyte(void)
 {
 	u_int8_t si, sj;
 
-	as->i = (as->i + 1);
-	si = as->s[as->i];
-	as->j = (as->j + si);
-	sj = as->s[as->j];
-	as->s[as->i] = sj;
-	as->s[as->j] = si;
-	return (as->s[(si + sj) & 0xff]);
+	rs.i = (rs.i + 1);
+	si = rs.s[rs.i];
+	rs.j = (rs.j + si);
+	sj = rs.s[rs.j];
+	rs.s[rs.i] = sj;
+	rs.s[rs.j] = si;
+	return (rs.s[(si + sj) & 0xff]);
 }
 
 u_int8_t
 __arc4_getbyte(void)
 {
+	u_int8_t val;
+
+	_ARC4_LOCK();
 	if (--arc4_count == 0 || !rs_initialized)
-		arc4random_stir();
-	return arc4_getbyte(&rs);
+		arc4_stir();
+	val = arc4_getbyte();
+	_ARC4_UNLOCK();
+	return val;
 }
 
 static inline u_int32_t
-arc4_getword(struct arc4_stream *as)
+arc4_getword(void)
 {
 	u_int32_t val;
-	val = arc4_getbyte(as) << 24;
-	val |= arc4_getbyte(as) << 16;
-	val |= arc4_getbyte(as) << 8;
-	val |= arc4_getbyte(as);
+	val = arc4_getbyte() << 24;
+	val |= arc4_getbyte() << 16;
+	val |= arc4_getbyte() << 8;
+	val |= arc4_getbyte();
 	return val;
 }
 
 void
 arc4random_stir(void)
 {
-	if (!rs_initialized) {
-		arc4_init(&rs);
-		rs_initialized = 1;
-	}
-	arc4_stir(&rs);
+	_ARC4_LOCK();
+	arc4_stir();
+	_ARC4_UNLOCK();
 }
 
 void
 arc4random_addrandom(u_char *dat, int datlen)
 {
+	_ARC4_LOCK();
 	if (!rs_initialized)
-		arc4random_stir();
-	arc4_addrandom(&rs, dat, datlen);
+		arc4_stir();
+	arc4_addrandom(dat, datlen);
+	_ARC4_UNLOCK();
 }
 
 u_int32_t
 arc4random(void)
 {
+	u_int32_t val;
+	_ARC4_LOCK();
 	arc4_count -= 4;
 	if (arc4_count <= 0 || !rs_initialized || arc4_stir_pid != getpid())
-		arc4random_stir();
-	return arc4_getword(&rs);
+		arc4_stir();
+	val = arc4_getword();
+	_ARC4_UNLOCK();
+	return val;
 }
 
 #if 0
diff --git a/lib/libc/include/thread_private.h b/lib/libc/include/thread_private.h
index 146f0b0a015..f55880f7bae 100644
--- a/lib/libc/include/thread_private.h
+++ b/lib/libc/include/thread_private.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: thread_private.h,v 1.21 2007/11/19 02:54:19 kurt Exp $ */
+/* $OpenBSD: thread_private.h,v 1.22 2008/01/01 00:43:39 kurt Exp $ */
 
 /* PUBLIC DOMAIN: No Rights Reserved. Marco S Hyman <marc@snafu.org> */
 
@@ -150,4 +150,16 @@ void	_thread_atexit_unlock(void);
 						_thread_atexit_unlock();\
 				} while (0)
 
+void	_thread_arc4_lock(void);
+void	_thread_arc4_unlock(void);
+
+#define _ARC4_LOCK()		do {					\
+					if (__isthreaded)		\
+						_thread_arc4_lock();	\
+				} while (0)
+#define _ARC4_UNLOCK()		do {					\
+					if (__isthreaded)		\
+						_thread_arc4_unlock();\
+				} while (0)
+
 #endif /* _THREAD_PRIVATE_H_ */
diff --git a/lib/libc/shlib_version b/lib/libc/shlib_version
index d5194cd8c2f..3c07d167bfa 100644
--- a/lib/libc/shlib_version
+++ b/lib/libc/shlib_version
@@ -1,4 +1,4 @@
 major=42
-minor=0
+minor=1
 # note: If changes were made to include/thread_private.h or if system
 # calls were added/changed then libpthread must also be updated.
diff --git a/lib/libc/thread/unithread_malloc_lock.c b/lib/libc/thread/unithread_malloc_lock.c
index f7231915d6f..ca5081ba780 100644
--- a/lib/libc/thread/unithread_malloc_lock.c
+++ b/lib/libc/thread/unithread_malloc_lock.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: unithread_malloc_lock.c,v 1.6 2006/02/22 07:16:32 otto Exp $	*/
+/*	$OpenBSD: unithread_malloc_lock.c,v 1.7 2008/01/01 00:43:39 kurt Exp $	*/
 
 #include <sys/time.h>
 #include "thread_private.h"
@@ -17,6 +17,12 @@ WEAK_PROTOTYPE(_thread_atexit_unlock);
 WEAK_ALIAS(_thread_atexit_lock);
 WEAK_ALIAS(_thread_atexit_unlock);
 
+WEAK_PROTOTYPE(_thread_arc4_lock);
+WEAK_PROTOTYPE(_thread_arc4_unlock);
+
+WEAK_ALIAS(_thread_arc4_lock);
+WEAK_ALIAS(_thread_arc4_unlock);
+
 void
 WEAK_NAME(_thread_malloc_lock)(void)
 {
@@ -46,3 +52,15 @@ WEAK_NAME(_thread_atexit_unlock)(void)
 {
 	return;
 }
+
+void
+WEAK_NAME(_thread_arc4_lock)(void)
+{
+	return;
+}
+
+void
+WEAK_NAME(_thread_arc4_unlock)(void)
+{
+	return;
+}
diff --git a/lib/libpthread/shlib_version b/lib/libpthread/shlib_version
index d0f0988b418..00604e64e7d 100644
--- a/lib/libpthread/shlib_version
+++ b/lib/libpthread/shlib_version
@@ -1,2 +1,2 @@
 major=8
-minor=0
+minor=1
diff --git a/lib/libpthread/thread/thread_malloc_lock.c b/lib/libpthread/thread/thread_malloc_lock.c
index 6e8b96bb656..6deebb53f66 100644
--- a/lib/libpthread/thread/thread_malloc_lock.c
+++ b/lib/libpthread/thread/thread_malloc_lock.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: thread_malloc_lock.c,v 1.5 2006/02/22 07:16:32 otto Exp $ */
+/* $OpenBSD: thread_malloc_lock.c,v 1.6 2008/01/01 00:43:39 kurt Exp $ */
 /* Public Domain <marc@snafu.org> */
 
 #include <pthread.h>
@@ -6,6 +6,7 @@
 
 static spinlock_t malloc_lock = _SPINLOCK_INITIALIZER;
 static spinlock_t atexit_lock = _SPINLOCK_INITIALIZER;
+static spinlock_t arc4_lock = _SPINLOCK_INITIALIZER;
 
 void
 _thread_malloc_lock()
@@ -35,3 +36,15 @@ _thread_atexit_unlock()
 {
 	_SPINUNLOCK(&atexit_lock);
 }
+
+void
+_thread_arc4_lock()
+{
+	_SPINLOCK(&arc4_lock);
+}
+
+void
+_thread_arc4_unlock()
+{
+	_SPINUNLOCK(&arc4_lock);
+}
diff --git a/lib/libpthread/uthread/uthread_init.c b/lib/libpthread/uthread/uthread_init.c
index d48e1173566..36559a5ae34 100644
--- a/lib/libpthread/uthread/uthread_init.c
+++ b/lib/libpthread/uthread/uthread_init.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uthread_init.c,v 1.40 2007/07/20 22:34:40 kettenis Exp $	*/
+/*	$OpenBSD: uthread_init.c,v 1.41 2008/01/01 00:43:39 kurt Exp $	*/
 /*
  * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
  * All rights reserved.
@@ -135,6 +135,8 @@ static void *references[] = {
 	&_thread_malloc_unlock,
 	&_thread_atexit_lock,
 	&_thread_atexit_unlock,
+	&_thread_arc4_lock,
+	&_thread_arc4_unlock,
 	&_thread_tag_lock,
 	&_thread_tag_unlock,
 	&_thread_tag_storage,
diff --git a/lib/librthread/rthread_libc.c b/lib/librthread/rthread_libc.c
index bf3c057d874..da0d92f8da5 100644
--- a/lib/librthread/rthread_libc.c
+++ b/lib/librthread/rthread_libc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: rthread_libc.c,v 1.4 2007/06/05 18:11:49 kurt Exp $ */
+/* $OpenBSD: rthread_libc.c,v 1.5 2008/01/01 00:43:39 kurt Exp $ */
 /* $snafu: libc_tag.c,v 1.4 2004/11/30 07:00:06 marc Exp $ */
 
 /* PUBLIC DOMAIN: No Rights Reserved. Marco S Hyman <marc@snafu.org> */
@@ -175,6 +175,23 @@ _thread_malloc_init(void)
 {
 }
 
+/*
+ * arc4random lock
+ */
+static _spinlock_lock_t arc4_lock = _SPINLOCK_UNLOCKED;
+
+void
+_thread_arc4_lock(void)
+{
+	_spinlock(&arc4_lock);
+}
+
+void
+_thread_arc4_unlock(void)
+{
+	_spinunlock(&arc4_lock);
+}
+
 #if 0
 /*
  * miscellaneous libc exported symbols we want to override