Change _rs_allocate so it can combine the two regions (rs and rsx)

into one if a system has an awesome getentropy().  In that case it
is valid to totally throw away the rsx state in the child.  If the
getentropy() is not very good and has a lazy reseed operation, this
combining is a bad idea, and the reseed should probably continue to
use the "something old, something new" mix.  _rs_allocate() can
accomodate either method, but not on the fly.
ok matthew

src/lib/libc/crypt/arc4random.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: arc4random.c,v 1.47 2014/07/18 02:05:55 deraadt Exp $	*/
+/*	$OpenBSD: arc4random.c,v 1.48 2014/07/19 00:08:41 deraadt Exp $	*/
 
 /*
  * Copyright (c) 1996, David Mazieres <dm@uun.org>
@@ -57,17 +57,16 @@ static struct _rs {
 	size_t		rs_count;	/* bytes till reseed */
 } *rs;
 
-static inline void *_rs_allocate(size_t len);
-static inline void _rs_forkdetect(void);
-static inline void _rs_forkdetectsetup(struct _rs *buf, size_t len);
-#include "arc4random.h"
-
-/* Preserved in fork children. */
-static struct {
+/* Maybe be preserved in fork children, if _rs_allocate() decides. */
+static struct _rsx {
 	chacha_ctx	rs_chacha;	/* chacha context for random keystream */
 	u_char		rs_buf[RSBUFSZ];	/* keystream blocks */
 } *rsx;
 
+static inline int _rs_allocate(struct _rs **, struct _rsx **);
+static inline void _rs_forkdetect(void);
+#include "arc4random.h"
+
 static inline void _rs_rekey(u_char *dat, size_t datlen);
 
 static inline void
@@ -77,12 +76,7 @@ _rs_init(u_char *buf, size_t n)
 		return;
 
 	if (rs == NULL) {
-		if ((rs = _rs_allocate(sizeof(*rs))) == NULL)
-			abort();
-		_rs_forkdetectsetup(rs, sizeof(*rs));
-	}
-	if (rsx == NULL) {
-		if ((rsx = _rs_allocate(sizeof(*rsx))) == NULL)
+		if (_rs_allocate(&rs, &rsx) == -1)
 			abort();
 	}
 

src/lib/libc/crypt/arc4random.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: arc4random.h,v 1.1 2014/07/18 02:05:55 deraadt Exp $	*/
+/*	$OpenBSD: arc4random.h,v 1.2 2014/07/19 00:08:41 deraadt Exp $	*/
 
 /*
  * Copyright (c) 1996, David Mazieres <dm@uun.org>
@@ -22,25 +22,28 @@
  * Stub functions for portability.
  */
 
-static inline void *
-_rs_allocate(size_t len)
+static inline int
+_rs_allocate(struct _rs **rsp, struct _rsx **rsxp)
 {
-	void *p;
+	struct {
+		struct _rs rs;
+		struct _rsx rsx;
+	} *p;
 
-	if ((p = mmap(NULL, sizeof(*rs), PROT_READ|PROT_WRITE,
+	if ((p = mmap(NULL, sizeof(*p), PROT_READ|PROT_WRITE,
 	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
-		return (NULL);
-	return (p);
-}
+		return (-1);
+	if (minherit(p, sizeof(*p), MAP_INHERIT_ZERO) == -1) {
+		munmap(p, sizeof(*p));
+		return (-1);
+	}
 
-static inline void
-_rs_forkdetect(void)
-{
+	*rsp = &p->rs;
+	*rsxp = &p->rsx;
+	return (0);
 }
 
 static inline void
-_rs_forkdetectsetup(struct _rs *rs, size_t len)
+_rs_forkdetect(void)
 {
-	if (minherit(rs, len, MAP_INHERIT_ZERO) == -1)
-		abort();
 }

src/lib/libcrypto/arc4random/arc4random_linux.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: arc4random_linux.h,v 1.2 2014/07/18 21:40:54 matthew Exp $	*/
+/*	$OpenBSD: arc4random_linux.h,v 1.3 2014/07/19 00:08:43 deraadt Exp $	*/
 
 /*
  * Copyright (c) 1996, David Mazieres <dm@uun.org>
@@ -22,15 +22,21 @@
  * Stub functions for portability.
  */
 
-static inline void *
-_rs_allocate(size_t len)
+static inline int
+_rs_allocate(struct _rs **rsp, struct _rsx **rsxp)
 {
-	void *p;
-
-	if ((p = mmap(NULL, len, PROT_READ|PROT_WRITE,
+	if ((*rsp = mmap(NULL, sizeof(**rsp), PROT_READ|PROT_WRITE,
 	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
-		return (NULL);
-	return (p);
+		return (-1);
+
+	if ((*rsxp = mmap(NULL, sizeof(**rsxp) PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
+		munmap(*rsxp, sizeof(**rsxp);
+		return (-1);
+	}
+
+	_ARC4_ATFORK(_rs_forkhandler);
+	return (0);
 }
 
 static volatile sig_atomic_t _rs_forked;
@@ -54,10 +60,3 @@ _rs_forkdetect(void)
 			memset(rs, 0, sizeof(*rs));
 	}
 }
-
-static inline void
-_rs_forkdetectsetup(struct _rs *rs, size_t len)
-{
-	_ARC4_ATFORK(_rs_forkhandler);
-}
-

src/lib/libcrypto/arc4random/arc4random_osx.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: arc4random_osx.h,v 1.2 2014/07/18 21:40:54 matthew Exp $	*/
+/*	$OpenBSD: arc4random_osx.h,v 1.3 2014/07/19 00:08:43 deraadt Exp $	*/
 
 /*
  * Copyright (c) 1996, David Mazieres <dm@uun.org>
@@ -22,15 +22,21 @@
  * Stub functions for portability.
  */
 
-static inline void *
-_rs_allocate(size_t len)
+static inline int
+_rs_allocate(struct _rs **rsp, struct _rsx **rsxp)
 {
-	void *p;
-
-	if ((p = mmap(NULL, len, PROT_READ|PROT_WRITE,
+	if ((*rsp = mmap(NULL, sizeof(**rsp), PROT_READ|PROT_WRITE,
 	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
-		return (NULL);
-	return (p);
+		return (-1);
+
+	if ((*rsxp = mmap(NULL, sizeof(**rsxp) PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
+		munmap(*rsxp, sizeof(**rsxp);
+		return (-1);
+	}
+
+	_ARC4_ATFORK(_rs_forkhandler);
+	return (0);
 }
 
 static volatile sig_atomic_t _rs_forked;
@@ -54,10 +60,3 @@ _rs_forkdetect(void)
 			memset(rs, 0, sizeof(*rs));
 	}
 }
-
-static inline void
-_rs_forkdetectsetup(struct _rs *rs, size_t len)
-{
-	_ARC4_ATFORK(_rs_forkhandler);
-}
-

src/lib/libcrypto/arc4random/arc4random_solaris.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: arc4random_solaris.h,v 1.2 2014/07/18 21:40:54 matthew Exp $	*/
+/*	$OpenBSD: arc4random_solaris.h,v 1.3 2014/07/19 00:08:43 deraadt Exp $	*/
 
 /*
  * Copyright (c) 1996, David Mazieres <dm@uun.org>
@@ -22,15 +22,21 @@
  * Stub functions for portability.
  */
 
-static inline void *
-_rs_allocate(size_t len)
+static inline int
+_rs_allocate(struct _rs **rsp, struct _rsx **rsxp)
 {
-	void *p;
-
-	if ((p = mmap(NULL, len, PROT_READ|PROT_WRITE,
+	if ((*rsp = mmap(NULL, sizeof(**rsp), PROT_READ|PROT_WRITE,
 	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
-		return (NULL);
-	return (p);
+		return (-1);
+
+	if ((*rsxp = mmap(NULL, sizeof(**rsxp) PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
+		munmap(*rsxp, sizeof(**rsxp);
+		return (-1);
+	}
+
+	_ARC4_ATFORK(_rs_forkhandler);
+	return (0);
 }
 
 static volatile sig_atomic_t _rs_forked;
@@ -54,10 +60,3 @@ _rs_forkdetect(void)
 			memset(rs, 0, sizeof(*rs));
 	}
 }
-
-static inline void
-_rs_forkdetectsetup(struct _rs *rs, size_t len)
-{
-	_ARC4_ATFORK(_rs_forkhandler);
-}
-

src/lib/libcrypto/arc4random/arc4random_win.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: arc4random_win.h,v 1.1 2014/07/18 02:05:55 deraadt Exp $	*/
+/*	$OpenBSD: arc4random_win.h,v 1.2 2014/07/19 00:08:43 deraadt Exp $	*/
 
 /*
  * Copyright (c) 1996, David Mazieres <dm@uun.org>
@@ -22,10 +22,19 @@
  * Stub functions for portability.
  */
 
-static inline void *
-_rs_allocate(size_t len)
+static inline int
+_rs_allocate(struct _rs **rsp, struct _rsx **rsxp)
 {
-	return calloc(1, sizeof(*rs));
+	*rsp = calloc(1, sizeof(**rsp));
+	if (*rsp == NULL)
+		return (-1);
+
+	*rsxp = calloc(1, sizeof(**rsxp));
+	if (*rsxp == NULL) {
+		free(*rsp);
+		return (-1);
+	}
+	return (0);
 }
 
 static inline void
@@ -37,9 +46,3 @@ static inline void
 _rs_forkdetect(void)
 {
 }
-
-static inline void
-_rs_forkdetectsetup(struct _rs *rs, size_t len)
-{
-}
-

src/lib/libcrypto/crypto/arc4random_linux.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: arc4random_linux.h,v 1.2 2014/07/18 21:40:54 matthew Exp $	*/
+/*	$OpenBSD: arc4random_linux.h,v 1.3 2014/07/19 00:08:43 deraadt Exp $	*/
 
 /*
  * Copyright (c) 1996, David Mazieres <dm@uun.org>
@@ -22,15 +22,21 @@
  * Stub functions for portability.
  */
 
-static inline void *
-_rs_allocate(size_t len)
+static inline int
+_rs_allocate(struct _rs **rsp, struct _rsx **rsxp)
 {
-	void *p;
-
-	if ((p = mmap(NULL, len, PROT_READ|PROT_WRITE,
+	if ((*rsp = mmap(NULL, sizeof(**rsp), PROT_READ|PROT_WRITE,
 	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
-		return (NULL);
-	return (p);
+		return (-1);
+
+	if ((*rsxp = mmap(NULL, sizeof(**rsxp) PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
+		munmap(*rsxp, sizeof(**rsxp);
+		return (-1);
+	}
+
+	_ARC4_ATFORK(_rs_forkhandler);
+	return (0);
 }
 
 static volatile sig_atomic_t _rs_forked;
@@ -54,10 +60,3 @@ _rs_forkdetect(void)
 			memset(rs, 0, sizeof(*rs));
 	}
 }
-
-static inline void
-_rs_forkdetectsetup(struct _rs *rs, size_t len)
-{
-	_ARC4_ATFORK(_rs_forkhandler);
-}
-

src/lib/libcrypto/crypto/arc4random_osx.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: arc4random_osx.h,v 1.2 2014/07/18 21:40:54 matthew Exp $	*/
+/*	$OpenBSD: arc4random_osx.h,v 1.3 2014/07/19 00:08:43 deraadt Exp $	*/
 
 /*
  * Copyright (c) 1996, David Mazieres <dm@uun.org>
@@ -22,15 +22,21 @@
  * Stub functions for portability.
  */
 
-static inline void *
-_rs_allocate(size_t len)
+static inline int
+_rs_allocate(struct _rs **rsp, struct _rsx **rsxp)
 {
-	void *p;
-
-	if ((p = mmap(NULL, len, PROT_READ|PROT_WRITE,
+	if ((*rsp = mmap(NULL, sizeof(**rsp), PROT_READ|PROT_WRITE,
 	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
-		return (NULL);
-	return (p);
+		return (-1);
+
+	if ((*rsxp = mmap(NULL, sizeof(**rsxp) PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
+		munmap(*rsxp, sizeof(**rsxp);
+		return (-1);
+	}
+
+	_ARC4_ATFORK(_rs_forkhandler);
+	return (0);
 }
 
 static volatile sig_atomic_t _rs_forked;
@@ -54,10 +60,3 @@ _rs_forkdetect(void)
 			memset(rs, 0, sizeof(*rs));
 	}
 }
-
-static inline void
-_rs_forkdetectsetup(struct _rs *rs, size_t len)
-{
-	_ARC4_ATFORK(_rs_forkhandler);
-}
-

src/lib/libcrypto/crypto/arc4random_solaris.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: arc4random_solaris.h,v 1.2 2014/07/18 21:40:54 matthew Exp $	*/
+/*	$OpenBSD: arc4random_solaris.h,v 1.3 2014/07/19 00:08:43 deraadt Exp $	*/
 
 /*
  * Copyright (c) 1996, David Mazieres <dm@uun.org>
@@ -22,15 +22,21 @@
  * Stub functions for portability.
  */
 
-static inline void *
-_rs_allocate(size_t len)
+static inline int
+_rs_allocate(struct _rs **rsp, struct _rsx **rsxp)
 {
-	void *p;
-
-	if ((p = mmap(NULL, len, PROT_READ|PROT_WRITE,
+	if ((*rsp = mmap(NULL, sizeof(**rsp), PROT_READ|PROT_WRITE,
 	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
-		return (NULL);
-	return (p);
+		return (-1);
+
+	if ((*rsxp = mmap(NULL, sizeof(**rsxp) PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
+		munmap(*rsxp, sizeof(**rsxp);
+		return (-1);
+	}
+
+	_ARC4_ATFORK(_rs_forkhandler);
+	return (0);
 }
 
 static volatile sig_atomic_t _rs_forked;
@@ -54,10 +60,3 @@ _rs_forkdetect(void)
 			memset(rs, 0, sizeof(*rs));
 	}
 }
-
-static inline void
-_rs_forkdetectsetup(struct _rs *rs, size_t len)
-{
-	_ARC4_ATFORK(_rs_forkhandler);
-}
-

src/lib/libcrypto/crypto/arc4random_win.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: arc4random_win.h,v 1.1 2014/07/18 02:05:55 deraadt Exp $	*/
+/*	$OpenBSD: arc4random_win.h,v 1.2 2014/07/19 00:08:43 deraadt Exp $	*/
 
 /*
  * Copyright (c) 1996, David Mazieres <dm@uun.org>
@@ -22,10 +22,19 @@
  * Stub functions for portability.
  */
 
-static inline void *
-_rs_allocate(size_t len)
+static inline int
+_rs_allocate(struct _rs **rsp, struct _rsx **rsxp)
 {
-	return calloc(1, sizeof(*rs));
+	*rsp = calloc(1, sizeof(**rsp));
+	if (*rsp == NULL)
+		return (-1);
+
+	*rsxp = calloc(1, sizeof(**rsxp));
+	if (*rsxp == NULL) {
+		free(*rsp);
+		return (-1);
+	}
+	return (0);
 }
 
 static inline void
@@ -37,9 +46,3 @@ static inline void
 _rs_forkdetect(void)
 {
 }
-
-static inline void
-_rs_forkdetectsetup(struct _rs *rs, size_t len)
-{
-}
-