From: guenther <guenther@openbsd.org>
Date: Fri, 10 Dec 2021 05:34:42 +0000 (+0000)
Subject: Revert "kbind(2): disable system call if not initialized before
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=6ac18ccb9b6851970e60b23060d3f6908d265ecd;p=openbsd

Revert "kbind(2): disable system call if not initialized before
first __tfork(2)"

The immediate issue is that a process linked with -znow will still
perform lazy relocation on objects loaded with dlopen(), but there
are possibly other dark corners to plumb to find a better invariant.

Problem reported by thfr@
---

diff --git a/sys/kern/kern_fork.c b/sys/kern/kern_fork.c
index 89bd3a7e5a1..6f400f4e457 100644
--- a/sys/kern/kern_fork.c
+++ b/sys/kern/kern_fork.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_fork.c,v 1.237 2021/12/05 22:00:42 cheloha Exp $	*/
+/*	$OpenBSD: kern_fork.c,v 1.238 2021/12/10 05:34:42 guenther Exp $	*/
 /*	$NetBSD: kern_fork.c,v 1.29 1996/02/09 18:59:34 christos Exp $	*/
 
 /*
@@ -137,13 +137,6 @@ sys___tfork(struct proc *p, void *v, register_t *retval)
 		return EINVAL;
 #endif /* TCB_INVALID */
 
-	/*
-	 * kbind(2) can only be used if it is initialized before the
-	 * process goes multithreaded.
-	 */
-	if (p->p_p->ps_kbind_addr == 0)
-		p->p_p->ps_kbind_addr = BOGO_PC;
-
 	return thread_fork(p, param.tf_stack, param.tf_tcb, param.tf_tid,
 	    retval);
 }
diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index 7b4b8db6ee4..112b3c6647f 100644
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: proc.h,v 1.322 2021/12/09 00:26:10 guenther Exp $	*/
+/*	$OpenBSD: proc.h,v 1.323 2021/12/10 05:34:42 guenther Exp $	*/
 /*	$NetBSD: proc.h,v 1.44 1996/04/22 01:23:21 christos Exp $	*/
 
 /*-
@@ -234,10 +234,8 @@ struct process {
 	uint64_t ps_pledge;
 	uint64_t ps_execpledge;
 
-	int64_t ps_kbind_cookie;	/* [K] */
-	u_long  ps_kbind_addr;		/* [K] */
-/* an address that can't be in userspace or kernelspace */
-#define BOGO_PC	(u_long)-1
+	int64_t ps_kbind_cookie;
+	u_long  ps_kbind_addr;
 
 /* End area that is copied on creation. */
 #define ps_endcopy	ps_refcnt
diff --git a/sys/uvm/uvm_mmap.c b/sys/uvm/uvm_mmap.c
index e499a573a9a..5d8570c2c12 100644
--- a/sys/uvm/uvm_mmap.c
+++ b/sys/uvm/uvm_mmap.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_mmap.c,v 1.165 2021/12/05 22:00:42 cheloha Exp $	*/
+/*	$OpenBSD: uvm_mmap.c,v 1.166 2021/12/10 05:34:42 guenther Exp $	*/
 /*	$NetBSD: uvm_mmap.c,v 1.49 2001/02/18 21:19:08 chs Exp $	*/
 
 /*
@@ -1073,6 +1073,8 @@ uvm_mmapfile(vm_map_t map, vaddr_t *addr, vsize_t size, vm_prot_t prot,
 	return error;
 }
 
+/* an address that can't be in userspace or kernelspace */
+#define	BOGO_PC	(u_long)-1
 int
 sys_kbind(struct proc *p, void *v, register_t *retval)
 {