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 89bd3a7..6f400f4 100644 (file)
--- 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 7b4b8db..112b3c6 100644 (file)
--- 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 e499a57..5d8570c 100644 (file)
--- 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)
 {