CVS commit: [netbsd-9] src/sys/arch/aarch64/aarch64

[Martin Husemann]

Module Name:    src
Committed By:   martin
Date:           Fri Jan  1 13:06:39 UTC 2021

Modified Files:
        src/sys/arch/aarch64/aarch64 [netbsd-9]: vm_machdep.c

Log Message:
Pull up following revision(s) (requested by rin in ticket #1174):

        sys/arch/aarch64/aarch64/vm_machdep.c: revision 1.9 (patch)

Fix clone(2) for COMPAT_NETBSD32.
(1) Set r13 (sp for arm32 processes) appropriately when stack is
     specified to fork1().
(2) For arm32 processes, align stack to 8-byte boundary, instead of
     16-byte for native aarch64 processes, to match our 32-bit ABI:
https://nxr.netbsd.org/xref/src/sys/arch/arm/arm32/vm_machdep.c#150

Note that sp alignment checking is disabled in aarch32 mode, and
this works fine with AARCH64_EL0_STACK_ALIGNMENT_CHECK option.

OK ryo


To generate a diff of this commit:
cvs rdiff -u -r1.5 -r1.5.4.1 src/sys/arch/aarch64/aarch64/vm_machdep.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.


Modified files:

Index: src/sys/arch/aarch64/aarch64/vm_machdep.c
diff -u src/sys/arch/aarch64/aarch64/vm_machdep.c:1.5 src/sys/arch/aarch64/aarch64/vm_machdep.c:1.5.4.1
--- src/sys/arch/aarch64/aarch64/vm_machdep.c:1.5	Thu Dec 27 09:55:27 2018
+++ src/sys/arch/aarch64/aarch64/vm_machdep.c	Fri Jan  1 13:06:39 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: vm_machdep.c,v 1.5 2018/12/27 09:55:27 mrg Exp $ */
+/* $NetBSD: vm_machdep.c,v 1.5.4.1 2021/01/01 13:06:39 martin Exp $ */
 
 /*-
  * Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -29,8 +29,10 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include "opt_compat_netbsd32.h"
+
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vm_machdep.c,v 1.5 2018/12/27 09:55:27 mrg Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vm_machdep.c,v 1.5.4.1 2021/01/01 13:06:39 martin Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -116,11 +118,19 @@ cpu_lwp_fork(struct lwp *l1, struct lwp 
 	*utf = *l1->l_md.md_utf;
 
 	/*
-	 * If specified, give the child a different stack
-	 * (make sure it's 16-byte aligned).
+	 * If specified, give the child a different stack (make sure it's
+	 * 16- or 8-byte aligned for 64- or 32-bit processes, respectively).
 	 */
-	if (stack != NULL)
-		utf->tf_sp = ((vaddr_t)(stack) + stacksize) & -16;
+	if (stack != NULL) {
+		utf->tf_sp = (vaddr_t)(stack) + stacksize;
+#ifdef COMPAT_NETBSD32
+		if (__predict_false(l2->l_proc->p_flag & PK_32)) {
+			utf->tf_sp &= -8;
+			utf->tf_reg[13] = utf->tf_sp;
+		} else
+#endif
+			utf->tf_sp &= -16;
+	}
 
 	/* build a new switchframe */
 	struct trapframe * const ktf = utf - 1;