Module Name: src
Committed By: thorpej
Date: Tue Jul 6 12:20:52 UTC 2021
Modified Files:
src/sys/arch/alpha/alpha: vm_machdep.c
src/sys/arch/alpha/include: param.h
Log Message:
- Define STACK_ALIGNBYTES to override the default and ensure that
stacks are 16-byte aligned, an assumption made by the compiler
and recommended by the Alpha Architecture Handbook.
- cpu_lwp_fork(): Ensure 16-byte stack alignment if the caller specified
one.
Addresses root casue of PR port-alpha/54307 and PR toolchain/56153.
Many thanks to rin@ for performing the root cause analysis and testing
changes.
To generate a diff of this commit:
cvs rdiff -u -r1.119 -r1.120 src/sys/arch/alpha/alpha/vm_machdep.c
cvs rdiff -u -r1.48 -r1.49 src/sys/arch/alpha/include/param.h
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/alpha/alpha/vm_machdep.c
diff -u src/sys/arch/alpha/alpha/vm_machdep.c:1.119 src/sys/arch/alpha/alpha/vm_machdep.c:1.120
--- src/sys/arch/alpha/alpha/vm_machdep.c:1.119 Sun Jul 4 22:42:35 2021
+++ src/sys/arch/alpha/alpha/vm_machdep.c Tue Jul 6 12:20:52 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: vm_machdep.c,v 1.119 2021/07/04 22:42:35 thorpej Exp $ */
+/* $NetBSD: vm_machdep.c,v 1.120 2021/07/06 12:20:52 thorpej Exp $ */
/*
* Copyright (c) 1994, 1995, 1996 Carnegie-Mellon University.
@@ -29,7 +29,7 @@
#include <sys/cdefs.h> /* RCS ID & Copyright macro defns */
-__KERNEL_RCSID(0, "$NetBSD: vm_machdep.c,v 1.119 2021/07/04 22:42:35 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vm_machdep.c,v 1.120 2021/07/06 12:20:52 thorpej Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -116,10 +116,12 @@ cpu_lwp_fork(struct lwp *l1, struct lwp
* Floating point state from the FP chip has already been saved.
*/
*pcb2 = *pcb1;
- if (stack != NULL)
- pcb2->pcb_hw.apcb_usp = (u_long)stack + stacksize;
- else
+ if (stack != NULL) {
+ pcb2->pcb_hw.apcb_usp =
+ ((u_long)stack + stacksize) & ~((u_long)STACK_ALIGNBYTES);
+ } else {
pcb2->pcb_hw.apcb_usp = alpha_pal_rdusp();
+ }
/*
* Put l2 on the kernel's page tables until its first trip
Index: src/sys/arch/alpha/include/param.h
diff -u src/sys/arch/alpha/include/param.h:1.48 src/sys/arch/alpha/include/param.h:1.49
--- src/sys/arch/alpha/include/param.h:1.48 Mon May 31 14:38:55 2021
+++ src/sys/arch/alpha/include/param.h Tue Jul 6 12:20:52 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: param.h,v 1.48 2021/05/31 14:38:55 simonb Exp $ */
+/* $NetBSD: param.h,v 1.49 2021/07/06 12:20:52 thorpej Exp $ */
/*
* Copyright (c) 1988 University of Utah.
@@ -57,6 +57,12 @@
#define ALPHA_PGSHIFT 13
#endif
+/*
+ * Compiler assumes 16 byte stack alignment, per recommendation of
+ * Alpha Architecture Handbook.
+ */
+#define STACK_ALIGNBYTES (16 - 1)
+
#define NBPG (1 << ALPHA_PGSHIFT) /* bytes/page */
#define PGOFSET (NBPG-1) /* byte off. into pg */
#define PGSHIFT ALPHA_PGSHIFT /* LOG2(NBPG) */
