Module Name: src
Committed By: tsutsui
Date: Sat Apr 24 16:14:08 UTC 2021
Modified Files:
src/sys/arch/m68k/m68k: sig_machdep.c
Log Message:
Restore comments for f_stackadj and reenter_syscall().
Taken from sys/compat/linux/arch/m68k/linux_machdep.c which was
originally implemented to use reenter_syscall() for sigreturn of
Linux binaries.
To generate a diff of this commit:
cvs rdiff -u -r1.50 -r1.51 src/sys/arch/m68k/m68k/sig_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/m68k/m68k/sig_machdep.c
diff -u src/sys/arch/m68k/m68k/sig_machdep.c:1.50 src/sys/arch/m68k/m68k/sig_machdep.c:1.51
--- src/sys/arch/m68k/m68k/sig_machdep.c:1.50 Tue Nov 27 14:09:54 2018
+++ src/sys/arch/m68k/m68k/sig_machdep.c Sat Apr 24 16:14:08 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: sig_machdep.c,v 1.50 2018/11/27 14:09:54 maxv Exp $ */
+/* $NetBSD: sig_machdep.c,v 1.51 2021/04/24 16:14:08 tsutsui Exp $ */
/*
* Copyright (c) 1988 University of Utah.
@@ -40,7 +40,7 @@
#include "opt_m68k_arch.h"
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sig_machdep.c,v 1.50 2018/11/27 14:09:54 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sig_machdep.c,v 1.51 2021/04/24 16:14:08 tsutsui Exp $");
#define __M68K_SIGNAL_PRIVATE
@@ -236,7 +236,16 @@ cpu_getmcontext(struct lwp *l, mcontext_
(void)memcpy(&mcp->__mc_pad.__mc_frame.__mcf_exframe,
&frame->F_u, (size_t)exframesize[format]);
- /* Leave indicators, see above. */
+ /*
+ * Leave indicators that we need to clean up the kernel
+ * stack. We do this by setting the "pad word" above the
+ * hardware stack frame to the amount the stack must be
+ * adjusted by.
+ *
+ * N.B. we increment rather than just set f_stackadj in
+ * case we are called from syscall when processing a
+ * sigreturn. In that case, f_stackadj may be non-zero.
+ */
frame->f_stackadj += exframesize[format];
frame->f_format = frame->f_vector = 0;
}
@@ -303,16 +312,26 @@ cpu_setmcontext(struct lwp *l, const mco
return (EINVAL);
if (frame->f_stackadj == 0) {
+ /*
+ * Extra stack space is required but not allocated.
+ * Allocate and re-enter syscall().
+ */
reenter_syscall(frame, sz);
/* NOTREACHED */
}
#ifdef DIAGNOSTIC
+ /* reenter_syscall() should adjust stack for the extra frame. */
if (sz != frame->f_stackadj)
panic("cpu_setmcontext: %d != %d",
sz, frame->f_stackadj);
#endif
+ /*
+ * Restore long stack frames. Note that we do not copy
+ * back the saved SR or PC, they were picked up below from
+ * the sigcontext structure.
+ */
frame->f_format = format;
frame->f_vector = mcp->__mc_pad.__mc_frame.__mcf_vector;
(void)memcpy(&frame->F_u,
