[src/trunk]: src/lib/libc/arch/x86_64/sys Restore RSP from mcontext

[kamil <kamil%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/0662f842c1b3
branches:  trunk
changeset: 956027:0662f842c1b3
user:      kamil <kamil%NetBSD.org@localhost>
date:      Mon Oct 19 11:29:26 2020 +0000

description:
Restore RSP from mcontext

Fixes unwinding of multiple frames without base pointer.

Patch by: Nikhil Benesch via PR lib/55719

diffstat:

 lib/libc/arch/x86_64/sys/__sigtramp2.S |  4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diffs (18 lines):

diff -r dc423d4f6c59 -r 0662f842c1b3 lib/libc/arch/x86_64/sys/__sigtramp2.S
--- a/lib/libc/arch/x86_64/sys/__sigtramp2.S    Mon Oct 19 10:28:47 2020 +0000
+++ b/lib/libc/arch/x86_64/sys/__sigtramp2.S    Mon Oct 19 11:29:26 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: __sigtramp2.S,v 1.8 2020/10/12 17:55:54 kamil Exp $    */
+/*     $NetBSD: __sigtramp2.S,v 1.9 2020/10/19 11:29:26 kamil Exp $    */
 
 /*
  * Copyright (c) 2001 Wasabi Systems, Inc.
@@ -58,7 +58,7 @@
        .cfi_offset rsi, UC_GREGS_RSI
        .cfi_offset rdi, UC_GREGS_RDI
        .cfi_offset rbp, UC_GREGS_RBP
-       /* The unwinder will use the CFA to restore RSP. */
+       .cfi_offset rsp, UC_GREGS_RSP
        .cfi_offset r8,  UC_GREGS_R8
        .cfi_offset r9,  UC_GREGS_R9
        .cfi_offset r10, UC_GREGS_R10