[src/trunk]: src/sys/lib/libkern revert rev 1.4 ("Add garbage instructions at...

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

details:   https://anonhg.NetBSD.org/src/rev/8b34874259af
branches:  trunk
changeset: 1027604:8b34874259af
user:      chs <chs%NetBSD.org@localhost>
date:      Mon Dec 13 01:33:32 2021 +0000

description:
revert rev 1.4 ("Add garbage instructions at end of kern_assert after vpanic.")

that change had no effect because vpanic() is marked __dead / noreturn
and thus the compiler would optimize away everything after a call to vpanic().
the original problem has now been fixed differently (but only for x86 so far).

diffstat:

 sys/lib/libkern/kern_assert.c |  11 +----------
 1 files changed, 1 insertions(+), 10 deletions(-)

diffs (23 lines):

diff -r e0fe801c7259 -r 8b34874259af sys/lib/libkern/kern_assert.c
--- a/sys/lib/libkern/kern_assert.c     Mon Dec 13 01:25:29 2021 +0000
+++ b/sys/lib/libkern/kern_assert.c     Mon Dec 13 01:33:32 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: kern_assert.c,v 1.4 2017/03/14 09:22:37 riastradh Exp $        */
+/*     $NetBSD: kern_assert.c,v 1.5 2021/12/13 01:33:32 chs Exp $      */
 
 /*
  * Copyright (c) 1996 Christopher G. Demetriou
@@ -50,13 +50,4 @@
        va_start(ap, fmt);
        vpanic(fmt, ap);
        va_end(ap);
-
-       /*
-        * Force instructions at the return address of vpanic before
-        * the next symbol, which otherwise the compiler may omit
-        * because vpanic is marked noreturn.  This prevents seeing
-        * whatever random symbol came after kern_assert in the linked
-        * kernel in stack traces for assertion failures.
-        */
-       asm volatile(".long 0");
 }