From b8ebf36b18949f1b90382651b04a3897e8a5dec8 Mon Sep 17 00:00:00 2001
From: Luke Gorrie <luke@snabb.co>
Date: Wed, 8 Nov 2017 07:31:36 +0000
Subject: [PATCH 1/2] lj_record.c: Record IFUNC/IFUNCV the same as FUNC/FUNCV

Record calls to blacklisted functions the same way as calls to
uncompiled functions. This allows for the possibility that a
blacklisted function can be successfully recorded as part of a larger
trace.

This is specifically intended to fix the problem where a tiny utility
function somewhere, such as `ntohs`, is not able to be compiled in
isolation for some reason and that ends up preventing all of its
callers from compiling too.

This has tended to happen for obscure reasons like "the utility
function ends with a tail-call to a C library routine" and with this
patch we should not need to worry about such minutiae anymore. (We
should be able to retire the "wrap in parenthesis to prevent a
tailcall" trick that some people are familiar with.)

More background:

- How the trace recorder treats function calls: raptorjit/raptorjit#118.
- Why this can be a problem: raptorjit/raptorjit#119.
- More on this specific solution: raptorjit/raptorjit#120.
---
 lib/luajit/src/lj_record.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/luajit/src/lj_record.c b/lib/luajit/src/lj_record.c
index 532e7ffda7..1190bb2809 100644
--- a/lib/luajit/src/lj_record.c
+++ b/lib/luajit/src/lj_record.c
@@ -2332,8 +2332,6 @@ void lj_record_ins(jit_State *J)
   case BC_IFORL:
   case BC_IITERL:
   case BC_ILOOP:
-  case BC_IFUNCF:
-  case BC_IFUNCV:
     lj_trace_err(J, LJ_TRERR_BLACKL);
     break;
 
@@ -2345,6 +2343,7 @@ void lj_record_ins(jit_State *J)
   /* -- Function headers -------------------------------------------------- */
 
   case BC_FUNCF:
+  case BC_IFUNCF:
     rec_func_lua(J);
     break;
   case BC_JFUNCF:
@@ -2352,6 +2351,7 @@ void lj_record_ins(jit_State *J)
     break;
 
   case BC_FUNCV:
+  case BC_IFUNCV:
     rec_func_vararg(J);
     rec_func_lua(J);
     break;

From 84695bc8486409606d674a9a2ce755f78c45b0cb Mon Sep 17 00:00:00 2001
From: Andy Wingo <wingo@igalia.com>
Date: Mon, 14 May 2018 14:47:57 +0200
Subject: [PATCH 2/2] Update changelog for v3.1.10

---
 src/program/lwaftr/doc/CHANGELOG.md | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/program/lwaftr/doc/CHANGELOG.md b/src/program/lwaftr/doc/CHANGELOG.md
index 1b83637093..3c55a58ec7 100644
--- a/src/program/lwaftr/doc/CHANGELOG.md
+++ b/src/program/lwaftr/doc/CHANGELOG.md
@@ -1,5 +1,13 @@
 # Change Log
 
+## [3.1.10] - 2018-05-14
+
+* Apply hot-fix to LuaJIT to prevent blacklisted functions from
+  permanently preventing optimization, even after a JIT flush.  For more
+  details, see:
+
+    https://github.com/snabbco/snabb/pull/1244
+
 ## [3.1.9] - 2017-05-18
 
 * Add "snabb --version" command-line argument.