File bcc-bsc1065593-switch-to-mcjit.patch of Package bcc

Overview Repositories Revisions Requests Users Attributes Meta

File bcc-bsc1065593-switch-to-mcjit.patch of Package bcc (Revision 776670d2a36e50b14bbdf2dc003b81d6)

Currently displaying revision 776670d2a36e50b14bbdf2dc003b81d6 , Show latest

From 4456d510d4d6da07d11314bce0a0b5b3f078f268 Mon Sep 17 00:00:00 2001
From: Gary Lin <glin@suse.com>
Date: Thu, 9 Nov 2017 11:52:45 +0800
Subject: [PATCH] bpf: use MCJIT explicitly for ExecutionEngine

When BPFModule finalized the module, it set UseOrcMCJITReplacement to
true to use OrcJIT for ExecutionEngine. However, this never worked.
First, in clang_libs.cmake, mcjit is in the library list instead of
orcjit, so ExecutionEngine always fell back to MCJIT.
Second, even if OrcJIT was linked correctly, it actually broke bcc.
For OrcJIT, finalizeObject() is just an empty function. The code
generation is delayed till getPointerToFunction() or runFunction(), so
the current implementation of BPFModule won't work for OrcJIT.

This bug was covered when using the separate LLVM share libraries. If
the system builds LLVM into an unified share library, then OrcJIT will
be used and bcc would fail to generate BPF bytecodes without any
warning.

Signed-off-by: Gary Lin <glin@suse.com>
---
 src/cc/bpf_module.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/cc/bpf_module.cc b/src/cc/bpf_module.cc
index cf1b09e..7f5e560 100644
--- a/src/cc/bpf_module.cc
+++ b/src/cc/bpf_module.cc
@@ -455,7 +455,7 @@ unique_ptr<ExecutionEngine> BPFModule::finalize_rw(unique_ptr<Module> m) {
   string err;
   EngineBuilder builder(move(m));
   builder.setErrorStr(&err);
-  builder.setUseOrcMCJITReplacement(true);
+  builder.setUseOrcMCJITReplacement(false);
   auto engine = unique_ptr<ExecutionEngine>(builder.create());
   if (!engine)
     fprintf(stderr, "Could not create ExecutionEngine: %s\n", err.c_str());
@@ -596,7 +596,7 @@ int BPFModule::finalize() {
   builder.setErrorStr(&err);
   builder.setMCJITMemoryManager(ebpf::make_unique<MyMemoryManager>(&sections_));
   builder.setMArch("bpf");
-  builder.setUseOrcMCJITReplacement(true);
+  builder.setUseOrcMCJITReplacement(false);
   engine_ = unique_ptr<ExecutionEngine>(builder.create());
   if (!engine_) {
     fprintf(stderr, "Could not create ExecutionEngine: %s\n", err.c_str());
-- 
2.14.3

Places

File bcc-bsc1065593-switch-to-mcjit.patch of Package bcc (Revision 776670d2a36e50b14bbdf2dc003b81d6)

Places