Fix invalid LLVM IR in join builtin

Add pointer casts to store instruction where required and use GEP instructions to do pointer arithmetic instead of incorrect use of add instruction. Fixes bpftrace#2222
lenticularis39 · Jul 12, 2022 · a633f84 · a633f84
1 parent dc01a88
commit a633f84
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Showing 3 changed files with 18 additions and 10 deletions.
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -114,7 +114,7 @@ jobs:
           TYPE: Release
           LLVM_VERSION: 14
           RUN_ALL_TESTS: 1
-          RUNTIME_TEST_DISABLE: probe.kprobe_offset_fail_size,call.join,call.join_delim,intptrcast.Casting ints,json-output.join_delim,variable.32-bit tracepoint arg
+          RUNTIME_TEST_DISABLE: probe.kprobe_offset_fail_size
           TOOLS_TEST_OLDVERSION: biosnoop.bt
           BASE: focal
           VENDOR_GTEST: ON

diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -27,6 +27,8 @@ and this project adheres to
   - [#2236](https://github.com/iovisor/bpftrace/pull/2236)
 - Fix compound assignments with non-unary expr
   - [#2291](https://github.com/iovisor/bpftrace/pull/2293)
+- Fix invalid LLVM IR in join builtin
+  - [#2296](https://github.com/iovisor/bpftrace/pull/2296)
 
 #### Added
 #### Docs

diff --git a/src/ast/passes/codegen_llvm.cpp b/src/ast/passes/codegen_llvm.cpp
@@ -669,18 +669,23 @@ void CodegenLLVM::visit(Call &call)
 
     // arg0
     b_.SetInsertPoint(notzero);
-    b_.CreateStore(b_.getInt64(asyncactionint(AsyncAction::join)), perfdata);
+    b_.CreateStore(b_.getInt64(asyncactionint(AsyncAction::join)),
+                   b_.CreatePointerCast(perfdata,
+                                        b_.getInt64Ty()->getPointerTo()));
     b_.CreateStore(b_.getInt64(join_id_),
-                   b_.CreateGEP(b_.getInt8Ty(), perfdata, b_.getInt64(8)));
+                   b_.CreatePointerCast(
+                       b_.CreateGEP(b_.getInt8Ty(), perfdata, b_.getInt64(8)),
+                       b_.getInt64Ty()->getPointerTo()));
     join_id_++;
     AllocaInst *arr = b_.CreateAllocaBPF(b_.getInt64Ty(), call.func + "_r0");
     b_.CreateProbeRead(ctx_, arr, 8, expr_, addrspace, call.loc);
-    b_.CreateProbeReadStr(ctx_,
-                          b_.CreateAdd(perfdata, b_.getInt64(8 + 8)),
-                          bpftrace_.join_argsize_,
-                          b_.CreateLoad(b_.getInt64Ty(), arr),
-                          addrspace,
-                          call.loc);
+    b_.CreateProbeReadStr(
+        ctx_,
+        b_.CreateGEP(b_.getInt8Ty(), perfdata, b_.getInt64(8 + 8)),
+        bpftrace_.join_argsize_,
+        b_.CreateLoad(b_.getInt64Ty(), arr),
+        addrspace,
+        call.loc);
 
     for (unsigned int i = 1; i < bpftrace_.join_argnum_; i++)
     {
@@ -694,7 +699,8 @@ void CodegenLLVM::visit(Call &call)
                          call.loc);
       b_.CreateProbeReadStr(
           ctx_,
-          b_.CreateAdd(perfdata,
+          b_.CreateGEP(b_.getInt8Ty(),
+                       perfdata,
                        b_.getInt64(8 + 8 + i * bpftrace_.join_argsize_)),
           bpftrace_.join_argsize_,
           b_.CreateLoad(b_.getInt64Ty(), second),