[llvm] [bolt] Account for stubs with symbols in plt. (PR #192716)

via llvm-commits llvm-commits at lists.llvm.org
Fri Apr 17 11:57:44 PDT 2026


llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-bolt

Author: Hemant Kulkarni (awshkulkar)

<details>
<summary>Changes</summary>

LLD and bfd do not generate functions symbols for stubs in PLT. However, mold does and trips the object discovery to create two functions (BF then PLTFunc). This can cause symbol to be resoved with BF with incorrect ADRP immediate field in AArch64.

The issue is described in more detail here: https://github.com/llvm/llvm-project/issues/192552

---

Patch is 39.67 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/192716.diff


3 Files Affected:

- (modified) bolt/lib/Rewrite/RewriteInstance.cpp (+4-2) 
- (added) bolt/test/AArch64/Inputs/plt-call-func-syms.yaml (+1049) 
- (added) bolt/test/AArch64/plt-func-symbols.test (+47) 


``````````diff
diff --git a/bolt/lib/Rewrite/RewriteInstance.cpp b/bolt/lib/Rewrite/RewriteInstance.cpp
index 698281bc98f86..54f5f9e9d53ab 100644
--- a/bolt/lib/Rewrite/RewriteInstance.cpp
+++ b/bolt/lib/Rewrite/RewriteInstance.cpp
@@ -1041,8 +1041,10 @@ void RewriteInstance::discoverFileObjects() {
 
     FileSymRefs.emplace(SymbolAddress, Symbol);
 
-    // Skip section symbols that will be registered by disassemblePLT().
-    if (SymbolType == SymbolRef::ST_Debug) {
+    // Skip symbols in PLT sections that will be registered by disassemblePLT().
+    // ST_Debug covers section markers (lld/GNU ld), ST_Function covers
+    // explicit stub symbols emitted by mold (e.g., malloc$plt).
+    if (SymbolType == SymbolRef::ST_Debug || SymbolType == SymbolRef::ST_Function) {
       ErrorOr<BinarySection &> BSection =
           BC->getSectionForAddress(SymbolAddress);
       if (BSection && getPLTSectionInfo(BSection->getName()))
diff --git a/bolt/test/AArch64/Inputs/plt-call-func-syms.yaml b/bolt/test/AArch64/Inputs/plt-call-func-syms.yaml
new file mode 100644
index 0000000000000..6aebd00304f45
--- /dev/null
+++ b/bolt/test/AArch64/Inputs/plt-call-func-syms.yaml
@@ -0,0 +1,1049 @@
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[truncated]

``````````

</details>


https://github.com/llvm/llvm-project/pull/192716


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