[llvm-branch-commits] ELF: Remove lock from MTE global relocation handling code. (PR #135123)

[via llvm-branch-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-lld-elf

Author: Peter Collingbourne (pcc)

<details>
<summary>Changes</summary>

This lock is unnecessary because we can add the relocations to
shards and let them be sorted later.


---
Full diff: https://github.com/llvm/llvm-project/pull/135123.diff


1 Files Affected:

- (modified) lld/ELF/Relocations.cpp (+2-3) 


``````````diff
diff --git a/lld/ELF/Relocations.cpp b/lld/ELF/Relocations.cpp
index 81de664fd1c23..277acb26987bc 100644
--- a/lld/ELF/Relocations.cpp
+++ b/lld/ELF/Relocations.cpp
@@ -847,9 +847,8 @@ static void addRelativeReloc(Ctx &ctx, InputSectionBase &isec,
   Partition &part = isec.getPartition(ctx);
 
   if (sym.isTagged()) {
-    std::lock_guard<std::mutex> lock(ctx.relocMutex);
-    part.relaDyn->addRelativeReloc(ctx.target->relativeRel, isec, offsetInSec,
-                                   sym, addend, type, expr);
+    part.relaDyn->addRelativeReloc<shard>(ctx.target->relativeRel, isec,
+                                          offsetInSec, sym, addend, type, expr);
     // With MTE globals, we always want to derive the address tag by `ldg`-ing
     // the symbol. When we have a RELATIVE relocation though, we no longer have
     // a reference to the symbol. Because of this, when we have an addend that

``````````

</details>


https://github.com/llvm/llvm-project/pull/135123