[PATCH] D147442: [JITLink][ELF] Only make sections with SHF_WRITE writable

[Job Noorman via Phabricator via llvm-commits]

jobnoorman created this revision.
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All non-executable sections used to be mapped as RW- causing read-only
sections such as .rodata to be writable.

Note that this patch doesn't include a test case since it's not entirely
clear to me if it's possible to test MemProt flags.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D147442

Files:
  llvm/lib/ExecutionEngine/JITLink/ELFLinkGraphBuilder.h


Index: llvm/lib/ExecutionEngine/JITLink/ELFLinkGraphBuilder.h
===================================================================
--- llvm/lib/ExecutionEngine/JITLink/ELFLinkGraphBuilder.h
+++ llvm/lib/ExecutionEngine/JITLink/ELFLinkGraphBuilder.h
@@ -360,11 +360,11 @@
     });
 
     // Get the section's memory protection flags.
-    orc::MemProt Prot;
+    orc::MemProt Prot = orc::MemProt::Read;
     if (Sec.sh_flags & ELF::SHF_EXECINSTR)
-      Prot = orc::MemProt::Read | orc::MemProt::Exec;
-    else
-      Prot = orc::MemProt::Read | orc::MemProt::Write;
+      Prot |= orc::MemProt::Exec;
+    if (Sec.sh_flags & ELF::SHF_WRITE)
+      Prot |= orc::MemProt::Write;
 
     // Look for existing sections first.
     auto *GraphSec = G->findSectionByName(*Name);


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