From: Keno Fischer <kfischer@college.harvard.edu>
Date: Wed, 21 Oct 2015 20:22:04 +0000 (+0000)
Subject: [RuntimeDyld] Ignore ST_FILE symbols when constructing GlobalSymbolTable
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=9e6956041749816a6ec05147c7a41aa866156391;p=llvm

[RuntimeDyld] Ignore ST_FILE symbols when constructing GlobalSymbolTable

Summary: ELF's STT_File symbols may overlap with regular globals in
other files, so we should ignore them here in order to avoid having
bogus entries in the symbol table that confuse us when resolving relocations.

Reviewers: lhames

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D13888

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250942 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
index 1c276a8728a..f24a49e8b29 100644
--- a/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
+++ b/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
@@ -179,7 +179,8 @@ RuntimeDyldImpl::loadObjectImpl(const object::ObjectFile &Obj) {
       if (Flags & SymbolRef::SF_Exported)
         RTDyldSymFlags |= JITSymbolFlags::Exported;
 
-      if (Flags & SymbolRef::SF_Absolute) {
+      if (Flags & SymbolRef::SF_Absolute &&
+          SymType != object::SymbolRef::ST_File) {
         auto Addr = I->getAddress();
         Check(Addr.getError());
         uint64_t SectOffset = *Addr;
diff --git a/test/ExecutionEngine/RuntimeDyld/X86/ELF_STT_FILE.s b/test/ExecutionEngine/RuntimeDyld/X86/ELF_STT_FILE.s
new file mode 100644
index 00000000000..50cc65079bd
--- /dev/null
+++ b/test/ExecutionEngine/RuntimeDyld/X86/ELF_STT_FILE.s
@@ -0,0 +1,14 @@
+# RUN: llvm-mc -triple=x86_64-pc-linux -relocation-model=pic -filetype=obj -o %T/test_ELF_STT_FILE_FILE_x86-64.o %p/Inputs/ELF_STT_FILE_FILE.s
+# RUN: llvm-mc -triple=x86_64-pc-linux -relocation-model=pic -filetype=obj -o %T/test_ELF_STT_FILE_GLOBAL_x86-64.o %p/Inputs/ELF_STT_FILE_GLOBAL.s
+# RUN: llvm-mc -triple=x86_64-pc-linux -relocation-model=pic -filetype=obj -o %T/test_ELF_STT_FILE_x86-64.o %s
+# RUN: llvm-rtdyld -triple=x86_64-pc-linux -verify %T/test_ELF_STT_FILE_GLOBAL_x86-64.o %T/test_ELF_STT_FILE_FILE_x86-64.o %T/test_ELF_STT_FILE_x86-64.o
+
+# Test that RTDyldELF ignores STT_FILE symbols, and in particular does
+# crash if we are relocating against a symbol that happens to have the
+# same name as an STT_FILE symbol.
+
+_main:
+    movq    foo.c@GOTPCREL(%rip), %rax
+    movq    bar.c@GOTPCREL(%rip), %rax
+    movq    $0, %rax
+    retq
diff --git a/test/ExecutionEngine/RuntimeDyld/X86/Inputs/ELF_STT_FILE_FILE.s b/test/ExecutionEngine/RuntimeDyld/X86/Inputs/ELF_STT_FILE_FILE.s
new file mode 100644
index 00000000000..7280c51b586
--- /dev/null
+++ b/test/ExecutionEngine/RuntimeDyld/X86/Inputs/ELF_STT_FILE_FILE.s
@@ -0,0 +1,3 @@
+.file "foo.c"
+.global bar.c
+bar.c:
diff --git a/test/ExecutionEngine/RuntimeDyld/X86/Inputs/ELF_STT_FILE_GLOBAL.s b/test/ExecutionEngine/RuntimeDyld/X86/Inputs/ELF_STT_FILE_GLOBAL.s
new file mode 100644
index 00000000000..a7e5342746e
--- /dev/null
+++ b/test/ExecutionEngine/RuntimeDyld/X86/Inputs/ELF_STT_FILE_GLOBAL.s
@@ -0,0 +1,2 @@
+.global foo.c
+foo.c: