[llvm] r250942 - [RuntimeDyld] Ignore ST_FILE symbols when constructing GlobalSymbolTable

[Keno Fischer via llvm-commits]

Author: kfischer
Date: Wed Oct 21 15:22:04 2015
New Revision: 250942

URL: http://llvm.org/viewvc/llvm-project?rev=250942&view=rev
Log:
[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

Added:
    llvm/trunk/test/ExecutionEngine/RuntimeDyld/X86/ELF_STT_FILE.s
    llvm/trunk/test/ExecutionEngine/RuntimeDyld/X86/Inputs/ELF_STT_FILE_FILE.s
    llvm/trunk/test/ExecutionEngine/RuntimeDyld/X86/Inputs/ELF_STT_FILE_GLOBAL.s
Modified:
    llvm/trunk/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp

Modified: llvm/trunk/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp?rev=250942&r1=250941&r2=250942&view=diff
==============================================================================
--- llvm/trunk/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp (original)
+++ llvm/trunk/lib/ExecutionEngine/RuntimeDyld/RuntimeDyld.cpp Wed Oct 21 15:22:04 2015
@@ -179,7 +179,8 @@ RuntimeDyldImpl::loadObjectImpl(const ob
       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;

Added: llvm/trunk/test/ExecutionEngine/RuntimeDyld/X86/ELF_STT_FILE.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/ExecutionEngine/RuntimeDyld/X86/ELF_STT_FILE.s?rev=250942&view=auto
==============================================================================
--- llvm/trunk/test/ExecutionEngine/RuntimeDyld/X86/ELF_STT_FILE.s (added)
+++ llvm/trunk/test/ExecutionEngine/RuntimeDyld/X86/ELF_STT_FILE.s Wed Oct 21 15:22:04 2015
@@ -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 at GOTPCREL(%rip), %rax
+    movq    bar.c at GOTPCREL(%rip), %rax
+    movq    $0, %rax
+    retq

Added: llvm/trunk/test/ExecutionEngine/RuntimeDyld/X86/Inputs/ELF_STT_FILE_FILE.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/ExecutionEngine/RuntimeDyld/X86/Inputs/ELF_STT_FILE_FILE.s?rev=250942&view=auto
==============================================================================
--- llvm/trunk/test/ExecutionEngine/RuntimeDyld/X86/Inputs/ELF_STT_FILE_FILE.s (added)
+++ llvm/trunk/test/ExecutionEngine/RuntimeDyld/X86/Inputs/ELF_STT_FILE_FILE.s Wed Oct 21 15:22:04 2015
@@ -0,0 +1,3 @@
+.file "foo.c"
+.global bar.c
+bar.c:

Added: llvm/trunk/test/ExecutionEngine/RuntimeDyld/X86/Inputs/ELF_STT_FILE_GLOBAL.s
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/ExecutionEngine/RuntimeDyld/X86/Inputs/ELF_STT_FILE_GLOBAL.s?rev=250942&view=auto
==============================================================================
--- llvm/trunk/test/ExecutionEngine/RuntimeDyld/X86/Inputs/ELF_STT_FILE_GLOBAL.s (added)
+++ llvm/trunk/test/ExecutionEngine/RuntimeDyld/X86/Inputs/ELF_STT_FILE_GLOBAL.s Wed Oct 21 15:22:04 2015
@@ -0,0 +1,2 @@
+.global foo.c
+foo.c: