[lld] r312757 - Revert "Revert r311468: If --dynamic-list is given, only those symbols are preemptible"
Rafael Avila de Espindola via llvm-commits
llvm-commits at lists.llvm.org
Thu Sep 7 18:07:01 PDT 2017
Will do. What do I have to do to run the cfi tests? Just add compiler-rt
to projects?
Cheers,
Rafael
Evgenii Stepanov <eugeni.stepanov at gmail.com> writes:
> CFI tests (simple check-cfi) are failing on my machine because of this change.
> The binary is looking absolutely crazy: it defines a function
> "atexit", which is not in the source code, and the new function, among
> other things, jumps to a randomly-looking .tbss symbol.
>
> Please revert.
>
>
> On Thu, Sep 7, 2017 at 4:19 PM, Rafael Espindola via llvm-commits
> <llvm-commits at lists.llvm.org> wrote:
>> Author: rafael
>> Date: Thu Sep 7 16:19:09 2017
>> New Revision: 312757
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=312757&view=rev
>> Log:
>> Revert "Revert r311468: If --dynamic-list is given, only those symbols are preemptible"
>>
>> If --dynamic-list is given, only those symbols are preemptible.
>>
>> This allows combining --dynamic-list and version scripts too. The
>> version script controls which symbols are visible, and --dynamic-list
>> controls which of those are preemptible.
>>
>> This fixes pr34053.
>>
>> Added:
>> lld/trunk/test/ELF/dynamic-list-preempt.s
>> Modified:
>> lld/trunk/ELF/Config.h
>> lld/trunk/ELF/ScriptParser.cpp
>> lld/trunk/ELF/SymbolTable.cpp
>> lld/trunk/ELF/SymbolTable.h
>> lld/trunk/ELF/Writer.cpp
>>
>> Modified: lld/trunk/ELF/Config.h
>> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Config.h?rev=312757&r1=312756&r2=312757&view=diff
>> ==============================================================================
>> --- lld/trunk/ELF/Config.h (original)
>> +++ lld/trunk/ELF/Config.h Thu Sep 7 16:19:09 2017
>> @@ -104,6 +104,7 @@ struct Configuration {
>> std::vector<llvm::StringRef> SearchPaths;
>> std::vector<llvm::StringRef> SymbolOrderingFile;
>> std::vector<llvm::StringRef> Undefined;
>> + std::vector<SymbolVersion> DynamicList;
>> std::vector<SymbolVersion> VersionScriptGlobals;
>> std::vector<SymbolVersion> VersionScriptLocals;
>> std::vector<uint8_t> BuildIdVector;
>>
>> Modified: lld/trunk/ELF/ScriptParser.cpp
>> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/ScriptParser.cpp?rev=312757&r1=312756&r2=312757&view=diff
>> ==============================================================================
>> --- lld/trunk/ELF/ScriptParser.cpp (original)
>> +++ lld/trunk/ELF/ScriptParser.cpp Thu Sep 7 16:19:09 2017
>> @@ -180,9 +180,22 @@ static ExprValue bitOr(ExprValue A, Expr
>>
>> void ScriptParser::readDynamicList() {
>> expect("{");
>> - readAnonymousDeclaration();
>> - if (!atEOF())
>> + std::vector<SymbolVersion> Locals;
>> + std::vector<SymbolVersion> Globals;
>> + std::tie(Locals, Globals) = readSymbols();
>> + expect(";");
>> +
>> + if (!atEOF()) {
>> setError("EOF expected, but got " + next());
>> + return;
>> + }
>> + if (!Locals.empty()) {
>> + setError("\"local:\" scope not supported in --dynamic-list");
>> + return;
>> + }
>> +
>> + for (SymbolVersion V : Globals)
>> + Config->DynamicList.push_back(V);
>> }
>>
>> void ScriptParser::readVersionScript() {
>>
>> Modified: lld/trunk/ELF/SymbolTable.cpp
>> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/SymbolTable.cpp?rev=312757&r1=312756&r2=312757&view=diff
>> ==============================================================================
>> --- lld/trunk/ELF/SymbolTable.cpp (original)
>> +++ lld/trunk/ELF/SymbolTable.cpp Thu Sep 7 16:19:09 2017
>> @@ -680,6 +680,24 @@ void SymbolTable::handleAnonymousVersion
>> assignWildcardVersion(Ver, VER_NDX_LOCAL);
>> }
>>
>> +// Handles -dynamic-list.
>> +void SymbolTable::handleDynamicList() {
>> + for (SymbolVersion &Ver : Config->DynamicList) {
>> + std::vector<SymbolBody *> Syms;
>> + if (Ver.HasWildcard)
>> + Syms = findByVersion(Ver);
>> + else
>> + Syms = findAllByVersion(Ver);
>> +
>> + for (SymbolBody *B : Syms) {
>> + if (!Config->Shared)
>> + B->symbol()->VersionId = VER_NDX_GLOBAL;
>> + else if (B->symbol()->includeInDynsym())
>> + B->IsPreemptible = true;
>> + }
>> + }
>> +}
>> +
>> // Set symbol versions to symbols. This function handles patterns
>> // containing no wildcard characters.
>> void SymbolTable::assignExactVersion(SymbolVersion Ver, uint16_t VersionId,
>> @@ -729,6 +747,7 @@ void SymbolTable::assignWildcardVersion(
>> void SymbolTable::scanVersionScript() {
>> // Handle edge cases first.
>> handleAnonymousVersion();
>> + handleDynamicList();
>>
>> // Now we have version definitions, so we need to set version ids to symbols.
>> // Each version definition has a glob pattern, and all symbols that match
>>
>> Modified: lld/trunk/ELF/SymbolTable.h
>> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/SymbolTable.h?rev=312757&r1=312756&r2=312757&view=diff
>> ==============================================================================
>> --- lld/trunk/ELF/SymbolTable.h (original)
>> +++ lld/trunk/ELF/SymbolTable.h Thu Sep 7 16:19:09 2017
>> @@ -90,6 +90,8 @@ public:
>>
>> void trace(StringRef Name);
>>
>> + void handleDynamicList();
>> +
>> private:
>> std::vector<SymbolBody *> findByVersion(SymbolVersion Ver);
>> std::vector<SymbolBody *> findAllByVersion(SymbolVersion Ver);
>>
>> Modified: lld/trunk/ELF/Writer.cpp
>> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Writer.cpp?rev=312757&r1=312756&r2=312757&view=diff
>> ==============================================================================
>> --- lld/trunk/ELF/Writer.cpp (original)
>> +++ lld/trunk/ELF/Writer.cpp Thu Sep 7 16:19:09 2017
>> @@ -1294,8 +1294,9 @@ template <class ELFT> void Writer<ELFT>:
>> applySynthetic({In<ELFT>::EhFrame},
>> [](SyntheticSection *SS) { SS->finalizeContents(); });
>>
>> - for (Symbol *S : Symtab->getSymbols())
>> - S->body()->IsPreemptible = computeIsPreemptible(*S->body());
>> + if (Config->DynamicList.empty())
>> + for (Symbol *S : Symtab->getSymbols())
>> + S->body()->IsPreemptible = computeIsPreemptible(*S->body());
>>
>> // Scan relocations. This must be done after every symbol is declared so that
>> // we can correctly decide if a dynamic relocation is needed.
>>
>> Added: lld/trunk/test/ELF/dynamic-list-preempt.s
>> URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/dynamic-list-preempt.s?rev=312757&view=auto
>> ==============================================================================
>> --- lld/trunk/test/ELF/dynamic-list-preempt.s (added)
>> +++ lld/trunk/test/ELF/dynamic-list-preempt.s Thu Sep 7 16:19:09 2017
>> @@ -0,0 +1,65 @@
>> +# REQUIRES: x86
>> +
>> +# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
>> +# RUN: echo "{ foo; zed; };" > %t.list
>> +# RUN: echo "{ global: foo; bar; local: *; };" > %t.vers
>> +# RUN: ld.lld -fatal-warnings -dynamic-list %t.list -version-script %t.vers -shared %t.o -o %t.so
>> +# RUN: llvm-readobj -r %t.so | FileCheck --check-prefix=RELOCS %s
>> +# RUN: llvm-readobj -dyn-symbols %t.so | FileCheck --check-prefix=DYNSYMS %s
>> +
>> +# RELOCS: Relocations [
>> +# RELOCS-NEXT: Section ({{.*}}) .rela.plt {
>> +# RELOCS-NEXT: R_X86_64_JUMP_SLOT foo 0x0
>> +# RELOCS-NEXT: }
>> +# RELOCS-NEXT: ]
>> +
>> +# DYNSYMS: DynamicSymbols [
>> +# DYNSYMS-NEXT: Symbol {
>> +# DYNSYMS-NEXT: Name: @ (0)
>> +# DYNSYMS-NEXT: Value: 0x0
>> +# DYNSYMS-NEXT: Size: 0
>> +# DYNSYMS-NEXT: Binding: Local
>> +# DYNSYMS-NEXT: Type: None
>> +# DYNSYMS-NEXT: Other: 0
>> +# DYNSYMS-NEXT: Section: Undefined
>> +# DYNSYMS-NEXT: }
>> +# DYNSYMS-NEXT: Symbol {
>> +# DYNSYMS-NEXT: Name: bar@
>> +# DYNSYMS-NEXT: Value:
>> +# DYNSYMS-NEXT: Size:
>> +# DYNSYMS-NEXT: Binding: Global
>> +# DYNSYMS-NEXT: Type:
>> +# DYNSYMS-NEXT: Other:
>> +# DYNSYMS-NEXT: Section:
>> +# DYNSYMS-NEXT: }
>> +# DYNSYMS-NEXT: Symbol {
>> +# DYNSYMS-NEXT: Name: foo@
>> +# DYNSYMS-NEXT: Value:
>> +# DYNSYMS-NEXT: Size:
>> +# DYNSYMS-NEXT: Binding: Global
>> +# DYNSYMS-NEXT: Type:
>> +# DYNSYMS-NEXT: Other:
>> +# DYNSYMS-NEXT: Section:
>> +# DYNSYMS-NEXT: }
>> +# DYNSYMS-NEXT: ]
>> +
>> + .globl foo
>> +foo:
>> + ret
>> +
>> + .globl bar
>> +bar:
>> + ret
>> +
>> + .globl baz
>> +baz:
>> + ret
>> +
>> + .globl zed
>> +zed:
>> + ret
>> +
>> + call foo at PLT
>> + call bar at PLT
>> + call baz at PLT
>> + call zed at PLT
>>
>>
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