Fix a bug that MIPS thunks can overwrite other section contents.
Peter Smith found while trying to support thunk creation for ARM that
LLD sometimes creates broken thunks for MIPS. The cause of the bug is
that we assign file offsets to input sections too early. We need to
create all sections and then assign section offsets because appending
thunks changes file offsets for all following sections.
This patch separates the pass to assign file offsets from thunk
creation pass. This effectively reverts r265673.
Differential Revision: http://reviews.llvm.org/D21598
llvm-svn: 273532
diff --git a/lld/ELF/Relocations.cpp b/lld/ELF/Relocations.cpp
index 87f7649..5cf0a61 100644
--- a/lld/ELF/Relocations.cpp
+++ b/lld/ELF/Relocations.cpp
@@ -103,7 +103,7 @@
{Target->TlsDescRel, Out<ELFT>::Got, Off, false, &Body, 0});
}
if (Expr != R_HINT)
- C.Relocations.push_back({Expr, Type, Offset, Addend, &Body});
+ C.Relocations.push_back({Expr, Type, &C, Offset, Addend, &Body});
return 1;
}
@@ -111,21 +111,21 @@
// Local-Dynamic relocs can be relaxed to Local-Exec.
if (!Config->Shared) {
C.Relocations.push_back(
- {R_RELAX_TLS_LD_TO_LE, Type, Offset, Addend, &Body});
+ {R_RELAX_TLS_LD_TO_LE, Type, &C, Offset, Addend, &Body});
return 2;
}
if (Out<ELFT>::Got->addTlsIndex())
Out<ELFT>::RelaDyn->addReloc({Target->TlsModuleIndexRel, Out<ELFT>::Got,
Out<ELFT>::Got->getTlsIndexOff(), false,
nullptr, 0});
- C.Relocations.push_back({Expr, Type, Offset, Addend, &Body});
+ C.Relocations.push_back({Expr, Type, &C, Offset, Addend, &Body});
return 1;
}
// Local-Dynamic relocs can be relaxed to Local-Exec.
if (Target->isTlsLocalDynamicRel(Type) && !Config->Shared) {
C.Relocations.push_back(
- {R_RELAX_TLS_LD_TO_LE, Type, Offset, Addend, &Body});
+ {R_RELAX_TLS_LD_TO_LE, Type, &C, Offset, Addend, &Body});
return 1;
}
@@ -144,7 +144,7 @@
Off + (uintX_t)sizeof(uintX_t), false,
&Body, 0});
}
- C.Relocations.push_back({Expr, Type, Offset, Addend, &Body});
+ C.Relocations.push_back({Expr, Type, &C, Offset, Addend, &Body});
return 1;
}
@@ -153,7 +153,7 @@
if (isPreemptible(Body, Type)) {
C.Relocations.push_back(
{Target->adjustRelaxExpr(Type, nullptr, R_RELAX_TLS_GD_TO_IE), Type,
- Offset, Addend, &Body});
+ &C, Offset, Addend, &Body});
if (!Body.isInGot()) {
Out<ELFT>::Got->addEntry(Body);
Out<ELFT>::RelaDyn->addReloc({Target->TlsGotRel, Out<ELFT>::Got,
@@ -163,7 +163,7 @@
return Target->TlsGdRelaxSkip;
}
C.Relocations.push_back(
- {Target->adjustRelaxExpr(Type, nullptr, R_RELAX_TLS_GD_TO_LE), Type,
+ {Target->adjustRelaxExpr(Type, nullptr, R_RELAX_TLS_GD_TO_LE), Type, &C,
Offset, Addend, &Body});
return Target->TlsGdRelaxSkip;
}
@@ -173,7 +173,7 @@
if (Target->isTlsInitialExecRel(Type) && !Config->Shared &&
!isPreemptible(Body, Type)) {
C.Relocations.push_back(
- {R_RELAX_TLS_IE_TO_LE, Type, Offset, Addend, &Body});
+ {R_RELAX_TLS_IE_TO_LE, Type, &C, Offset, Addend, &Body});
return 1;
}
return 0;
@@ -497,8 +497,9 @@
if (HasError)
continue;
- uintX_t Offset = C.getOffset(RI.r_offset);
- if (Offset == (uintX_t)-1)
+ // Skip a relocation that points to a dead piece
+ // in a mergeable section.
+ if (C.getOffset(RI.r_offset) == (uintX_t)-1)
continue;
// This relocation does not require got entry, but it is relative to got and
@@ -508,8 +509,8 @@
uintX_t Addend = computeAddend(File, Buf, E, RI, Expr, Body);
- if (unsigned Processed =
- handleTlsRelocation<ELFT>(Type, Body, C, Offset, Addend, Expr)) {
+ if (unsigned Processed = handleTlsRelocation<ELFT>(
+ Type, Body, C, RI.r_offset, Addend, Expr)) {
I += (Processed - 1);
continue;
}
@@ -529,17 +530,17 @@
// relocation. We can process some of it and and just ask the dynamic
// linker to add the load address.
if (!Constant)
- AddDyn({Target->RelativeRel, C.OutSec, Offset, true, &Body, Addend});
+ AddDyn({Target->RelativeRel, &C, RI.r_offset, true, &Body, Addend});
// If the produced value is a constant, we just remember to write it
// when outputting this section. We also have to do it if the format
// uses Elf_Rel, since in that case the written value is the addend.
if (Constant || !RelTy::IsRela)
- C.Relocations.push_back({Expr, Type, Offset, Addend, &Body});
+ C.Relocations.push_back({Expr, Type, &C, RI.r_offset, Addend, &Body});
} else {
// We don't know anything about the finaly symbol. Just ask the dynamic
// linker to handle the relocation for us.
- AddDyn({Target->getDynRel(Type), C.OutSec, Offset, false, &Body, Addend});
+ AddDyn({Target->getDynRel(Type), &C, RI.r_offset, false, &Body, Addend});
// MIPS ABI turns using of GOT and dynamic relocations inside out.
// While regular ABI uses dynamic relocations to fill up GOT entries
// MIPS ABI requires dynamic linker to fills up GOT entries using