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Don't include PHDRs if linker script doesn't want them 

This script below shouldn't include file and program headers
to PT_LOAD segment, because it doesn't have PHDRS and FILEHDR
attributes:

PHDRS { all PT_LOAD; }
SECTIONS { /* list of sections here */ }

Differential revision: https://reviews.llvm.org/D25774

llvm-svn: 284709
This commit is contained in:
Eugene Leviant 2016-10-20 09:39:09 +00:00
parent 58fa5243cc
commit db35fdf70f
2 changed files with 36 additions and 0 deletions
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9
lld/ELF/LinkerScript.cpp
View File

@ -652,7 +652,16 @@ void LinkerScript<ELFT>::assignAddresses(std::vector<PhdrEntry<ELFT>> &Phdrs) {
std::find_if(Phdrs.begin(), Phdrs.end(), [](const PhdrEntry<ELFT> &E) {
return E.H.p_type == PT_LOAD;
});
if (HeaderSize <= MinVA && FirstPTLoad != Phdrs.end()) {
// If linker script specifies program headers and first PT_LOAD doesn't
// have both PHDRS and FILEHDR attributes then do nothing
if (!Opt.PhdrsCommands.empty()) {
size_t SegNum = std::distance(Phdrs.begin(), FirstPTLoad);
if (!Opt.PhdrsCommands[SegNum].HasPhdrs ||
!Opt.PhdrsCommands[SegNum].HasFilehdr)
return;
}
// ELF and Program headers need to be right before the first section in
// memory. Set their addresses accordingly.
MinVA = alignDown(MinVA - HeaderSize, Target->PageSize);

27
lld/test/ELF/linkerscript/phdrs.s
View File

@ -9,6 +9,17 @@
# RUN: ld.lld -o %t1 --script %t.script %t
# RUN: llvm-readobj -program-headers %t1 | FileCheck %s
## Check that program headers are not written, unless we explicitly tell
## lld to do this.
# RUN: echo "PHDRS {all PT_LOAD;} \
# RUN: SECTIONS { \
# RUN: . = 0x10000200; \
# RUN: /DISCARD/ : {*(.text*)} \
# RUN: .foo : {*(.foo.*)} :all \
# RUN: }" > %t.script
# RUN: ld.lld -o %t1 --script %t.script %t
# RUN: llvm-readobj -program-headers %t1 | FileCheck --check-prefix=NOPHDR %s
## Check the AT(expr)
# RUN: echo "PHDRS {all PT_LOAD FILEHDR PHDRS AT(0x500 + 0x500) ;} \
# RUN: SECTIONS { \
@ -42,6 +53,22 @@
# CHECK-NEXT: PF_X (0x1)
# CHECK-NEXT: ]
# NOPHDR: ProgramHeaders [
# NOPHDR-NEXT: ProgramHeader {
# NOPHDR-NEXT: Type: PT_LOAD (0x1)
# NOPHDR-NEXT: Offset: 0x200
# NOPHDR-NEXT: VirtualAddress: 0x10000200
# NOPHDR-NEXT: PhysicalAddress: 0x10000200
# NOPHDR-NEXT: FileSize: 8
# NOPHDR-NEXT: MemSize: 8
# NOPHDR-NEXT: Flags [ (0x6)
# NOPHDR-NEXT: PF_R (0x4)
# NOPHDR-NEXT: PF_W (0x2)
# NOPHDR-NEXT: ]
# NOPHDR-NEXT: Alignment: 4096
# NOPHDR-NEXT: }
# NOPHDR-NEXT: ]
# AT: ProgramHeaders [
# AT-NEXT: ProgramHeader {
# AT-NEXT: Type: PT_LOAD (0x1)