Index: ELF/LinkerScript.h =================================================================== --- ELF/LinkerScript.h +++ ELF/LinkerScript.h @@ -274,6 +274,7 @@ bool HasSectionsCommand = false; bool ErrorOnMissingSection = false; + bool AllocateHeaders = false; // List of section patterns specified with KEEP commands. They will // be kept even if they are unused and --gc-sections is specified. Index: ELF/LinkerScript.cpp =================================================================== --- ELF/LinkerScript.cpp +++ ELF/LinkerScript.cpp @@ -855,6 +855,15 @@ return nullptr; } +static uint64_t computeBase(uint64_t Min) { + // If there is no SECTIONS or if the linkerscript is explicit about program + // headers, do our best to allocate them. + if (!Script->HasSectionsCommand || Script->AllocateHeaders) + return 0; + // Otherwise only allocate program headers if that would not add a page. + return alignDown(Min, Config->MaxPageSize); +} + // Try to find an address for the file and program headers output sections, // which were unconditionally added to the first PT_LOAD segment earlier. // @@ -879,14 +888,14 @@ PhdrEntry *FirstPTLoad = *It; uint64_t HeaderSize = getHeaderSize(); - // When linker script with SECTIONS is being used, don't output headers - // unless there's a space for them. - uint64_t Base = HasSectionsCommand ? alignDown(Min, Config->MaxPageSize) : 0; - if (HeaderSize <= Min - Base || Script->hasPhdrsCommands()) { + if (HeaderSize <= Min - computeBase(Min)) { Min = alignDown(Min - HeaderSize, Config->MaxPageSize); Out::ElfHeader->Addr = Min; Out::ProgramHeaders->Addr = Min + Out::ElfHeader->Size; return; + } else if (Script->AllocateHeaders) { + // Error if we were explicitly asked to allocate headers. + error("Could not allocate headers"); } Out::ElfHeader->PtLoad = nullptr; Index: ELF/ScriptParser.cpp =================================================================== --- ELF/ScriptParser.cpp +++ ELF/ScriptParser.cpp @@ -410,6 +410,8 @@ else setError("unexpected header attribute: " + next()); } + if (Cmd.HasPhdrs || Cmd.HasFilehdr) + Script->AllocateHeaders = true; Script->PhdrsCommands.push_back(Cmd); } Index: test/ELF/linkerscript/header-phdr2.s =================================================================== --- /dev/null +++ test/ELF/linkerscript/header-phdr2.s @@ -0,0 +1,11 @@ +# REQUIRES: x86 +# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o +# RUN: echo "PHDRS { foobar PT_LOAD FILEHDR PHDRS; }" > %t.script +# RUN: echo "SECTIONS { .text : { *(.text) } : foobar }" >> %t.script +# RUN: not ld.lld --script %t.script %t.o -o %t 2>&1 | FileCheck %s + +# CHECK: Could not allocate headers + + .global _start +_start: + retq