<div dir="ltr">Merged to 6.0 along with dependents in r323733 (PR36136).</div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Jan 29, 2018 at 4:44 AM, Rafael Espindola via llvm-commits <span dir="ltr"><<a href="mailto:llvm-commits@lists.llvm.org" target="_blank">llvm-commits@lists.llvm.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Author: rafael<br>
Date: Sun Jan 28 19:44:44 2018<br>
New Revision: 323625<br>
<br>
URL: <a href="http://llvm.org/viewvc/llvm-project?rev=323625&view=rev" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-<wbr>project?rev=323625&view=rev</a><br>
Log:<br>
Put the header in the first PT_LOAD even if that PT_LOAD has a LMAExpr.<br>
<br>
This should fix PR36017.<br>
<br>
The root problem is that we were creating a PT_LOAD just for the<br>
header. That was technically valid, but inconvenient: we should not be<br>
making the ELF discontinuous.<br>
<br>
The solution is to allow a section with LMAExpr to be added to a<br>
PT_LOAD if that PT_LOAD doesn't already have a LMAExpr.<br>
<br>
Added:<br>
lld/trunk/test/ELF/<wbr>linkerscript/merge-header-<wbr>load.s<br>
Modified:<br>
lld/trunk/ELF/Writer.cpp<br>
lld/trunk/ELF/Writer.h<br>
<br>
Modified: lld/trunk/ELF/Writer.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Writer.cpp?rev=323625&r1=323624&r2=323625&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-<wbr>project/lld/trunk/ELF/Writer.<wbr>cpp?rev=323625&r1=323624&r2=<wbr>323625&view=diff</a><br>
==============================<wbr>==============================<wbr>==================<br>
--- lld/trunk/ELF/Writer.cpp (original)<br>
+++ lld/trunk/ELF/Writer.cpp Sun Jan 28 19:44:44 2018<br>
@@ -822,6 +822,8 @@ void PhdrEntry::add(OutputSection *Sec)<br>
p_align = std::max(p_align, Sec->Alignment);<br>
if (p_type == PT_LOAD)<br>
Sec->PtLoad = this;<br>
+ if (Sec->LMAExpr)<br>
+ ASectionHasLMA = true;<br>
}<br>
<br>
// The beginning and the ending of .rel[a].plt section are marked<br>
@@ -1626,8 +1628,9 @@ template <class ELFT> std::vector<PhdrEn<br>
// different flags or is loaded at a discontiguous address using AT linker<br>
// script command.<br>
uint64_t NewFlags = computeFlags(Sec-><wbr>getPhdrFlags());<br>
- if (Sec->LMAExpr || Sec->MemRegion != Load->FirstSec->MemRegion ||<br>
- Flags != NewFlags) {<br>
+ if ((Sec->LMAExpr && Load->ASectionHasLMA) ||<br>
+ Sec->MemRegion != Load->FirstSec->MemRegion || Flags != NewFlags) {<br>
+<br>
Load = AddHdr(PT_LOAD, NewFlags);<br>
Flags = NewFlags;<br>
}<br>
<br>
Modified: lld/trunk/ELF/Writer.h<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Writer.h?rev=323625&r1=323624&r2=323625&view=diff" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-<wbr>project/lld/trunk/ELF/Writer.<wbr>h?rev=323625&r1=323624&r2=<wbr>323625&view=diff</a><br>
==============================<wbr>==============================<wbr>==================<br>
--- lld/trunk/ELF/Writer.h (original)<br>
+++ lld/trunk/ELF/Writer.h Sun Jan 28 19:44:44 2018<br>
@@ -44,6 +44,12 @@ struct PhdrEntry {<br>
OutputSection *FirstSec = nullptr;<br>
OutputSection *LastSec = nullptr;<br>
bool HasLMA = false;<br>
+<br>
+ // True if one of the sections in this program header has a LMA specified via<br>
+ // linker script: AT(addr). We never allow 2 or more sections with LMA in the<br>
+ // same program header.<br>
+ bool ASectionHasLMA = false;<br>
+<br>
uint64_t LMAOffset = 0;<br>
};<br>
<br>
<br>
Added: lld/trunk/test/ELF/<wbr>linkerscript/merge-header-<wbr>load.s<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/linkerscript/merge-header-load.s?rev=323625&view=auto" rel="noreferrer" target="_blank">http://llvm.org/viewvc/llvm-<wbr>project/lld/trunk/test/ELF/<wbr>linkerscript/merge-header-<wbr>load.s?rev=323625&view=auto</a><br>
==============================<wbr>==============================<wbr>==================<br>
--- lld/trunk/test/ELF/<wbr>linkerscript/merge-header-<wbr>load.s (added)<br>
+++ lld/trunk/test/ELF/<wbr>linkerscript/merge-header-<wbr>load.s Sun Jan 28 19:44:44 2018<br>
@@ -0,0 +1,21 @@<br>
+# REQUIRES: x86<br>
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o<br>
+# RUN: echo "SECTIONS { \<br>
+# RUN: . = 0xffffffff80000200; \<br>
+# RUN: .text : AT (0x4200) { *(.text) } \<br>
+# RUN: }" > %t.script<br>
+# RUN: ld.lld %t.o --script %t.script -o %t<br>
+# RUN: llvm-readelf -program-headers %t | FileCheck %s<br>
+<br>
+# Test that we put the header in the first PT_LOAD. We used to create a PT_LOAD<br>
+# just for it and it would have a different virtual to physical address delta.<br>
+<br>
+# CHECK: Program Headers:<br>
+# CHECK: Type Offset VirtAddr PhysAddr<br>
+# CHECK-NEXT: PHDR 0x000040 0xffffffff80000040 0x0000000000004040<br>
+# CHECK-NEXT: LOAD 0x000000 0xffffffff80000000 0x0000000000004000<br>
+# CHECK-NOT: LOAD<br>
+<br>
+.global _start<br>
+_start:<br>
+nop<br>
<br>
<br>
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</blockquote></div><br></div>