[lld] r338679 - [LLD] - Improve handling of AT> linker script commands
George Rimar via llvm-commits
llvm-commits at lists.llvm.org
Thu Aug 2 01:07:07 PDT 2018
Author: grimar
Date: Thu Aug 2 01:07:07 2018
New Revision: 338679
URL: http://llvm.org/viewvc/llvm-project?rev=338679&view=rev
Log:
[LLD] - Improve handling of AT> linker script commands
Patch by Konstantin Schwarz!
The condition to create a new phdr must also check the usage of "AT>"
linker script command, and create a new PT_LOAD header if a new LMARegion is used.
This fixes PR38307
Differential revision: https://reviews.llvm.org/D50052
Added:
lld/trunk/test/ELF/linkerscript/Inputs/at6.s
lld/trunk/test/ELF/linkerscript/at6.test
Modified:
lld/trunk/ELF/Writer.cpp
Modified: lld/trunk/ELF/Writer.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Writer.cpp?rev=338679&r1=338678&r2=338679&view=diff
==============================================================================
--- lld/trunk/ELF/Writer.cpp (original)
+++ lld/trunk/ELF/Writer.cpp Thu Aug 2 01:07:07 2018
@@ -1815,12 +1815,14 @@ template <class ELFT> std::vector<PhdrEn
// Segments are contiguous memory regions that has the same attributes
// (e.g. executable or writable). There is one phdr for each segment.
// Therefore, we need to create a new phdr when the next section has
- // different flags or is loaded at a discontiguous address using AT linker
- // script command. At the same time, we don't want to create a separate
- // load segment for the headers, even if the first output section has
- // an AT attribute.
+ // different flags or is loaded at a discontiguous address or memory
+ // region using AT or AT> linker script command, respectively. At the same
+ // time, we don't want to create a separate load segment for the headers,
+ // even if the first output section has an AT or AT> attribute.
uint64_t NewFlags = computeFlags(Sec->getPhdrFlags());
- if ((Sec->LMAExpr && Load->LastSec != Out::ProgramHeaders) ||
+ if (((Sec->LMAExpr ||
+ (Sec->LMARegion && (Sec->LMARegion != Load->FirstSec->LMARegion))) &&
+ Load->LastSec != Out::ProgramHeaders) ||
Sec->MemRegion != Load->FirstSec->MemRegion || Flags != NewFlags) {
Load = AddHdr(PT_LOAD, NewFlags);
Added: lld/trunk/test/ELF/linkerscript/Inputs/at6.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/linkerscript/Inputs/at6.s?rev=338679&view=auto
==============================================================================
--- lld/trunk/test/ELF/linkerscript/Inputs/at6.s (added)
+++ lld/trunk/test/ELF/linkerscript/Inputs/at6.s Thu Aug 2 01:07:07 2018
@@ -0,0 +1,11 @@
+.global _start
+.text
+_start:
+nop
+
+.section .sec1,"aw", at progbits
+.long 1
+
+.section .sec2,"aw", at progbits
+.long 2
+
Added: lld/trunk/test/ELF/linkerscript/at6.test
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/linkerscript/at6.test?rev=338679&view=auto
==============================================================================
--- lld/trunk/test/ELF/linkerscript/at6.test (added)
+++ lld/trunk/test/ELF/linkerscript/at6.test Thu Aug 2 01:07:07 2018
@@ -0,0 +1,30 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %p/Inputs/at6.s -o %t.o
+# RUN: ld.lld %t.o --script %s -o %t
+# RUN: llvm-readelf -sections -program-headers %t | FileCheck %s
+
+MEMORY {
+ FLASH : ORIGIN = 0x08000000, LENGTH = 0x100
+ RAM : ORIGIN = 0x20000000, LENGTH = 0x200
+}
+
+SECTIONS {
+ .text : { *(.text) } > FLASH
+ .sec1 : { *(.sec1) } > RAM
+ .sec2 : { *(.sec2) } > RAM AT > FLASH
+}
+
+# Make sure we create a separate PT_LOAD entry for .sec2. Previously,
+# it was added to the PT_LOAD entry of .sec1
+
+# CHECK: Name Type Address Off
+# CHECK: .text PROGBITS 0000000008000000 001000
+# CHECK: .sec1 PROGBITS 0000000020000000 002000
+# CHECK: .sec2 PROGBITS 0000000020000004 002004
+
+# CHECK: Program Headers:
+# CHECK: Type Offset VirtAddr PhysAddr
+# CHECK-NEXT: LOAD 0x001000 0x0000000008000000 0x0000000008000000
+# CHECK-NEXT: LOAD 0x002000 0x0000000020000000 0x0000000020000000
+# CHECK-NEXT: LOAD 0x002004 0x0000000020000004 0x0000000008000001
+# CHECK-NOT: LOAD
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