[llvm] r356136 - [llvm-objcopy]Don't implicitly strip sections in segments
James Henderson via llvm-commits
llvm-commits at lists.llvm.org
Thu Mar 14 04:47:41 PDT 2019
Author: jhenderson
Date: Thu Mar 14 04:47:41 2019
New Revision: 356136
URL: http://llvm.org/viewvc/llvm-project?rev=356136&view=rev
Log:
[llvm-objcopy]Don't implicitly strip sections in segments
This patch changes llvm-objcopy's behaviour to not strip sections that
are in segments, if they otherwise would be due to a stripping operation
(--strip-all, --strip-sections, --strip-non-alloc). This preserves the
segment contents. It does not change the behaviour of --strip-all-gnu
(although we could choose to do so), because GNU objcopy's behaviour in
this case seems to be to strip the section, nor does it prevent removing
of sections in segments with --remove-section (if a user REALLY wants to
remove a section, we should probably let them, although I could be
persuaded that warning might be appropriate). Tests have been added to
show this latter behaviour.
This fixes https://bugs.llvm.org/show_bug.cgi?id=41006.
Reviewed by: grimar, rupprecht, jakehehrlich
Differential Revision: https://reviews.llvm.org/D59293
This is a reland of r356129, attempting to fix greendragon failures
due to a suspected compatibility issue with od on the greendragon bots
versus other versions.
Added:
llvm/trunk/test/tools/llvm-objcopy/ELF/remove-section-in-segment.test
- copied, changed from r356132, llvm/trunk/test/tools/llvm-objcopy/ELF/remove-section-in-segment.test
Modified:
llvm/trunk/test/tools/llvm-objcopy/ELF/strip-all-gnu.test
llvm/trunk/test/tools/llvm-objcopy/ELF/strip-all.test
llvm/trunk/test/tools/llvm-objcopy/ELF/strip-non-alloc.test
llvm/trunk/test/tools/llvm-objcopy/ELF/strip-sections.test
llvm/trunk/tools/llvm-objcopy/ELF/ELFObjcopy.cpp
llvm/trunk/tools/llvm-objcopy/ObjcopyOpts.td
llvm/trunk/tools/llvm-objcopy/StripOpts.td
Copied: llvm/trunk/test/tools/llvm-objcopy/ELF/remove-section-in-segment.test (from r356132, llvm/trunk/test/tools/llvm-objcopy/ELF/remove-section-in-segment.test)
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objcopy/ELF/remove-section-in-segment.test?p2=llvm/trunk/test/tools/llvm-objcopy/ELF/remove-section-in-segment.test&p1=llvm/trunk/test/tools/llvm-objcopy/ELF/remove-section-in-segment.test&r1=356132&r2=356136&rev=356136&view=diff
==============================================================================
--- llvm/trunk/test/tools/llvm-objcopy/ELF/remove-section-in-segment.test (original)
+++ llvm/trunk/test/tools/llvm-objcopy/ELF/remove-section-in-segment.test Thu Mar 14 04:47:41 2019
@@ -6,20 +6,20 @@
# RUN: llvm-objcopy %t %t.copy
# Skip to the start of the sections, which should be immediately after the
# program header table (i.e. sizeof(Elf64_Ehdr) + sizeof(Elf64_Phdr) == 120).
-# RUN: od %t.copy -t x1 -N 16 -j 120 | FileCheck %s --check-prefix=COPY
+# RUN: od -t x1 -N 16 -j 120 %t.copy | FileCheck %s --check-prefix=COPY
# COPY: 11 22 33 44 55 66 77 88
# RUN: llvm-objcopy --remove-section non_alloc %t %t.nonalloc
# RUN: llvm-readelf --sections %t.nonalloc | FileCheck %s --check-prefix=NONALLOC-SHDRS
-# RUN: od %t.nonalloc -t x1 -N 16 -j 120 | FileCheck %s --check-prefix=NONALLOC-BYTES
+# RUN: od -t x1 -N 16 -j 120 %t.nonalloc | FileCheck %s --check-prefix=NONALLOC-BYTES
# NONALLOC-SHDRS-NOT: non_alloc
# NONALLOC-BYTES: 11 22 33 44 00 00 00 00
# RUN: llvm-objcopy --remove-section shf_alloc %t %t.alloc
# RUN: llvm-readelf --sections %t.alloc | FileCheck %s --check-prefix=ALLOC-SHDRS
-# RUN: od %t.alloc -t x1 -N 16 -j 120 | FileCheck %s --check-prefix=ALLOC-BYTES
+# RUN: od -t x1 -N 16 -j 120 %t.alloc | FileCheck %s --check-prefix=ALLOC-BYTES
# ALLOC-SHDRS-NOT: shf_alloc
# ALLOC-BYTES: 00 00 00 00 55 66 77 88
Modified: llvm/trunk/test/tools/llvm-objcopy/ELF/strip-all-gnu.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objcopy/ELF/strip-all-gnu.test?rev=356136&r1=356135&r2=356136&view=diff
==============================================================================
--- llvm/trunk/test/tools/llvm-objcopy/ELF/strip-all-gnu.test (original)
+++ llvm/trunk/test/tools/llvm-objcopy/ELF/strip-all-gnu.test Thu Mar 14 04:47:41 2019
@@ -1,10 +1,15 @@
# RUN: yaml2obj %s > %t
-# RUN: cp %t %t1
# RUN: llvm-objcopy --strip-all-gnu %t %t2
# RUN: llvm-strip --strip-all-gnu %t -o %t3
# RUN: llvm-readobj --file-headers --sections %t2 | FileCheck %s
# RUN: cmp %t2 %t3
+# Show that the debug section in a segment was removed, to match GNU.
+# First validate that the offset in use is correct.
+# RUN: llvm-objcopy %t %t4
+# RUN: od -t x1 -N 4 -j 120 %t4 | FileCheck %s --check-prefix=COPY-BYTES
+# RUN: od -t x1 -N 4 -j 120 %t2 | FileCheck %s --check-prefix=STRIP-BYTES
+
!ELF
FileHeader:
Class: ELFCLASS64
@@ -12,6 +17,10 @@ FileHeader:
Type: ET_REL
Machine: EM_X86_64
Sections:
+ - Name: .debug_in_segment
+ Type: SHT_PROGBITS
+ Flags: [ ]
+ Content: "deadbeef"
- Name: .dynstr
Type: SHT_STRTAB
Flags: [ SHF_ALLOC ]
@@ -45,6 +54,11 @@ Sections:
- Name: .rela.text
Type: SHT_RELA
Info: .text
+ProgramHeaders:
+ # Use an arbitrary segment type to show that the segment type is unimportant.
+ - Type: 0x61234567
+ Sections:
+ - Section: .debug_in_segment
# CHECK: SectionHeaderCount: 8
@@ -55,3 +69,6 @@ Sections:
# CHECK: Name: .comment
# CHECK: Name: .random_section_name
# CHECK: Name: .shstrtab
+
+# COPY-BYTES: de ad be ef
+# STRIP-BYTES: 00 00 00 00
Modified: llvm/trunk/test/tools/llvm-objcopy/ELF/strip-all.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objcopy/ELF/strip-all.test?rev=356136&r1=356135&r2=356136&view=diff
==============================================================================
--- llvm/trunk/test/tools/llvm-objcopy/ELF/strip-all.test (original)
+++ llvm/trunk/test/tools/llvm-objcopy/ELF/strip-all.test Thu Mar 14 04:47:41 2019
@@ -57,6 +57,10 @@ FileHeader:
Type: ET_REL
Machine: EM_X86_64
Sections:
+ - Name: non_alloc_in_segment
+ Type: SHT_PROGBITS
+ Flags: [ ]
+ Size: 4
- Name: .bss
Type: SHT_NOBITS
Flags: [ SHF_ALLOC ]
@@ -68,9 +72,15 @@ Sections:
Flags: [ ]
- Name: .gnu.warning.foo
Type: SHT_PROGBITS
+ProgramHeaders:
+ # Use an arbitrary segment type to show that the segment type is unimportant.
+ - Type: 0x61234567
+ Sections:
+ - Section: non_alloc_in_segment
-# CHECK: SectionHeaderCount: 5
+# CHECK: SectionHeaderCount: 6
+# CHECK: Name: non_alloc_in_segment
# CHECK: Name: .bss
# CHECK: Name: .text
# CHECK: Name: .gnu.warning.foo
Modified: llvm/trunk/test/tools/llvm-objcopy/ELF/strip-non-alloc.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objcopy/ELF/strip-non-alloc.test?rev=356136&r1=356135&r2=356136&view=diff
==============================================================================
--- llvm/trunk/test/tools/llvm-objcopy/ELF/strip-non-alloc.test (original)
+++ llvm/trunk/test/tools/llvm-objcopy/ELF/strip-non-alloc.test Thu Mar 14 04:47:41 2019
@@ -9,6 +9,10 @@ FileHeader:
Type: ET_REL
Machine: EM_X86_64
Sections:
+ - Name: non_alloc_in_segment
+ Type: SHT_PROGBITS
+ Flags: [ ]
+ Size: 4
- Name: .bss
Type: SHT_NOBITS
Flags: [ SHF_ALLOC ]
@@ -18,9 +22,15 @@ Sections:
- Name: .blarg
Type: SHT_PROGBITS
Flags: [ ]
+ProgramHeaders:
+ # Use an arbitrary segment type to show that the segment type is unimportant.
+ - Type: 0x61234567
+ Sections:
+ - Section: non_alloc_in_segment
-# CHECK: SectionHeaderCount: 4
+# CHECK: SectionHeaderCount: 5
+# CHECK: Name: non_alloc_in_segment
# CHECK: Name: .bss
# CHECK: Name: .text
# CHECK: Name: .shstrtab
Modified: llvm/trunk/test/tools/llvm-objcopy/ELF/strip-sections.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-objcopy/ELF/strip-sections.test?rev=356136&r1=356135&r2=356136&view=diff
==============================================================================
--- llvm/trunk/test/tools/llvm-objcopy/ELF/strip-sections.test (original)
+++ llvm/trunk/test/tools/llvm-objcopy/ELF/strip-sections.test Thu Mar 14 04:47:41 2019
@@ -15,13 +15,18 @@ Sections:
Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
AddressAlign: 0x0000000000001000
Content: "DEADBEEF"
+ - Name: .non_alloc_in_segment
+ Type: SHT_PROGBITS
+ Flags: [ ]
+ Content: "CAFEBABE"
ProgramHeaders:
- Type: PT_LOAD
Flags: [ PF_X, PF_R ]
Sections:
- Section: .text
+ - Section: .non_alloc_in_segment
-#DATA: 0010000 de ad be ef
+#DATA: 0010000 de ad be ef ca fe ba be
#CHECK: ElfHeader {
#CHECK-NEXT: Ident {
@@ -55,8 +60,8 @@ ProgramHeaders:
#CHECK-NEXT: Offset: 0x1000
#CHECK-NEXT: VirtualAddress: 0x0
#CHECK-NEXT: PhysicalAddress: 0x0
-#CHECK-NEXT: FileSize: 4
-#CHECK-NEXT: MemSize: 4
+#CHECK-NEXT: FileSize: 8
+#CHECK-NEXT: MemSize: 8
#CHECK-NEXT: Flags [ (0x5)
#CHECK-NEXT: PF_R (0x4)
#CHECK-NEXT: PF_X (0x1)
Modified: llvm/trunk/tools/llvm-objcopy/ELF/ELFObjcopy.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objcopy/ELF/ELFObjcopy.cpp?rev=356136&r1=356135&r2=356136&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-objcopy/ELF/ELFObjcopy.cpp (original)
+++ llvm/trunk/tools/llvm-objcopy/ELF/ELFObjcopy.cpp Thu Mar 14 04:47:41 2019
@@ -403,7 +403,7 @@ static Error handleArgs(const CopyConfig
if (Config.StripSections) {
RemovePred = [RemovePred](const SectionBase &Sec) {
- return RemovePred(Sec) || (Sec.Flags & SHF_ALLOC) == 0;
+ return RemovePred(Sec) || Sec.ParentSegment == nullptr;
};
}
@@ -419,7 +419,7 @@ static Error handleArgs(const CopyConfig
return true;
if (&Sec == Obj.SectionNames)
return false;
- return (Sec.Flags & SHF_ALLOC) == 0;
+ return (Sec.Flags & SHF_ALLOC) == 0 && Sec.ParentSegment == nullptr;
};
if (Config.StripAll)
@@ -430,6 +430,8 @@ static Error handleArgs(const CopyConfig
return false;
if (StringRef(Sec.Name).startswith(".gnu.warning"))
return false;
+ if (Sec.ParentSegment != nullptr)
+ return false;
return (Sec.Flags & SHF_ALLOC) == 0;
};
Modified: llvm/trunk/tools/llvm-objcopy/ObjcopyOpts.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objcopy/ObjcopyOpts.td?rev=356136&r1=356135&r2=356136&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-objcopy/ObjcopyOpts.td (original)
+++ llvm/trunk/tools/llvm-objcopy/ObjcopyOpts.td Thu Mar 14 04:47:41 2019
@@ -103,10 +103,9 @@ defm set_section_flags
"rom, share, contents, merge, strings.">,
MetaVarName<"section=flag1[,flag2,...]">;
-def strip_all
- : Flag<["-", "--"], "strip-all">,
- HelpText<
- "Remove non-allocated sections other than .gnu.warning* sections">;
+def strip_all : Flag<["-", "--"], "strip-all">,
+ HelpText<"Remove non-allocated sections outside segments. "
+ ".gnu.warning* sections are not removed">;
def S : Flag<["-"], "S">, Alias<strip_all>;
def strip_all_gnu : Flag<["-", "--"], "strip-all-gnu">,
HelpText<"Compatible with GNU objcopy's --strip-all">;
@@ -116,13 +115,15 @@ def g : Flag<["-"], "g">, Alias<strip_de
HelpText<"Alias for --strip-debug">;
def strip_dwo : Flag<["-", "--"], "strip-dwo">,
HelpText<"Remove all DWARF .dwo sections from file">;
-def strip_sections : Flag<["-", "--"], "strip-sections">,
- HelpText<"Remove all section headers">;
-def strip_non_alloc : Flag<["-", "--"], "strip-non-alloc">,
- HelpText<"Remove all non-allocated sections">;
+def strip_sections
+ : Flag<["-", "--"], "strip-sections">,
+ HelpText<"Remove all section headers and all sections not in segments">;
+def strip_non_alloc
+ : Flag<["-", "--"], "strip-non-alloc">,
+ HelpText<"Remove all non-allocated sections outside segments">;
def strip_unneeded : Flag<["-", "--"], "strip-unneeded">,
HelpText<"Remove all symbols not needed by relocations">;
-defm strip_unneeded_symbol
+defm strip_unneeded_symbol
: Eq<"strip-unneeded-symbol",
"Remove symbol <symbol> if it is not needed by relocations">,
MetaVarName<"symbol">;
Modified: llvm/trunk/tools/llvm-objcopy/StripOpts.td
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-objcopy/StripOpts.td?rev=356136&r1=356135&r2=356136&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-objcopy/StripOpts.td (original)
+++ llvm/trunk/tools/llvm-objcopy/StripOpts.td Thu Mar 14 04:47:41 2019
@@ -31,10 +31,9 @@ def preserve_dates : Flag<["-", "--"], "
HelpText<"Preserve access and modification timestamps">;
def p : Flag<["-"], "p">, Alias<preserve_dates>;
-def strip_all
- : Flag<["-", "--"], "strip-all">,
- HelpText<
- "Remove non-allocated sections other than .gnu.warning* sections">;
+def strip_all : Flag<["-", "--"], "strip-all">,
+ HelpText<"Remove non-allocated sections outside segments. "
+ ".gnu.warning* sections are not removed">;
def s : Flag<["-"], "s">, Alias<strip_all>;
def strip_all_gnu : Flag<["-", "--"], "strip-all-gnu">,
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