[llvm] r351592 - [elfabi] Add support for reading DT_NEEDED from binaries
Armando Montanez via llvm-commits
llvm-commits at lists.llvm.org
Fri Jan 18 12:56:03 PST 2019
Author: amontanez
Date: Fri Jan 18 12:56:03 2019
New Revision: 351592
URL: http://llvm.org/viewvc/llvm-project?rev=351592&view=rev
Log:
[elfabi] Add support for reading DT_NEEDED from binaries
This patch gives elfabi the ability to read DT_NEEDED entries from ELF binaries
to populate NeededLibs in TextAPI's ELFStub.
Differential Revision: https://reviews.llvm.org/D55852
Added:
llvm/trunk/test/tools/llvm-elfabi/binary-read-neededlibs-bad-offset.test
llvm/trunk/test/tools/llvm-elfabi/binary-read-neededlibs.test
Modified:
llvm/trunk/tools/llvm-elfabi/ELFObjHandler.cpp
Added: llvm/trunk/test/tools/llvm-elfabi/binary-read-neededlibs-bad-offset.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-elfabi/binary-read-neededlibs-bad-offset.test?rev=351592&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-elfabi/binary-read-neededlibs-bad-offset.test (added)
+++ llvm/trunk/test/tools/llvm-elfabi/binary-read-neededlibs-bad-offset.test Fri Jan 18 12:56:03 2019
@@ -0,0 +1,45 @@
+# RUN: yaml2obj %s > %t
+# RUN: not llvm-elfabi --elf %t --emit-tbe=%t.tbe 2>&1 | FileCheck %s
+
+!ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_DYN
+ Machine: EM_X86_64
+Sections:
+ - Name: .dynstr
+ Type: SHT_STRTAB
+ Flags: [ SHF_ALLOC ]
+ Address: 0x1000
+ # "\0libfoo.so\0libbar.so\0somelib.so\0foo\0"
+ Content: "006c6962666f6f2e736f006c69626261722e736f00736f6d656c69622e736f00666f6f00"
+ - Name: .dynamic
+ Type: SHT_DYNAMIC
+ Flags: [ SHF_ALLOC ]
+ Address: 0x1024
+ Content: "010000000000000001000000000000000e0000000000000015000000000000000100000000000000ffff0000000000000a0000000000000024000000000000000500000000000000001000000000000000000000000000000000000000000000"
+ # DT_NEEDED 1 (0x01)
+ # DT_SONAME 21 (0x15)
+ # Bad DT_NEEDED entry (offset outside string table):
+ # DT_NEEDED 65535 (0xffff)
+ # DT_STRSZ 36 (0x24)
+ # DT_STRTAB 0x1000
+ # DT_NULL 0x0
+ Size: 96
+ProgramHeaders:
+ - Type: PT_LOAD
+ Flags: [ PF_R ]
+ VAddr: 0x1000
+ PAddr: 0x1000
+ Align: 8
+ Sections:
+ - Section: .dynstr
+ - Section: .dynamic
+ - Type: PT_DYNAMIC
+ Flags: [ PF_X, PF_R ]
+ VAddr: 0x1024
+ PAddr: 0x1024
+ Sections:
+
+# CHECK: DT_NEEDED string offset (0x000000000000ffff) outside of dynamic string table
Added: llvm/trunk/test/tools/llvm-elfabi/binary-read-neededlibs.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-elfabi/binary-read-neededlibs.test?rev=351592&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-elfabi/binary-read-neededlibs.test (added)
+++ llvm/trunk/test/tools/llvm-elfabi/binary-read-neededlibs.test Fri Jan 18 12:56:03 2019
@@ -0,0 +1,47 @@
+# RUN: yaml2obj %s -o %t
+# RUN: llvm-elfabi --elf %t --emit-tbe=- | FileCheck %s
+
+!ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_DYN
+ Machine: EM_X86_64
+Sections:
+ - Name: .dynstr
+ Type: SHT_STRTAB
+ Flags: [ SHF_ALLOC ]
+ Address: 0x1000
+ # "\0libfoo.so\0libbar.so\0somelib.so\0foo\0"
+ Content: "006c6962666f6f2e736f006c69626261722e736f00736f6d656c69622e736f00666f6f00"
+ - Name: .dynamic
+ Type: SHT_DYNAMIC
+ Flags: [ SHF_ALLOC ]
+ Address: 0x1024
+ Content: "010000000000000001000000000000000e00000000000000150000000000000001000000000000000b000000000000000a0000000000000024000000000000000500000000000000001000000000000000000000000000000000000000000000"
+ # DT_NEEDED 1 (0x01)
+ # DT_SONAME 21 (0x15)
+ # DT_NEEDED 11 (0x0b)
+ # DT_STRSZ 36 (0x24)
+ # DT_STRTAB 0x1000
+ # DT_NULL 0x0
+ Size: 96
+ProgramHeaders:
+ - Type: PT_LOAD
+ Flags: [ PF_R ]
+ VAddr: 0x1000
+ PAddr: 0x1000
+ Align: 8
+ Sections:
+ - Section: .dynstr
+ - Section: .dynamic
+ - Type: PT_DYNAMIC
+ Flags: [ PF_X, PF_R ]
+ VAddr: 0x1024
+ PAddr: 0x1024
+ Sections:
+
+# CHECK: NeededLibs:
+# CHECK-NEXT: - libfoo.so{{$}}
+# CHECK-NEXT: - libbar.so{{$}}
+# CHECK-NEXT: Symbols: {}
Modified: llvm/trunk/tools/llvm-elfabi/ELFObjHandler.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-elfabi/ELFObjHandler.cpp?rev=351592&r1=351591&r2=351592&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-elfabi/ELFObjHandler.cpp (original)
+++ llvm/trunk/tools/llvm-elfabi/ELFObjHandler.cpp Fri Jan 18 12:56:03 2019
@@ -31,6 +31,7 @@ struct DynamicEntries {
uint64_t StrTabAddr = 0;
uint64_t StrSize = 0;
Optional<uint64_t> SONameOffset;
+ std::vector<uint64_t> NeededLibNames;
};
/// This function behaves similarly to StringRef::substr(), but attempts to
@@ -94,6 +95,9 @@ static Error populateDynamic(DynamicEntr
Dyn.StrSize = Entry.d_un.d_val;
FoundDynStrSz = true;
break;
+ case DT_NEEDED:
+ Dyn.NeededLibNames.push_back(Entry.d_un.d_val);
+ break;
}
}
@@ -111,6 +115,14 @@ static Error populateDynamic(DynamicEntr
"DT_SONAME string offset (0x%016x) outside of dynamic string table",
*Dyn.SONameOffset);
}
+ for (uint64_t Offset : Dyn.NeededLibNames) {
+ if (Offset >= Dyn.StrSize) {
+ return createStringError(
+ object_error::parse_failed,
+ "DT_NEEDED string offset (0x%016x) outside of dynamic string table",
+ Offset);
+ }
+ }
return Error::success();
}
@@ -164,7 +176,16 @@ buildStub(const ELFObjectFile<ELFT> &Elf
DestStub->SoName = *NameOrErr;
}
- // TODO: Populate NeededLibs from .dynamic entries and linked string table.
+ // Populate NeededLibs from .dynamic entries and dynamic string table.
+ for (uint64_t NeededStrOffset : DynEnt.NeededLibNames) {
+ Expected<StringRef> LibNameOrErr =
+ terminatedSubstr(DynStr, NeededStrOffset);
+ if (!LibNameOrErr) {
+ return appendToError(LibNameOrErr.takeError(), "when reading DT_NEEDED");
+ }
+ DestStub->NeededLibs.push_back(*LibNameOrErr);
+ }
+
// TODO: Populate Symbols from .dynsym table and linked string table.
return std::move(DestStub);
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