[llvm] r351361 - [elfabi] Add support for reading DT_SONAME from binaries
Armando Montanez via llvm-commits
llvm-commits at lists.llvm.org
Wed Jan 16 09:47:16 PST 2019
Author: amontanez
Date: Wed Jan 16 09:47:16 2019
New Revision: 351361
URL: http://llvm.org/viewvc/llvm-project?rev=351361&view=rev
Log:
[elfabi] Add support for reading DT_SONAME from binaries
This change gives the llvm-elfabi tool the ability to read DT_SONAME from a binary ELF file into an ELFStub.
Added:
- DynamicEntries struct for storing dynamic entries that are relevant to elfabi.
- terminatedSubstr() retrieves a null-terminated substring from a StringRef.
- appendToError() appends a string to an error, allowing more specific error messages.
Differential Revision: https://reviews.llvm.org/D55629
Added:
llvm/trunk/test/tools/llvm-elfabi/binary-read-add-soname.test
llvm/trunk/test/tools/llvm-elfabi/binary-read-bad-soname.test
llvm/trunk/test/tools/llvm-elfabi/binary-read-bad-vaddr.test
llvm/trunk/test/tools/llvm-elfabi/binary-read-no-dt-strsz.test
llvm/trunk/test/tools/llvm-elfabi/binary-read-no-dt-strtab.test
llvm/trunk/test/tools/llvm-elfabi/binary-read-no-dynamic.test
llvm/trunk/test/tools/llvm-elfabi/binary-read-replace-soname.test
llvm/trunk/test/tools/llvm-elfabi/binary-read-soname-no-null.test
llvm/trunk/test/tools/llvm-elfabi/binary-read-soname.test
Removed:
llvm/trunk/test/tools/llvm-elfabi/replace-soname-tbe.test
Modified:
llvm/trunk/test/tools/llvm-elfabi/binary-read-arch.test
llvm/trunk/tools/llvm-elfabi/ELFObjHandler.cpp
Added: llvm/trunk/test/tools/llvm-elfabi/binary-read-add-soname.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-elfabi/binary-read-add-soname.test?rev=351361&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-elfabi/binary-read-add-soname.test (added)
+++ llvm/trunk/test/tools/llvm-elfabi/binary-read-add-soname.test Wed Jan 16 09:47:16 2019
@@ -0,0 +1,48 @@
+# RUN: yaml2obj %s > %t
+# RUN: llvm-elfabi --elf %t --emit-tbe=- --soname=best.so | FileCheck %s
+
+!ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_DYN
+ Machine: EM_AARCH64
+Sections:
+ - Name: .dynstr
+ Type: SHT_STRTAB
+ Flags: [ SHF_ALLOC ]
+ Address: 0x0000
+ Content: "00"
+ - Name: .dynamic
+ Type: SHT_DYNAMIC
+ Flags: [ SHF_ALLOC ]
+ Address: 0x0008
+ AddressAlign: 8
+ Content: "0a0000000000000001000000000000000500000000000000000000000000000000000000000000000000000000000000"
+ # DT_STRSZ 1 (0x1)
+ # DT_STRTAB 0x0
+ # DT_NULL 0x0
+ Size: 48
+ Link: .dynstr
+ProgramHeaders:
+ - Type: PT_LOAD
+ Flags: [ PF_R ]
+ VAddr: 0x0000
+ PAddr: 0x0000
+ Align: 8
+ Sections:
+ - Section: .dynstr
+ - Section: .dynamic
+ - Type: PT_DYNAMIC
+ Flags: [ PF_X, PF_R ]
+ VAddr: 0x0008
+ PAddr: 0x0008
+ Sections:
+ - Section: .dynamic
+
+# CHECK: --- !tapi-tbe
+# CHECK-NEXT: TbeVersion: {{[1-9]\d*\.(0|([1-9]\d*))}}
+# CHECK-NEXT: SoName: best.so{{$}}
+# CHECK-NEXT: Arch: AArch64
+# CHECK-NEXT: Symbols: {}
+# CHECK-NEXT: ...
Modified: llvm/trunk/test/tools/llvm-elfabi/binary-read-arch.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-elfabi/binary-read-arch.test?rev=351361&r1=351360&r2=351361&view=diff
==============================================================================
--- llvm/trunk/test/tools/llvm-elfabi/binary-read-arch.test (original)
+++ llvm/trunk/test/tools/llvm-elfabi/binary-read-arch.test Wed Jan 16 09:47:16 2019
@@ -1,5 +1,5 @@
# RUN: yaml2obj %s > %t
-# RUN: llvm-elfabi %t --emit-tbe=- | FileCheck %s
+# RUN: llvm-elfabi --elf %t --emit-tbe=- | FileCheck %s
!ELF
FileHeader:
@@ -7,6 +7,38 @@ FileHeader:
Data: ELFDATA2LSB
Type: ET_DYN
Machine: EM_X86_64
+Sections:
+ - Name: .dynstr
+ Type: SHT_STRTAB
+ Flags: [ SHF_ALLOC ]
+ Address: 0x0000
+ Content: "00"
+ - Name: .dynamic
+ Type: SHT_DYNAMIC
+ Flags: [ SHF_ALLOC ]
+ Address: 0x0008
+ AddressAlign: 8
+ Content: "0a0000000000000001000000000000000500000000000000000000000000000000000000000000000000000000000000"
+ # DT_STRSZ 1 (0x1)
+ # DT_STRTAB 0x0
+ # DT_NULL 0x0
+ Size: 48
+ Link: .dynstr
+ProgramHeaders:
+ - Type: PT_LOAD
+ Flags: [ PF_R ]
+ VAddr: 0x0000
+ PAddr: 0x0000
+ Align: 8
+ Sections:
+ - Section: .dynstr
+ - Section: .dynamic
+ - Type: PT_DYNAMIC
+ Flags: [ PF_X, PF_R ]
+ VAddr: 0x0008
+ PAddr: 0x0008
+ Sections:
+ - Section: .dynamic
# CHECK: --- !tapi-tbe
# CHECK-NEXT: TbeVersion: {{[1-9]\d*\.(0|([1-9]\d*))}}
Added: llvm/trunk/test/tools/llvm-elfabi/binary-read-bad-soname.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-elfabi/binary-read-bad-soname.test?rev=351361&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-elfabi/binary-read-bad-soname.test (added)
+++ llvm/trunk/test/tools/llvm-elfabi/binary-read-bad-soname.test Wed Jan 16 09:47:16 2019
@@ -0,0 +1,44 @@
+# 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: 0x0000
+ Content: "00"
+ - Name: .dynamic
+ Type: SHT_DYNAMIC
+ Flags: [ SHF_ALLOC ]
+ Address: 0x0008
+ AddressAlign: 8
+ Content: "0e000000000000000d000000000000000a0000000000000001000000000000000500000000000000000000000000000000000000000000000000000000000000"
+ # DT_SONAME 13 (0x0d)
+ # DT_STRSZ 1 (0x01)
+ # DT_STRTAB 0x0
+ # DT_NULL 0x0
+ Size: 64
+ Link: .dynstr
+ProgramHeaders:
+ - Type: PT_LOAD
+ Flags: [ PF_R ]
+ VAddr: 0x0000
+ PAddr: 0x0000
+ Align: 8
+ Sections:
+ - Section: .dynstr
+ - Section: .dynamic
+ - Type: PT_DYNAMIC
+ Flags: [ PF_X, PF_R ]
+ VAddr: 0x0008
+ PAddr: 0x0008
+ Sections:
+ - Section: .dynamic
+
+# CHECK: DT_SONAME string offset (0x000000000000000d) outside of dynamic string table
Added: llvm/trunk/test/tools/llvm-elfabi/binary-read-bad-vaddr.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-elfabi/binary-read-bad-vaddr.test?rev=351361&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-elfabi/binary-read-bad-vaddr.test (added)
+++ llvm/trunk/test/tools/llvm-elfabi/binary-read-bad-vaddr.test Wed Jan 16 09:47:16 2019
@@ -0,0 +1,44 @@
+# 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
+ Content: "00"
+ - Name: .dynamic
+ Type: SHT_DYNAMIC
+ Flags: [ SHF_ALLOC ]
+ Address: 0x1008
+ AddressAlign: 8
+ Content: "0e0000000000000000000000000000000a0000000000000001000000000000000500000000000000600200000000000000000000000000000000000000000000"
+ # DT_SONAME 0
+ # DT_STRSZ 1
+ # DT_STRTAB 0x0260 # Bad vaddr (no PT_LOAD for 0x0000 to 0x0FFF)
+ # DT_NULL 0x0
+ Size: 64
+ Link: .dynstr
+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: 0x1008
+ PAddr: 0x1008
+ Sections:
+ - Section: .dynamic
+
+# CHECK: Virtual address is not in any segment when locating .dynstr section contents
Added: llvm/trunk/test/tools/llvm-elfabi/binary-read-no-dt-strsz.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-elfabi/binary-read-no-dt-strsz.test?rev=351361&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-elfabi/binary-read-no-dt-strsz.test (added)
+++ llvm/trunk/test/tools/llvm-elfabi/binary-read-no-dt-strsz.test Wed Jan 16 09:47:16 2019
@@ -0,0 +1,43 @@
+# 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: 0x0000
+# \0 b a z\0
+ Content: "0062617a00"
+ - Name: .dynamic
+ Type: SHT_DYNAMIC
+ Flags: [ SHF_ALLOC ]
+ Address: 0x0008
+ AddressAlign: 8
+ Content: "0500000000000000000000000000000000000000000000000000000000000000"
+ # DT_STRTAB 0x0
+ # DT_NULL 0x0
+ Size: 32
+ Link: .dynstr
+ProgramHeaders:
+ - Type: PT_LOAD
+ Flags: [ PF_R ]
+ VAddr: 0x0000
+ PAddr: 0x0000
+ Align: 8
+ Sections:
+ - Section: .dynstr
+ - Section: .dynamic
+ - Type: PT_DYNAMIC
+ Flags: [ PF_X, PF_R ]
+ VAddr: 0x0008
+ PAddr: 0x0008
+ Sections:
+ - Section: .dynamic
+
+# CHECK: Couldn't determine dynamic string table size (no DT_STRSZ entry)
Added: llvm/trunk/test/tools/llvm-elfabi/binary-read-no-dt-strtab.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-elfabi/binary-read-no-dt-strtab.test?rev=351361&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-elfabi/binary-read-no-dt-strtab.test (added)
+++ llvm/trunk/test/tools/llvm-elfabi/binary-read-no-dt-strtab.test Wed Jan 16 09:47:16 2019
@@ -0,0 +1,42 @@
+# 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: 0x0000
+ Content: "00"
+ - Name: .dynamic
+ Type: SHT_DYNAMIC
+ Flags: [ SHF_ALLOC ]
+ Address: 0x0008
+ AddressAlign: 8
+ Content: "0a00000000000000010000000000000000000000000000000000000000000000"
+ # DT_STRSZ 1 (0x1)
+ # DT_NULL 0x0
+ Size: 32
+ Link: .dynstr
+ProgramHeaders:
+ - Type: PT_LOAD
+ Flags: [ PF_R ]
+ VAddr: 0x0000
+ PAddr: 0x0000
+ Align: 8
+ Sections:
+ - Section: .dynstr
+ - Section: .dynamic
+ - Type: PT_DYNAMIC
+ Flags: [ PF_X, PF_R ]
+ VAddr: 0x0008
+ PAddr: 0x0008
+ Sections:
+ - Section: .dynamic
+
+# CHECK: Couldn't locate dynamic string table (no DT_STRTAB entry)
Added: llvm/trunk/test/tools/llvm-elfabi/binary-read-no-dynamic.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-elfabi/binary-read-no-dynamic.test?rev=351361&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-elfabi/binary-read-no-dynamic.test (added)
+++ llvm/trunk/test/tools/llvm-elfabi/binary-read-no-dynamic.test Wed Jan 16 09:47:16 2019
@@ -0,0 +1,11 @@
+# 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
+
+# CHECK: No .dynamic section found
Added: llvm/trunk/test/tools/llvm-elfabi/binary-read-replace-soname.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-elfabi/binary-read-replace-soname.test?rev=351361&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-elfabi/binary-read-replace-soname.test (added)
+++ llvm/trunk/test/tools/llvm-elfabi/binary-read-replace-soname.test Wed Jan 16 09:47:16 2019
@@ -0,0 +1,48 @@
+# RUN: yaml2obj %s > %t
+# RUN: llvm-elfabi --elf %t --emit-tbe=- | FileCheck %s --check-prefix=ORIGINAL
+# RUN: llvm-elfabi --elf %t --emit-tbe=- --soname=libbest.so | FileCheck %s --check-prefix=REPLACED
+
+!ELF
+FileHeader:
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_DYN
+ Machine: EM_X86_64
+Sections:
+ - Name: .dynstr
+ Type: SHT_STRTAB
+ Flags: [ SHF_ALLOC ]
+ Address: 0x1000
+# \0 b a z\0 s o m e l i b . s o\0 f o o\0
+ Content: "0062617a00736f6d656c69622e736f00666f6f00"
+ - Name: .dynamic
+ Type: SHT_DYNAMIC
+ Flags: [ SHF_ALLOC ]
+ Address: 0x1018
+ AddressAlign: 8
+ Content: "0e0000000000000005000000000000000a0000000000000014000000000000000500000000000000001000000000000000000000000000000000000000000000"
+ # DT_SONAME 5 (0x05)
+ # DT_STRSZ 20 (0x14)
+ # DT_STRTAB 0x1000
+ # DT_NULL 0x0
+ Size: 64
+ Link: .dynstr
+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: 0x1018
+ PAddr: 0x1018
+ Sections:
+ - Section: .dynamic
+
+# ORIGINAL: SoName: somelib.so{{$}}
+
+# REPLACED: SoName: libbest.so{{$}}
Added: llvm/trunk/test/tools/llvm-elfabi/binary-read-soname-no-null.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-elfabi/binary-read-soname-no-null.test?rev=351361&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-elfabi/binary-read-soname-no-null.test (added)
+++ llvm/trunk/test/tools/llvm-elfabi/binary-read-soname-no-null.test Wed Jan 16 09:47:16 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
+# \0 b a z\0 s o m e l i b . s o z z z
+ Content: "0062617a00736f6d656c69622e736f7a7a7a"
+ - Name: .dynamic
+ Type: SHT_DYNAMIC
+ Flags: [ SHF_ALLOC ]
+ Address: 0x1018
+ AddressAlign: 8
+ Content: "0e0000000000000005000000000000000a000000000000000f000000000000000500000000000000001000000000000000000000000000000000000000000000"
+ # DT_SONAME 5 (0x05)
+ # DT_STRSZ 15 (0x0F)
+ # DT_STRTAB 0x1000
+ # DT_NULL 0x0
+ Size: 64
+ Link: .dynstr
+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: 0x1018
+ PAddr: 0x1018
+ Sections:
+ - Section: .dynamic
+
+# CHECK: String overran bounds of string table (no null terminator) when reading DT_SONAME
Added: llvm/trunk/test/tools/llvm-elfabi/binary-read-soname.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-elfabi/binary-read-soname.test?rev=351361&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-elfabi/binary-read-soname.test (added)
+++ llvm/trunk/test/tools/llvm-elfabi/binary-read-soname.test Wed Jan 16 09:47:16 2019
@@ -0,0 +1,50 @@
+# RUN: yaml2obj %s > %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
+# \0 b a z\0 s o m e l i b . s o\0 f o o\0
+ Content: "0062617a00736f6d656c69622e736f00666f6f00"
+ - Name: .dynamic
+ Type: SHT_DYNAMIC
+ Flags: [ SHF_ALLOC ]
+ Address: 0x1018
+ AddressAlign: 8
+ Content: "0e0000000000000005000000000000000a0000000000000014000000000000000500000000000000001000000000000000000000000000000000000000000000"
+ # DT_SONAME 5 (0x05)
+ # DT_STRSZ 20 (0x14)
+ # DT_STRTAB 0x1000
+ # DT_NULL 0x0
+ Size: 64
+ Link: .dynstr
+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: 0x1018
+ PAddr: 0x1018
+ Sections:
+ - Section: .dynamic
+
+# CHECK: --- !tapi-tbe
+# CHECK-NEXT: TbeVersion: {{[1-9]\d*\.(0|([1-9]\d*))}}
+# CHECK-NEXT: SoName: somelib.so{{$}}
+# CHECK-NEXT: Arch: x86_64
+# CHECK-NEXT: Symbols: {}
+# CHECK-NEXT: ...
Removed: llvm/trunk/test/tools/llvm-elfabi/replace-soname-tbe.test
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/tools/llvm-elfabi/replace-soname-tbe.test?rev=351360&view=auto
==============================================================================
--- llvm/trunk/test/tools/llvm-elfabi/replace-soname-tbe.test (original)
+++ llvm/trunk/test/tools/llvm-elfabi/replace-soname-tbe.test (removed)
@@ -1,16 +0,0 @@
-# RUN: yaml2obj %s > %t
-# RUN: llvm-elfabi %t --emit-tbe=- --soname=best.so | FileCheck %s
-
-!ELF
-FileHeader:
- Class: ELFCLASS64
- Data: ELFDATA2LSB
- Type: ET_DYN
- Machine: EM_AARCH64
-
-# CHECK: --- !tapi-tbe
-# CHECK-NEXT: TbeVersion: {{[1-9]\d*\.(0|([1-9]\d*))}}
-# CHECK-NEXT: SoName: best.so
-# CHECK-NEXT: Arch: AArch64
-# CHECK-NEXT: Symbols: {}
-# CHECK-NEXT: ...
Modified: llvm/trunk/tools/llvm-elfabi/ELFObjHandler.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/tools/llvm-elfabi/ELFObjHandler.cpp?rev=351361&r1=351360&r2=351361&view=diff
==============================================================================
--- llvm/trunk/tools/llvm-elfabi/ELFObjHandler.cpp (original)
+++ llvm/trunk/tools/llvm-elfabi/ELFObjHandler.cpp Wed Jan 16 09:47:16 2019
@@ -21,23 +21,149 @@ using llvm::object::ELFObjectFile;
using namespace llvm;
using namespace llvm::object;
-using namespace llvm::elfabi;
using namespace llvm::ELF;
namespace llvm {
namespace elfabi {
+// Simple struct to hold relevant .dynamic entries.
+struct DynamicEntries {
+ uint64_t StrTabAddr = 0;
+ uint64_t StrSize = 0;
+ Optional<uint64_t> SONameOffset;
+};
+
+/// This function behaves similarly to StringRef::substr(), but attempts to
+/// terminate the returned StringRef at the first null terminator. If no null
+/// terminator is found, an error is returned.
+///
+/// @param Str Source string to create a substring from.
+/// @param Offset The start index of the desired substring.
+static Expected<StringRef> terminatedSubstr(StringRef Str, size_t Offset) {
+ size_t StrEnd = Str.find('\0', Offset);
+ if (StrEnd == StringLiteral::npos) {
+ return createError(
+ "String overran bounds of string table (no null terminator)");
+ }
+
+ size_t StrLen = StrEnd - Offset;
+ return Str.substr(Offset, StrLen);
+}
+
+/// This function takes an error, and appends a string of text to the end of
+/// that error. Since "appending" to an Error isn't supported behavior of an
+/// Error, this function technically creates a new error with the combined
+/// message and consumes the old error.
+///
+/// @param Err Source error.
+/// @param After Text to append at the end of Err's error message.
+Error appendToError(Error Err, StringRef After) {
+ std::string Message;
+ raw_string_ostream Stream(Message);
+ Stream << Err;
+ Stream << " " << After;
+ consumeError(std::move(Err));
+ return createError(Stream.str().c_str());
+}
+
+/// This function populates a DynamicEntries struct using an ELFT::DynRange.
+/// After populating the struct, the members are validated with
+/// some basic sanity checks.
+///
+/// @param Dyn Target DynamicEntries struct to populate.
+/// @param DynTable Source dynamic table.
+template <class ELFT>
+static Error populateDynamic(DynamicEntries &Dyn,
+ typename ELFT::DynRange DynTable) {
+ if (DynTable.empty())
+ return createError("No .dynamic section found");
+
+ // Search .dynamic for relevant entries.
+ bool FoundDynStr = false;
+ bool FoundDynStrSz = false;
+ for (auto &Entry : DynTable) {
+ switch (Entry.d_tag) {
+ case DT_SONAME:
+ Dyn.SONameOffset = Entry.d_un.d_val;
+ break;
+ case DT_STRTAB:
+ Dyn.StrTabAddr = Entry.d_un.d_ptr;
+ FoundDynStr = true;
+ break;
+ case DT_STRSZ:
+ Dyn.StrSize = Entry.d_un.d_val;
+ FoundDynStrSz = true;
+ break;
+ }
+ }
+
+ if (!FoundDynStr) {
+ return createError(
+ "Couldn't locate dynamic string table (no DT_STRTAB entry)");
+ }
+ if (!FoundDynStrSz) {
+ return createError(
+ "Couldn't determine dynamic string table size (no DT_STRSZ entry)");
+ }
+ if (Dyn.SONameOffset.hasValue() && *Dyn.SONameOffset >= Dyn.StrSize) {
+ return createStringError(
+ object_error::parse_failed,
+ "DT_SONAME string offset (0x%016x) outside of dynamic string table",
+ *Dyn.SONameOffset);
+ }
+
+ return Error::success();
+}
+
/// Returns a new ELFStub with all members populated from an ELFObjectFile.
/// @param ElfObj Source ELFObjectFile.
template <class ELFT>
-Expected<std::unique_ptr<ELFStub>>
+static Expected<std::unique_ptr<ELFStub>>
buildStub(const ELFObjectFile<ELFT> &ElfObj) {
+ using Elf_Dyn_Range = typename ELFT::DynRange;
+ using Elf_Phdr_Range = typename ELFT::PhdrRange;
std::unique_ptr<ELFStub> DestStub = make_unique<ELFStub>();
const ELFFile<ELFT> *ElfFile = ElfObj.getELFFile();
+ // Fetch .dynamic table.
+ Expected<Elf_Dyn_Range> DynTable = ElfFile->dynamicEntries();
+ if (!DynTable) {
+ return DynTable.takeError();
+ }
+
+ // Fetch program headers.
+ Expected<Elf_Phdr_Range> PHdrs = ElfFile->program_headers();
+ if (!PHdrs) {
+ return PHdrs.takeError();
+ }
+
+ // Collect relevant .dynamic entries.
+ DynamicEntries DynEnt;
+ if (Error Err = populateDynamic<ELFT>(DynEnt, *DynTable))
+ return std::move(Err);
+
+ // Convert .dynstr address to an offset.
+ Expected<const uint8_t *> DynStrPtr =
+ ElfFile->toMappedAddr(DynEnt.StrTabAddr);
+ if (!DynStrPtr)
+ return appendToError(DynStrPtr.takeError(),
+ "when locating .dynstr section contents");
+ StringRef DynStr(reinterpret_cast<const char *>(DynStrPtr.get()),
+ DynEnt.StrSize);
+
+ // Populate Arch from ELF header.
DestStub->Arch = ElfFile->getHeader()->e_machine;
- // TODO: Populate SoName from .dynamic entries and linked string table.
+ // Populate SoName from .dynamic entries and dynamic string table.
+ if (DynEnt.SONameOffset.hasValue()) {
+ Expected<StringRef> NameOrErr =
+ terminatedSubstr(DynStr, *DynEnt.SONameOffset);
+ if (!NameOrErr) {
+ return appendToError(NameOrErr.takeError(), "when reading DT_SONAME");
+ }
+ DestStub->SoName = *NameOrErr;
+ }
+
// TODO: Populate NeededLibs from .dynamic entries and linked string table.
// TODO: Populate Symbols from .dynsym table and linked string table.
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