[lld] r234740 - ELF/AArch64: Add support for checking PREL32 for overflow
Adhemerval Zanella
azanella at linux.vnet.ibm.com
Mon Apr 13 04:36:51 PDT 2015
Author: azanella
Date: Mon Apr 13 06:36:51 2015
New Revision: 234740
URL: http://llvm.org/viewvc/llvm-project?rev=234740&view=rev
Log:
ELF/AArch64: Add support for checking PREL32 for overflow
Add support for overflow checking when processing R_AARCH64_PREL32
relocations and add tests.
Patch by Will Newton.
Added:
lld/trunk/test/elf/AArch64/rel-prel32-overflow.test
lld/trunk/test/elf/AArch64/rel-prel32.test
Modified:
lld/trunk/lib/ReaderWriter/ELF/AArch64/AArch64RelocationHandler.cpp
Modified: lld/trunk/lib/ReaderWriter/ELF/AArch64/AArch64RelocationHandler.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/ELF/AArch64/AArch64RelocationHandler.cpp?rev=234740&r1=234739&r2=234740&view=diff
==============================================================================
--- lld/trunk/lib/ReaderWriter/ELF/AArch64/AArch64RelocationHandler.cpp (original)
+++ lld/trunk/lib/ReaderWriter/ELF/AArch64/AArch64RelocationHandler.cpp Mon Apr 13 06:36:51 2015
@@ -39,13 +39,6 @@ static void relocR_AARCH64_ABS64(uint8_t
write64le(location, result | read64le(location));
}
-/// \brief R_AARCH64_PREL32 - word32: S + A - P
-static void relocR_AARCH64_PREL32(uint8_t *location, uint64_t P, uint64_t S,
- int64_t A) {
- int32_t result = (int32_t)(S + A - P);
- write32le(location, result + (int32_t)read32le(location));
-}
-
/// \brief R_AARCH64_ABS32 - word32: S + A
static std::error_code relocR_AARCH64_ABS32(uint8_t *location, uint64_t P,
uint64_t S, int64_t A) {
@@ -76,6 +69,23 @@ static std::error_code relocR_AARCH64_AB
return std::error_code();
}
+/// \brief R_AARCH64_PREL32 - word32: S + A - P
+static std::error_code relocR_AARCH64_PREL32(uint8_t *location, uint64_t P,
+ uint64_t S, int64_t A) {
+ int64_t result = S + A - P;
+ // ELF for the ARM 64-bit architecture manual states the overflow
+ // for R_AARCH64_PREL32 to be -2^(-31) <= X < 2^32
+ if (!withinSignedUnsignedRange(result, 32))
+ return make_out_of_range_reloc_error();
+ DEBUG(llvm::dbgs() << "\t\tHandle " << LLVM_FUNCTION_NAME << " -";
+ llvm::dbgs() << " S: 0x" << Twine::utohexstr(S);
+ llvm::dbgs() << " A: 0x" << Twine::utohexstr(A);
+ llvm::dbgs() << " P: 0x" << Twine::utohexstr(P);
+ llvm::dbgs() << " result: 0x" << Twine::utohexstr(result) << "\n");
+ write32le(location, result + read32le(location));
+ return std::error_code();
+}
+
/// \brief R_AARCH64_ADR_PREL_PG_HI21 - Page(S+A) - Page(P)
static void relocR_AARCH64_ADR_PREL_PG_HI21(uint8_t *location, uint64_t P,
uint64_t S, int64_t A) {
@@ -351,13 +361,12 @@ std::error_code AArch64TargetRelocationH
case R_AARCH64_ABS64:
relocR_AARCH64_ABS64(loc, reloc, target, addend);
break;
- case R_AARCH64_PREL32:
- relocR_AARCH64_PREL32(loc, reloc, target, addend);
- break;
case R_AARCH64_ABS32:
return relocR_AARCH64_ABS32(loc, reloc, target, addend);
case R_AARCH64_ABS16:
return relocR_AARCH64_ABS16(loc, reloc, target, addend);
+ case R_AARCH64_PREL32:
+ return relocR_AARCH64_PREL32(loc, reloc, target, addend);
// Runtime only relocations. Ignore here.
case R_AARCH64_RELATIVE:
case R_AARCH64_IRELATIVE:
Added: lld/trunk/test/elf/AArch64/rel-prel32-overflow.test
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/elf/AArch64/rel-prel32-overflow.test?rev=234740&view=auto
==============================================================================
--- lld/trunk/test/elf/AArch64/rel-prel32-overflow.test (added)
+++ lld/trunk/test/elf/AArch64/rel-prel32-overflow.test Mon Apr 13 06:36:51 2015
@@ -0,0 +1,53 @@
+# Check handling of R_AARCH64_PREL32 relocation overflow.
+# RUN: yaml2obj -format=elf %s > %t-obj
+# RUN: not lld -flavor gnu -target arm64 -o %t-exe %t-obj 2>&1 | FileCheck %s
+
+# CHECK: Relocation out of range in file {{.*}}: reference from data1+0 to data2+34359738369 of type 261 (R_AARCH64_PREL32)
+# CHECK: Relocation out of range in file {{.*}}: reference from data2+0 to data1+34359738369 of type 261 (R_AARCH64_PREL32)
+
+!ELF
+FileHeader: !FileHeader
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_REL
+ Machine: EM_AARCH64
+
+Sections:
+- Name: .text
+ Type: SHT_PROGBITS
+ Content: "00000000"
+ AddressAlign: 16
+ Flags: [SHF_ALLOC, SHF_EXECINSTR]
+- Name: .data
+ Type: SHT_PROGBITS
+ Content: "0000000000000000"
+ AddressAlign: 16
+ Flags: [SHF_ALLOC, SHF_WRITE]
+
+- Name: .rela.data
+ Type: SHT_RELA
+ Info: .data
+ AddressAlign: 8
+ Relocations:
+ - Offset: 0x0
+ Symbol: data2
+ Type: R_AARCH64_PREL32
+ Addend: 0x800000001
+ - Offset: 0x4
+ Symbol: data1
+ Type: R_AARCH64_PREL32
+ Addend: 0x800000001
+
+Symbols:
+ Global:
+ - Name: _start
+ Section: .text
+ Value: 0x0
+ Size: 4
+ - Name: data1
+ Section: .data
+ Size: 4
+ - Name: data2
+ Section: .data
+ Value: 0x4
+ Size: 4
Added: lld/trunk/test/elf/AArch64/rel-prel32.test
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/elf/AArch64/rel-prel32.test?rev=234740&view=auto
==============================================================================
--- lld/trunk/test/elf/AArch64/rel-prel32.test (added)
+++ lld/trunk/test/elf/AArch64/rel-prel32.test Mon Apr 13 06:36:51 2015
@@ -0,0 +1,59 @@
+# Check handling of R_AARCH64_PREL32 relocation.
+# RUN: yaml2obj -format=elf %s > %t-obj
+# RUN: lld -flavor gnu -target arm64 -o %t-exe %t-obj
+# RUN: llvm-objdump -s -t %t-exe | FileCheck %s
+
+# CHECK: Contents of section .data:
+# CHECK-NEXT: 401060 05000080 fdffff7f ........
+# ^^ data2 - data1 + 0x80000001 = 0x80000005
+# ^^ data1 - data2 + 0x80000001 = 0x7ffffffd
+# CHECK: SYMBOL TABLE:
+# CHECK: 00401060 g .data 00000004 data1
+# CHECK: 00401064 g .data 00000004 data2
+
+!ELF
+FileHeader: !FileHeader
+ Class: ELFCLASS64
+ Data: ELFDATA2LSB
+ Type: ET_REL
+ Machine: EM_AARCH64
+
+Sections:
+- Name: .text
+ Type: SHT_PROGBITS
+ Content: "00000000"
+ AddressAlign: 16
+ Flags: [SHF_ALLOC, SHF_EXECINSTR]
+- Name: .data
+ Type: SHT_PROGBITS
+ Content: "0000000000000000"
+ AddressAlign: 16
+ Flags: [SHF_ALLOC, SHF_WRITE]
+
+- Name: .rela.data
+ Type: SHT_RELA
+ Info: .data
+ AddressAlign: 8
+ Relocations:
+ - Offset: 0x0
+ Symbol: data2
+ Type: R_AARCH64_PREL32
+ Addend: 0x80000001
+ - Offset: 0x4
+ Symbol: data1
+ Type: R_AARCH64_PREL32
+ Addend: 0x80000001
+
+Symbols:
+ Global:
+ - Name: _start
+ Section: .text
+ Value: 0x0
+ Size: 4
+ - Name: data1
+ Section: .data
+ Size: 4
+ - Name: data2
+ Section: .data
+ Value: 0x4
+ Size: 4
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