[PATCH] ELF/AArch64: Add support for checking PREL32 for overflow
Will Newton
will.newton at linaro.org
Thu Feb 12 22:53:50 PST 2015
Add support for overflow checking when processing R_AARCH64_PREL32
relocations and add tests.
---
.../ELF/AArch64/AArch64RelocationHandler.cpp | 28 +++++-----
test/elf/AArch64/rel-prel32-overflow.test | 53 +++++++++++++++++++
test/elf/AArch64/rel-prel32.test | 59 ++++++++++++++++++++++
3 files changed, 127 insertions(+), 13 deletions(-)
create mode 100644 test/elf/AArch64/rel-prel32-overflow.test
create mode 100644 test/elf/AArch64/rel-prel32.test
diff --git a/lib/ReaderWriter/ELF/AArch64/AArch64RelocationHandler.cpp b/lib/ReaderWriter/ELF/AArch64/AArch64RelocationHandler.cpp
index 7be9ee9..b001104 100644
--- a/lib/ReaderWriter/ELF/AArch64/AArch64RelocationHandler.cpp
+++ b/lib/ReaderWriter/ELF/AArch64/AArch64RelocationHandler.cpp
@@ -37,15 +37,6 @@ static void relocR_AARCH64_ABS64(uint8_t *location, uint64_t P, uint64_t S,
(int64_t) * reinterpret_cast<llvm::support::little64_t *>(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);
- *reinterpret_cast<llvm::support::little32_t *>(location) =
- result +
- (int32_t) * reinterpret_cast<llvm::support::little32_t *>(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) {
@@ -82,6 +73,18 @@ static std::error_code relocR_AARCH64_ABS16(uint8_t *location, uint64_t P,
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;
+ if (!withinSignedUnsignedRange(result, 32))
+ return make_out_of_range_reloc_error();
+ *reinterpret_cast<llvm::support::little32_t *>(location) =
+ result +
+ (int32_t) * reinterpret_cast<llvm::support::little32_t *>(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) {
@@ -407,16 +410,15 @@ std::error_code AArch64TargetRelocationHandler::applyRelocation(
case R_AARCH64_ABS64:
relocR_AARCH64_ABS64(location, relocVAddress, targetVAddress, ref.addend());
break;
- case R_AARCH64_PREL32:
- relocR_AARCH64_PREL32(location, relocVAddress, targetVAddress,
- ref.addend());
- break;
case R_AARCH64_ABS32:
return relocR_AARCH64_ABS32(location, relocVAddress, targetVAddress,
ref.addend());
case R_AARCH64_ABS16:
return relocR_AARCH64_ABS16(location, relocVAddress, targetVAddress,
ref.addend());
+ case R_AARCH64_PREL32:
+ return relocR_AARCH64_PREL32(location, relocVAddress, targetVAddress,
+ ref.addend());
// Runtime only relocations. Ignore here.
case R_AARCH64_RELATIVE:
case R_AARCH64_IRELATIVE:
diff --git a/test/elf/AArch64/rel-prel32-overflow.test b/test/elf/AArch64/rel-prel32-overflow.test
new file mode 100644
index 0000000..a838a7e
--- /dev/null
+++ b/test/elf/AArch64/rel-prel32-overflow.test
@@ -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
diff --git a/test/elf/AArch64/rel-prel32.test b/test/elf/AArch64/rel-prel32.test
new file mode 100644
index 0000000..11d235a
--- /dev/null
+++ b/test/elf/AArch64/rel-prel32.test
@@ -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
--
2.1.0
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