[lld] r337610 - [ELF] Check eh_frame_hdr overflow with PC offsets instead of PC absolute addresses
Fangrui Song via llvm-commits
llvm-commits at lists.llvm.org
Fri Jul 20 13:27:42 PDT 2018
Author: maskray
Date: Fri Jul 20 13:27:42 2018
New Revision: 337610
URL: http://llvm.org/viewvc/llvm-project?rev=337610&view=rev
Log:
[ELF] Check eh_frame_hdr overflow with PC offsets instead of PC absolute addresses
Reviewers: grimar, ruiu, espindola
Subscribers: emaste, arichardson, llvm-commits
Differential Revision: https://reviews.llvm.org/D49607
Added:
lld/trunk/test/ELF/Inputs/eh-frame-pcrel-overflow.s
lld/trunk/test/ELF/eh-frame-pcrel-overflow.s
Removed:
lld/trunk/test/ELF/eh-frame-pcaddr-overflow.s
Modified:
lld/trunk/ELF/SyntheticSections.cpp
lld/trunk/ELF/SyntheticSections.h
Modified: lld/trunk/ELF/SyntheticSections.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/SyntheticSections.cpp?rev=337610&r1=337609&r2=337610&view=diff
==============================================================================
--- lld/trunk/ELF/SyntheticSections.cpp (original)
+++ lld/trunk/ELF/SyntheticSections.cpp Fri Jul 20 13:27:42 2018
@@ -502,16 +502,31 @@ std::vector<EhFrameSection::FdeData> EhF
uint8_t *Buf = getParent()->Loc + OutSecOff;
std::vector<FdeData> Ret;
+ uint64_t VA = InX::EhFrameHdr->getVA();
for (CieRecord *Rec : CieRecords) {
uint8_t Enc = getFdeEncoding(Rec->Cie);
for (EhSectionPiece *Fde : Rec->Fdes) {
uint64_t Pc = getFdePc(Buf, Fde->OutputOff, Enc);
- if (Pc > UINT32_MAX)
- fatal(toString(Fde->Sec) + ": PC address is too large: " + Twine(Pc));
- uint32_t FdeVA = getParent()->Addr + Fde->OutputOff;
- Ret.push_back({(uint32_t)Pc, FdeVA});
+ uint64_t FdeVA = getParent()->Addr + Fde->OutputOff;
+ if (!isInt<32>(Pc - VA))
+ fatal(toString(Fde->Sec) + ": PC offset is too large: 0x" +
+ Twine::utohexstr(Pc - VA));
+ Ret.push_back({uint32_t(Pc - VA), uint32_t(FdeVA - VA)});
}
}
+
+ // Sort the FDE list by their PC and uniqueify. Usually there is only
+ // one FDE for a PC (i.e. function), but if ICF merges two functions
+ // into one, there can be more than one FDEs pointing to the address.
+ auto Less = [](const FdeData &A, const FdeData &B) {
+ return A.PcRel < B.PcRel;
+ };
+ std::stable_sort(Ret.begin(), Ret.end(), Less);
+ auto Eq = [](const FdeData &A, const FdeData &B) {
+ return A.PcRel == B.PcRel;
+ };
+ Ret.erase(std::unique(Ret.begin(), Ret.end(), Eq), Ret.end());
+
return Ret;
}
@@ -2532,14 +2547,6 @@ void EhFrameHeader::writeTo(uint8_t *Buf
std::vector<FdeData> Fdes = InX::EhFrame->getFdeData();
- // Sort the FDE list by their PC and uniqueify. Usually there is only
- // one FDE for a PC (i.e. function), but if ICF merges two functions
- // into one, there can be more than one FDEs pointing to the address.
- auto Less = [](const FdeData &A, const FdeData &B) { return A.Pc < B.Pc; };
- std::stable_sort(Fdes.begin(), Fdes.end(), Less);
- auto Eq = [](const FdeData &A, const FdeData &B) { return A.Pc == B.Pc; };
- Fdes.erase(std::unique(Fdes.begin(), Fdes.end(), Eq), Fdes.end());
-
Buf[0] = 1;
Buf[1] = DW_EH_PE_pcrel | DW_EH_PE_sdata4;
Buf[2] = DW_EH_PE_udata4;
@@ -2548,10 +2555,9 @@ void EhFrameHeader::writeTo(uint8_t *Buf
write32(Buf + 8, Fdes.size());
Buf += 12;
- uint64_t VA = this->getVA();
for (FdeData &Fde : Fdes) {
- write32(Buf, Fde.Pc - VA);
- write32(Buf + 4, Fde.FdeVA - VA);
+ write32(Buf, Fde.PcRel);
+ write32(Buf + 4, Fde.FdeVARel);
Buf += 8;
}
}
Modified: lld/trunk/ELF/SyntheticSections.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/SyntheticSections.h?rev=337610&r1=337609&r2=337610&view=diff
==============================================================================
--- lld/trunk/ELF/SyntheticSections.h (original)
+++ lld/trunk/ELF/SyntheticSections.h Fri Jul 20 13:27:42 2018
@@ -79,8 +79,8 @@ public:
size_t NumFdes = 0;
struct FdeData {
- uint32_t Pc;
- uint32_t FdeVA;
+ uint32_t PcRel;
+ uint32_t FdeVARel;
};
std::vector<FdeData> getFdeData() const;
Added: lld/trunk/test/ELF/Inputs/eh-frame-pcrel-overflow.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/Inputs/eh-frame-pcrel-overflow.s?rev=337610&view=auto
==============================================================================
--- lld/trunk/test/ELF/Inputs/eh-frame-pcrel-overflow.s (added)
+++ lld/trunk/test/ELF/Inputs/eh-frame-pcrel-overflow.s Fri Jul 20 13:27:42 2018
@@ -0,0 +1,25 @@
+.text
+.global foo
+foo:
+ ret
+
+.section .eh_frame, "a"
+ .long 12 # Size
+ .long 0x00 # ID
+ .byte 0x01 # Version.
+
+ .byte 0x52 # Augmentation string: 'R','\0'
+ .byte 0x00
+
+ .byte 0x01
+
+ .byte 0x01 # LEB128
+ .byte 0x01 # LEB128
+
+ .byte 0x00 # DW_EH_PE_absptr
+
+ .byte 0xFF
+
+ .long 12 # Size
+ .long 0x14 # ID
+ .quad foo + 0x90000000
Removed: lld/trunk/test/ELF/eh-frame-pcaddr-overflow.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/eh-frame-pcaddr-overflow.s?rev=337609&view=auto
==============================================================================
--- lld/trunk/test/ELF/eh-frame-pcaddr-overflow.s (original)
+++ lld/trunk/test/ELF/eh-frame-pcaddr-overflow.s (removed)
@@ -1,32 +0,0 @@
-# REQUIRES: x86
-
-# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
-# RUN: not ld.lld --eh-frame-hdr --section-start .text=0x1000000000000000 \
-# RUN: %t.o -o /dev/null 2>&1 | FileCheck %s
-# CHECK: error: {{.*}}.o:(.eh_frame): PC address is too large: 2387527121043355528
-
-.text
-.global foo
-foo:
- nop
-
-.section .eh_frame, "a"
- .long 12 # Size
- .long 0x00 # ID
- .byte 0x01 # Version.
-
- .byte 0x52 # Augmentation string: 'R','\0'
- .byte 0x00
-
- .byte 0x01
-
- .byte 0x01 # LEB128
- .byte 0x01 # LEB128
-
- .byte 0x00 # DW_EH_PE_absptr
-
- .byte 0xFF
-
- .long 12 # Size
- .long 0x14 # ID
- .quad foo + 0x1122334455667788
Added: lld/trunk/test/ELF/eh-frame-pcrel-overflow.s
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/eh-frame-pcrel-overflow.s?rev=337610&view=auto
==============================================================================
--- lld/trunk/test/ELF/eh-frame-pcrel-overflow.s (added)
+++ lld/trunk/test/ELF/eh-frame-pcrel-overflow.s Fri Jul 20 13:27:42 2018
@@ -0,0 +1,33 @@
+# REQUIRES: x86
+
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %p/Inputs/eh-frame-pcrel-overflow.s -o %t1.o
+# RUN: ld.lld --eh-frame-hdr -Ttext=0x90000000 %t.o -o /dev/null
+# RUN: not ld.lld --eh-frame-hdr %t.o %t1.o -o /dev/null 2>&1 | FileCheck %s
+# CHECK: error: {{.*}}.o:(.eh_frame): PC offset is too large: 0x90000eac
+
+.text
+.global _start
+_start:
+ ret
+
+.section .eh_frame, "a"
+ .long 12 # Size
+ .long 0x00 # ID
+ .byte 0x01 # Version.
+
+ .byte 0x52 # Augmentation string: 'R','\0'
+ .byte 0x00
+
+ .byte 0x01
+
+ .byte 0x01 # LEB128
+ .byte 0x01 # LEB128
+
+ .byte 0x00 # DW_EH_PE_absptr
+
+ .byte 0xFF
+
+ .long 12 # Size
+ .long 0x14 # ID
+ .quad _start + 0x70000000
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