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[lld][ELF][AVR] Add range check for R_AVR_13_PCREL #67636

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Merged
merged 1 commit into from
Oct 6, 2023
Merged

[lld][ELF][AVR] Add range check for R_AVR_13_PCREL #67636

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4 changes: 3 additions & 1 deletion lld/ELF/Arch/AVR.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -231,13 +231,14 @@ void AVR::relocate(uint8_t *loc, const Relocation &rel, uint64_t val) const {

// Since every jump destination is word aligned we gain an extra bit
case R_AVR_7_PCREL: {
checkInt(loc, val, 7, rel);
checkInt(loc, val - 2, 7, rel);
checkAlignment(loc, val, 2, rel);
const uint16_t target = (val - 2) >> 1;
write16le(loc, (read16le(loc) & 0xfc07) | ((target & 0x7f) << 3));
break;
}
case R_AVR_13_PCREL: {
checkInt(loc, val - 2, 13, rel);
checkAlignment(loc, val, 2, rel);
const uint16_t target = (val - 2) >> 1;
write16le(loc, (read16le(loc) & 0xf000) | (target & 0xfff));
Expand All @@ -255,6 +256,7 @@ void AVR::relocate(uint8_t *loc, const Relocation &rel, uint64_t val) const {
break;

case R_AVR_CALL: {
checkAlignment(loc, val, 2, rel);
uint16_t hi = val >> 17;
uint16_t lo = val >> 1;
write16le(loc, read16le(loc) | ((hi >> 1) << 4) | (hi & 1));
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53 changes: 53 additions & 0 deletions lld/test/ELF/avr-reloc-error.s
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@@ -0,0 +1,53 @@
# REQUIRES: avr

# RUN: rm -rf %t && split-file %s %t && cd %t

# RUN: llvm-mc -filetype=obj -triple=avr -mcpu=atmega328 avr-pcrel-7.s -o avr-pcrel-7.o
# RUN: not ld.lld avr-pcrel-7.o -o /dev/null -Ttext=0x1000 --defsym=callee0=0x1040 --defsym=callee1=0x1044 --defsym=callee2=0x100f 2>&1 | \
# RUN: FileCheck %s --check-prefix=PCREL7
# RUN: llvm-mc -filetype=obj -triple=avr -mcpu=atmega328 avr-pcrel-13.s -o avr-pcrel-13.o
# RUN: not ld.lld avr-pcrel-13.o -o /dev/null -Ttext=0x1000 --defsym=callee0=0x2000 --defsym=callee1=0x2004 --defsym=callee2=0x100f 2>&1 | \
# RUN: FileCheck %s --check-prefix=PCREL13
# RUN: llvm-mc -filetype=obj -triple=avr -mcpu=atmega328 avr-abs.s -o avr-abs.o
# RUN: not ld.lld avr-abs.o -o /dev/null -Ttext=0x1000 --defsym=callee0=0x1009 --defsym=callee1=0x1010 2>&1 | \
# RUN: FileCheck %s --check-prefix=ABS

#--- avr-pcrel-7.s

.section .LDI,"ax",@progbits

.globl __start
__start:

# PCREL7-NOT: callee0
# PCREL7: error: {{.*}} relocation R_AVR_7_PCREL out of range: {{.*}} is not in [-64, 63]; references 'callee1'
# PCREL7: error: {{.*}} improper alignment for relocation R_AVR_7_PCREL: {{.*}} is not aligned to 2 bytes
brne callee0
breq callee1
brlt callee2

#--- avr-pcrel-13.s

.section .LDI,"ax",@progbits

.globl __start
__start:

# PCREL13-NOT: callee0
# PCREL13: error: {{.*}} relocation R_AVR_13_PCREL out of range: {{.*}} is not in [-4096, 4095]; references 'callee1'
# PCREL13: error: {{.*}} improper alignment for relocation R_AVR_13_PCREL: {{.*}} is not aligned to 2 bytes
rjmp callee0
rcall callee1
rjmp callee2

#--- avr-abs.s

.section .LDI,"ax",@progbits

.globl __start
__start:

# ABS: error: {{.*}} improper alignment for relocation R_AVR_CALL: 0x1009 is not aligned to 2 bytes
# ABS-NOT: 0x1010
call callee0
jmp callee1