[lld] [LLD][AArch64] Increase alignment of AArch64AbsLongThunk to 8 (PR #133738)
Peter Smith via llvm-commits
llvm-commits at lists.llvm.org
Mon Mar 31 10:21:02 PDT 2025
https://github.com/smithp35 updated https://github.com/llvm/llvm-project/pull/133738
>From 348f6d0bdb595eff61367c0d805d2aee14fdff65 Mon Sep 17 00:00:00 2001
From: Peter Smith <peter.smith at arm.com>
Date: Mon, 31 Mar 2025 16:05:57 +0100
Subject: [PATCH 1/2] [LLD][AArch64] Increase alignment of AArch64AbsLongThunk
to 8
This permits an AArch64AbsLongThunk to be used in an environment
where unaligned accesses are disabled.
The AArch64AbsLongThunk does a load of an 8-byte address. When
unaligned accesses are disabled this address must be 8-byte
aligned.
The vast majority of AArch64 systems will have unaligned accesses
enabled in userspace. However, after a reset, before the MMU
has been enabled, all memory accesses are to "device" memory,
which requires aligned accesses. In systems with multi-stage
boot loaders a thunk may be required to a later stage before the
MMU has been enabled.
As we only want to increase the alignment when the ldr is used
we delay the increase in thunk alignment until we know we are
going to write an ldr. We also need to account for the ThunkSection
alignment increase when this happens.
In some of the test updates, particularly those with shared
CHECK lines with position independent thunks it was easier to
ensure that the thunks started at an 8-byte aligned address in
all cases.
---
lld/ELF/SyntheticSections.cpp | 7 +-
lld/ELF/Thunks.cpp | 3 +
lld/test/ELF/aarch64-call26-thunk.s | 16 +-
.../ELF/aarch64-cortex-a53-843419-thunk.s | 2 +-
lld/test/ELF/aarch64-jump26-thunk.s | 15 +-
.../ELF/aarch64-range-thunk-extension-plt32.s | 10 +-
lld/test/ELF/aarch64-thunk-align.s | 42 +++++
lld/test/ELF/aarch64-thunk-bti-multipass.s | 4 +-
lld/test/ELF/aarch64-thunk-bti.s | 150 +++++++++---------
9 files changed, 150 insertions(+), 99 deletions(-)
create mode 100644 lld/test/ELF/aarch64-thunk-align.s
diff --git a/lld/ELF/SyntheticSections.cpp b/lld/ELF/SyntheticSections.cpp
index b03c4282ab1aa..83287efced069 100644
--- a/lld/ELF/SyntheticSections.cpp
+++ b/lld/ELF/SyntheticSections.cpp
@@ -4317,14 +4317,19 @@ InputSection *ThunkSection::getTargetInputSection() const {
bool ThunkSection::assignOffsets() {
uint64_t off = 0;
+ bool alignChange = false;
for (Thunk *t : thunks) {
+ if (t->alignment > addralign) {
+ addralign = t->alignment;
+ alignChange = true;
+ }
off = alignToPowerOf2(off, t->alignment);
t->setOffset(off);
uint32_t size = t->size();
t->getThunkTargetSym()->size = size;
off += size;
}
- bool changed = off != size;
+ bool changed = (off != size) || alignChange;
size = off;
return changed;
}
diff --git a/lld/ELF/Thunks.cpp b/lld/ELF/Thunks.cpp
index 0008ee3a0de67..bad1b4b85735a 100644
--- a/lld/ELF/Thunks.cpp
+++ b/lld/ELF/Thunks.cpp
@@ -674,6 +674,9 @@ void AArch64ABSLongThunk::addSymbols(ThunkSection &isec) {
void AArch64ABSLongThunk::addLongMapSyms() {
addSymbol("$d", STT_NOTYPE, 8, *tsec);
+ // The ldr in the long Thunk requires 8-byte alignment when
+ // unaligned accesses are disabled.
+ alignment = 8;
}
void AArch64ABSXOLongThunk::writeLong(uint8_t *buf) {
diff --git a/lld/test/ELF/aarch64-call26-thunk.s b/lld/test/ELF/aarch64-call26-thunk.s
index 8c3034f568b39..4200bb09eaef7 100644
--- a/lld/test/ELF/aarch64-call26-thunk.s
+++ b/lld/test/ELF/aarch64-call26-thunk.s
@@ -9,13 +9,13 @@
_start:
bl big
-// CHECK: Disassembly of section .text:
+// CHECK-LABEL: <_start>:
+// CHECK-NEXT: 210120: bl 0x210128 <__AArch64AbsLongThunk_big>
+// CHECK-NEXT: udf #0x0
// CHECK-EMPTY:
-// CHECK-NEXT: <_start>:
-// CHECK-NEXT: 210120: bl 0x210124
-// CHECK: <__AArch64AbsLongThunk_big>:
-// CHECK-NEXT: 210124: ldr x16, 0x21012c
-// CHECK-NEXT: 210128: br x16
-// CHECK-NEXT: 21012c: 00 00 00 00 .word 0x00000000
-// CHECK-NEXT: 210130: 10 00 00 00 .word 0x00000010
+// CHECK-LABEL: <__AArch64AbsLongThunk_big>:
+// CHECK-NEXT: 210128: ldr x16, 0x210130 <__AArch64AbsLongThunk_big+0x8>
+// CHECK-NEXT: br x16
+// CHECK-NEXT: 00 00 00 00 .word 0x00000000
+// CHECK-NEXT: 10 00 00 00 .word 0x00000010
diff --git a/lld/test/ELF/aarch64-cortex-a53-843419-thunk.s b/lld/test/ELF/aarch64-cortex-a53-843419-thunk.s
index 484de11ac5541..4fca2113c39a6 100644
--- a/lld/test/ELF/aarch64-cortex-a53-843419-thunk.s
+++ b/lld/test/ELF/aarch64-cortex-a53-843419-thunk.s
@@ -24,7 +24,7 @@ _start:
/// Thunk to far_away, size 16-bytes goes here.
.section .text.02, "ax", %progbits
- .space 4096 - 28
+ .space 4096 - 32
/// Erratum sequence will only line up at address 0 modulo 0xffc when
/// Thunk is inserted.
diff --git a/lld/test/ELF/aarch64-jump26-thunk.s b/lld/test/ELF/aarch64-jump26-thunk.s
index 7fea5eebc3668..3c9ce69920efc 100644
--- a/lld/test/ELF/aarch64-jump26-thunk.s
+++ b/lld/test/ELF/aarch64-jump26-thunk.s
@@ -11,10 +11,11 @@ _start:
// CHECK: Disassembly of section .text:
// CHECK-EMPTY:
-// CHECK-NEXT: <_start>:
-// CHECK-NEXT: 210120: b 0x210124
-// CHECK: <__AArch64AbsLongThunk_big>:
-// CHECK-NEXT: 210124: ldr x16, 0x21012c
-// CHECK-NEXT: 210128: br x16
-// CHECK-NEXT: 21012c: 00 00 00 00 .word 0x00000000
-// CHECK-NEXT: 210130: 10 00 00 00 .word 0x00000010
+// CHECK-LABEL: <_start>:
+// CHECK-NEXT: 210120: b 0x210128
+// CHECK-NEXT: udf #0x0
+// CHECK-LABEL: <__AArch64AbsLongThunk_big>:
+// CHECK-NEXT: 210128: ldr x16, 0x210130
+// CHECK-NEXT: br x16
+// CHECK-NEXT: 00 00 00 00 .word 0x00000000
+// CHECK-NEXT: 10 00 00 00 .word 0x00000010
diff --git a/lld/test/ELF/aarch64-range-thunk-extension-plt32.s b/lld/test/ELF/aarch64-range-thunk-extension-plt32.s
index 1d09012a2295c..9ebf7f5c69526 100644
--- a/lld/test/ELF/aarch64-range-thunk-extension-plt32.s
+++ b/lld/test/ELF/aarch64-range-thunk-extension-plt32.s
@@ -9,14 +9,14 @@
// The word should be an offset to the range extension thunk.
// CHECK-LABEL: <_start>:
-// CHECK-NEXT: 10000: 04 00 00 00 .word 0x00000004
+// CHECK-NEXT: 10000: 08 00 00 00 .word 0x00000008
// The thunk redirects to the address of callee.
// CHECK-LABEL: <__AArch64AbsLongThunk_callee>:
-// CHECK-NEXT: 10004: ldr x16, 0x1000c <__AArch64AbsLongThunk_callee+0x8>
-// CHECK-NEXT: 10008: br x16
-// CHECK-NEXT: 1000c: 00 00 00 00 .word 0x00000000
-// CHECK-NEXT: 10010: 02 00 00 00 .word 0x00000002
+// CHECK-NEXT: 10008: ldr x16, 0x10010 <__AArch64AbsLongThunk_callee+0x8>
+// CHECK-NEXT: br x16
+// CHECK-NEXT: 00 00 00 00 .word 0x00000000
+// CHECK-NEXT: 02 00 00 00 .word 0x00000002
// CHECK-LABEL: <callee>:
// CHECK-NEXT: 200000000: ret
diff --git a/lld/test/ELF/aarch64-thunk-align.s b/lld/test/ELF/aarch64-thunk-align.s
new file mode 100644
index 0000000000000..425a00c7564a4
--- /dev/null
+++ b/lld/test/ELF/aarch64-thunk-align.s
@@ -0,0 +1,42 @@
+// REQUIRES: aarch64
+// RUN: llvm-mc -filetype=obj -triple=aarch64 %s -o %t
+// RUN: ld.lld -Ttext=0x12000 -defsym long=0x10000000 -defsym short=0x8012004 -defsym short2=0x8012008 -defsym short3=0x801200c %t -o %t.exe
+// RUN: llvm-objdump -d --no-show-raw-insn %t.exe | FileCheck %s
+
+/// The AArch64AbsLongThunk requires 8-byte alignment just in case unaligned
+/// accesses are disabled. This increases the thunk section alignment to 8,
+/// and the alignment of the AArch64AbsLongThunk to 8. The short thunk form
+/// can still use 4-byte alignment.
+.text
+.type _start, %function
+.globl _start
+_start:
+ b short
+ b short2
+ b short3
+ b long
+ nop
+
+// CHECK-LABEL: <_start>:
+// CHECK-NEXT: 12000: b 0x12018 <__AArch64AbsLongThunk_short>
+// CHECK-NEXT: b 0x1201c <__AArch64AbsLongThunk_short2>
+// CHECK-NEXT: b 0x12020 <__AArch64AbsLongThunk_short3>
+// CHECK-NEXT: b 0x12028 <__AArch64AbsLongThunk_long>
+// CHECK-NEXT: nop
+// CHECK-NEXT: udf #0x0
+// CHECK-EMPTY:
+// CHECK-LABEL: <__AArch64AbsLongThunk_short>:
+// CHECK-NEXT: 12018: b 0x8012004 <__AArch64AbsLongThunk_long+0x7ffffdc>
+// CHECK-EMPY:
+// CHECK-LABEL: <__AArch64AbsLongThunk_short2>:
+// CHECK-NEXT: 1201c: b 0x8012008 <__AArch64AbsLongThunk_long+0x7ffffe0>
+// CHECK-EMPTY:
+// CHECK-LABEL: <__AArch64AbsLongThunk_short3>:
+// CHECK-NEXT: 12020: b 0x801200c <__AArch64AbsLongThunk_long+0x7ffffe4>
+// CHECK-NEXT: udf #0x0
+// CHECK-EMPTY:
+// CHECK-LABEL: <__AArch64AbsLongThunk_long>:
+// CHECK-NEXT: 12028: ldr x16, 0x12030 <__AArch64AbsLongThunk_long+0x8>
+// CHECK-NEXT: br x16
+// CHECK-NEXT: 00 00 00 10 .word 0x10000000
+// CHECK-NEXT: 00 00 00 00 .word 0x00000000
diff --git a/lld/test/ELF/aarch64-thunk-bti-multipass.s b/lld/test/ELF/aarch64-thunk-bti-multipass.s
index 4f0d7343cc6bf..f2ff914fb850d 100644
--- a/lld/test/ELF/aarch64-thunk-bti-multipass.s
+++ b/lld/test/ELF/aarch64-thunk-bti-multipass.s
@@ -38,10 +38,10 @@ _start:
/// and will need a long branch thunk, which in turn needs a BTI landing pad.
// CHECK-LABEL: <_start>:
-// CHECK-NEXT: 10001000: bl 0x10002004 <__AArch64AbsLongThunk_fn1>
+// CHECK-NEXT: 10001000: bl 0x10002008 <__AArch64AbsLongThunk_fn1>
// CHECK-LABEL: <__AArch64AbsLongThunk_fn1>:
-// CHECK-NEXT: 10002004: ldr x16, 0x1000200c <__AArch64AbsLongThunk_fn1+0x8>
+// CHECK-NEXT: 10002008: ldr x16, 0x10002010 <__AArch64AbsLongThunk_fn1+0x8>
// CHECK-NEXT: br x16
// CHECK-NEXT: 00 30 00 18 .word 0x18003000
// CHECK-NEXT: 00 00 00 00 .word 0x00000000
diff --git a/lld/test/ELF/aarch64-thunk-bti.s b/lld/test/ELF/aarch64-thunk-bti.s
index a447fe4ee9274..0672ad75d8094 100644
--- a/lld/test/ELF/aarch64-thunk-bti.s
+++ b/lld/test/ELF/aarch64-thunk-bti.s
@@ -52,19 +52,17 @@ _start:
bl via_plt
/// We cannot add landing pads for absolute symbols.
bl absolute
-
/// padding so that we require thunks that can be placed after this section.
/// The thunks are close enough to the target to be short.
+ .balign 8
.space 0x1000
// CHECK-PADS-LABEL: <_start>:
-// CHECK-PADS-NEXT: 10001000: bl 0x1000203c
-// CHECK-PADS-NEXT: bl 0x10002040
+// CHECK-PADS-NEXT: 10001000: bl 0x10002040
// CHECK-PADS-NEXT: bl 0x10002044
// CHECK-PADS-NEXT: bl 0x10002048
// CHECK-PADS-NEXT: bl 0x1000204c
// CHECK-PADS-NEXT: bl 0x10002050
-// CHECK-PADS-NEXT: b 0x10002050
// CHECK-PADS-NEXT: bl 0x10002054
// CHECK-PADS-NEXT: b 0x10002054
// CHECK-PADS-NEXT: bl 0x10002058
@@ -72,73 +70,75 @@ _start:
// CHECK-PADS-NEXT: bl 0x1000205c
// CHECK-PADS-NEXT: b 0x1000205c
// CHECK-PADS-NEXT: bl 0x10002060
+// CHECK-PADS-NEXT: b 0x10002060
// CHECK-PADS-NEXT: bl 0x10002064
+// CHECK-PADS-NEXT: bl 0x10002068
// CHECK-LABEL: <__AArch64ADRPThunk_>:
-// CHECK-NEXT: 1000203c: b 0x18001000 <bti_c_target>
+// CHECK-NEXT: 10002040: b 0x18001000 <bti_c_target>
// CHECK-LABEL: <__AArch64ADRPThunk_>:
-// CHECK-NEXT: 10002040: b 0x18001008 <bti_j_target>
+// CHECK-NEXT: 10002044: b 0x18001008 <bti_j_target>
// CHECK-LABEL: <__AArch64ADRPThunk_>:
-// CHECK-NEXT: 10002044: b 0x18001010 <bti_jc_target>
+// CHECK-NEXT: 10002048: b 0x18001010 <bti_jc_target>
// CHECK-LABEL: <__AArch64ADRPThunk_>:
-// CHECK-NEXT: 10002048: b 0x18001018 <paciasp_target>
+// CHECK-NEXT: 1000204c: b 0x18001018 <paciasp_target>
// CHECK-LABEL: <__AArch64ADRPThunk_>:
-// CHECK-NEXT: 1000204c: b 0x18001020 <pacibsp_target>
+// CHECK-NEXT: 10002050: b 0x18001020 <pacibsp_target>
// CHECK-LABEL: <__AArch64ADRPThunk_>:
-// CHECK-NEXT: 10002050: b 0x18001038 <fn2>
+// CHECK-NEXT: 10002054: b 0x18001038 <fn2>
// CHECK-LABEL: <__AArch64ADRPThunk_>:
-// CHECK-NEXT: 10002054: b 0x18001034 <fn1>
+// CHECK-NEXT: 10002058: b 0x18001034 <fn1>
// CHECK-LABEL: <__AArch64ADRPThunk_>:
-// CHECK-NEXT: 10002058: b 0x18001040 <fn3>
+// CHECK-NEXT: 1000205c: b 0x18001040 <fn3>
// CHECK-LABEL: <__AArch64ADRPThunk_>:
-// CHECK-NEXT: 1000205c: b 0x18001050 <fn4>
+// CHECK-NEXT: 10002060: b 0x18001050 <fn4>
// CHECK-LABEL: <__AArch64ADRPThunk_via_plt>:
-// CHECK-NEXT: 10002060: b 0x18001080 <via_plt at plt>
+// CHECK-NEXT: 10002064: b 0x18001080 <via_plt at plt>
// CHECK-LABEL: <__AArch64ADRPThunk_absolute>:
-// CHECK-NEXT: 10002064: b 0x18001098 <absolute at plt>
+// CHECK-NEXT: 10002068: b 0x18001098 <absolute at plt>
// CHECK-EXE-LABEL: <__AArch64AbsLongThunk_>:
-// CHECK-EXE-NEXT: 1000203c: b 0x18001000 <bti_c_target>
+// CHECK-EXE-NEXT: 10002040: b 0x18001000 <bti_c_target>
// CHECK-EXE-LABEL: <__AArch64AbsLongThunk_>:
-// CHECK-EXE-NEXT: 10002040: b 0x18001008 <bti_j_target>
+// CHECK-EXE-NEXT: 10002044: b 0x18001008 <bti_j_target>
// CHECK-EXE-LABEL: <__AArch64AbsLongThunk_>:
-// CHECK-EXE-NEXT: 10002044: b 0x18001010 <bti_jc_target>
+// CHECK-EXE-NEXT: 10002048: b 0x18001010 <bti_jc_target>
// CHECK-EXE-LABEL: <__AArch64AbsLongThunk_>:
-// CHECK-EXE-NEXT: 10002048: b 0x18001018 <paciasp_target>
+// CHECK-EXE-NEXT: 1000204c: b 0x18001018 <paciasp_target>
// CHECK-EXE-LABEL: <__AArch64AbsLongThunk_>:
-// CHECK-EXE-NEXT: 1000204c: b 0x18001020 <pacibsp_target>
+// CHECK-EXE-NEXT: 10002050: b 0x18001020 <pacibsp_target>
// CHECK-EXE-LABEL: <__AArch64AbsLongThunk_>:
-// CHECK-EXE-NEXT: 10002050: b 0x18001038 <fn2>
+// CHECK-EXE-NEXT: 10002054: b 0x18001038 <fn2>
// CHECK-EXE-LABEL: <__AArch64AbsLongThunk_>:
-// CHECK-EXE-NEXT: 10002054: b 0x18001034 <fn1>
+// CHECK-EXE-NEXT: 10002058: b 0x18001034 <fn1>
// CHECK-EXE-LABEL: <__AArch64AbsLongThunk_>:
-// CHECK-EXE-NEXT: 10002058: b 0x18001040 <fn3>
+// CHECK-EXE-NEXT: 1000205c: b 0x18001040 <fn3>
// CHECK-EXE-LABEL: <__AArch64AbsLongThunk_>:
-// CHECK-EXE-NEXT: 1000205c: b 0x18001050 <fn4>
+// CHECK-EXE-NEXT: 10002060: b 0x18001050 <fn4>
// CHECK-EXE-LABEL: <__AArch64AbsLongThunk_via_plt>:
-// CHECK-EXE-NEXT: 10002060: b 0x18001080 <via_plt at plt>
+// CHECK-EXE-NEXT: 10002064: b 0x18001080 <via_plt at plt>
// CHECK-EXE-LABEL: <__AArch64AbsLongThunk_absolute>:
-// CHECK-EXE-NEXT: 10002064: ldr x16, 0x1000206c <__AArch64AbsLongThunk_absolute+0x8>
+// CHECK-EXE-NEXT: 10002068: ldr x16, 0x10002070 <__AArch64AbsLongThunk_absolute+0x8>
// CHECK-EXE-NEXT: br x16
// CHECK-EXE-NEXT: 00 00 00 f0 .word 0xf0000000
// CHECK-EXE-NEXT: 00 00 00 00 .word 0x00000000
@@ -278,21 +278,21 @@ long_calls:
bl via_plt
/// We cannot add landing pads for absolute symbols.
bl absolute
-
+ .balign 8
/// PLT entries have BTI at start.
// CHECK-LABEL: <via_plt at plt>:
// CHECK-NEXT: bti c
// CHECK-NEXT: adrp x16, 0x30000000
-// CHECK-NEXT: ldr x17, [x16, #0x198]
-// CHECK-NEXT: add x16, x16, #0x198
+// CHECK-NEXT: ldr x17, [x16, #0x1a0]
+// CHECK-NEXT: add x16, x16, #0x1a0
// CHECK-NEXT: br x17
// CHECK-NEXT: nop
// CHECK: <absolute at plt>:
// CHECK-NEXT: bti c
// CHECK-NEXT: adrp x16, 0x30000000
-// CHECK-NEXT: ldr x17, [x16, #0x1a0]
-// CHECK-NEXT: add x16, x16, #0x1a0
+// CHECK-NEXT: ldr x17, [x16, #0x1a8]
+// CHECK-NEXT: add x16, x16, #0x1a8
// CHECK-NEXT: br x17
// CHECK-NEXT: nop
@@ -305,25 +305,25 @@ long_calls:
// CHECK-EXE-NEXT: nop
// CHECK-LABEL: <long_calls>:
-// CHECK-NEXT: 30000000: bl 0x3000003c <__AArch64ADRPThunk_>
-// CHECK-NEXT: bl 0x30000048 <__AArch64ADRPThunk_>
-// CHECK-NEXT: bl 0x30000054 <__AArch64ADRPThunk_>
-// CHECK-NEXT: bl 0x30000060 <__AArch64ADRPThunk_>
-// CHECK-NEXT: bl 0x3000006c <__AArch64ADRPThunk_>
-// CHECK-NEXT: bl 0x30000078 <__AArch64ADRPThunk_>
-// CHECK-NEXT: b 0x30000078 <__AArch64ADRPThunk_>
-// CHECK-NEXT: bl 0x30000084 <__AArch64ADRPThunk_>
-// CHECK-NEXT: b 0x30000084 <__AArch64ADRPThunk_>
-// CHECK-NEXT: bl 0x30000090 <__AArch64ADRPThunk_>
-// CHECK-NEXT: b 0x30000090 <__AArch64ADRPThunk_>
-// CHECK-NEXT: bl 0x3000009c <__AArch64ADRPThunk_>
-// CHECK-NEXT: b 0x3000009c <__AArch64ADRPThunk_>
-// CHECK-NEXT: bl 0x300000a8 <__AArch64ADRPThunk_via_plt>
-// CHECK-NEXT: bl 0x300000b4 <__AArch64ADRPThunk_absolute>
+// CHECK-NEXT: 30000000: bl 0x30000040 <__AArch64ADRPThunk_>
+// CHECK-NEXT: bl 0x3000004c <__AArch64ADRPThunk_>
+// CHECK-NEXT: bl 0x30000058 <__AArch64ADRPThunk_>
+// CHECK-NEXT: bl 0x30000064 <__AArch64ADRPThunk_>
+// CHECK-NEXT: bl 0x30000070 <__AArch64ADRPThunk_>
+// CHECK-NEXT: bl 0x3000007c <__AArch64ADRPThunk_>
+// CHECK-NEXT: b 0x3000007c <__AArch64ADRPThunk_>
+// CHECK-NEXT: bl 0x30000088 <__AArch64ADRPThunk_>
+// CHECK-NEXT: b 0x30000088 <__AArch64ADRPThunk_>
+// CHECK-NEXT: bl 0x30000094 <__AArch64ADRPThunk_>
+// CHECK-NEXT: b 0x30000094 <__AArch64ADRPThunk_>
+// CHECK-NEXT: bl 0x300000a0 <__AArch64ADRPThunk_>
+// CHECK-NEXT: b 0x300000a0 <__AArch64ADRPThunk_>
+// CHECK-NEXT: bl 0x300000ac <__AArch64ADRPThunk_via_plt>
+// CHECK-NEXT: bl 0x300000b8 <__AArch64ADRPThunk_absolute>
/// bti_c_target.
// CHECK-LABEL: <__AArch64ADRPThunk_>:
-// CHECK-NEXT: 3000003c: adrp x16, 0x18001000 <bti_c_target>
+// CHECK-NEXT: 30000040: adrp x16, 0x18001000 <bti_c_target>
// CHECK-NEXT: add x16, x16, #0x0
// CHECK-NEXT: br x16
/// bti_j_target.
@@ -378,84 +378,84 @@ long_calls:
// CHECK-NEXT: br x16
// CHECK-EXE-LABEL: <long_calls>:
-// CHECK-EXE-NEXT: 30000000: bl 0x3000003c <__AArch64AbsLongThunk_>
-// CHECK-EXE-NEXT: bl 0x3000004c <__AArch64AbsLongThunk_>
-// CHECK-EXE-NEXT: bl 0x3000005c <__AArch64AbsLongThunk_>
-// CHECK-EXE-NEXT: bl 0x3000006c <__AArch64AbsLongThunk_>
-// CHECK-EXE-NEXT: bl 0x3000007c <__AArch64AbsLongThunk_>
-// CHECK-EXE-NEXT: bl 0x3000008c <__AArch64AbsLongThunk_>
-// CHECK-EXE-NEXT: b 0x3000008c <__AArch64AbsLongThunk_>
-// CHECK-EXE-NEXT: bl 0x3000009c <__AArch64AbsLongThunk_>
-// CHECK-EXE-NEXT: b 0x3000009c <__AArch64AbsLongThunk_>
-// CHECK-EXE-NEXT: bl 0x300000ac <__AArch64AbsLongThunk_>
-// CHECK-EXE-NEXT: b 0x300000ac <__AArch64AbsLongThunk_>
-// CHECK-EXE-NEXT: bl 0x300000bc <__AArch64AbsLongThunk_>
-// CHECK-EXE-NEXT: b 0x300000bc <__AArch64AbsLongThunk_>
-// CHECK-EXE-NEXT: bl 0x300000cc <__AArch64AbsLongThunk_via_plt>
-// CHECK-EXE-NEXT: bl 0x300000dc <__AArch64AbsLongThunk_absolute>
-
-// CHECK-EXE-LABEL: 000000003000003c <__AArch64AbsLongThunk_>:
-// CHECK-EXE-NEXT: 3000003c: ldr x16, 0x30000044 <__AArch64AbsLongThunk_+0x8>
+// CHECK-EXE-NEXT: 30000000: bl 0x30000040 <__AArch64AbsLongThunk_>
+// CHECK-EXE-NEXT: bl 0x30000050 <__AArch64AbsLongThunk_>
+// CHECK-EXE-NEXT: bl 0x30000060 <__AArch64AbsLongThunk_>
+// CHECK-EXE-NEXT: bl 0x30000070 <__AArch64AbsLongThunk_>
+// CHECK-EXE-NEXT: bl 0x30000080 <__AArch64AbsLongThunk_>
+// CHECK-EXE-NEXT: bl 0x30000090 <__AArch64AbsLongThunk_>
+// CHECK-EXE-NEXT: b 0x30000090 <__AArch64AbsLongThunk_>
+// CHECK-EXE-NEXT: bl 0x300000a0 <__AArch64AbsLongThunk_>
+// CHECK-EXE-NEXT: b 0x300000a0 <__AArch64AbsLongThunk_>
+// CHECK-EXE-NEXT: bl 0x300000b0 <__AArch64AbsLongThunk_>
+// CHECK-EXE-NEXT: b 0x300000b0 <__AArch64AbsLongThunk_>
+// CHECK-EXE-NEXT: bl 0x300000c0 <__AArch64AbsLongThunk_>
+// CHECK-EXE-NEXT: b 0x300000c0 <__AArch64AbsLongThunk_>
+// CHECK-EXE-NEXT: bl 0x300000d0 <__AArch64AbsLongThunk_via_plt>
+// CHECK-EXE-NEXT: bl 0x300000e0 <__AArch64AbsLongThunk_absolute>
+
+// CHECK-EXE-LABEL: 0000000030000040 <__AArch64AbsLongThunk_>:
+// CHECK-EXE-NEXT: 30000040: ldr x16, 0x30000048 <__AArch64AbsLongThunk_+0x8>
// CHECK-EXE-NEXT: br x16
// CHECK-EXE-NEXT: 00 10 00 18 .word 0x18001000
// CHECK-EXE-NEXT: 00 00 00 00 .word 0x00000000
// CHECK-EXE-LABEL: <__AArch64AbsLongThunk_>:
-// CHECK-EXE-NEXT: 3000004c: ldr x16, 0x30000054 <__AArch64AbsLongThunk_+0x8>
+// CHECK-EXE-NEXT: 30000050: ldr x16, 0x30000058 <__AArch64AbsLongThunk_+0x8>
// CHECK-EXE-NEXT: br x16
// CHECK-EXE-NEXT: 08 10 00 18 .word 0x18001008
// CHECK-EXE-NEXT: 00 00 00 00 .word 0x00000000
// CHECK-EXE-LABEL: <__AArch64AbsLongThunk_>:
-// CHECK-EXE-NEXT: 3000005c: ldr x16, 0x30000064 <__AArch64AbsLongThunk_+0x8>
+// CHECK-EXE-NEXT: 30000060: ldr x16, 0x30000068 <__AArch64AbsLongThunk_+0x8>
// CHECK-EXE-NEXT: br x16
// CHECK-EXE-NEXT: 10 10 00 18 .word 0x18001010
// CHECK-EXE-NEXT: 00 00 00 00 .word 0x00000000
// CHECK-EXE-LABEL: <__AArch64AbsLongThunk_>:
-// CHECK-EXE-NEXT: 3000006c: ldr x16, 0x30000074 <__AArch64AbsLongThunk_+0x8>
+// CHECK-EXE-NEXT: 30000070: ldr x16, 0x30000078 <__AArch64AbsLongThunk_+0x8>
// CHECK-EXE-NEXT: br x16
// CHECK-EXE-NEXT: 18 10 00 18 .word 0x18001018
// CHECK-EXE-NEXT: 00 00 00 00 .word 0x00000000
// CHECK-EXE-LABEL: <__AArch64AbsLongThunk_>:
-// CHECK-EXE-NEXT: 3000007c: ldr x16, 0x30000084 <__AArch64AbsLongThunk_+0x8>
+// CHECK-EXE-NEXT: 30000080: ldr x16, 0x30000088 <__AArch64AbsLongThunk_+0x8>
// CHECK-EXE-NEXT: br x16
// CHECK-EXE-NEXT: 20 10 00 18 .word 0x18001020
// CHECK-EXE-NEXT: 00 00 00 00 .word 0x00000000
// CHECK-EXE-LABEL: <__AArch64AbsLongThunk_>:
-// CHECK-EXE-NEXT: 3000008c: ldr x16, 0x30000094 <__AArch64AbsLongThunk_+0x8>
+// CHECK-EXE-NEXT: 30000090: ldr x16, 0x30000098 <__AArch64AbsLongThunk_+0x8>
// CHECK-EXE-NEXT: br x16
// CHECK-EXE-NEXT: 28 10 00 18 .word 0x18001028
// CHECK-EXE-NEXT: 00 00 00 00 .word 0x00000000
// CHECK-EXE-LABEL: <__AArch64AbsLongThunk_>:
-// CHECK-EXE-NEXT: 3000009c: ldr x16, 0x300000a4 <__AArch64AbsLongThunk_+0x8>
+// CHECK-EXE-NEXT: 300000a0: ldr x16, 0x300000a8 <__AArch64AbsLongThunk_+0x8>
// CHECK-EXE-NEXT: br x16
// CHECK-EXE-NEXT: 30 10 00 18 .word 0x18001030
// CHECK-EXE-NEXT: 00 00 00 00 .word 0x00000000
// CHECK-EXE-LABEL: <__AArch64AbsLongThunk_>:
-// CHECK-EXE-NEXT: 300000ac: ldr x16, 0x300000b4 <__AArch64AbsLongThunk_+0x8>
+// CHECK-EXE-NEXT: 300000b0: ldr x16, 0x300000b8 <__AArch64AbsLongThunk_+0x8>
// CHECK-EXE-NEXT: br x16
// CHECK-EXE-NEXT: 3c 10 00 18 .word 0x1800103c
// CHECK-EXE-NEXT: 00 00 00 00 .word 0x00000000
// CHECK-EXE-LABEL: <__AArch64AbsLongThunk_>:
-// CHECK-EXE-NEXT: 300000bc: ldr x16, 0x300000c4 <__AArch64AbsLongThunk_+0x8>
+// CHECK-EXE-NEXT: 300000c0: ldr x16, 0x300000c8 <__AArch64AbsLongThunk_+0x8>
// CHECK-EXE-NEXT: br x16
// CHECK-EXE-NEXT: 44 10 00 18 .word 0x18001044
// CHECK-EXE-NEXT: 00 00 00 00 .word 0x00000000
// CHECK-EXE-LABEL: <__AArch64AbsLongThunk_via_plt>:
-// CHECK-EXE-NEXT: 300000cc: ldr x16, 0x300000d4 <__AArch64AbsLongThunk_via_plt+0x8>
+// CHECK-EXE-NEXT: 300000d0: ldr x16, 0x300000d8 <__AArch64AbsLongThunk_via_plt+0x8>
// CHECK-EXE-NEXT: br x16
// CHECK-EXE-NEXT: 80 10 00 18 .word 0x18001080
// CHECK-EXE-NEXT: 00 00 00 00 .word 0x00000000
// CHECK-EXE-LABEL: <__AArch64AbsLongThunk_absolute>:
-// CHECK-EXE-NEXT: 300000dc: ldr x16, 0x300000e4 <__AArch64AbsLongThunk_absolute+0x8>
+// CHECK-EXE-NEXT: 300000e0: ldr x16, 0x300000e8 <__AArch64AbsLongThunk_absolute+0x8>
// CHECK-EXE-NEXT: br x16
// CHECK-EXE-NEXT: 00 00 00 f0 .word 0xf0000000
// CHECK-EXE-NEXT: 00 00 00 00 .word 0x00000000
>From a2ee7ff086322b76cdd36476b9dab095f4569914 Mon Sep 17 00:00:00 2001
From: Peter Smith <peter.smith at arm.com>
Date: Mon, 31 Mar 2025 18:14:10 +0100
Subject: [PATCH 2/2] Review comment, use changed rather than adding new
variable
---
lld/ELF/SyntheticSections.cpp | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/lld/ELF/SyntheticSections.cpp b/lld/ELF/SyntheticSections.cpp
index 83287efced069..3bb9815336a7c 100644
--- a/lld/ELF/SyntheticSections.cpp
+++ b/lld/ELF/SyntheticSections.cpp
@@ -4317,11 +4317,11 @@ InputSection *ThunkSection::getTargetInputSection() const {
bool ThunkSection::assignOffsets() {
uint64_t off = 0;
- bool alignChange = false;
+ bool changed = false;
for (Thunk *t : thunks) {
if (t->alignment > addralign) {
addralign = t->alignment;
- alignChange = true;
+ changed = true;
}
off = alignToPowerOf2(off, t->alignment);
t->setOffset(off);
@@ -4329,7 +4329,8 @@ bool ThunkSection::assignOffsets() {
t->getThunkTargetSym()->size = size;
off += size;
}
- bool changed = (off != size) || alignChange;
+ if (off != size)
+ changed = true;
size = off;
return changed;
}
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