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[LLD][COFF] Align EC code ranges to page boundaries (#168222)

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We already ensure that code for different architectures is always placed
in different pages in `assignAddresses`. We represent those ranges using
their first and last chunks. However, the RVAs of those chunks may not
be page-aligned, for example, due to extra padding for entry-thunk
offsets. Align the chunk RVAs to the page boundary so that the emitted
ranges correctly include the entire region.

This change affects an existing test that checks corner cases triggered
by merging a data section into a code section. We may now include such
data in the code range. This differs from MSVC’s behavior, but it should
not cause practical issues, and the new behavior is arguably more
correct.

Fixes #168119.
This commit is contained in:
Jacek Caban 2025-11-17 12:44:22 +01:00 committed by GitHub
parent 550522d07e
commit af45b0202c
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GPG Key ID: B5690EEEBB952194
2 changed files with 34 additions and 4 deletions
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2
lld/COFF/Chunks.cpp
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@ -946,7 +946,7 @@ void ECCodeMapChunk::writeTo(uint8_t *buf) const {
auto table = reinterpret_cast<chpe_range_entry *>(buf);
for (uint32_t i = 0; i < map.size(); i++) {
const ECCodeMapEntry &entry = map[i];
uint32_t start = entry.first->getRVA();
uint32_t start = entry.first->getRVA() & ~0xfff;
table[i].StartOffset = start | entry.type;
table[i].Length = entry.last->getRVA() + entry.last->getSize() - start;
}

36
lld/test/COFF/arm64ec-codemap.test
View File

@ -7,6 +7,7 @@ RUN: llvm-mc -filetype=obj -triple=arm64ec-windows arm64ec-func-sym2.s -o arm64e
RUN: llvm-mc -filetype=obj -triple=arm64ec-windows data-sec.s -o data-sec.obj
RUN: llvm-mc -filetype=obj -triple=arm64ec-windows data-sec2.s -o data-sec2.obj
RUN: llvm-mc -filetype=obj -triple=arm64ec-windows empty-sec.s -o arm64ec-empty-sec.obj
RUN: llvm-mc -filetype=obj -triple=arm64ec-windows entry-thunk.s -o entry-thunk.obj
RUN: llvm-mc -filetype=obj -triple=x86_64-windows x86_64-func-sym.s -o x86_64-func-sym.obj
RUN: llvm-mc -filetype=obj -triple=x86_64-windows empty-sec.s -o x86_64-empty-sec.obj
RUN: llvm-mc -filetype=obj -triple=aarch64-windows %S/Inputs/loadconfig-arm64.s -o loadconfig-arm64.obj
@ -162,15 +163,17 @@ RUN: loadconfig-arm64ec.obj -dll -noentry -merge:test=.testdata -merge:
RUN: llvm-readobj --coff-load-config testcm.dll | FileCheck -check-prefix=CODEMAPCM %s
CODEMAPCM: CodeMap [
CODEMAPCM-NEXT: 0x4008 - 0x4016 X64
CODEMAPCM-NEXT: 0x4000 - 0x4016 X64
CODEMAPCM-NEXT: ]
RUN: llvm-objdump -d testcm.dll | FileCheck -check-prefix=DISASMCM %s
DISASMCM: Disassembly of section .testdat:
DISASMCM-EMPTY:
DISASMCM-NEXT: 0000000180004000 <.testdat>:
DISASMCM-NEXT: 180004000: 00000001 udf #0x1
DISASMCM-NEXT: 180004004: 00000000 udf #0x0
DISASMCM-NEXT: 180004000: 01 00 addl %eax, (%rax)
DISASMCM-NEXT: 180004002: 00 00 addb %al, (%rax)
DISASMCM-NEXT: 180004004: 00 00 addb %al, (%rax)
DISASMCM-NEXT: 180004006: 00 00 addb %al, (%rax)
DISASMCM-NEXT: 180004008: b8 03 00 00 00 movl $0x3, %eax
DISASMCM-NEXT: 18000400d: c3 retq
DISASMCM-NEXT: 18000400e: 00 00 addb %al, (%rax)
@ -207,6 +210,14 @@ DISASMMS-NEXT: 0000000180006000 <test2>:
DISASMMS-NEXT: 180006000: 528000a0 mov w0, #0x5 // =5
DISASMMS-NEXT: 180006004: d65f03c0 ret
Test the code map that includes an ARM64EC function padded by its entry-thunk offset.
RUN: lld-link -out:testpad.dll -machine:arm64ec entry-thunk.obj loadconfig-arm64ec.obj -dll -noentry -include:func
RUN: llvm-readobj --coff-load-config testpad.dll | FileCheck -check-prefix=CODEMAPPAD %s
CODEMAPPAD: CodeMap [
CODEMAPPAD: 0x1000 - 0x1010 ARM64EC
CODEMAPPAD-NEXT: ]
#--- arm64-func-sym.s
.text
@ -266,3 +277,22 @@ x86_64_func_sym2:
.section .empty1, "xr"
.section .empty2, "xr"
.section .empty3, "xr"
#--- entry-thunk.s
.section .text,"xr",discard,func
.globl func
.p2align 2, 0x0
func:
mov w0, #1
ret
.section .wowthk$aa,"xr",discard,thunk
.globl thunk
.p2align 2
thunk:
ret
.section .hybmp$x,"yi"
.symidx func
.symidx thunk
.word 1 // entry thunk