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[lld/MachO] Fix assert on unsorted data-in-code entries (#81758)

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When the data-in-code entries are in separate sections, they are not
guaranteed to be sorted. In particular, 68b1cc36f3df marked some libc++
string functions as noinline, which leads to global ctors involving
strings now producing data-in-code sections in __TEXT,__StaticInit,
which is why this now happens in practice.

Since data-in-code entries are relatively rare and small, just sort
them. No observed performance impact.

See also crbug.com/41487860
This commit is contained in:
Nico Weber 2024-02-16 07:46:58 -05:00 committed by GitHub
parent c2fea4cf38
commit 624ea349d7
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GPG Key ID: B5690EEEBB952194
2 changed files with 24 additions and 9 deletions
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11
lld/MachO/SyntheticSections.cpp
View File

@ -1050,10 +1050,13 @@ static std::vector<MachO::data_in_code_entry> collectDataInCodeEntries() {
if (entries.empty())
continue;
assert(is_sorted(entries, [](const data_in_code_entry &lhs,
std::vector<MachO::data_in_code_entry> sortedEntries;
sortedEntries.assign(entries.begin(), entries.end());
llvm::sort(sortedEntries, [](const data_in_code_entry &lhs,
const data_in_code_entry &rhs) {
return lhs.offset < rhs.offset;
}));
});
// For each code subsection find 'data in code' entries residing in it.
// Compute the new offset values as
// <offset within subsection> + <subsection address> - <__TEXT address>.
@ -1066,12 +1069,12 @@ static std::vector<MachO::data_in_code_entry> collectDataInCodeEntries() {
continue;
const uint64_t beginAddr = section->addr + subsec.offset;
auto it = llvm::lower_bound(
entries, beginAddr,
sortedEntries, beginAddr,
[](const MachO::data_in_code_entry &entry, uint64_t addr) {
return entry.offset < addr;
});
const uint64_t endAddr = beginAddr + isec->getSize();
for (const auto end = entries.end();
for (const auto end = sortedEntries.end();
it != end && it->offset + it->length <= endAddr; ++it)
dataInCodeEntries.push_back(
{static_cast<uint32_t>(isec->getVA(it->offset - beginAddr) -

22
lld/test/MachO/data-in-code.s
View File

@ -6,7 +6,7 @@
# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/bar.s -o %t/bar.o
# RUN: %lld -lSystem %t/foo.o %t/bar.o -o %t/main.exe
# RUN: llvm-otool -l %t/main.exe > %t/objdump
# RUN: llvm-objdump --macho --data-in-code %t/main.exe >> %t/objdump
# RUN: llvm-otool -Gv %t/main.exe >> %t/objdump
# RUN: FileCheck %s < %t/objdump
# CHECK-LABEL: sectname __text
@ -18,12 +18,13 @@
# CHECK-LABEL: cmd LC_DATA_IN_CODE
# CHECK-NEXT: cmdsize 16
# CHECK-NEXT: dataoff
# CHECK-NEXT: datasize 16
# CHECK-NEXT: datasize 24
# CHECK-LABEL: Data in code table (2 entries)
# CHECK-LABEL: Data in code table (3 entries)
# CHECK-NEXT: offset length kind
# CHECK-NEXT: [[#%x,TEXT + 28]] 24 JUMP_TABLE32
# CHECK-NEXT: [[#%x,TEXT + 68]] 12 JUMP_TABLE32
# CHECK-NEXT: [[#%x,TEXT + 68]] 8 JUMP_TABLE32
# CHECK-NEXT: [[#%x,TEXT + 84]] 12 JUMP_TABLE32
# RUN: %lld -lSystem %t/foo.o %t/bar.o -no_data_in_code_info -o %t/main.exe
# RUN: llvm-otool -l %t/main.exe | FileCheck --check-prefix=OMIT %s
@ -32,11 +33,22 @@
# RUN: %lld -lSystem %t/foo.o %t/bar.o -no_data_in_code_info -data_in_code_info -o %t/main.exe
# RUN: llvm-otool -l %t/main.exe > %t/objdump
# RUN: llvm-objdump --macho --data-in-code %t/main.exe >> %t/objdump
# RUN: llvm-otool -Gv %t/main.exe >> %t/objdump
# RUN: FileCheck %s < %t/objdump
#--- foo.s
.text
.section __TEXT,__StaticInit,regular,pure_instructions
.p2align 4, 0x90
_some_init_function:
retq
.p2align 2, 0x90
.data_region jt32
.long 0
.long 0
.end_data_region
.section __TEXT,__text,regular,pure_instructions
.globl _main
.p2align 4, 0x90
_main: