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[lld/mac] Allow -segprot having stricter initprot than maxprot on mac #107269

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Merged
merged 2 commits into from
Sep 5, 2024
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[lld/mac] Allow -segprot having stricter initprot than maxprot on mac #107269

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[lld/mac] Allow -segprot having stricter initprot than maxprot on mac
nico Sep 4, 2024
e6a44a1
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nico Sep 5, 2024
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18 changes: 15 additions & 3 deletions lld/MachO/Driver.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1882,9 +1882,21 @@ bool link(ArrayRef<const char *> argsArr, llvm::raw_ostream &stdoutOS,
StringRef segName = arg->getValue(0);
uint32_t maxProt = parseProtection(arg->getValue(1));
uint32_t initProt = parseProtection(arg->getValue(2));
if (maxProt != initProt && config->arch() != AK_i386)
error("invalid argument '" + arg->getAsString(args) +
"': max and init must be the same for non-i386 archs");

// FIXME: Check if this works on more platforms.
bool allowsDifferentInitAndMaxProt =
config->platform() == PLATFORM_MACOS ||
config->platform() == PLATFORM_MACCATALYST;
if (allowsDifferentInitAndMaxProt) {
if (initProt > maxProt)
error("invalid argument '" + arg->getAsString(args) +
"': init must not be more permissive than max");
} else {
if (maxProt != initProt && config->arch() != AK_i386)
error("invalid argument '" + arg->getAsString(args) +
"': max and init must be the same for non-macOS non-i386 archs");
}

if (segName == segment_names::linkEdit)
error("-segprot cannot be used to change __LINKEDIT's protections");
config->segmentProtections.push_back({segName, maxProt, initProt});
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6 changes: 6 additions & 0 deletions lld/MachO/OutputSegment.cpp
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Expand Up @@ -42,6 +42,12 @@ static uint32_t initProt(StringRef name) {
static uint32_t maxProt(StringRef name) {
assert(config->arch() != AK_i386 &&
"TODO: i386 has different maxProt requirements");
auto it = find_if(
config->segmentProtections,
[&](const SegmentProtection &segprot) { return segprot.name == name; });
if (it != config->segmentProtections.end())
return it->maxProt;

return initProt(name);
}

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41 changes: 35 additions & 6 deletions lld/test/MachO/segprot.s
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Expand Up @@ -2,7 +2,10 @@
# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %s -o %t.o

## Make sure the option parser doesn't think --x and -w are flags.
# RUN: %lld -dylib -o %t %t.o -segprot FOO rwx xwr -segprot BAR --x --x -segprot BAZ -w -w
# RUN: %lld -dylib -o %t %t.o \
# RUN: -segprot FOO rwx xwr \
# RUN: -segprot BAR --x --x \
# RUN: -segprot BAZ -w -w
# RUN: llvm-readobj --macho-segment %t | FileCheck %s

# CHECK: Name: FOO
Expand Down Expand Up @@ -32,12 +35,38 @@
# CHECK-NEXT: maxprot: -w-
# CHECK-NEXT: initprot: -w-

# RUN: not %lld -dylib -o /dev/null %t.o -segprot FOO rwx rw 2>&1 | FileCheck %s --check-prefix=MISMATCH
# RUN: not %lld -dylib -o /dev/null %t.o -segprot __LINKEDIT rwx rwx 2>&1 | FileCheck %s --check-prefix=NO-LINKEDIT
# RUN: not %lld -dylib -o /dev/null %t.o -segprot FOO uhh wat 2>&1 | FileCheck %s --check-prefix=MISPARSE
# RUN: not %lld -dylib -o /dev/null %t.o -segprot FOO rwx 2>&1 | FileCheck %s --check-prefix=MISSING
# RUN: %lld -dylib -o %t.different %t.o -segprot FOO rw r
# RUN: llvm-readobj --macho-segment %t.different \
# RUN: | FileCheck %s --check-prefix=DIFFERENT

# MISMATCH: error: invalid argument '-segprot FOO rwx rw': max and init must be the same for non-i386 archs
# RUN: %no-arg-lld -arch x86_64 -platform_version "mac catalyst" 14.0.0 17.5 \
# RUN: -dylib -o /dev/null %t.o -segprot FOO rw r
# RUN: llvm-readobj --macho-segment %t.different \
# RUN: | FileCheck %s --check-prefix=DIFFERENT

# DIFFERENT: Name: FOO
# DIFFERENT-NEXT: Size:
# DIFFERENT-NEXT: vmaddr:
# DIFFERENT-NEXT: vmsize:
# DIFFERENT-NEXT: fileoff:
# DIFFERENT-NEXT: filesize:
# DIFFERENT-NEXT: maxprot: rw-
# DIFFERENT-NEXT: initprot: r--

# RUN: not %no-arg-lld -arch x86_64 -platform_version ios-simulator 14.0 15.0 \
# RUN: -dylib -o /dev/null %t.o -segprot FOO rwx rw 2>&1 \
# RUN: | FileCheck %s --check-prefix=MISMATCH
# RUN: not %lld -dylib -o /dev/null %t.o -segprot FOO r rw 2>&1 \
# RUN: | FileCheck %s --check-prefix=INITTOOPERMISSIVE
# RUN: not %lld -dylib -o /dev/null %t.o -segprot __LINKEDIT rwx rwx 2>&1 \
# RUN: | FileCheck %s --check-prefix=NO-LINKEDIT
# RUN: not %lld -dylib -o /dev/null %t.o -segprot FOO uhh wat 2>&1 \
# RUN: | FileCheck %s --check-prefix=MISPARSE
# RUN: not %lld -dylib -o /dev/null %t.o -segprot FOO rwx 2>&1 \
# RUN: | FileCheck %s --check-prefix=MISSING

# MISMATCH: error: invalid argument '-segprot FOO rwx rw': max and init must be the same for non-macOS non-i386 archs
# INITTOOPERMISSIVE: error: invalid argument '-segprot FOO r rw': init must not be more permissive than max
# NO-LINKEDIT: error: -segprot cannot be used to change __LINKEDIT's protections
# MISPARSE: error: unknown -segprot letter 'u' in uhh
# MISPARSE: error: unknown -segprot letter 'a' in wat
Expand Down
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