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ELF: Rename RandomizePaddingSection to PaddingSection. #155540

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ELF: Rename RandomizePaddingSection to PaddingSection. #155540

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[𝘀𝗽𝗿] initial version
pcc Aug 27, 2025
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pcc Aug 27, 2025
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pcc Sep 12, 2025
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pcc Oct 6, 2025
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7 changes: 3 additions & 4 deletions lld/ELF/SyntheticSections.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2749,14 +2749,13 @@ RelroPaddingSection::RelroPaddingSection(Ctx &ctx)
: SyntheticSection(ctx, ".relro_padding", SHT_NOBITS, SHF_ALLOC | SHF_WRITE,
1) {}

RandomizePaddingSection::RandomizePaddingSection(Ctx &ctx, uint64_t size,
OutputSection *parent)
: SyntheticSection(ctx, ".randomize_padding", SHT_PROGBITS, SHF_ALLOC, 1),
PaddingSection::PaddingSection(Ctx &ctx, uint64_t size, OutputSection *parent)
: SyntheticSection(ctx, ".padding", SHT_PROGBITS, SHF_ALLOC, 1),
size(size) {
this->parent = parent;
}

void RandomizePaddingSection::writeTo(uint8_t *buf) {
void PaddingSection::writeTo(uint8_t *buf) {
std::array<uint8_t, 4> filler = getParent()->getFiller(ctx);
uint8_t *end = buf + size;
for (; buf + 4 <= end; buf += 4)
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4 changes: 2 additions & 2 deletions lld/ELF/SyntheticSections.h
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Expand Up @@ -779,11 +779,11 @@ class RelroPaddingSection final : public SyntheticSection {
void writeTo(uint8_t *buf) override {}
};

class RandomizePaddingSection final : public SyntheticSection {
class PaddingSection final : public SyntheticSection {
uint64_t size;

public:
RandomizePaddingSection(Ctx &ctx, uint64_t size, OutputSection *parent);
PaddingSection(Ctx &ctx, uint64_t size, OutputSection *parent);
size_t getSize() const override { return size; }
void writeTo(uint8_t *buf) override;
};
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7 changes: 3 additions & 4 deletions lld/ELF/Writer.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1495,15 +1495,14 @@ static void randomizeSectionPadding(Ctx &ctx) {
if (auto *isd = dyn_cast<InputSectionDescription>(bc)) {
SmallVector<InputSection *, 0> tmp;
if (os->ptLoad != curPtLoad) {
tmp.push_back(make<RandomizePaddingSection>(
ctx, g() % ctx.arg.maxPageSize, os));
tmp.push_back(
make<PaddingSection>(ctx, g() % ctx.arg.maxPageSize, os));
curPtLoad = os->ptLoad;
}
for (InputSection *isec : isd->sections) {
// Probability of inserting padding is 1 in 16.
if (g() % 16 == 0)
tmp.push_back(
make<RandomizePaddingSection>(ctx, isec->addralign, os));
tmp.push_back(make<PaddingSection>(ctx, isec->addralign, os));
tmp.push_back(isec);
}
isd->sections = std::move(tmp);
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