[lld] [ELF] Align the end of PT_GNU_RELRO associated PT_LOAD to a common-page-size boundary (PR #66042)

[Peter Smith via llvm-commits]

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@@ -1196,9 +1202,17 @@ void LinkerScript::adjustOutputSections() {
     if (sec->sectionIndex != UINT32_MAX)
       maybePropagatePhdrs(*sec, defPhdrs);
 
+    // Discard .relro_padding if we have not seen one non-NOBITS RELRO section.
+    // Note: when .tbss is the only RELRO section, it's difficult to pick a
+    // suitable padding size (see computeFilOffset). For simplicity, don't
+    // retain .relro_padding in this case.
+    if (in.relroPadding && in.relroPadding->getParent() == sec && !seenRelro)
+      discardable = true;
     if (discardable) {
       sec->markDead();
       cmd = nullptr;
+    } else {
+      seenRelro |= sec->relro && sec->type != SHT_NOBITS;
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smithp35 wrote:

Would it be worth restricting this to sec->type != SHT_NOBITS && (sec->flags & SHF_TLS)

https://github.com/llvm/llvm-project/pull/66042