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[ELD] Avoid assigning addresses to headers outside the layout #2065

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Merged
Shankar Easwaran (quic-seaswara) merged 1 commit into from
Oct 8, 2026
Merged

[ELD] Avoid assigning addresses to headers outside the layout #2065

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8 changes: 5 additions & 3 deletions lib/Target/GNULDBackend.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -5420,12 +5420,14 @@ bool GNULDBackend::allocateHeaders() {
uint64_t ModifiedAddr =
llvm::alignDown(VAddr.value() - headerSize, abiPageSize());
uint64_t ModifiedPAddr = PAddr.value() + (ModifiedAddr - VAddr.value());
if (m_ehdr) {
if (isEhdrInLayout()) {
m_ehdr->setAddr(ModifiedAddr);
m_ehdr->setPaddr(ModifiedPAddr);
}
m_phdr->setAddr(ModifiedAddr + getOneEhdrSize());
m_phdr->setPaddr(ModifiedPAddr + getOneEhdrSize());
if (isPhdrInLayout()) {
m_phdr->setAddr(ModifiedAddr + getOneEhdrSize());
m_phdr->setPaddr(ModifiedPAddr + getOneEhdrSize());
}
return true;
}
return false;
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36 changes: 36 additions & 0 deletions ...tandalone/linkerscript/PHDRS/HeadersWithoutOutputSection/HeadersWithoutOutputSection.test
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Original file line number Diff line number Diff line change
@@ -0,0 +1,36 @@
# Headers omitted from the layout have no output section. Allocating space for
# the other header must not try to assign addresses to the omitted header.
# RUN: split-file %s %t
# RUN: %clang %clangg0opts -c %t/input.c -o %t.o
# RUN: %link %linkopts -z max-page-size=4096 %t.o -T %t/phdrs.t -o %t.phdrs.out
# RUN: %readelf -lW %t.phdrs.out | %filecheck %s --check-prefix=PHDRS
# RUN: %link %linkopts -z max-page-size=4096 %t.o -T %t/filehdr.t -o %t.filehdr.out
# RUN: %readelf -lW %t.filehdr.out | %filecheck %s --check-prefix=FILEHDR

# PHDRS: LOAD {{0x0*(34|40)}} {{0x0*(34|40)}} {{0x0*(34|40)}}
# PHDRS: LOAD {{0x[0-9a-f]+}} {{0x0*1000}} {{0x0*1000}}
# FILEHDR: LOAD {{0x0+}} {{0x0+}} {{0x0+}}
# FILEHDR: LOAD {{0x[0-9a-f]+}} {{0x0*1000}} {{0x0*1000}}

#--- input.c
int data = 1;

#--- phdrs.t
PHDRS {
headers PT_LOAD PHDRS;
data PT_LOAD;
}
SECTIONS {
. = 0x1000;
.data 0x1000 : { *(.data*) *(.sdata*) } :data
}

#--- filehdr.t
PHDRS {
headers PT_LOAD FILEHDR;
data PT_LOAD;
}
SECTIONS {
. = 0x1000;
.data 0x1000 : { *(.data*) *(.sdata*) } :data
}
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