[yaml2obj] Set p_align to the maximum sh_addralign of contained sections
The address difference between two sections in a PT_LOAD is a constant.
Consider a hypothetical case (pagesize can be very small, say, 4).
```
.text sh_addralign=4
.text.hot sh_addralign=16
```
If we set p_align to 4, the PT_LOAD will be loaded at an address which
is a multiple of 4. The address of .text.hot is guaranteed to be a
multiple of 4, but not necessarily a multiple of 16.
This patch deletes the constraint
if (SHeader->sh_offset == PHeader.p_offset)
Reviewed By: grimar, jhenderson
Differential Revision: https://reviews.llvm.org/D67260
llvm-svn: 371501
diff --git a/llvm/lib/ObjectYAML/ELFEmitter.cpp b/llvm/lib/ObjectYAML/ELFEmitter.cpp
index 531f0d4..72063a5 100644
--- a/llvm/lib/ObjectYAML/ELFEmitter.cpp
+++ b/llvm/lib/ObjectYAML/ELFEmitter.cpp
@@ -645,16 +645,15 @@
PHeader.p_memsz = YamlPhdr.MemSize ? uint64_t(*YamlPhdr.MemSize)
: MemOffset - PHeader.p_offset;
- // Set the alignment of the segment to be the same as the maximum alignment
- // of the sections with the same offset so that by default the segment
- // has a valid and sensible alignment.
if (YamlPhdr.Align) {
PHeader.p_align = *YamlPhdr.Align;
} else {
+ // Set the alignment of the segment to be the maximum alignment of the
+ // sections so that by default the segment has a valid and sensible
+ // alignment.
PHeader.p_align = 1;
for (Elf_Shdr *SHeader : Sections)
- if (SHeader->sh_offset == PHeader.p_offset)
- PHeader.p_align = std::max(PHeader.p_align, SHeader->sh_addralign);
+ PHeader.p_align = std::max(PHeader.p_align, SHeader->sh_addralign);
}
}
}