Commit Graph

3 Commits

Author SHA1 Message Date
Peter Smith 3b1622d63a [LLD][ELF][ARM] recommit Fix ARM Exidx order for non monotonic section order
Fixed error detected by msan. The size field of the .ARM.exidx synthetic
section needs to be initialized to at least estimation level before
calling assignAddresses as that will use the size field.

This was previously reverted in 1ca16fc4f5.

Differential Revision: https://reviews.llvm.org/D78422
2020-04-24 13:47:28 +01:00
Peter Smith 1ca16fc4f5 Revert "[LLD][ELF][ARM] Fix ARM Exidx order for non monotonic section order"
This reverts commit f969c2aa65.

There are some msan buildbot failures sanitzer-x86_64-linux-fast that
I need to investigate.

Differential Revision: https://reviews.llvm.org/D78422
2020-04-23 16:58:50 +01:00
Peter Smith f969c2aa65 [LLD][ELF][ARM] Fix ARM Exidx order for non monotonic section order
The contents of the .ARM.exidx section must be ordered by SHF_LINK_ORDER
rules. We don't need to know the precise address for this order, but we
do need to know the relative order of sections. We have been using the
sectionIndex for this purpose, this works when the OutputSection order
has a monotonically increasing virtual address, but it is possible to
write a linker script with non-monotonically increasing virtual address.
For these cases we need to evaluate the base address of the OutputSection
so that we can order the .ARM.exidx sections properly.

This change moves the finalisation of .ARM.exidx till after the first
call to AssignAddresses. This permits us to sort on virtual address which
is linker script safe. It also permits a fix for part of pr44824 where
we generate .ARM.exidx section for the vector table when that table is so
far away it is out of range of the .ARM.exidx section. This fix will come
in a follow up patch.

Differential Revision: https://reviews.llvm.org/D78422
2020-04-23 15:46:44 +01:00