Commit abd20cb637 and
ebdcad3fdd introduced additional
complexity into the paths run by the RISC-V relaxation pass in order to
resolve the issue of accurately keeping track of pcrel_hi and pcrel_lo
pairs. The first commit split up relaxation of these relocs into a pass
which occurred after other relaxations in order to prevent the situation
where bytes were deleted in between a pcrel_lo/pcrel_hi pair, inhibiting
our ability to find the corresponding pcrel_hi relocation from the
address attached to the pcrel_lo.
Since the relaxation was split into two passes the 'again' parameter
could not be used to perform the entire relaxation process again and so
the second commit added a way to restart ldelf_map_segments, thus
starting the whole process again.
Unfortunately this process could not account for the fact that we were
not finished with the relaxation process so in some cases - such as the
case where code would not fit in a memory region before the
R_RISCV_ALIGN relocation was relaxed - sanity checks in generic code
would fail.
This patch fixes all three of these concerns by reverting back to a
system of having only one target relax pass but updating entries in the
table of pcrel_hi/pcrel_lo relocs every time any bytes are deleted. Thus
we can keep track of the pairs accurately, and we can use the 'again'
parameter to restart the entire target relax pass, behaving in the way
that generic code expects. Unfortunately we must still have an
additional pass to delay deleting AUIPC bytes to avoid ambiguity between
pcrel_hi relocs stored in the table after deletion. This pass can only
be run once so we may potentially miss out on relaxation opportunities
but this is likely to be rare.
https://sourceware.org/bugzilla/show_bug.cgi?id=28410
bfd/
* elfnn-riscv.c (riscv_elf_link_hash_table): Removed restart_relax.
(riscv_elf_link_hash_table_create): Updated.
(riscv_relax_delete_bytes): Moved after the riscv_update_pcgp_relocs.
Update the pcgp_relocs table whenever bytes are deleted.
(riscv_update_pcgp_relocs): Add function to update the section
offset of pcrel_hi and pcrel_lo, and also update the symbol value
of pcrel_hi.
(_bfd_riscv_relax_call): Need to update the pcgp_relocs table
when deleting codes.
(_bfd_riscv_relax_lui): Likewise.
(_bfd_riscv_relax_tls_le): Likewise.
(_bfd_riscv_relax_align): Once we've handled an R_RISCV_ALIGN,
we can't relax anything else, so set the sec->sec_flg0 to true.
Besides, we don't need to update the pcgp_relocs table at this
stage, so just pass NULL pointer as the pcgp_relocs table for
riscv_relax_delete_bytes.
(_bfd_riscv_relax_section): Use only one pass for all target
relaxations.
(_bfd_riscv_relax_delete): Likewise, we don't need to update
the pcgp_relocs table at this stage, and don't need to set
the `again' since restart_relax mechanism is abandoned.
(bfd_elfNN_riscv_restart_relax_sections): Removed.
(_bfd_riscv_relax_section): Updated.
* elfxx-riscv.h (bfd_elf32_riscv_restart_relax_sections): Removed.
(bfd_elf64_riscv_restart_relax_sections): Likewise.
ld/
* emultempl/riscvelf.em: Revert restart_relax changes and set
relax_pass to 3.
* testsuite/ld-riscv-elf/align-small-region.d: New testcase.
* testsuite/ld-riscv-elf/align-small-region.ld: Likewise.
* testsuite/ld-riscv-elf/align-small-region.s: Likewise.
* testsuite/ld-riscv-elf/restart-relax.d: Removed sine the
restart_relax mechanism is abandoned.
* testsuite/ld-riscv-elf/restart-relax.s: Likewise.
* testsuite/ld-riscv-elf/ld-riscv-elf.exp: Updated.
This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
BFD is an object file library. It permits applications to use the
same routines to process object files regardless of their format.
BFD is used by the GNU debugger, assembler, linker, and the binary
utilities.
The documentation on using BFD is scanty and may be occasionally
incorrect. Pointers to documentation problems, or an entirely
rewritten manual, would be appreciated.
There is some BFD internals documentation in doc/bfdint.texi which may
help programmers who want to modify BFD.
BFD is normally built as part of another package. See the build
instructions for that package, probably in a README file in the
appropriate directory.
BFD supports the following configure options:
--target=TARGET
The default target for which to build the library. TARGET is
a configuration target triplet, such as sparc-sun-solaris.
--enable-targets=TARGET,TARGET,TARGET...
Additional targets the library should support. To include
support for all known targets, use --enable-targets=all.
--enable-64-bit-bfd
Include support for 64 bit targets. This is automatically
turned on if you explicitly request a 64 bit target, but not
for --enable-targets=all. This requires a compiler with a 64
bit integer type, such as gcc.
--enable-shared
Build BFD as a shared library.
--with-mmap
Use mmap when accessing files. This is faster on some hosts,
but slower on others. It may not work on all hosts.
Report bugs with BFD to bug-binutils@gnu.org.
Patches are encouraged. When sending patches, always send the output
of diff -u or diff -c from the original file to the new file. Do not
send default diff output. Do not make the diff from the new file to
the original file. Remember that any patch must not break other
systems. Remember that BFD must support cross compilation from any
host to any target, so patches which use ``#ifdef HOST'' are not
acceptable. Please also read the ``Reporting Bugs'' section of the
gcc manual.
Bug reports without patches will be remembered, but they may never get
fixed until somebody volunteers to fix them.
Copyright (C) 2012-2021 Free Software Foundation, Inc.
Copying and distribution of this file, with or without modification,
are permitted in any medium without royalty provided the copyright
notice and this notice are preserved.
9abcdc10b2