Summary: | Size and alignment from as-needed shared library bss symbols affect commons | ||
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Product: | binutils | Reporter: | Alan Modra <amodra> |
Component: | ld | Assignee: | Alan Modra <amodra> |
Status: | RESOLVED FIXED | ||
Severity: | normal | CC: | nickc |
Priority: | P2 | ||
Version: | 2.36 | ||
Target Milestone: | 2.36 | ||
Host: | Target: | ||
Build: | Last reconfirmed: |
Description
Alan Modra
2020-09-08 02:35:20 UTC
The master branch has been updated by Alan Modra <amodra@sourceware.org>: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=7ba115508aa02ffbb01a09613b5dffdd0c6563e3 commit 7ba115508aa02ffbb01a09613b5dffdd0c6563e3 Author: Alan Modra <amodra@gmail.com> Date: Tue Sep 8 13:02:31 2020 +0930 PR26580, Size and alignment of commons vs as-needed shared lib Two pieces to this puzzle: 1) Revert HJ's fix for PR13250 so that size and alignment isn't sticky, instead attack the real underlying problem that _bfd_generic_link_add_one_symbol does the wrong thing in making a common section in a shared library bfd. 2) Save and restore common u.c.p fields, which hold the section and alignment. A better fix for (2) would be to throw away all of that horrible code saving and restoring the hash table when loading as-needed library symbols, and instead do a scan over as-needed library symbols before adding anything. bfd/ PR 13250 PR 26580 * elflink.c (_bfd_elf_merge_symbol): Make "override" a bfd**. Return oldbfd in override when old common should override new common. (_bfd_elf_add_default_symbol): Adjust to suit. (elf_link_add_object_symbols): Likewise. Pass "override" to _bfd_generic_link_add_one_symbol. Save and restore common u.c.p field for --as-needed shared libraries. Revert pr13250 changes. ld/ * testsuite/ld-elf/pr26580-a.s, * testsuite/ld-elf/pr26580-b.s, * testsuite/ld-elf/pr26580-1.sd, * testsuite/ld-elf/pr26580-2.sd: New tests * testsuite/ld-elf/comm-data.exp: Run new tests. * testsuite/ld-elf/pr26580-a.c, * testsuite/ld-elf/pr26580-b.c, * testsuite/ld-elf/pr26580-3.out, * testsuite/ld-elf/pr26580-4.out: New tests. * testsuite/ld-elf/shared.exp: Run new tests. Fixed Hi Alan, I am seeing new linker testsuite failures for the pr26580-2 test for the following targets: mips-elf extra regexps in ld/testsuite/ld-elf/pr26580-2.sd starting with "^.* 8 OBJECT GLOBAL DEFAULT .* one$" mn10300-elf ./ld-new: tmpdir/pr26580-2: error: PHDR segment not covered by LOAD segment score-elf ./ld-new: tmpdir/pr26580-2: error: PHDR segment not covered by LOAD segment Are these expected, or do we need to investigate further ? Cheers Nick bfin-elf ./ld-new: the bfin target does not currently support the generation of copy relocations and other mips targets too. I saw all of these myself before committing the test, and decided they were sufficently unusual that I shouldn't just hide them with an xfail. At least not until investigating further. The master branch has been updated by Alan Modra <amodra@sourceware.org>: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=36efe0aea5f7e5088f79e4c8d0265de0c0ec2be9 commit 36efe0aea5f7e5088f79e4c8d0265de0c0ec2be9 Author: Alan Modra <amodra@gmail.com> Date: Thu Sep 10 18:46:14 2020 +0930 Re: PR26580, Size and alignment of commons vs as-needed shared lib Some MIPS targets, for reasons I didn't analyse, use the larger common symbol in a shared lib rather than a smaller common in an executable. That doesn't seem unreasonable, so allow that to pass for pr26580-2. bfin-elf complains about not supporting copy relocs, but it's quite silly to want a copy reloc for common symbols, so leave the fail there. mn10300-elf and score-elf both fail the test with "PHDR segment not covered by LOAD segment". Other tests fail similarly so one more doesn't hurt. The failure is a consequence of supporting dynamic objects but setting EMBEDDED in ld scripts. PR 26580 * testsuite/ld-elf/pr26580-2.sd: Accept undefined symbol. |