From 3be08ea4728b56d35e136af4e6fd3086ade17764 Mon Sep 17 00:00:00 2001 From: Simon Atanasyan Date: Thu, 3 May 2018 17:17:46 +0100 Subject: BFD: Prevent writing the MIPS _gp_disp symbol into symbol tables The _gp_disp is a magic symbol, always implicitly defined by the linker. It does not make a sense to write it into symbol tables for output files. Moreover, now if the linker gets a version script, the _gp_disp symbol gets zero version definition index. The zero index means[1]: "The symbol is local, not available outside the object." But the _gp_disp symbol has GLOBAL binding. That confuses some tools like for example the LLD linker when they get such files as inputs. This patch fixes the problem - it prevents writing the _gp_disp symbol in regular and dynamic symbol tables. This was tested by running LD test suite on a mipsel-linux board. References: [1] "Linux Standard Base Specification", Section "10.7.2 Symbol Version Table", p. 32 2018-05-03 Simon Atanasyan bfd/ * elf32-mips.c: (elf32_mips_fixup_symbol): New function. (elf_backend_fixup_symbol): New macro. * elfxx-mips.c: (mips_elf_output_extsym): Discard _gp_disp handling. (_bfd_mips_elf_finish_dynamic_symbol): Likewise. ld/ * testsuite/ld-mips-elf/gp-disp-sym.d: New test. * testsuite/ld-mips-elf/gp-disp-sym.s: New test source. * testsuite/ld-mips-elf/mips-elf.exp: Run the new test. * testsuite/ld-mips-elf/mips16-pic-2.ad: Update for _gp_disp symbol removal. * testsuite/ld-mips-elf/mips16-pic-2.nd: Likewise. * testsuite/ld-mips-elf/pic-and-nonpic-3a.dd: Likewise. * testsuite/ld-mips-elf/tlslib-o32-hidden.got: Likewise. * testsuite/ld-mips-elf/tlslib-o32-ver.got: Likewise. * testsuite/ld-mips-elf/tlslib-o32.got: Likewise. --- bfd/elf32-mips.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'bfd/elf32-mips.c') diff --git a/bfd/elf32-mips.c b/bfd/elf32-mips.c index 87147b5..23a5712 100644 --- a/bfd/elf32-mips.c +++ b/bfd/elf32-mips.c @@ -2420,6 +2420,17 @@ elf32_mips_write_core_note (bfd *abfd, char *buf, int *bufsiz, int note_type, } } } + +/* Remove the magic _gp_disp symbol from the symbol tables. */ + +static bfd_boolean +elf32_mips_fixup_symbol (struct bfd_link_info *info, + struct elf_link_hash_entry *h) +{ + if (strcmp (h->root.root.string, "_gp_disp") == 0) + _bfd_elf_link_hash_hide_symbol (info, h, TRUE); + return TRUE; +} /* Depending on the target vector we generate some version of Irix executables or "normal" MIPS ELF ABI executables. */ @@ -2523,6 +2534,7 @@ static const struct ecoff_debug_swap mips_elf32_ecoff_debug_swap = { #define elf_backend_gc_mark_hook _bfd_mips_elf_gc_mark_hook #define elf_backend_copy_indirect_symbol \ _bfd_mips_elf_copy_indirect_symbol +#define elf_backend_fixup_symbol elf32_mips_fixup_symbol #define elf_backend_grok_prstatus elf32_mips_grok_prstatus #define elf_backend_grok_psinfo elf32_mips_grok_psinfo #define elf_backend_ecoff_debug_swap &mips_elf32_ecoff_debug_swap -- cgit v1.1