From 6f365fda85a2e2682b197540d14adf66c4261b19 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Thu, 17 Jun 2021 14:11:28 -0700 Subject: elf: Add GNU_PROPERTY_1_NEEDED check If GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS is set on any input relocatable files: 1. Don't generate copy relocations. 2. Turn off extern_protected_data since it implies GNU_PROPERTY_NO_COPY_ON_PROTECTED. 3. Treate reference to protected symbols with indirect external access as local. 4. Set GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS on output. 5. When generating executable, clear this bit when there are non-GOT or non-PLT relocations in input relocatable files without the bit set. 6. Add -z [no]indirect-extern-access to control indirect external access. bfd/ * elf-bfd (elf_obj_tdata): Add has_indirect_extern_access. (elf_has_indirect_extern_access): New. * elf-properties.c (_bfd_elf_parse_gnu_properties): Set elf_has_indirect_extern_access and elf_has_no_copy_on_protected when seeing GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS. (elf_write_gnu_propertie): Add an argument to pass link_info. Set needed_1_p for GNU_PROPERTY_1_NEEDED in memory. (_bfd_elf_link_setup_gnu_properties): Handle GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS for -z indirect-extern-access. Set nocopyreloc to true and extern_protected_data to false for indirect external access. (_bfd_elf_convert_gnu_properties): Updated. * elf32-i386.c (elf_i386_check_relocs): Set non_got_ref_without_indirect_extern_access on legacy non-GOT or non-PLT references. * elf64-x86-64.c (elf_x86_64_check_relocs): Likewise. * elflink.c (_bfd_elf_symbol_refs_local_p): Return true for STV_PROTECTED symbols with indirect external access. * elfxx-x86.c (_bfd_x86_elf_adjust_dynamic_symbol): Clear indirect_extern_access for legacy non-GOT/non-PLT references. * elfxx-x86.h (elf_x86_link_hash_entry): Add non_got_ref_without_indirect_extern_access. include/ * bfdlink.h (bfd_link_info): Add indirect_extern_access and needed_1_p. Change nocopyreloc to int. ld/ * NEWS: Mention -z [no]indirect-extern-access * ld.texi: Document -z [no]indirect-extern-access * ldmain.c (main): Initialize link_info.indirect_extern_access to -1. * emulparams/extern_protected_data.sh: Support -z [no]indirect-extern-access. * testsuite/ld-elf/indirect-extern-access-1.rd: New file * testsuite/ld-elf/indirect-extern-access-1a.c: Likewise. * testsuite/ld-elf/indirect-extern-access-1b.c: Likewise. * testsuite/ld-elf/indirect-extern-access-2.rd: Likewise. * testsuite/ld-elf/indirect-extern-access-2a.c: Likewise. * testsuite/ld-elf/indirect-extern-access-2b.c: Likewise. * testsuite/ld-elf/indirect-extern-access-3.rd: Likewise. * testsuite/ld-elf/indirect-extern-access.S: Likewise. * testsuite/ld-elf/property-1_needed-1b.d: Likewise. * testsuite/ld-elf/property-1_needed-1c.d: Likewise. * testsuite/ld-x86-64/indirect-extern-access.rd: Likewise. * testsuite/ld-x86-64/protected-data-1.h: Likewise. * testsuite/ld-x86-64/protected-data-1a.c: Likewise. * testsuite/ld-x86-64/protected-data-1b.c: Likewise. * testsuite/ld-x86-64/protected-data-2a.S: Likewise. * testsuite/ld-x86-64/protected-data-2b.S: Likewise. * testsuite/ld-x86-64/protected-func-2a.S: Likewise. * testsuite/ld-x86-64/protected-func-2b.S: Likewise. * testsuite/ld-x86-64/protected-func-2c.c: Likewise. * testsuite/ld-elf/linux-x86.exp: Run test with GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS. * testsuite/ld-x86-64/x86-64.exp: Run tests for protected function and data with indirect external access. --- bfd/elfxx-x86.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'bfd/elfxx-x86.c') diff --git a/bfd/elfxx-x86.c b/bfd/elfxx-x86.c index 088f6e5..fe4a822 100644 --- a/bfd/elfxx-x86.c +++ b/bfd/elfxx-x86.c @@ -1824,6 +1824,25 @@ _bfd_x86_elf_adjust_dynamic_symbol (struct bfd_link_info *info, eh = (struct elf_x86_link_hash_entry *) h; + /* Clear GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS if it is turned + on by an input relocatable file and there is a non-GOT/non-PLT + reference from another relocatable file without it. + NB: There can be non-GOT reference in data sections in input with + GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS. */ + if (eh->non_got_ref_without_indirect_extern_access + && info->indirect_extern_access == 1 + && bfd_link_executable (info)) + { + unsigned int needed_1; + info->indirect_extern_access = 0; + /* Turn off nocopyreloc if implied by indirect_extern_access. */ + if (info->nocopyreloc == 2) + info->nocopyreloc = 0; + needed_1 = bfd_h_get_32 (info->output_bfd, info->needed_1_p); + needed_1 &= ~GNU_PROPERTY_1_NEEDED_INDIRECT_EXTERN_ACCESS; + bfd_h_put_32 (info->output_bfd, needed_1, info->needed_1_p); + } + /* STT_GNU_IFUNC symbol must go through PLT. */ if (h->type == STT_GNU_IFUNC) { -- cgit v1.1