From a91e1603afb6704545793e967a1a3dfe96b389de Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Tue, 4 Apr 2017 09:05:48 -0700 Subject: Support ELF SHF_GNU_MBIND and PT_GNU_MBIND_XXX Mark an ALLOC section, which should be placed in special memory area, with SHF_GNU_MBIND. Its sh_info field indicates the special memory type. GNU_MBIND section names start with ".mbind" so that they are placed as orphan sections by linker. All input GNU_MBIND sections with the same sh_type, sh_flags and sh_info are placed in one output GNU_MBIND section. In executable and shared object, create a GNU_MBIND segment for each GNU_MBIND section and its segment type is PT_GNU_MBIND_LO plus the sh_info value. Each GNU_MBIND segment is aligned at page boundary. The assembler syntax: .section .mbind.foo,"adx",%progbits ^ 0: Special memory type. | 'd' for SHF_GNU_MBIND. .section .mbind.foo,"adx",%progbits,0x1 ^ 1: Special memory type. | 'd' for SHF_GNU_MBIND. .section .mbind.bar,"adG",%progbits,.foo_group,comdat,0x2 ^ 2: Special memory type. | 'd' for SHF_GNU_MBIND. bfd/ * elf.c (get_program_header_size): Add a GNU_MBIND segment for each GNU_MBIND section and align GNU_MBIND section to page size. (_bfd_elf_map_sections_to_segments): Create a GNU_MBIND segment for each GNU_MBIND section. (_bfd_elf_init_private_section_data): Copy sh_info from input for GNU_MBIND section. binutils/ * NEWS: Mention support for ELF SHF_GNU_MBIND and PT_GNU_MBIND_XXX. * readelf.c (get_segment_type): Handle PT_GNU_MBIND_XXX. (get_elf_section_flags): Handle SHF_GNU_MBIND. (process_section_headers): Likewise. * testsuite/binutils-all/mbind1.s: New file. * testsuite/binutils-all/objcopy.exp: Run readelf test on mbind1.s. gas/ * NEWS: Mention support for ELF SHF_GNU_MBIND. * config/obj-elf.c (section_match): New. (get_section): Match both sh_info and group name. (obj_elf_change_section): Add argument for sh_info. Pass both sh_info and group name to get_section. Issue an error for SHF_GNU_MBIND section without SHF_ALLOC. Set sh_info. (obj_elf_parse_section_letters): Set SHF_GNU_MBIND for 'd'. (obj_elf_section): Support SHF_GNU_MBIND section info. * config/obj-elf.h (obj_elf_change_section): Add argument for sh_info. * config/tc-arm.c (start_unwind_section): Pass 0 as sh_info to obj_elf_change_section. * config/tc-ia64.c (obj_elf_vms_common): Likewise. * config/tc-microblaze.c (microblaze_s_data): Likewise. (microblaze_s_sdata): Likewise. (microblaze_s_rdata): Likewise. (microblaze_s_bss): Likewise. * config/tc-mips.c (s_change_section): Likewise. * config/tc-msp430.c (msp430_profiler): Likewise. * config/tc-rx.c (parse_rx_section): Likewise. * config/tc-tic6x.c (tic6x_start_unwind_section): Likewise. * doc/as.texinfo: Document 'd' for SHF_GNU_MBIND. * testsuite/gas/elf/elf.exp: Run section12a, section12b and section13. * testsuite/gas/elf/section10.d: Updated. * testsuite/gas/elf/section10.s: Likewise. * testsuite/gas/elf/section12.s: New file. * testsuite/gas/elf/section12a.d: Likewise. * testsuite/gas/elf/section12b.d: Likewise. * testsuite/gas/elf/section13.l: Likewise. * testsuite/gas/elf/section13.d: Likewise. * testsuite/gas/elf/section13.s: Likewise. include/ * elf/common.h (PT_GNU_MBIND_NUM): New. (PT_GNU_MBIND_LO): Likewise. (PT_GNU_MBIND_HI): Likewise. (SHF_GNU_MBIND): Likewise. ld/ * NEWS: Mention support for ELF SHF_GNU_MBIND and PT_GNU_MBIND_XXX. * emultempl/elf32.em (gld${EMULATION_NAME}_place_orphan): Place input GNU_MBIND sections with the same type, attributes and sh_info field into a single output GNU_MBIND section. * testsuite/ld-elf/elf.exp: Run mbind2a and mbind2b. * testsuite/ld-elf/mbind1.s: New file. * testsuite/ld-elf/mbind1a.d: Likewise. * testsuite/ld-elf/mbind1b.d: Likewise. * testsuite/ld-elf/mbind1c.d: Likewise. * testsuite/ld-elf/mbind2a.s: Likewise. * testsuite/ld-elf/mbind2b.c: Likewise. --- ld/emultempl/elf32.em | 46 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 45 insertions(+), 1 deletion(-) (limited to 'ld/emultempl') diff --git a/ld/emultempl/elf32.em b/ld/emultempl/elf32.em index 007e48d..3442c95 100644 --- a/ld/emultempl/elf32.em +++ b/ld/emultempl/elf32.em @@ -2093,6 +2093,47 @@ gld${EMULATION_NAME}_place_orphan (asection *s, } } + if (!bfd_link_relocatable (&link_info) + && (s->flags & SEC_ALLOC) != 0 + && (elf_section_flags (s) & SHF_GNU_MBIND) != 0) + { + /* Find the output mbind section with the same type, attributes + and sh_info field. */ + for (os = &lang_output_section_statement.head->output_section_statement; + os != NULL; + os = os->next) + if (os->bfd_section != NULL + && !bfd_is_abs_section (os->bfd_section) + && (elf_section_flags (os->bfd_section) & SHF_GNU_MBIND) != 0 + && ((s->flags & (SEC_ALLOC + | SEC_LOAD + | SEC_HAS_CONTENTS + | SEC_READONLY + | SEC_CODE)) + == (os->bfd_section->flags & (SEC_ALLOC + | SEC_LOAD + | SEC_HAS_CONTENTS + | SEC_READONLY + | SEC_CODE))) + && (elf_section_data (os->bfd_section)->this_hdr.sh_info + == elf_section_data (s)->this_hdr.sh_info)) + { + lang_add_section (&os->children, s, NULL, os); + return os; + } + + /* Create the output mbind section with the ".mbind." prefix + in section name. */ + if ((s->flags & (SEC_LOAD | SEC_HAS_CONTENTS)) == 0) + secname = ".mbind.bss"; + else if ((s->flags & SEC_READONLY) == 0) + secname = ".mbind.data"; + else if ((s->flags & SEC_CODE) == 0) + secname = ".mbind.rodata"; + else + secname = ".mbind.text"; + } + /* Look through the script to see where to place this section. */ if (constraint == 0) for (os = lang_output_section_find (secname); @@ -2105,8 +2146,11 @@ gld${EMULATION_NAME}_place_orphan (asection *s, /* SEC_EXCLUDE is cleared when doing a relocatable link. But we can't merge 2 input sections with the same name when only - one of them has SHF_EXCLUDE. */ + one of them has SHF_EXCLUDE. Don't merge 2 sections with + different sh_info. */ if (os->bfd_section != NULL + && (elf_section_data (os->bfd_section)->this_hdr.sh_info + == elf_section_data (s)->this_hdr.sh_info) && (os->bfd_section->flags == 0 || ((!bfd_link_relocatable (&link_info) || (iself && (((elf_section_flags (s) -- cgit v1.1