From ced505c47a961691e3f1e252ba5ea2aec4152397 Mon Sep 17 00:00:00 2001 From: "H.J. Lu" Date: Wed, 4 Mar 2015 08:57:30 -0800 Subject: [PATCH] Add extern_protected_data and set it for x86 With copy relocation, address of protected data defined in the shared library may be external. This patch adds extern_protected_data and changes _bfd_elf_symbol_refs_local_p to return false for protecteddata if extern_protected_data is true. --- bfd/elf-bfd.h | 4 ++++ bfd/elf32-i386.c | 1 + bfd/elf64-x86-64.c | 1 + bfd/elflink.c | 9 ++++++--- bfd/elfxx-target.h | 6 +++++- ld/testsuite/ld-i386/protected3.d | 3 ++- ld/testsuite/ld-i386/protected3.s | 3 ++- ld/testsuite/ld-x86-64/protected3.d | 3 ++- ld/testsuite/ld-x86-64/protected3.s | 3 ++- 9 files changed, 25 insertions(+), 8 deletions(-) diff --git a/bfd/elf-bfd.h b/bfd/elf-bfd.h index 156eec7..13c32e0 100644 --- a/bfd/elf-bfd.h +++ b/bfd/elf-bfd.h @@ -1359,6 +1359,10 @@ struct elf_backend_data in length rather than sec->size in length, if sec->rawsize is non-zero and smaller than sec->size. */ unsigned caches_rawsize : 1; + + /* Address of protected data defined in the shared library may be + external, i.e., due to copy relocation. */ + unsigned extern_protected_data : 1; }; /* Information about reloc sections associated with a bfd_elf_section_data diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c index 3f16fc1..52f4d33 100644 --- a/bfd/elf32-i386.c +++ b/bfd/elf32-i386.c @@ -5292,6 +5292,7 @@ elf_i386_add_symbol_hook (bfd * abfd, #define elf_backend_want_plt_sym 0 #define elf_backend_got_header_size 12 #define elf_backend_plt_alignment 4 +#define elf_backend_extern_protected_data 1 /* Support RELA for objdump of prelink objects. */ #define elf_info_to_howto elf_i386_info_to_howto_rel diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c index a4974ce..74d1d06 100644 --- a/bfd/elf64-x86-64.c +++ b/bfd/elf64-x86-64.c @@ -5868,6 +5868,7 @@ static const struct bfd_elf_special_section #define elf_backend_got_header_size (GOT_ENTRY_SIZE*3) #define elf_backend_rela_normal 1 #define elf_backend_plt_alignment 4 +#define elf_backend_extern_protected_data 1 #define elf_info_to_howto elf_x86_64_info_to_howto diff --git a/bfd/elflink.c b/bfd/elflink.c index ec1e4df..6ee6499 100644 --- a/bfd/elflink.c +++ b/bfd/elflink.c @@ -2671,7 +2671,9 @@ _bfd_elf_adjust_dynamic_copy (struct bfd_link_info *info, /* Increment the size of DYNBSS to make room for the symbol. */ dynbss->size += h->size; - if (h->protected_def) + /* No error if extern_protected_data is true. */ + if (h->protected_def + && !get_elf_backend_data (dynbss->owner)->extern_protected_data) { info->callbacks->einfo (_("%P: copy reloc against protected `%T' is invalid\n"), @@ -2835,8 +2837,9 @@ _bfd_elf_symbol_refs_local_p (struct elf_link_hash_entry *h, bed = get_elf_backend_data (hash_table->dynobj); - /* STV_PROTECTED non-function symbols are local. */ - if (!bed->is_function_type (h->type)) + /* If extern_protected_data is false, STV_PROTECTED non-function + symbols are local. */ + if (!bed->extern_protected_data && !bed->is_function_type (h->type)) return TRUE; /* Function pointer equality tests may require that STV_PROTECTED diff --git a/bfd/elfxx-target.h b/bfd/elfxx-target.h index 211c0a1..9760db4 100644 --- a/bfd/elfxx-target.h +++ b/bfd/elfxx-target.h @@ -117,6 +117,9 @@ #ifndef elf_backend_caches_rawsize #define elf_backend_caches_rawsize 0 #endif +#ifndef elf_backend_extern_protected_data +#define elf_backend_extern_protected_data 0 +#endif #ifndef elf_backend_stack_align #define elf_backend_stack_align 16 #endif @@ -801,7 +804,8 @@ static struct elf_backend_data elfNN_bed = elf_backend_want_dynbss, elf_backend_want_p_paddr_set_to_zero, elf_backend_default_execstack, - elf_backend_caches_rawsize + elf_backend_caches_rawsize, + elf_backend_extern_protected_data }; /* Forward declaration for use when initialising alternative_target field. */ diff --git a/ld/testsuite/ld-i386/protected3.d b/ld/testsuite/ld-i386/protected3.d index aafa2d8..47ab4e1 100644 --- a/ld/testsuite/ld-i386/protected3.d +++ b/ld/testsuite/ld-i386/protected3.d @@ -8,6 +8,7 @@ Disassembly of section .text: 0+[a-f0-9]+ : -[ ]*[a-f0-9]+: 8b 81 [a-f0-9][a-f0-9] [a-f0-9][a-f0-9] 00 00 mov 0x[a-f0-9]+\(%ecx\),%eax +[ ]*[a-f0-9]+: 8b 81 [a-f0-9][a-f0-9] [a-f0-9][a-f0-9] ff ff mov -0x[a-f0-9]+\(%ecx\),%eax +[ ]*[a-f0-9]+: 8b 00 mov \(%eax\),%eax [ ]*[a-f0-9]+: c3 ret #pass diff --git a/ld/testsuite/ld-i386/protected3.s b/ld/testsuite/ld-i386/protected3.s index 7a605a2..4dd2115 100644 --- a/ld/testsuite/ld-i386/protected3.s +++ b/ld/testsuite/ld-i386/protected3.s @@ -10,6 +10,7 @@ foo: .globl bar .type bar, @function bar: - movl foo@GOTOFF(%ecx), %eax + movl foo@GOT(%ecx), %eax + movl (%eax), %eax ret .size bar, .-bar diff --git a/ld/testsuite/ld-x86-64/protected3.d b/ld/testsuite/ld-x86-64/protected3.d index 22a36ac..d8f09da 100644 --- a/ld/testsuite/ld-x86-64/protected3.d +++ b/ld/testsuite/ld-x86-64/protected3.d @@ -8,6 +8,7 @@ Disassembly of section .text: 0+[a-f0-9]+ : -[ ]*[a-f0-9]+: 8b 05 ([0-9a-f]{2} ){4} * mov 0x[a-f0-9]+\(%rip\),%eax # [a-f0-9]+ +[ ]*[a-f0-9]+: 48 8b 05 ([0-9a-f]{2} ){4} * mov 0x[a-f0-9]+\(%rip\),%rax # [a-f0-9]+ <_DYNAMIC\+0x[a-f0-9]+> +[ ]*[a-f0-9]+: 8b 00 mov \(%rax\),%eax [ ]*[a-f0-9]+: c3 retq * #pass diff --git a/ld/testsuite/ld-x86-64/protected3.s b/ld/testsuite/ld-x86-64/protected3.s index e4af6e7..7538050 100644 --- a/ld/testsuite/ld-x86-64/protected3.s +++ b/ld/testsuite/ld-x86-64/protected3.s @@ -10,6 +10,7 @@ foo: .globl bar .type bar, @function bar: - movl foo(%rip), %eax + movq foo@GOTPCREL(%rip), %rax + movl (%rax), %eax ret .size bar, .-bar -- 1.9.3