From e76790600aeba4939225eda32e59642ed2813ac8 Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Tue, 26 Nov 2019 22:32:51 +1030 Subject: [PATCH] PR23652, Use symbols from debug bfd for _bfd_elf_find_function Sometimes DWARF info for a function is incomplete, and the function can be retrieved by examining symbols. However, when separate debug files are used it may be that the original file is completely stripped of symbols. This patch teaches BFD to look at symbols from the debug file in that case. The patch also removes arm_elf_find_function, instead implementing elf_backend_maybe_function_sym. arm_elf_find_function was written before the generic _bfd_elf_find_function called maybe_function_sym. aarch64 copied arm, so that file gets the same treatment. There is some chance this will speed up arm and aarch64 lookup of function/line. PR 23652 * dwarf2.c (_bfd_dwarf2_stash_syms): New function. (_bfd_dwarf2_find_nearest_line): Use it here, passing syms to _bfd_elf_find_function. Call _bfd_elf_find_function in cases where _bfd_elf_find_nearest_line would do so. * elf.c (_bfd_elf_find_nearest_line): Omit _bfd_elf_find_function for dwarf2. * elfxx-mips.c (_bfd_mips_elf_find_nearest_line): Similarly. Tidy. * elf32-arm.c (elf32_arm_maybe_function_sym): New function. (elf_backend_maybe_function_sym): Define. (arm_elf_find_function, elf32_arm_find_nearest_line): Delete. (bfd_elf32_find_nearest_line): Don't define. * elfnn-aarch64.c (elfNN_aarch64_maybe_function_sym): New function. (elf_backend_maybe_function_sym): Define. (aarch64_elf_find_function, elfNN_aarch64_find_nearest_line): Delete. (bfd_elfNN_find_nearest_line): Don't define. --- bfd/ChangeLog | 19 ++++++ bfd/dwarf2.c | 58 +++++++++++++++--- bfd/elf.c | 9 +-- bfd/elf32-arm.c | 141 ++++++++++--------------------------------- bfd/elfnn-aarch64.c | 143 ++++++++++---------------------------------- bfd/elfxx-mips.c | 30 ++++------ 6 files changed, 147 insertions(+), 253 deletions(-) diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 3ef8515e222..4a0852e577d 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,22 @@ +2019-11-27 Alan Modra + + PR 23652 + * dwarf2.c (_bfd_dwarf2_stash_syms): New function. + (_bfd_dwarf2_find_nearest_line): Use it here, passing syms to + _bfd_elf_find_function. Call _bfd_elf_find_function in cases + where _bfd_elf_find_nearest_line would do so. + * elf.c (_bfd_elf_find_nearest_line): Omit _bfd_elf_find_function + for dwarf2. + * elfxx-mips.c (_bfd_mips_elf_find_nearest_line): Similarly. Tidy. + * elf32-arm.c (elf32_arm_maybe_function_sym): New function. + (elf_backend_maybe_function_sym): Define. + (arm_elf_find_function, elf32_arm_find_nearest_line): Delete. + (bfd_elf32_find_nearest_line): Don't define. + * elfnn-aarch64.c (elfNN_aarch64_maybe_function_sym): New function. + (elf_backend_maybe_function_sym): Define. + (aarch64_elf_find_function, elfNN_aarch64_find_nearest_line): Delete. + (bfd_elfNN_find_nearest_line): Don't define. + 2019-11-27 Alan Modra * elf32-sh.c (sh_reloc): Use a bfd_vma insn. diff --git a/bfd/dwarf2.c b/bfd/dwarf2.c index c3d9ffc3c5f..e42483a535a 100644 --- a/bfd/dwarf2.c +++ b/bfd/dwarf2.c @@ -3894,6 +3894,40 @@ set_debug_vma (bfd *orig_bfd, bfd *debug_bfd) } } +/* If the dwarf2 info was found in a separate debug file, return the + debug file section corresponding to the section in the original file + and the debug file symbols. */ + +static void +_bfd_dwarf2_stash_syms (struct dwarf2_debug *stash, bfd *abfd, + asection **sec, asymbol ***syms) +{ + if (stash->bfd_ptr != abfd) + { + asection *s, *d; + + if (*sec == NULL) + { + *syms = stash->syms; + return; + } + + for (s = abfd->sections, d = stash->bfd_ptr->sections; + s != NULL && d != NULL; + s = s->next, d = d->next) + { + if ((d->flags & SEC_DEBUGGING) != 0) + break; + if (s == *sec + && strcmp (s->name, d->name) == 0) + { + *sec = d; + *syms = stash->syms; + } + } + } +} + /* Unset vmas for adjusted sections in STASH. */ static void @@ -4888,16 +4922,26 @@ _bfd_dwarf2_find_nearest_line (bfd *abfd, } done: - if (function) + if (functionname_ptr && function && function->is_linkage) + *functionname_ptr = function->name; + else if (functionname_ptr + && ((found && !*functionname_ptr) + || (function && !function->is_linkage))) { - if (!function->is_linkage) + asymbol *fun; + asymbol **syms = symbols; + asection *sec = section; + + if (symbols == NULL || *symbols == NULL) + _bfd_dwarf2_stash_syms (stash, abfd, &sec, &syms); + fun = _bfd_elf_find_function (abfd, syms, sec, offset, + *filename_ptr ? NULL : filename_ptr, + functionname_ptr); + + if (function && !function->is_linkage) { - asymbol *fun; bfd_vma sec_vma; - fun = _bfd_elf_find_function (abfd, symbols, section, offset, - *filename_ptr ? NULL : filename_ptr, - functionname_ptr); sec_vma = section->vma; if (section->output_section != NULL) sec_vma = section->output_section->vma + section->output_offset; @@ -4908,8 +4952,8 @@ _bfd_dwarf2_find_nearest_line (bfd *abfd, to stop a repeated search of symbols. */ function->is_linkage = TRUE; } - *functionname_ptr = function->name; } + if ((abfd->flags & (EXEC_P | DYNAMIC)) == 0) unset_sections (stash); diff --git a/bfd/elf.c b/bfd/elf.c index a4f26dac71d..1aa2603ee8c 100644 --- a/bfd/elf.c +++ b/bfd/elf.c @@ -9030,10 +9030,11 @@ _bfd_elf_find_nearest_line (bfd *abfd, filename_ptr, functionname_ptr, line_ptr, discriminator_ptr, dwarf_debug_sections, - &elf_tdata (abfd)->dwarf2_find_line_info) - || _bfd_dwarf1_find_nearest_line (abfd, symbols, section, offset, - filename_ptr, functionname_ptr, - line_ptr)) + &elf_tdata (abfd)->dwarf2_find_line_info)) + return TRUE; + + if (_bfd_dwarf1_find_nearest_line (abfd, symbols, section, offset, + filename_ptr, functionname_ptr, line_ptr)) { if (!*functionname_ptr) _bfd_elf_find_function (abfd, symbols, section, offset, diff --git a/bfd/elf32-arm.c b/bfd/elf32-arm.c index dca208f06aa..37b5b64dc60 100644 --- a/bfd/elf32-arm.c +++ b/bfd/elf32-arm.c @@ -16040,125 +16040,44 @@ elf32_arm_is_target_special_symbol (bfd * abfd ATTRIBUTE_UNUSED, asymbol * sym) BFD_ARM_SPECIAL_SYM_TYPE_ANY); } -/* This is a version of _bfd_elf_find_function() from dwarf2.c except that - ARM mapping symbols are ignored when looking for function names - and STT_ARM_TFUNC is considered to a function type. */ +/* If the ELF symbol SYM might be a function in SEC, return the + function size and set *CODE_OFF to the function's entry point, + otherwise return zero. */ -static bfd_boolean -arm_elf_find_function (bfd * abfd, - asymbol ** symbols, - asection * section, - bfd_vma offset, - const char ** filename_ptr, - const char ** functionname_ptr) -{ - const char * filename = NULL; - asymbol * func = NULL; - bfd_vma low_func = 0; - asymbol ** p; - - if (symbols == NULL) - return FALSE; - - if (bfd_get_flavour (abfd) != bfd_target_elf_flavour) - return FALSE; - - for (p = symbols; *p != NULL; p++) - { - elf_symbol_type *q; +static bfd_size_type +elf32_arm_maybe_function_sym (const asymbol *sym, asection *sec, + bfd_vma *code_off) +{ + bfd_size_type size; - q = (elf_symbol_type *) *p; + if ((sym->flags & (BSF_SECTION_SYM | BSF_FILE | BSF_OBJECT + | BSF_THREAD_LOCAL | BSF_RELC | BSF_SRELC)) != 0 + || sym->section != sec) + return 0; - switch (ELF_ST_TYPE (q->internal_elf_sym.st_info)) - { - default: - break; - case STT_FILE: - filename = bfd_asymbol_name (&q->symbol); - break; + if (!(sym->flags & BSF_SYNTHETIC)) + switch (ELF_ST_TYPE (((elf_symbol_type *) sym)->internal_elf_sym.st_info)) + { case STT_FUNC: case STT_ARM_TFUNC: case STT_NOTYPE: - /* Skip mapping symbols. */ - if ((q->symbol.flags & BSF_LOCAL) - && bfd_is_arm_special_symbol_name (q->symbol.name, - BFD_ARM_SPECIAL_SYM_TYPE_ANY)) - continue; - /* Fall through. */ - if (bfd_asymbol_section (&q->symbol) == section - && q->symbol.value >= low_func - && q->symbol.value <= offset) - { - func = (asymbol *) q; - low_func = q->symbol.value; - } break; - } - } - - if (func == NULL) - return FALSE; - - if (filename_ptr) - *filename_ptr = filename; - if (functionname_ptr) - *functionname_ptr = bfd_asymbol_name (func); - - return TRUE; -} - - -/* Find the nearest line to a particular section and offset, for error - reporting. This code is a duplicate of the code in elf.c, except - that it uses arm_elf_find_function. */ - -static bfd_boolean -elf32_arm_find_nearest_line (bfd * abfd, - asymbol ** symbols, - asection * section, - bfd_vma offset, - const char ** filename_ptr, - const char ** functionname_ptr, - unsigned int * line_ptr, - unsigned int * discriminator_ptr) -{ - bfd_boolean found = FALSE; - - if (_bfd_dwarf2_find_nearest_line (abfd, symbols, NULL, section, offset, - filename_ptr, functionname_ptr, - line_ptr, discriminator_ptr, - dwarf_debug_sections, - & elf_tdata (abfd)->dwarf2_find_line_info)) - { - if (!*functionname_ptr) - arm_elf_find_function (abfd, symbols, section, offset, - *filename_ptr ? NULL : filename_ptr, - functionname_ptr); - - return TRUE; - } - - /* Skip _bfd_dwarf1_find_nearest_line since no known ARM toolchain - uses DWARF1. */ - - if (! _bfd_stab_section_find_nearest_line (abfd, symbols, section, offset, - & found, filename_ptr, - functionname_ptr, line_ptr, - & elf_tdata (abfd)->line_info)) - return FALSE; - - if (found && (*functionname_ptr || *line_ptr)) - return TRUE; - - if (symbols == NULL) - return FALSE; + default: + return 0; + } - if (! arm_elf_find_function (abfd, symbols, section, offset, - filename_ptr, functionname_ptr)) - return FALSE; + if ((sym->flags & BSF_LOCAL) + && bfd_is_arm_special_symbol_name (sym->name, + BFD_ARM_SPECIAL_SYM_TYPE_ANY)) + return 0; - *line_ptr = 0; - return TRUE; + *code_off = sym->value; + size = 0; + if (!(sym->flags & BSF_SYNTHETIC)) + size = ((elf_symbol_type *) sym)->internal_elf_sym.st_size; + if (size == 0) + size = 1; + return size; } static bfd_boolean @@ -20488,7 +20407,6 @@ elf32_arm_backend_symbol_processing (bfd *abfd, asymbol *sym) #define bfd_elf32_bfd_link_hash_table_create elf32_arm_link_hash_table_create #define bfd_elf32_bfd_reloc_type_lookup elf32_arm_reloc_type_lookup #define bfd_elf32_bfd_reloc_name_lookup elf32_arm_reloc_name_lookup -#define bfd_elf32_find_nearest_line elf32_arm_find_nearest_line #define bfd_elf32_find_inliner_info elf32_arm_find_inliner_info #define bfd_elf32_new_section_hook elf32_arm_new_section_hook #define bfd_elf32_bfd_is_target_special_symbol elf32_arm_is_target_special_symbol @@ -20496,6 +20414,7 @@ elf32_arm_backend_symbol_processing (bfd *abfd, asymbol *sym) #define bfd_elf32_get_synthetic_symtab elf32_arm_get_synthetic_symtab #define elf_backend_get_symbol_type elf32_arm_get_symbol_type +#define elf_backend_maybe_function_sym elf32_arm_maybe_function_sym #define elf_backend_gc_mark_hook elf32_arm_gc_mark_hook #define elf_backend_gc_mark_extra_sections elf32_arm_gc_mark_extra_sections #define elf_backend_check_relocs elf32_arm_check_relocs diff --git a/bfd/elfnn-aarch64.c b/bfd/elfnn-aarch64.c index a71071161c7..51d7526a720 100644 --- a/bfd/elfnn-aarch64.c +++ b/bfd/elfnn-aarch64.c @@ -7999,122 +7999,43 @@ elfNN_aarch64_is_target_special_symbol (bfd *abfd ATTRIBUTE_UNUSED, BFD_AARCH64_SPECIAL_SYM_TYPE_ANY); } -/* This is a version of _bfd_elf_find_function() from dwarf2.c except that - AArch64 mapping symbols are ignored when looking for function names. */ +/* If the ELF symbol SYM might be a function in SEC, return the + function size and set *CODE_OFF to the function's entry point, + otherwise return zero. */ -static bfd_boolean -aarch64_elf_find_function (bfd * abfd, - asymbol ** symbols, - asection * section, - bfd_vma offset, - const char ** filename_ptr, - const char ** functionname_ptr) -{ - const char *filename = NULL; - asymbol *func = NULL; - bfd_vma low_func = 0; - asymbol **p; - - if (symbols == NULL) - return FALSE; - - if (bfd_get_flavour (abfd) != bfd_target_elf_flavour) - return FALSE; - - for (p = symbols; *p != NULL; p++) - { - elf_symbol_type *q; +static bfd_size_type +elfNN_aarch64_maybe_function_sym (const asymbol *sym, asection *sec, + bfd_vma *code_off) +{ + bfd_size_type size; - q = (elf_symbol_type *) * p; + if ((sym->flags & (BSF_SECTION_SYM | BSF_FILE | BSF_OBJECT + | BSF_THREAD_LOCAL | BSF_RELC | BSF_SRELC)) != 0 + || sym->section != sec) + return 0; - switch (ELF_ST_TYPE (q->internal_elf_sym.st_info)) - { - default: - break; - case STT_FILE: - filename = bfd_asymbol_name (&q->symbol); - break; + if (!(sym->flags & BSF_SYNTHETIC)) + switch (ELF_ST_TYPE (((elf_symbol_type *) sym)->internal_elf_sym.st_info)) + { case STT_FUNC: case STT_NOTYPE: - /* Skip mapping symbols. */ - if ((q->symbol.flags & BSF_LOCAL) - && (bfd_is_aarch64_special_symbol_name - (q->symbol.name, BFD_AARCH64_SPECIAL_SYM_TYPE_ANY))) - continue; - /* Fall through. */ - if (bfd_asymbol_section (&q->symbol) == section - && q->symbol.value >= low_func && q->symbol.value <= offset) - { - func = (asymbol *) q; - low_func = q->symbol.value; - } break; - } - } - - if (func == NULL) - return FALSE; - - if (filename_ptr) - *filename_ptr = filename; - if (functionname_ptr) - *functionname_ptr = bfd_asymbol_name (func); - - return TRUE; -} - - -/* Find the nearest line to a particular section and offset, for error - reporting. This code is a duplicate of the code in elf.c, except - that it uses aarch64_elf_find_function. */ - -static bfd_boolean -elfNN_aarch64_find_nearest_line (bfd *abfd, - asymbol **symbols, - asection *section, - bfd_vma offset, - const char **filename_ptr, - const char **functionname_ptr, - unsigned int *line_ptr, - unsigned int *discriminator_ptr) -{ - bfd_boolean found = FALSE; - - if (_bfd_dwarf2_find_nearest_line (abfd, symbols, NULL, section, offset, - filename_ptr, functionname_ptr, - line_ptr, discriminator_ptr, - dwarf_debug_sections, - &elf_tdata (abfd)->dwarf2_find_line_info)) - { - if (!*functionname_ptr) - aarch64_elf_find_function (abfd, symbols, section, offset, - *filename_ptr ? NULL : filename_ptr, - functionname_ptr); - - return TRUE; - } - - /* Skip _bfd_dwarf1_find_nearest_line since no known AArch64 - toolchain uses DWARF1. */ - - if (!_bfd_stab_section_find_nearest_line (abfd, symbols, section, offset, - &found, filename_ptr, - functionname_ptr, line_ptr, - &elf_tdata (abfd)->line_info)) - return FALSE; - - if (found && (*functionname_ptr || *line_ptr)) - return TRUE; - - if (symbols == NULL) - return FALSE; + default: + return 0; + } - if (!aarch64_elf_find_function (abfd, symbols, section, offset, - filename_ptr, functionname_ptr)) - return FALSE; + if ((sym->flags & BSF_LOCAL) + && bfd_is_aarch64_special_symbol_name (sym->name, + BFD_AARCH64_SPECIAL_SYM_TYPE_ANY)) + return 0; - *line_ptr = 0; - return TRUE; + *code_off = sym->value; + size = 0; + if (!(sym->flags & BSF_SYNTHETIC)) + size = ((elf_symbol_type *) sym)->internal_elf_sym.st_size; + if (size == 0) + size = 1; + return size; } static bfd_boolean @@ -10123,9 +10044,6 @@ const struct elf_size_info elfNN_aarch64_size_info = #define bfd_elfNN_find_inliner_info \ elfNN_aarch64_find_inliner_info -#define bfd_elfNN_find_nearest_line \ - elfNN_aarch64_find_nearest_line - #define bfd_elfNN_get_synthetic_symtab \ elfNN_aarch64_get_synthetic_symtab @@ -10170,6 +10088,9 @@ const struct elf_size_info elfNN_aarch64_size_info = #define elf_backend_output_arch_local_syms \ elfNN_aarch64_output_arch_local_syms +#define elf_backend_maybe_function_sym \ + elfNN_aarch64_maybe_function_sym + #define elf_backend_plt_sym_val \ elfNN_aarch64_plt_sym_val diff --git a/bfd/elfxx-mips.c b/bfd/elfxx-mips.c index 3982ed25e91..e9af7abd4b5 100644 --- a/bfd/elfxx-mips.c +++ b/bfd/elfxx-mips.c @@ -13078,27 +13078,17 @@ _bfd_mips_elf_find_nearest_line (bfd *abfd, asymbol **symbols, filename_ptr, functionname_ptr, line_ptr, discriminator_ptr, dwarf_debug_sections, - &elf_tdata (abfd)->dwarf2_find_line_info) - || _bfd_dwarf1_find_nearest_line (abfd, symbols, section, offset, - filename_ptr, functionname_ptr, - line_ptr)) - { - /* PR 22789: If the function name or filename was not found through - the debug information, then try an ordinary lookup instead. */ - if ((functionname_ptr != NULL && *functionname_ptr == NULL) - || (filename_ptr != NULL && *filename_ptr == NULL)) - { - /* Do not override already discovered names. */ - if (functionname_ptr != NULL && *functionname_ptr != NULL) - functionname_ptr = NULL; - - if (filename_ptr != NULL && *filename_ptr != NULL) - filename_ptr = NULL; - - _bfd_elf_find_function (abfd, symbols, section, offset, - filename_ptr, functionname_ptr); - } + &elf_tdata (abfd)->dwarf2_find_line_info)) + return TRUE; + if (_bfd_dwarf1_find_nearest_line (abfd, symbols, section, offset, + filename_ptr, functionname_ptr, + line_ptr)) + { + if (!*functionname_ptr) + _bfd_elf_find_function (abfd, symbols, section, offset, + *filename_ptr ? NULL : filename_ptr, + functionname_ptr); return TRUE; } -- 2.30.2