From 0f489445070cf65d96db7938f80ad118921c1f6a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Magnus=20L=C3=A5ng?= Date: Tue, 10 May 2016 17:22:25 +0200 Subject: hipe: Extract some records into elf_format.hrl This allows for much more robust interpretation of relocations, symbols and sections in hipe_llvm_main, without the clunkiness of an abstract interface between two internal modules that belong to the same subsystem anyway. --- lib/hipe/llvm/elf_format.erl | 140 +++++++++++++++++-------------------------- 1 file changed, 56 insertions(+), 84 deletions(-) (limited to 'lib/hipe/llvm/elf_format.erl') diff --git a/lib/hipe/llvm/elf_format.erl b/lib/hipe/llvm/elf_format.erl index e56ccce626..4155dff7c4 100644 --- a/lib/hipe/llvm/elf_format.erl +++ b/lib/hipe/llvm/elf_format.erl @@ -13,18 +13,16 @@ -module(elf_format). --export([get_tab_entries/1, - %% Relocations - get_rodata_relocs/1, - get_text_relocs/1, +-export([%% Relocations extract_rela/2, - get_rela_addends/1, %% Note extract_note/2, %% Executable code extract_text/1, %% GCC Exception Table get_exn_handlers/1, + %% Symbols + elf_symbols/1, %% Main interface read/1 ]). @@ -40,14 +38,7 @@ -type lp() :: non_neg_integer(). % landing pad -type num() :: non_neg_integer(). -type index() :: non_neg_integer(). --type offset() :: non_neg_integer(). --type size() :: non_neg_integer(). -type start() :: non_neg_integer(). --type reloc_type() :: atom(). - --type valueoff() :: offset(). - --type name() :: string(). -type tuple(X) :: {} | {X} | {X, X} | tuple(). @@ -91,38 +82,6 @@ }). %% -type elf_ehdr_ident() :: #elf_ehdr_ident{}. -%% Section header entries --record(elf_shdr, {name :: string(), % Section name - type, % Section type - flags, % Section attributes - addr, % Virtual address in memory - offset :: offset(), % Offset in file - size :: size(), % Size of section - link, % Link to other section - info, % Miscellaneous information - addralign, % Address align boundary - entsize % Size of entries, if section has table - }). --type elf_shdr() :: #elf_shdr{}. - -%% Symbol table entries --record(elf_sym, {name :: string(), % Symbol name - info, % Type and Binding attributes - other, % Reserved - section :: undefined | abs | elf_shdr(), - value :: valueoff(), % Symbol value - size :: size() % Size of object - }). --type elf_sym() :: #elf_sym{}. - -%% Relocations --record(elf_rel, {offset :: offset() - ,type :: reloc_type() - ,addend :: offset() | undefined - ,symbol :: elf_sym() - }). --type elf_rel() :: #elf_rel{}. - %% %% Program header table %% -record(elf_phdr, {type, % Type of segment %% flags, % Segment attributes @@ -201,13 +160,13 @@ mk_shdr(Name, Type, Flags, Addr, Offset, Size, Link, Info, AddrAlign, EntSize) - %%%------------------------- %%% Symbol Table Entries %%%------------------------- -mk_sym(Name, Info, Other, Section, Value, Size) -> - #elf_sym{name = Name, info = Info, other = Other, +mk_sym(Name, Bind, Type, Section, Value, Size) -> + #elf_sym{name = Name, bind = Bind, type = Type, section = Section, value = Value, size = Size}. --spec sym_name(elf_sym()) -> string(). -sym_name(#elf_sym{name = Name}) -> Name. - +%% -spec sym_name(elf_sym()) -> string(). +%% sym_name(#elf_sym{name = Name}) -> Name. +%% %% -spec sym_value(elf_sym()) -> valueoff(). %% sym_value(#elf_sym{value = Value}) -> Value. %% @@ -327,24 +286,32 @@ get_shdrtab_entries(ShdrTab, ShStrTab) -> Entsize:?bits(?SH_ENTSIZE_SIZE)/integer-little, Rest/binary >> = ShdrTab, - Entry = mk_shdr(get_strtab_entry(Name, ShStrTab), Type, Flags, Addr, Offset, - Size, Link, Info, Addralign, Entsize), + Entry = mk_shdr(get_strtab_entry(Name, ShStrTab), decode_shdr_type(Type), + Flags, Addr, Offset, Size, Link, Info, Addralign, Entsize), [Entry | get_shdrtab_entries(Rest, ShStrTab)]. +decode_shdr_type(?SHT_NULL) -> 'null'; +decode_shdr_type(?SHT_PROGBITS) -> 'progbits'; +decode_shdr_type(?SHT_SYMTAB) -> 'symtab'; +decode_shdr_type(?SHT_STRTAB) -> 'strtab'; +decode_shdr_type(?SHT_RELA) -> 'rela'; +decode_shdr_type(?SHT_HASH) -> 'hash'; %unused +decode_shdr_type(?SHT_DYNAMIC) -> 'dynamic'; %unused +decode_shdr_type(?SHT_NOTE) -> 'note'; %unused +decode_shdr_type(?SHT_NOBITS) -> 'nobits'; +decode_shdr_type(?SHT_REL) -> 'rel'; +decode_shdr_type(?SHT_SHLIB) -> 'shlib'; %unused +decode_shdr_type(?SHT_DYNSYM) -> 'dynsym'; %unused +decode_shdr_type(OS) when ?SHT_LOOS =< OS, OS =< ?SHT_HIOS -> {os, OS}; +decode_shdr_type(Proc) when ?SHT_LOPROC =< Proc, Proc =< ?SHT_HIPROC -> + {proc, Proc}. + -spec elf_section(non_neg_integer(), elf()) -> undefined | abs | elf_shdr(). elf_section(0, #elf{}) -> undefined; elf_section(?SHN_ABS, #elf{}) -> abs; elf_section(Index, #elf{sec_idx=SecIdx}) when Index =< tuple_size(SecIdx) -> element(Index, SecIdx). -%%------------------------------------------------------------------------------ - --spec get_tab_entries(elf()) -> [{name(), valueoff(), size()}]. -get_tab_entries(#elf{sym_idx=SymIdx}) -> - [{Name, Value, Size div ?ELF_XWORD_SIZE} - || #elf_sym{name = Name, value = Value, size = Size} - <- tuple_to_list(SymIdx), Name =/= ""]. - %%------------------------------------------------------------------------------ %% Functions to manipulate Symbol Table %%------------------------------------------------------------------------------ @@ -360,30 +327,51 @@ parse_sym(<<%% Structural pattern matching on fields. Value:?bits(?ST_VALUE_SIZE)/integer-little, Size:?bits(?ST_SIZE_SIZE)/integer-little, Info:?bits(?ST_INFO_SIZE)/integer-little, - Other:?bits(?ST_OTHER_SIZE)/integer-little, + _Other:?bits(?ST_OTHER_SIZE)/integer-little, Shndx:?bits(?ST_SHNDX_SIZE)/integer-little>>, Elf, StrTab) -> - mk_sym(get_strtab_entry(Name, StrTab), Info, Other, elf_section(Shndx, Elf), - Value, Size). + mk_sym(get_strtab_entry(Name, StrTab), decode_symbol_bind(?ELF_ST_BIND(Info)), + decode_symbol_type(?ELF_ST_TYPE(Info)), elf_section(Shndx, Elf), Value, + Size). -else. parse_sym(<<%% Same fields in different order: Name:?bits(?ST_NAME_SIZE)/integer-little, Info:?bits(?ST_INFO_SIZE)/integer-little, - Other:?bits(?ST_OTHER_SIZE)/integer-little, + _Other:?bits(?ST_OTHER_SIZE)/integer-little, Shndx:?bits(?ST_SHNDX_SIZE)/integer-little, Value:?bits(?ST_VALUE_SIZE)/integer-little, Size:?bits(?ST_SIZE_SIZE)/integer-little>>, Elf, StrTab) -> - mk_sym(get_strtab_entry(Name, StrTab), Info, Other, elf_section(Shndx, Elf), - Value, Size). + mk_sym(get_strtab_entry(Name, StrTab), decode_symbol_bind(?ELF_ST_BIND(Info)), + decode_symbol_type(?ELF_ST_TYPE(Info)), elf_section(Shndx, Elf), Value, + Size). -endif. +decode_symbol_bind(?STB_LOCAL) -> 'local'; +decode_symbol_bind(?STB_GLOBAL) -> 'global'; +decode_symbol_bind(?STB_WEAK) -> 'weak'; %unused +decode_symbol_bind(OS) when ?STB_LOOS =< OS, OS =< ?STB_HIOS -> {os, OS}; +decode_symbol_bind(Proc) when ?STB_LOPROC =< Proc, Proc =< ?STB_HIPROC -> + {proc, Proc}. + +decode_symbol_type(?STT_NOTYPE) -> 'notype'; +decode_symbol_type(?STT_OBJECT) -> 'object'; +decode_symbol_type(?STT_FUNC) -> 'func'; +decode_symbol_type(?STT_SECTION) -> 'section'; +decode_symbol_type(?STT_FILE) -> 'file'; +decode_symbol_type(OS) when ?STT_LOOS =< OS, OS =< ?STT_HIOS -> {os, OS}; +decode_symbol_type(Proc) when ?STT_LOPROC =< Proc, Proc =< ?STT_HIPROC -> + {proc, Proc}. + %% @doc Extracts a specific entry from the Symbol Table. -spec elf_symbol(0, elf()) -> undefined; (pos_integer(), elf()) -> elf_sym(). elf_symbol(0, #elf{}) -> undefined; elf_symbol(Index, #elf{sym_idx=SymIdx}) -> element(Index, SymIdx). +-spec elf_symbols(elf()) -> [elf_sym()]. +elf_symbols(#elf{sym_idx=SymIdx}) -> tuple_to_list(SymIdx). + %%------------------------------------------------------------------------------ %% Functions to manipulate String Table %%------------------------------------------------------------------------------ @@ -415,22 +403,6 @@ bin_get_string(<>) -> [Char|bin_get_string(Rest)]. %% Functions to manipulate Relocations %%------------------------------------------------------------------------------ -%% @doc This function gets as argument an ELF binary file and returns a list -%% with all .rela.rodata labels (i.e. constants and literals in code) -%% or an empty list if no ".rela.rodata" section exists in code. --spec get_rodata_relocs(elf()) -> [offset()]. -get_rodata_relocs(Elf) -> get_rela_addends(extract_rela(Elf, ?RODATA)). - --spec get_rela_addends([elf_rel()]) -> [offset()]. -get_rela_addends(RelaEntries) -> [A || #elf_rel{addend=A} <- RelaEntries]. - -%% @doc Extract a list of the form `[{SymbolName, Offset}]' with all relocatable -%% symbols and their offsets in the code from the ".text" section. --spec get_text_relocs(elf()) -> [{name(), offset()}]. -get_text_relocs(Elf) -> - [{sym_name(Symbol), Offset} - || #elf_rel{offset=Offset, symbol=Symbol} <- extract_rela(Elf, ?TEXT)]. - %% @doc Extract the Relocations segment for section `Name' (that is passed %% as second argument) from an ELF formated Object file binary. -spec extract_rela(elf(), name()) -> [elf_rel()]. @@ -442,7 +414,7 @@ extract_rela(Elf, Name) -> type=decode_reloc_type(?ELF_R_TYPE(Info)), addend=read_implicit_addend(Offset, SecData)} || <> <= extract_segment_by_name(Elf, ?REL(Name))]. %% The only types HiPE knows how to patch @@ -451,7 +423,7 @@ decode_reloc_type(2) -> 'pc32'. read_implicit_addend(Offset, Section) -> %% All x86 relocation types uses 'word32' relocation fields; i.e. 32-bit LE. - <<_:Offset/binary, Addend:32/little, _/binary>> = Section, + <<_:Offset/binary, Addend:32/signed-little, _/binary>> = Section, Addend. -else. %% BIT32 @@ -460,7 +432,7 @@ extract_rela(Elf, Name) -> type=decode_reloc_type(?ELF_R_TYPE(Info)), addend=Addend} || <> <= extract_segment_by_name(Elf, ?RELA(Name))]. decode_reloc_type(1) -> '64'; -- cgit v1.2.3