From 56ec17296fb350f1eed5486b8d9b575be5afb7a8 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Magnus=20L=C3=A5ng?= Date: Mon, 9 May 2016 12:53:05 +0200 Subject: hipe: Remove runtime elf_format class switching The elf_format module was written in such a way that some of the customisation to ELF-32 vs ELF-64 was made at compile-time and some of it at run-time. As such it was not actually possible to read 32-bit files with a module compiled for 64-bit support, or vice versa. As the run-time selection uses some process dictionary ugliness, it was removed, shifting all the customisation to be compile-time. --- lib/hipe/llvm/elf_format.erl | 170 ++++++++++++++++++------------------------- 1 file changed, 72 insertions(+), 98 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 260da9b5e6..9fc9da9203 100644 --- a/lib/hipe/llvm/elf_format.erl +++ b/lib/hipe/llvm/elf_format.erl @@ -24,10 +24,7 @@ %% Executable code extract_text/1, %% GCC Exception Table - get_exn_handlers/1, - %% Misc. - set_architecture_flag/1, - is64bit/0 + get_exn_handlers/1 ]). -include("elf_format.hrl"). @@ -110,16 +107,19 @@ -type elf_sym() :: #elf_sym{}. %% Relocations +-ifdef(BIT32). -record(elf_rel, {r_offset :: offset(), % Address of reference r_info :: info() % Symbol index and type of relocation }). --type elf_rel() :: #elf_rel{}. +-type reloc() :: #elf_rel{}. +-else. -record(elf_rela, {r_offset :: offset(), % Address of reference r_info :: info(), % Symbol index and type of relocation r_addend :: offset() % Constant part of expression }). --type elf_rela() :: #elf_rela{}. +-type reloc() :: #elf_rela{}. +-endif. %% %% Program header table %% -record(elf_phdr, {type, % Type of segment @@ -215,28 +215,36 @@ sym_name(#elf_sym{name = Name}) -> Name. %%%------------------------- %%% Relocations %%%------------------------- --spec mk_rel(offset(), info()) -> elf_rel(). -mk_rel(Offset, Info) -> - #elf_rel{r_offset = Offset, r_info = Info}. + %% The following two functions capitalize on the fact that the two kinds of %% relocation records (for 32- and 64-bit architectures have similar structure. +-spec r_offset(reloc()) -> offset(). +-spec r_info(reloc()) -> info(). --spec r_offset(elf_rel() | elf_rela()) -> offset(). -r_offset(#elf_rel{r_offset = Offset}) -> Offset; -r_offset(#elf_rela{r_offset = Offset}) -> Offset. +-ifdef(BIT32). --spec r_info(elf_rel() | elf_rela()) -> info(). -r_info(#elf_rel{r_info = Info}) -> Info; -r_info(#elf_rela{r_info = Info}) -> Info. +-spec mk_rel(offset(), info()) -> reloc(). +mk_rel(Offset, Info) -> + #elf_rel{r_offset = Offset, r_info = Info}. --spec mk_rela(offset(), info(), offset()) -> elf_rela(). +r_offset(#elf_rel{r_offset = Offset}) -> Offset. +r_info(#elf_rel{r_info = Info}) -> Info. + +-else.%%BIT32 + +-spec mk_rela(offset(), info(), offset()) -> reloc(). mk_rela(Offset, Info, Addend) -> #elf_rela{r_offset = Offset, r_info = Info, r_addend = Addend}. --spec rela_addend(elf_rela()) -> offset(). +r_offset(#elf_rela{r_offset = Offset}) -> Offset. +r_info(#elf_rela{r_info = Info}) -> Info. + +-spec rela_addend(reloc()) -> offset(). rela_addend(#elf_rela{r_addend = Addend}) -> Addend. +-endif.%%BIT32 + %% %%%------------------------- %% %%% GCC exception table %% %%%------------------------- @@ -388,29 +396,29 @@ get_symtab_entries(<<>>, Acc) -> lists:reverse(Acc); get_symtab_entries(Symtab_bin, Acc) -> <> = Symtab_bin, - case is64bit() of - true -> - <<%% Structural pattern matching on fields. - Name:?bits(?ST_NAME_SIZE)/integer-little, - Info:?bits(?ST_INFO_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 - >> = SymE_bin; - false -> - << %% Same fields in different order: - Name:?bits(?ST_NAME_SIZE)/integer-little, - 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, - Shndx:?bits(?ST_SHNDX_SIZE)/integer-little - >> = SymE_bin - end, - SymE = mk_sym(Name, Info, Other, Shndx, Value, Size), + SymE = parse_sym(SymE_bin), get_symtab_entries(MoreSymE, [SymE | Acc]). +-ifdef(BIT32). +parse_sym(<<%% Structural pattern matching on fields. + Name:?bits(?ST_NAME_SIZE)/integer-little, + 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, + Shndx:?bits(?ST_SHNDX_SIZE)/integer-little>>) -> + mk_sym(Name, Info, Other, Shndx, 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, + Shndx:?bits(?ST_SHNDX_SIZE)/integer-little, + Value:?bits(?ST_VALUE_SIZE)/integer-little, + Size:?bits(?ST_SIZE_SIZE)/integer-little>>) -> + mk_sym(Name, Info, Other, Shndx, Value, Size). +-endif. + %% @doc Extracts a specific entry from the Symbol Table (as binary). %% This function takes as arguments the Symbol Table (`SymTab') %% and the entry's serial number and returns that entry (`sym'). @@ -447,20 +455,16 @@ get_strtab_entry(Strtab, Offset) -> %% 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()]. +-spec get_rela_addends([reloc()]) -> [offset()]. +-ifdef(BIT32). get_rodata_relocs(Elf) -> - case is64bit() of - true -> - %% Only care about the addends (== offsets): - get_rela_addends(extract_rela(Elf, ?RODATA)); - false -> - %% Find offsets hardcoded in ".rodata" entry - %%XXX: Treat all 0s as padding and skip them! - [SkipPadding || SkipPadding <- extract_rodata(Elf), SkipPadding =/= 0] - end. + [SkipPadding || SkipPadding <- extract_rodata(Elf), SkipPadding =/= 0]. +get_rela_addends(_RelaEntries) -> error(notsup). +-else. +get_rodata_relocs(Elf) -> get_rela_addends(extract_rela(Elf, ?RODATA)). +get_rela_addends(RelaEntries) -> [rela_addend(E) || E <- RelaEntries]. +-endif. --spec get_rela_addends([elf_rela()]) -> [offset()]. -get_rela_addends(RelaEntries) -> - [rela_addend(E) || E <- RelaEntries]. %% @doc Extract a list of the form `[{SymbolName, Offset}]' with all relocatable %% symbols and their offsets in the code from the ".text" section. @@ -488,37 +492,23 @@ get_text_relocs(Elf) -> %% @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() | elf_rela()]. +-spec extract_rela(elf(), name()) -> [reloc()]. + +-ifdef(BIT32). extract_rela(Elf, Name) -> - SegName = - case is64bit() of - true -> ?RELA(Name); % ELF-64 uses ".rela" - false -> ?REL(Name) % ...while ELF-32 uses ".rel" - end, - Rela_bin = extract_segment_by_name(Elf, SegName), - get_rela_entries(Rela_bin, []). - -get_rela_entries(<<>>, Acc) -> - lists:reverse(Acc); -get_rela_entries(Bin, Acc) -> - E = case is64bit() of - true -> - <<%% Structural pattern matching on fields of a Rela Entry. - Offset:?bits(?R_OFFSET_SIZE)/integer-little, - Info:?bits(?R_INFO_SIZE)/integer-little, - Addend:?bits(?R_ADDEND_SIZE)/integer-little, - Rest/binary - >> = Bin, - mk_rela(Offset, Info, Addend); - false -> - <<%% Structural pattern matching on fields of a Rel Entry. - Offset:?bits(?R_OFFSET_SIZE)/integer-little, - Info:?bits(?R_INFO_SIZE)/integer-little, - Rest/binary - >> = Bin, - mk_rel(Offset, Info) - end, - get_rela_entries(Rest, [E | Acc]). + %% Structural pattern matching on fields of a Rel Entry. + [mk_rel(Offset, Info) + || <> <= extract_segment_by_name(Elf, ?REL(Name))]. +-else. +extract_rela(Elf, Name) -> + [mk_rela(Offset, Info, Addend) + || <> <= extract_segment_by_name(Elf, ?RELA(Name))]. +-endif. %% %% @doc Extract the `EntryNum' (serial number) Relocation Entry. %% get_rela_entry(Rela, EntryNum) -> @@ -617,6 +607,7 @@ get_gccexntab_callsites(CSTab, Acc) -> %%------------------------------------------------------------------------------ %% Functions to manipulate Read-only Data (.rodata) %%------------------------------------------------------------------------------ +-ifdef(BIT32). extract_rodata(Elf) -> Rodata_bin = extract_segment_by_name(Elf, ?RODATA), get_rodata_entries(Rodata_bin, []). @@ -626,6 +617,7 @@ get_rodata_entries(<<>>, Acc) -> get_rodata_entries(Rodata_bin, Acc) -> <> = Rodata_bin, get_rodata_entries(More, [Num | Acc]). +-endif. %%------------------------------------------------------------------------------ %% Helper functions @@ -770,21 +762,3 @@ leb128_decode(LebNum, NoOfBits, Acc) -> <> = <>, {Num, MoreLebNums} end. - -%% @doc Extract ELF Class from ELF header and export symbol to process -%% dictionary. --spec set_architecture_flag(elf()) -> 'ok'. -set_architecture_flag(Elf) -> - %% Extract information about ELF Class from ELF Header - <<16#7f, $E, $L, $F, EI_Class, _MoreHeader/binary>> - = get_binary_segment(Elf, 0, ?ELF_EHDR_SIZE), - put(elf_class, EI_Class), - ok. - -%% @doc Read from object file header if the file class is ELF32 or ELF64. --spec is64bit() -> boolean(). -is64bit() -> - case get(elf_class) of - ?ELFCLASS64 -> true; - ?ELFCLASS32 -> false - end. -- cgit v1.2.3