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Diffstat (limited to 'libdwarf/dwarf_frame.h')
| -rw-r--r-- | libdwarf/dwarf_frame.h | 419 |
1 files changed, 419 insertions, 0 deletions
diff --git a/libdwarf/dwarf_frame.h b/libdwarf/dwarf_frame.h new file mode 100644 index 0000000..61d2a56 --- /dev/null +++ b/libdwarf/dwarf_frame.h @@ -0,0 +1,419 @@ +/* + + Copyright (C) 2000, 2004, 2006 Silicon Graphics, Inc. All Rights Reserved. + Portions Copyright (C) 2011 David Anderson. All Rights Reserved. + + This program is free software; you can redistribute it and/or modify it + under the terms of version 2.1 of the GNU Lesser General Public License + as published by the Free Software Foundation. + + This program is distributed in the hope that it would be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + + Further, this software is distributed without any warranty that it is + free of the rightful claim of any third person regarding infringement + or the like. Any license provided herein, whether implied or + otherwise, applies only to this software file. Patent licenses, if + any, provided herein do not apply to combinations of this program with + other software, or any other product whatsoever. + + You should have received a copy of the GNU Lesser General Public + License along with this program; if not, write the Free Software + Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston MA 02110-1301, + USA. + + Contact information: Silicon Graphics, Inc., 1500 Crittenden Lane, + Mountain View, CA 94043, or: + + http://www.sgi.com + + For further information regarding this notice, see: + + http://oss.sgi.com/projects/GenInfo/NoticeExplan + +*/ + + + +/* The dwarf 2.0 standard dictates that only the following + fields can be read when an unexpected augmentation string + (in the cie) is encountered: CIE length, CIE_id, version and + augmentation; FDE: length, CIE pointer, initial location and + address range. Unfortunately, with the above restrictions, it + is impossible to read the instruction table from a CIE or a FDE + when a new augmentation string is encountered. + To fix this problem, the following layout is used, if the + augmentation string starts with the string "z". + CIE FDE + length length + CIE_id CIE_pointer + version initial_location + augmentation address_range + + - length_of_augmented_fields (*NEW*) + code_alignment_factor Any new fields as necessary + data_alignment_factor instruction_table + return_address + length_of_augmented fields + Any new fields as necessary + initial_instructions + + The type of all the old data items are the same as what is + described in dwarf 2.0 standard. The length_of_augmented_fields + is an LEB128 data item that denotes the size (in bytes) of + the augmented fields (not including the size of + "length_of_augmented_fields" itself). + + Handling of cie augmentation strings is necessarly a heuristic. + See dwarf_frame.c for the currently known augmentation strings. + + + ---START SGI-ONLY COMMENT: + SGI-IRIX versions of cie or fde were intended to use "z1", "z2" as the + augmenter strings if required for new augmentation. + However, that never happened (as of March 2005). + + The fde's augmented by the string "z" have a new field + (signed constant, 4 byte field) + called offset_into_exception_tables, following the + length_of_augmented field. This field contains an offset + into the "_MIPS_eh_region", which describes + the IRIX CC exception handling tables. + ---END SGI-ONLY COMMENT + + + GNU .eh_frame has an augmentation string of z[RLP]* (gcc 3.4) + The similarity to IRIX 'z' (and proposed but never + implemented IRIX z1, z2 etc) was confusing things. + If the section is .eh_frame then 'z' means GNU exception + information 'Augmentation Data' not IRIX 'z'. + See The Linux Standard Base Core Specification version 3.0 +*/ + +#define DW_DEBUG_FRAME_VERSION 1 /* DWARF2 */ +#define DW_DEBUG_FRAME_VERSION3 3 /* DWARF3 */ +#define DW_DEBUG_FRAME_VERSION4 4 /* DWARF4 */ +/* The following is SGI/IRIX specific, and probably no longer + in use anywhere. */ +#define DW_DEBUG_FRAME_AUGMENTER_STRING "mti v1" + +/* The value of the offset field for Cie's. */ +#define DW_CIE_OFFSET ~(0x0) + +/* The augmentation string may be NULL. */ +#define DW_EMPTY_STRING "" + +#define DW_FRAME_INSTR_OPCODE_SHIFT 6 +#define DW_FRAME_INSTR_OFFSET_MASK 0x3f + +/* + This struct denotes the rule for a register in a row of + the frame table. In other words, it is one element of + the table. +*/ +struct Dwarf_Reg_Rule_s { + + /* Is a flag indicating whether the rule includes the offset + field, ie whether the ru_offset field is valid or not. + Applies only if DW_EXPR_OFFSET or DW_EXPR_VAL_OFFSET. + It is important, since reg+offset (offset of 0) is different from + just 'register' since the former means 'read memory at address + given by the sum of register contents plus offset to get the + value'. whereas the latter means 'the value is in the register'. + + The 'register' numbers are either real registers (ie, table + columns defined as real registers) or defined entries that are + not really hardware registers, such as DW_FRAME_SAME_VAL or + DW_FRAME_CFA_COL. */ + Dwarf_Sbyte ru_is_off; + + /* DW_EXPR_OFFSET (0, DWARF2) + DW_EXPR_VAL_OFFSET 1 (dwarf2/3) + DW_EXPR_EXPRESSION 2 (dwarf2/3) + DW_EXPR_VAL_EXPRESSION 3 (dwarf2/3) + See dwarf_frame.h. */ + Dwarf_Sbyte ru_value_type; + + /* Register involved in this rule. */ + Dwarf_Half ru_register; + + /* Offset to add to register, if indicated by ru_is_offset + and if DW_EXPR_OFFSET or DW_EXPR_VAL_OFFSET. + If DW_EXPR_EXPRESSION or DW_EXPR_VAL_EXPRESSION + this is DW_FORM_block block-length, not offset. */ + Dwarf_Unsigned ru_offset_or_block_len; + + /* For DW_EXPR_EXPRESSION DW_EXPR_VAL_EXPRESSION these is set, + else 0. */ + Dwarf_Small *ru_block; +}; + +typedef struct Dwarf_Frame_s *Dwarf_Frame; + +/* + This structure represents a row of the frame table. + Fr_loc is the pc value for this row, and Fr_reg + contains the rule for each column. + + Entry DW_FRAME_CFA_COL of fr_reg was the tradional MIPS + way of setting CFA. cfa_rule is the new one. +*/ +struct Dwarf_Frame_s { + + /* Pc value corresponding to this row of the frame table. */ + Dwarf_Addr fr_loc; + + /* Rules for all the registers in this row. */ + struct Dwarf_Reg_Rule_s fr_cfa_rule; + + /* fr_reg_count is the the number of + entries of the fr_reg array. */ + unsigned long fr_reg_count; + struct Dwarf_Reg_Rule_s *fr_reg; + + Dwarf_Frame fr_next; +}; + +typedef struct Dwarf_Frame_Op_List_s *Dwarf_Frame_Op_List; + +/* This is used to chain together Dwarf_Frame_Op structures. */ +struct Dwarf_Frame_Op_List_s { + Dwarf_Frame_Op *fl_frame_instr; + Dwarf_Frame_Op_List fl_next; +}; + +/* See dwarf_frame.c for the heuristics used to set the + Dwarf_Cie ci_augmentation_type. + + This succinctly helps interpret the size and meaning of .debug_frame + and (for gcc) .eh_frame. + + In the case of gcc .eh_frame (gcc 3.3, 3.4) + z may be followed by one or more of + L R P. + +*/ +enum Dwarf_augmentation_type { + aug_empty_string, /* Default empty augmentation string. */ + aug_irix_exception_table, /* IRIX plain "z", + for exception handling, IRIX CC compiler. + Proposed z1 z2 ... never implemented. */ + aug_gcc_eh_z, /* gcc z augmentation, (including + L R P variations). gcc 3.3 3.4 exception + handling in eh_frame. */ + aug_irix_mti_v1, /* IRIX "mti v1" augmentation string. Probably + never in any released SGI-IRIX compiler. */ + aug_eh, /* For gcc .eh_frame, "eh" is the string., + gcc 1,2, egcs. Older values. */ + aug_armcc, /* "armcc+" meaning the cfa calculation + is corrected to be standard (output by + Arm C RVCT 3.0 SP1 and later). See + http://sourceware.org/ml/gdb-patches/2006-12/msg00249.html + for details. */ + aug_unknown, /* Unknown augmentation, we cannot do much. */ + aug_past_last +}; + + +/* + This structure contains all the pertinent info for a Cie. Most + of the fields are taken straight from the definition of a Cie. + Ci_cie_start points to the address (in .debug_frame) where this + Cie begins. Ci_cie_instr_start points to the first byte of the + frame instructions for this Cie. Ci_dbg points to the associated + Dwarf_Debug structure. Ci_initial_table is a pointer to the table + row generated by the instructions for this Cie. +*/ +struct Dwarf_Cie_s { + Dwarf_Unsigned ci_length; + char *ci_augmentation; + Dwarf_Small ci_code_alignment_factor; + Dwarf_Sbyte ci_data_alignment_factor; + Dwarf_Small ci_return_address_register; + Dwarf_Small *ci_cie_start; + Dwarf_Small *ci_cie_instr_start; + Dwarf_Debug ci_dbg; + Dwarf_Frame ci_initial_table; + Dwarf_Cie ci_next; + Dwarf_Small ci_length_size; + Dwarf_Small ci_extension_size; + Dwarf_Half ci_cie_version_number; + enum Dwarf_augmentation_type ci_augmentation_type; + + /* The following 2 for GNU .eh_frame exception handling + Augmentation Data. Set if ci_augmentation_type + is aug_gcc_eh_z. Zero if unused. */ + Dwarf_Unsigned ci_gnu_eh_augmentation_len; + Dwarf_Ptr ci_gnu_eh_augmentation_bytes; + + /* These are extracted from the gnu eh_frame + augmentation if the + augmentation begins with 'z'. See Linux LSB documents. + Otherwize these are zero. */ + unsigned char ci_gnu_personality_handler_encoding; + unsigned char ci_gnu_lsda_encoding; + unsigned char ci_gnu_fde_begin_encoding; + + /* If 'P' augmentation present, is handler addr. Else + is zero. */ + Dwarf_Addr ci_gnu_personality_handler_addr; + + + /* In creating list of cie's (which will become an array) + record the position so fde can get it on fde creation. */ + Dwarf_Unsigned ci_index; + Dwarf_Small * ci_section_ptr; + /* DWARF4 adds address size and segment size to the CIE: the .debug_info + section may not always be present to allow libdwarf to + find address_size from the compilation-unit. */ + Dwarf_Half ci_address_size; + Dwarf_Half ci_segment_size; + +}; + +/* + This structure contains all the pertinent info for a Fde. + Most of the fields are taken straight from the definition. + fd_cie_index is the index of the Cie associated with this + Fde in the list of Cie's for this debug_frame. Fd_cie + points to the corresponsing Dwarf_Cie structure. Fd_fde_start + points to the start address of the Fde. Fd_fde_instr_start + points to the start of the instructions for this Fde. Fd_dbg + points to the associated Dwarf_Debug structure. +*/ +struct Dwarf_Fde_s { + Dwarf_Unsigned fd_length; + Dwarf_Addr fd_cie_offset; + Dwarf_Unsigned fd_cie_index; + Dwarf_Cie fd_cie; + Dwarf_Addr fd_initial_location; + Dwarf_Small *fd_initial_loc_pos; + Dwarf_Addr fd_address_range; + Dwarf_Small *fd_fde_start; + Dwarf_Small *fd_fde_instr_start; + Dwarf_Debug fd_dbg; + + /* fd_offset_into_exception_tables is SGI/IRIX exception table + offset. Unused and zero if not IRIX .debug_frame. */ + Dwarf_Signed fd_offset_into_exception_tables; + + Dwarf_Fde fd_next; + Dwarf_Small fd_length_size; + Dwarf_Small fd_extension_size; + /* So we know from an fde which 'count' of fde-s in + Dwarf_Debug applies: eh or standard. */ + Dwarf_Small fd_is_eh; + /* The following 2 for GNU .eh_frame exception handling + Augmentation Data. Set if CIE ci_augmentation_type + is aug_gcc_eh_z. Zero if unused. */ + Dwarf_Unsigned fd_gnu_eh_augmentation_len; + Dwarf_Ptr fd_gnu_eh_augmentation_bytes; + Dwarf_Addr fd_gnu_eh_lsda; /* If 'L' augmentation letter + present: is address of the + Language Specific Data Area (LSDA). If not 'L" is zero. */ + + /* The following 3 are about the Elf section the FDEs come from. */ + Dwarf_Small * fd_section_ptr; + Dwarf_Unsigned fd_section_length; + Dwarf_Unsigned fd_section_index; + +}; + + +int +_dwarf_frame_address_offsets(Dwarf_Debug dbg, Dwarf_Addr ** addrlist, + Dwarf_Off ** offsetlist, + Dwarf_Signed * returncount, + Dwarf_Error * err); + +int +_dwarf_get_fde_list_internal(Dwarf_Debug dbg, + Dwarf_Cie ** cie_data, + Dwarf_Signed * cie_element_count, + Dwarf_Fde ** fde_data, + Dwarf_Signed * fde_element_count, + Dwarf_Small * section_ptr, + Dwarf_Unsigned section_index, + Dwarf_Unsigned section_length, + Dwarf_Unsigned cie_id_value, + int use_gnu_cie_calc, /* If non-zero, + this is gcc eh_frame. */ + Dwarf_Error * error); + +enum Dwarf_augmentation_type +_dwarf_get_augmentation_type(Dwarf_Debug dbg, + Dwarf_Small *augmentation_string, + int is_gcc_eh_frame); + +Dwarf_Unsigned _dwarf_get_return_address_reg(Dwarf_Small *frame_ptr, + int version, + unsigned long *size); + +/* Temporary recording of crucial cie/fde prefix data. + Vastly simplifies some argument lists. */ +struct cie_fde_prefix_s { + /* cf_start_addr is a pointer to the first byte of this fde/cie + we are reading now. */ + Dwarf_Small * cf_start_addr; + Dwarf_Small * cf_addr_after_prefix; + Dwarf_Unsigned cf_length; + int cf_local_length_size; + int cf_local_extension_size; + Dwarf_Unsigned cf_cie_id; + Dwarf_Small * cf_cie_id_addr; /* used for eh_frame calculations. */ + + /* Simplifies passing around these values to create fde having + these here. */ + /* cf_section_ptr is a pointer to the first byte + of the object section the prefix is read from. */ + Dwarf_Small * cf_section_ptr; + Dwarf_Unsigned cf_section_index; + Dwarf_Unsigned cf_section_length; +}; + +int +_dwarf_exec_frame_instr(Dwarf_Bool make_instr, + Dwarf_Frame_Op ** ret_frame_instr, + Dwarf_Bool search_pc, + Dwarf_Addr search_pc_val, + Dwarf_Addr initial_loc, + Dwarf_Small * start_instr_ptr, + Dwarf_Small * final_instr_ptr, + Dwarf_Frame table, + Dwarf_Cie cie, + Dwarf_Debug dbg, + Dwarf_Half reg_num_of_cfa, + Dwarf_Sword * returned_count, + int *returned_error); + + +int dwarf_read_cie_fde_prefix(Dwarf_Debug dbg, + Dwarf_Small *frame_ptr_in, + Dwarf_Small *section_ptr_in, + Dwarf_Unsigned section_index_in, + Dwarf_Unsigned section_length_in, + struct cie_fde_prefix_s *prefix_out, + Dwarf_Error *error); + +int dwarf_create_fde_from_after_start(Dwarf_Debug dbg, + struct cie_fde_prefix_s * prefix, + Dwarf_Small *section_pointer, + Dwarf_Small *frame_ptr, + int use_gnu_cie_calc, + Dwarf_Cie cie_ptr_in, + Dwarf_Fde *fde_ptr_out, + Dwarf_Error *error); + +int dwarf_create_cie_from_after_start(Dwarf_Debug dbg, + struct cie_fde_prefix_s *prefix, + Dwarf_Small* section_pointer, + Dwarf_Small* frame_ptr, + Dwarf_Unsigned cie_count, + int use_gnu_cie_calc, + Dwarf_Cie *cie_ptr_out, + Dwarf_Error *error); + + +int _dwarf_frame_constructor(Dwarf_Debug dbg,void * ); +void _dwarf_frame_destructor (void *); |