/*
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.
*/
/* 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. */
/* HC, From http://sourceforge.net/p/elftoolchain/tickets/397/ */
aug_metaware,
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_Small *ci_cie_end;
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;
Dwarf_Unsigned ci_section_length;
Dwarf_Small * ci_section_end;
/* 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_Small *fd_fde_end;
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_Bool fd_gnu_eh_aug_present;
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;
Dwarf_Small * fd_section_end;
/* If fd_eh_table_value_set is true, then fd_eh_table_value is
meaningful. Never meaningful for .debug_frame, is
part of .eh_frame. */
Dwarf_Unsigned fd_eh_table_value;
Dwarf_Bool fd_eh_table_value_set;
/* The following are memoization to save recalculation. */
struct Dwarf_Frame_s fd_fde_table;
Dwarf_Addr fd_fde_pc_requested;
Dwarf_Bool fd_have_fde_tab;
};
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);
int _dwarf_get_return_address_reg(Dwarf_Small *frame_ptr,
int version,
Dwarf_Debug dbg,
Dwarf_Byte_Ptr section_end,
unsigned long *size,
Dwarf_Unsigned *return_address_register,
Dwarf_Error *error);
/* 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 (meaning the length field itself) */
Dwarf_Small * cf_start_addr;
/* cf_addr_after_prefix is a pointer
to the first byte of this fde/cie
we are reading now, immediately following
the length field read by READ_AREA_LENGTH. */
Dwarf_Small * cf_addr_after_prefix;
/* cf_length is the length field value from the cie/fde
header. */
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,
Dwarf_Bool * has_more_rows,
Dwarf_Addr * subsequent_pc,
Dwarf_Error * 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,
Dwarf_Small *section_ptr_end,
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_Small *section_ptr_end,
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 *);
void _dwarf_fde_destructor (void *);