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Diffstat (limited to 'src/libdw/cfi.h')
| -rw-r--r-- | src/libdw/cfi.h | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/src/libdw/cfi.h b/src/libdw/cfi.h new file mode 100644 index 00000000..ef9cd7e1 --- /dev/null +++ b/src/libdw/cfi.h @@ -0,0 +1,256 @@ +/* Internal definitions for libdw CFI interpreter. + Copyright (C) 2009-2010 Red Hat, Inc. + This file is part of Red Hat elfutils. + + Red Hat elfutils is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by the + Free Software Foundation; version 2 of the License. + + Red Hat elfutils is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received a copy of the GNU General Public License along + with Red Hat elfutils; if not, write to the Free Software Foundation, + Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. + + In addition, as a special exception, Red Hat, Inc. gives You the + additional right to link the code of Red Hat elfutils with code licensed + under any Open Source Initiative certified open source license + (http://www.opensource.org/licenses/index.php) which requires the + distribution of source code with any binary distribution and to + distribute linked combinations of the two. Non-GPL Code permitted under + this exception must only link to the code of Red Hat elfutils through + those well defined interfaces identified in the file named EXCEPTION + found in the source code files (the "Approved Interfaces"). The files + of Non-GPL Code may instantiate templates or use macros or inline + functions from the Approved Interfaces without causing the resulting + work to be covered by the GNU General Public License. Only Red Hat, + Inc. may make changes or additions to the list of Approved Interfaces. + Red Hat's grant of this exception is conditioned upon your not adding + any new exceptions. If you wish to add a new Approved Interface or + exception, please contact Red Hat. You must obey the GNU General Public + License in all respects for all of the Red Hat elfutils code and other + code used in conjunction with Red Hat elfutils except the Non-GPL Code + covered by this exception. If you modify this file, you may extend this + exception to your version of the file, but you are not obligated to do + so. If you do not wish to provide this exception without modification, + you must delete this exception statement from your version and license + this file solely under the GPL without exception. + + Red Hat elfutils is an included package of the Open Invention Network. + An included package of the Open Invention Network is a package for which + Open Invention Network licensees cross-license their patents. No patent + license is granted, either expressly or impliedly, by designation as an + included package. Should you wish to participate in the Open Invention + Network licensing program, please visit www.openinventionnetwork.com + <http://www.openinventionnetwork.com>. */ + +#ifndef _UNWINDP_H +#define _UNWINDP_H 1 + +#include "libdwP.h" +#include "libelfP.h" +struct ebl; + +/* Cached CIE representation. */ +struct dwarf_cie +{ + Dwarf_Off offset; /* Our position, as seen in FDEs' CIE_pointer. */ + + Dwarf_Word code_alignment_factor; + Dwarf_Sword data_alignment_factor; + Dwarf_Word return_address_register; + + size_t fde_augmentation_data_size; + + // play out to initial state + const uint8_t *initial_instructions; + const uint8_t *initial_instructions_end; + + const Dwarf_Frame *initial_state; + + uint8_t fde_encoding; /* DW_EH_PE_* for addresses in FDEs. */ + uint8_t lsda_encoding; /* DW_EH_PE_* for LSDA in FDE augmentation. */ + + bool sized_augmentation_data; /* Saw 'z': FDEs have self-sized data. */ + bool signal_frame; /* Saw 'S': FDE is for a signal frame. */ +}; + +/* Cached FDE representation. */ +struct dwarf_fde +{ + struct dwarf_cie *cie; + + /* This FDE describes PC values in [start, end). */ + Dwarf_Addr start; + Dwarf_Addr end; + + const uint8_t *instructions; + const uint8_t *instructions_end; +}; + +/* This holds everything we cache about the CFI from each ELF file's + .debug_frame or .eh_frame section. */ +struct Dwarf_CFI_s +{ + /* Dwarf handle we came from. If null, this is .eh_frame data. */ + Dwarf *dbg; +#define CFI_IS_EH(cfi) ((cfi)->dbg == NULL) + + /* Data of the .debug_frame or .eh_frame section. */ + Elf_Data_Scn *data; + const unsigned char *e_ident; /* For EI_DATA and EI_CLASS. */ + + Dwarf_Addr frame_vaddr; /* DW_EH_PE_pcrel, address of frame section. */ + Dwarf_Addr textrel; /* DW_EH_PE_textrel base address. */ + Dwarf_Addr datarel; /* DW_EH_PE_datarel base address. */ + + /* Location of next unread entry in the section. */ + Dwarf_Off next_offset; + + /* Search tree for the CIEs, indexed by CIE_pointer (section offset). */ + void *cie_tree; + + /* Search tree for the FDEs, indexed by PC address. */ + void *fde_tree; + + /* Search tree for parsed DWARF expressions, indexed by raw pointer. */ + void *expr_tree; + + /* Backend hook. */ + struct ebl *ebl; + + /* Binary search table in .eh_frame_hdr section. */ + const uint8_t *search_table; + Dwarf_Addr search_table_vaddr; + size_t search_table_entries; + uint8_t search_table_encoding; + + /* True if the file has a byte order different from the host. */ + bool other_byte_order; + + /* Default rule for registers not previously mentioned + is same_value, not undefined. */ + bool default_same_value; +}; + + +enum dwarf_frame_rule + { + reg_unspecified, /* Uninitialized state. */ + reg_undefined, /* DW_CFA_undefined */ + reg_same_value, /* DW_CFA_same_value */ + reg_offset, /* DW_CFA_offset_extended et al */ + reg_val_offset, /* DW_CFA_val_offset et al */ + reg_register, /* DW_CFA_register */ + reg_expression, /* DW_CFA_expression */ + reg_val_expression, /* DW_CFA_val_expression */ + }; + +/* This describes what we know about an individual register. */ +struct dwarf_frame_register +{ + enum dwarf_frame_rule rule:3; + + /* The meaning of the value bits depends on the rule: + + Rule Value + ---- ----- + undefined unused + same_value unused + offset(N) N (register saved at CFA + value) + val_offset(N) N (register = CFA + value) + register(R) R (register = register #value) + expression(E) section offset of DW_FORM_block containing E + (register saved at address E computes) + val_expression(E) section offset of DW_FORM_block containing E + (register = value E computes) + */ + Dwarf_Sword value:(sizeof (Dwarf_Sword) * 8 - 3); +}; + +/* This holds everything we know about the state of the frame + at a particular PC location described by an FDE. */ +struct Dwarf_Frame_s +{ + /* This frame description covers PC values in [start, end). */ + Dwarf_Addr start; + Dwarf_Addr end; + + Dwarf_CFI *cache; + + /* Previous state saved by DW_CFA_remember_state, or .cie->initial_state, + or NULL in an initial_state pseudo-frame. */ + Dwarf_Frame *prev; + + /* The FDE that generated this frame state. This points to its CIE, + which has the return_address_register and signal_frame flag. */ + struct dwarf_fde *fde; + + /* The CFA is unknown, is R+N, or is computed by a DWARF expression. + A bogon in the CFI can indicate an invalid/incalculable rule. + We store that as cfa_invalid rather than barfing when processing it, + so callers can ignore the bogon unless they really need that CFA. */ + enum { cfa_undefined, cfa_offset, cfa_expr, cfa_invalid } cfa_rule; + union + { + Dwarf_Op offset; + Dwarf_Block expr; + } cfa_data; + /* We store an offset rule as a DW_OP_bregx operation. */ +#define cfa_val_reg cfa_data.offset.number +#define cfa_val_offset cfa_data.offset.number2 + + size_t nregs; + struct dwarf_frame_register regs[]; +}; + + +/* Clean up the data structure and all it points to. */ +extern void __libdw_destroy_frame_cache (Dwarf_CFI *cache) + __nonnull_attribute__ (1) internal_function; + +/* Enter a CIE encountered while reading through for FDEs. */ +extern void __libdw_intern_cie (Dwarf_CFI *cache, Dwarf_Off offset, + const Dwarf_CIE *info) + __nonnull_attribute__ (1, 3) internal_function; + +/* Look up a CIE_pointer for random access. */ +extern struct dwarf_cie *__libdw_find_cie (Dwarf_CFI *cache, Dwarf_Off offset) + __nonnull_attribute__ (1) internal_function; + + +/* Look for an FDE covering the given PC address. */ +extern struct dwarf_fde *__libdw_find_fde (Dwarf_CFI *cache, + Dwarf_Addr address) + __nonnull_attribute__ (1) internal_function; + +/* Look for an FDE by its offset in the section. */ +extern struct dwarf_fde *__libdw_fde_by_offset (Dwarf_CFI *cache, + Dwarf_Off offset) + __nonnull_attribute__ (1) internal_function; + +/* Process the FDE that contains the given PC address, + to yield the frame state when stopped there. + The return value is a DWARF_E_* error code. */ +extern int __libdw_frame_at_address (Dwarf_CFI *cache, struct dwarf_fde *fde, + Dwarf_Addr address, Dwarf_Frame **frame) + __nonnull_attribute__ (1, 2, 4) internal_function; + + +/* Dummy struct for memory-access.h macros. */ +#define BYTE_ORDER_DUMMY(var, e_ident) \ + const struct { bool other_byte_order; } var = \ + { ((BYTE_ORDER == LITTLE_ENDIAN && e_ident[EI_DATA] == ELFDATA2MSB) \ + || (BYTE_ORDER == BIG_ENDIAN && e_ident[EI_DATA] == ELFDATA2LSB)) } + + +INTDECL (dwarf_next_cfi) +INTDECL (dwarf_getcfi) +INTDECL (dwarf_getcfi_elf) +INTDECL (dwarf_cfi_end) +INTDECL (dwarf_cfi_addrframe) + +#endif /* unwindP.h */ |