| /*--------------------------------------------------------------------*/ |
| /*--- Read DWARF2 debug info. vg_dwarf.c ---*/ |
| /*--------------------------------------------------------------------*/ |
| |
| /* |
| This file is part of Valgrind, a dynamic binary instrumentation |
| framework. |
| |
| Copyright (C) 2000-2005 Julian Seward |
| jseward@acm.org |
| |
| This program 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; either version 2 of the |
| License, or (at your option) any later version. |
| |
| This program 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 this program; if not, write to the Free Software |
| Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307, USA. |
| |
| The GNU General Public License is contained in the file COPYING. |
| */ |
| |
| #include "core.h" |
| #include "vg_symtab2.h" |
| |
| |
| /* Structure found in the .debug_line section. */ |
| typedef struct |
| { |
| UChar li_length [4]; |
| UChar li_version [2]; |
| UChar li_prologue_length [4]; |
| UChar li_min_insn_length [1]; |
| UChar li_default_is_stmt [1]; |
| UChar li_line_base [1]; |
| UChar li_line_range [1]; |
| UChar li_opcode_base [1]; |
| } |
| DWARF2_External_LineInfo; |
| |
| typedef struct |
| { |
| UInt li_length; |
| UShort li_version; |
| UInt li_prologue_length; |
| UChar li_min_insn_length; |
| UChar li_default_is_stmt; |
| Int li_line_base; |
| UChar li_line_range; |
| UChar li_opcode_base; |
| } |
| DWARF2_Internal_LineInfo; |
| |
| /* Line number opcodes. */ |
| enum dwarf_line_number_ops |
| { |
| DW_LNS_extended_op = 0, |
| DW_LNS_copy = 1, |
| DW_LNS_advance_pc = 2, |
| DW_LNS_advance_line = 3, |
| DW_LNS_set_file = 4, |
| DW_LNS_set_column = 5, |
| DW_LNS_negate_stmt = 6, |
| DW_LNS_set_basic_block = 7, |
| DW_LNS_const_add_pc = 8, |
| DW_LNS_fixed_advance_pc = 9, |
| /* DWARF 3. */ |
| DW_LNS_set_prologue_end = 10, |
| DW_LNS_set_epilogue_begin = 11, |
| DW_LNS_set_isa = 12 |
| }; |
| |
| /* Line number extended opcodes. */ |
| enum dwarf_line_number_x_ops |
| { |
| DW_LNE_end_sequence = 1, |
| DW_LNE_set_address = 2, |
| DW_LNE_define_file = 3 |
| }; |
| |
| typedef struct State_Machine_Registers |
| { |
| /* Information for the last statement boundary. |
| * Needed to calculate statement lengths. */ |
| Addr last_address; |
| UInt last_file; |
| UInt last_line; |
| |
| Addr address; |
| UInt file; |
| UInt line; |
| UInt column; |
| Int is_stmt; |
| Int basic_block; |
| Int end_sequence; |
| /* This variable hold the number of the last entry seen |
| in the File Table. */ |
| UInt last_file_entry; |
| } SMR; |
| |
| |
| static |
| UInt read_leb128 ( UChar* data, Int* length_return, Int sign ) |
| { |
| UInt result = 0; |
| UInt num_read = 0; |
| Int shift = 0; |
| UChar byte; |
| |
| do |
| { |
| byte = * data ++; |
| num_read ++; |
| |
| result |= (byte & 0x7f) << shift; |
| |
| shift += 7; |
| |
| } |
| while (byte & 0x80); |
| |
| if (length_return != NULL) |
| * length_return = num_read; |
| |
| if (sign && (shift < 32) && (byte & 0x40)) |
| result |= -1 << shift; |
| |
| return result; |
| } |
| |
| |
| static SMR state_machine_regs; |
| |
| static |
| void reset_state_machine ( Int is_stmt ) |
| { |
| if (0) VG_(printf)("smr.a := %p (reset)\n", 0 ); |
| state_machine_regs.last_address = 0; |
| state_machine_regs.last_file = 1; |
| state_machine_regs.last_line = 1; |
| state_machine_regs.address = 0; |
| state_machine_regs.file = 1; |
| state_machine_regs.line = 1; |
| state_machine_regs.column = 0; |
| state_machine_regs.is_stmt = is_stmt; |
| state_machine_regs.basic_block = 0; |
| state_machine_regs.end_sequence = 0; |
| state_machine_regs.last_file_entry = 0; |
| } |
| |
| /* Handled an extend line op. Returns true if this is the end |
| of sequence. */ |
| static |
| int process_extended_line_op( SegInfo *si, Char*** fnames, |
| UChar* data, Int is_stmt) |
| { |
| UChar op_code; |
| Int bytes_read; |
| UInt len; |
| UChar * name; |
| Addr adr; |
| |
| len = read_leb128 (data, & bytes_read, 0); |
| data += bytes_read; |
| |
| if (len == 0) |
| { |
| VG_(message)(Vg_UserMsg, |
| "badly formed extended line op encountered!\n"); |
| return bytes_read; |
| } |
| |
| len += bytes_read; |
| op_code = * data ++; |
| |
| if (0) VG_(printf)("dwarf2: ext OPC: %d\n", op_code); |
| |
| switch (op_code) |
| { |
| case DW_LNE_end_sequence: |
| if (0) VG_(printf)("1001: si->o %p, smr.a %p\n", |
| si->offset, state_machine_regs.address ); |
| state_machine_regs.end_sequence = 1; /* JRS: added for compliance |
| with spec; is pointless due to reset_state_machine below |
| */ |
| if (state_machine_regs.is_stmt) { |
| if (state_machine_regs.last_address) |
| VG_(addLineInfo) (si, (*fnames)[state_machine_regs.last_file], |
| si->offset + state_machine_regs.last_address, |
| si->offset + state_machine_regs.address, |
| state_machine_regs.last_line, 0); |
| } |
| reset_state_machine (is_stmt); |
| break; |
| |
| case DW_LNE_set_address: |
| adr = *((Addr *)data); |
| if (0) VG_(printf)("smr.a := %p\n", adr ); |
| state_machine_regs.address = adr; |
| break; |
| |
| case DW_LNE_define_file: |
| ++ state_machine_regs.last_file_entry; |
| name = data; |
| if (*fnames == NULL) |
| *fnames = VG_(arena_malloc)(VG_AR_SYMTAB, sizeof (Char *) * 2); |
| else |
| *fnames = VG_(arena_realloc)( |
| VG_AR_SYMTAB, *fnames, |
| sizeof(Char *) * (state_machine_regs.last_file_entry + 1)); |
| (*fnames)[state_machine_regs.last_file_entry] = VG_(addStr) (si,name, -1); |
| data += VG_(strlen) ((char *) data) + 1; |
| read_leb128 (data, & bytes_read, 0); |
| data += bytes_read; |
| read_leb128 (data, & bytes_read, 0); |
| data += bytes_read; |
| read_leb128 (data, & bytes_read, 0); |
| break; |
| |
| default: |
| break; |
| } |
| |
| return len; |
| } |
| |
| |
| void VG_(read_debuginfo_dwarf2) ( SegInfo* si, UChar* dwarf2, Int dwarf2_sz ) |
| { |
| DWARF2_External_LineInfo * external; |
| DWARF2_Internal_LineInfo info; |
| UChar * standard_opcodes; |
| UChar * data = dwarf2; |
| UChar * end = dwarf2 + dwarf2_sz; |
| UChar * end_of_sequence; |
| Char ** fnames = NULL; |
| |
| /* Fails due to gcc padding ... |
| vg_assert(sizeof(DWARF2_External_LineInfo) |
| == sizeof(DWARF2_Internal_LineInfo)); |
| */ |
| |
| while (data < end) |
| { |
| external = (DWARF2_External_LineInfo *) data; |
| |
| /* Check the length of the block. */ |
| info.li_length = * ((UInt *)(external->li_length)); |
| |
| if (info.li_length == 0xffffffff) |
| { |
| VG_(symerr)("64-bit DWARF line info is not supported yet."); |
| break; |
| } |
| |
| if (info.li_length + sizeof (external->li_length) > dwarf2_sz) |
| { |
| VG_(symerr)("DWARF line info appears to be corrupt " |
| "- the section is too small"); |
| return; |
| } |
| |
| /* Check its version number. */ |
| info.li_version = * ((UShort *) (external->li_version)); |
| if (info.li_version != 2) |
| { |
| VG_(symerr)("Only DWARF version 2 line info " |
| "is currently supported."); |
| return; |
| } |
| |
| info.li_prologue_length = * ((UInt *) (external->li_prologue_length)); |
| info.li_min_insn_length = * ((UChar *)(external->li_min_insn_length)); |
| |
| info.li_default_is_stmt = True; |
| /* WAS: = * ((UChar *)(external->li_default_is_stmt)); */ |
| /* Josef Weidendorfer (20021021) writes: |
| |
| It seems to me that the Intel Fortran compiler generates |
| bad DWARF2 line info code: It sets "is_stmt" of the state |
| machine in the the line info reader to be always |
| false. Thus, there is never a statement boundary generated |
| and therefore never a instruction range/line number |
| mapping generated for valgrind. |
| |
| Please have a look at the DWARF2 specification, Ch. 6.2 |
| (x86.ddj.com/ftp/manuals/tools/dwarf.pdf). Perhaps I |
| understand this wrong, but I don't think so. |
| |
| I just had a look at the GDB DWARF2 reader... They |
| completely ignore "is_stmt" when recording line info ;-) |
| That's the reason "objdump -S" works on files from the the |
| intel fortran compiler. |
| */ |
| |
| |
| /* JRS: changed (UInt*) to (UChar*) */ |
| info.li_line_base = * ((UChar *)(external->li_line_base)); |
| |
| info.li_line_range = * ((UChar *)(external->li_line_range)); |
| info.li_opcode_base = * ((UChar *)(external->li_opcode_base)); |
| |
| if (0) VG_(printf)("dwarf2: line base: %d, range %d, opc base: %d\n", |
| info.li_line_base, info.li_line_range, info.li_opcode_base); |
| |
| /* Sign extend the line base field. */ |
| info.li_line_base <<= 24; |
| info.li_line_base >>= 24; |
| |
| end_of_sequence = data + info.li_length |
| + sizeof (external->li_length); |
| |
| reset_state_machine (info.li_default_is_stmt); |
| |
| /* Read the contents of the Opcodes table. */ |
| standard_opcodes = data + sizeof (* external); |
| |
| /* Read the contents of the Directory table. */ |
| data = standard_opcodes + info.li_opcode_base - 1; |
| |
| if (* data == 0) |
| { |
| } |
| else |
| { |
| /* We ignore the directory table, since gcc gives the entire |
| path as part of the filename */ |
| while (* data != 0) |
| { |
| data += VG_(strlen) ((char *) data) + 1; |
| } |
| } |
| |
| /* Skip the NUL at the end of the table. */ |
| if (*data != 0) { |
| VG_(symerr)("can't find NUL at end of DWARF2 directory table"); |
| return; |
| } |
| data ++; |
| |
| /* Read the contents of the File Name table. */ |
| if (* data == 0) |
| { |
| } |
| else |
| { |
| while (* data != 0) |
| { |
| UChar * name; |
| Int bytes_read; |
| |
| ++ state_machine_regs.last_file_entry; |
| name = data; |
| /* Since we don't have realloc (0, ....) == malloc (...) |
| semantics, we need to malloc the first time. */ |
| |
| if (fnames == NULL) |
| fnames = VG_(arena_malloc)(VG_AR_SYMTAB, sizeof (Char *) * 2); |
| else |
| fnames = VG_(arena_realloc)(VG_AR_SYMTAB, fnames, |
| sizeof(Char *) |
| * (state_machine_regs.last_file_entry + 1)); |
| data += VG_(strlen) ((Char *) data) + 1; |
| fnames[state_machine_regs.last_file_entry] = VG_(addStr) (si,name, -1); |
| |
| read_leb128 (data, & bytes_read, 0); |
| data += bytes_read; |
| read_leb128 (data, & bytes_read, 0); |
| data += bytes_read; |
| read_leb128 (data, & bytes_read, 0); |
| data += bytes_read; |
| } |
| } |
| |
| /* Skip the NUL at the end of the table. */ |
| if (*data != 0) { |
| VG_(symerr)("can't find NUL at end of DWARF2 file name table"); |
| return; |
| } |
| data ++; |
| |
| /* Now display the statements. */ |
| |
| while (data < end_of_sequence) |
| { |
| UChar op_code; |
| Int adv; |
| Int bytes_read; |
| |
| op_code = * data ++; |
| |
| if (0) VG_(printf)("dwarf2: OPC: %d\n", op_code); |
| |
| if (op_code >= info.li_opcode_base) |
| { |
| Int advAddr; |
| op_code -= info.li_opcode_base; |
| adv = (op_code / info.li_line_range) |
| * info.li_min_insn_length; |
| advAddr = adv; |
| state_machine_regs.address += adv; |
| if (0) VG_(printf)("smr.a += %p\n", adv ); |
| adv = (op_code % info.li_line_range) + info.li_line_base; |
| if (0) VG_(printf)("1002: si->o %p, smr.a %p\n", |
| si->offset, state_machine_regs.address ); |
| state_machine_regs.line += adv; |
| |
| if (state_machine_regs.is_stmt) { |
| /* only add a statement if there was a previous boundary */ |
| if (state_machine_regs.last_address) |
| VG_(addLineInfo) (si, fnames[state_machine_regs.last_file], |
| si->offset + state_machine_regs.last_address, |
| si->offset + state_machine_regs.address, |
| state_machine_regs.last_line, 0); |
| state_machine_regs.last_address = state_machine_regs.address; |
| state_machine_regs.last_file = state_machine_regs.file; |
| state_machine_regs.last_line = state_machine_regs.line; |
| } |
| } |
| else switch (op_code) |
| { |
| case DW_LNS_extended_op: |
| data += process_extended_line_op ( |
| si, &fnames, data, |
| info.li_default_is_stmt); |
| break; |
| |
| case DW_LNS_copy: |
| if (0) VG_(printf)("1002: si->o %p, smr.a %p\n", |
| si->offset, state_machine_regs.address ); |
| if (state_machine_regs.is_stmt) { |
| /* only add a statement if there was a previous boundary */ |
| if (state_machine_regs.last_address) |
| VG_(addLineInfo) (si, fnames[state_machine_regs.last_file], |
| si->offset + state_machine_regs.last_address, |
| si->offset + state_machine_regs.address, |
| state_machine_regs.last_line, 0); |
| state_machine_regs.last_address = state_machine_regs.address; |
| state_machine_regs.last_file = state_machine_regs.file; |
| state_machine_regs.last_line = state_machine_regs.line; |
| } |
| state_machine_regs.basic_block = 0; /* JRS added */ |
| break; |
| |
| case DW_LNS_advance_pc: |
| adv = info.li_min_insn_length |
| * read_leb128 (data, & bytes_read, 0); |
| data += bytes_read; |
| state_machine_regs.address += adv; |
| if (0) VG_(printf)("smr.a += %p\n", adv ); |
| break; |
| |
| case DW_LNS_advance_line: |
| adv = read_leb128 (data, & bytes_read, 1); |
| data += bytes_read; |
| state_machine_regs.line += adv; |
| break; |
| |
| case DW_LNS_set_file: |
| adv = read_leb128 (data, & bytes_read, 0); |
| data += bytes_read; |
| state_machine_regs.file = adv; |
| break; |
| |
| case DW_LNS_set_column: |
| adv = read_leb128 (data, & bytes_read, 0); |
| data += bytes_read; |
| state_machine_regs.column = adv; |
| break; |
| |
| case DW_LNS_negate_stmt: |
| adv = state_machine_regs.is_stmt; |
| adv = ! adv; |
| state_machine_regs.is_stmt = adv; |
| break; |
| |
| case DW_LNS_set_basic_block: |
| state_machine_regs.basic_block = 1; |
| break; |
| |
| case DW_LNS_const_add_pc: |
| adv = (((255 - info.li_opcode_base) / info.li_line_range) |
| * info.li_min_insn_length); |
| state_machine_regs.address += adv; |
| if (0) VG_(printf)("smr.a += %p\n", adv ); |
| break; |
| |
| case DW_LNS_fixed_advance_pc: |
| /* XXX: Need something to get 2 bytes */ |
| adv = *((UShort *)data); |
| data += 2; |
| state_machine_regs.address += adv; |
| if (0) VG_(printf)("smr.a += %p\n", adv ); |
| break; |
| |
| case DW_LNS_set_prologue_end: |
| break; |
| |
| case DW_LNS_set_epilogue_begin: |
| break; |
| |
| case DW_LNS_set_isa: |
| adv = read_leb128 (data, & bytes_read, 0); |
| data += bytes_read; |
| break; |
| |
| default: |
| { |
| int j; |
| for (j = standard_opcodes[op_code - 1]; j > 0 ; --j) |
| { |
| read_leb128 (data, &bytes_read, 0); |
| data += bytes_read; |
| } |
| } |
| break; |
| } |
| } |
| VG_(arena_free)(VG_AR_SYMTAB, fnames); |
| fnames = NULL; |
| } |
| } |
| |
| |
| /*------------------------------------------------------------*/ |
| /*--- Read DWARF1 format line number info. ---*/ |
| /*------------------------------------------------------------*/ |
| |
| /* DWARF1 appears to be redundant, but nevertheless the Lahey Fortran |
| compiler generates it. |
| */ |
| |
| /* The following three enums (dwarf_tag, dwarf_form, dwarf_attribute) |
| are taken from the file include/elf/dwarf.h in the GNU gdb-6.0 |
| sources, which are Copyright 1992, 1993, 1995, 1999 Free Software |
| Foundation, Inc and naturally licensed under the GNU General Public |
| License version 2 or later. |
| */ |
| |
| /* Tag names and codes. */ |
| |
| enum dwarf_tag { |
| TAG_padding = 0x0000, |
| TAG_array_type = 0x0001, |
| TAG_class_type = 0x0002, |
| TAG_entry_point = 0x0003, |
| TAG_enumeration_type = 0x0004, |
| TAG_formal_parameter = 0x0005, |
| TAG_global_subroutine = 0x0006, |
| TAG_global_variable = 0x0007, |
| /* 0x0008 -- reserved */ |
| /* 0x0009 -- reserved */ |
| TAG_label = 0x000a, |
| TAG_lexical_block = 0x000b, |
| TAG_local_variable = 0x000c, |
| TAG_member = 0x000d, |
| /* 0x000e -- reserved */ |
| TAG_pointer_type = 0x000f, |
| TAG_reference_type = 0x0010, |
| TAG_compile_unit = 0x0011, |
| TAG_string_type = 0x0012, |
| TAG_structure_type = 0x0013, |
| TAG_subroutine = 0x0014, |
| TAG_subroutine_type = 0x0015, |
| TAG_typedef = 0x0016, |
| TAG_union_type = 0x0017, |
| TAG_unspecified_parameters = 0x0018, |
| TAG_variant = 0x0019, |
| TAG_common_block = 0x001a, |
| TAG_common_inclusion = 0x001b, |
| TAG_inheritance = 0x001c, |
| TAG_inlined_subroutine = 0x001d, |
| TAG_module = 0x001e, |
| TAG_ptr_to_member_type = 0x001f, |
| TAG_set_type = 0x0020, |
| TAG_subrange_type = 0x0021, |
| TAG_with_stmt = 0x0022, |
| |
| /* GNU extensions */ |
| |
| TAG_format_label = 0x8000, /* for FORTRAN 77 and Fortran 90 */ |
| TAG_namelist = 0x8001, /* For Fortran 90 */ |
| TAG_function_template = 0x8002, /* for C++ */ |
| TAG_class_template = 0x8003 /* for C++ */ |
| }; |
| |
| /* Form names and codes. */ |
| |
| enum dwarf_form { |
| FORM_ADDR = 0x1, |
| FORM_REF = 0x2, |
| FORM_BLOCK2 = 0x3, |
| FORM_BLOCK4 = 0x4, |
| FORM_DATA2 = 0x5, |
| FORM_DATA4 = 0x6, |
| FORM_DATA8 = 0x7, |
| FORM_STRING = 0x8 |
| }; |
| |
| /* Attribute names and codes. */ |
| |
| enum dwarf_attribute { |
| AT_sibling = (0x0010|FORM_REF), |
| AT_location = (0x0020|FORM_BLOCK2), |
| AT_name = (0x0030|FORM_STRING), |
| AT_fund_type = (0x0050|FORM_DATA2), |
| AT_mod_fund_type = (0x0060|FORM_BLOCK2), |
| AT_user_def_type = (0x0070|FORM_REF), |
| AT_mod_u_d_type = (0x0080|FORM_BLOCK2), |
| AT_ordering = (0x0090|FORM_DATA2), |
| AT_subscr_data = (0x00a0|FORM_BLOCK2), |
| AT_byte_size = (0x00b0|FORM_DATA4), |
| AT_bit_offset = (0x00c0|FORM_DATA2), |
| AT_bit_size = (0x00d0|FORM_DATA4), |
| /* (0x00e0|FORM_xxxx) -- reserved */ |
| AT_element_list = (0x00f0|FORM_BLOCK4), |
| AT_stmt_list = (0x0100|FORM_DATA4), |
| AT_low_pc = (0x0110|FORM_ADDR), |
| AT_high_pc = (0x0120|FORM_ADDR), |
| AT_language = (0x0130|FORM_DATA4), |
| AT_member = (0x0140|FORM_REF), |
| AT_discr = (0x0150|FORM_REF), |
| AT_discr_value = (0x0160|FORM_BLOCK2), |
| /* (0x0170|FORM_xxxx) -- reserved */ |
| /* (0x0180|FORM_xxxx) -- reserved */ |
| AT_string_length = (0x0190|FORM_BLOCK2), |
| AT_common_reference = (0x01a0|FORM_REF), |
| AT_comp_dir = (0x01b0|FORM_STRING), |
| AT_const_value_string = (0x01c0|FORM_STRING), |
| AT_const_value_data2 = (0x01c0|FORM_DATA2), |
| AT_const_value_data4 = (0x01c0|FORM_DATA4), |
| AT_const_value_data8 = (0x01c0|FORM_DATA8), |
| AT_const_value_block2 = (0x01c0|FORM_BLOCK2), |
| AT_const_value_block4 = (0x01c0|FORM_BLOCK4), |
| AT_containing_type = (0x01d0|FORM_REF), |
| AT_default_value_addr = (0x01e0|FORM_ADDR), |
| AT_default_value_data2 = (0x01e0|FORM_DATA2), |
| AT_default_value_data4 = (0x01e0|FORM_DATA4), |
| AT_default_value_data8 = (0x01e0|FORM_DATA8), |
| AT_default_value_string = (0x01e0|FORM_STRING), |
| AT_friends = (0x01f0|FORM_BLOCK2), |
| AT_inline = (0x0200|FORM_STRING), |
| AT_is_optional = (0x0210|FORM_STRING), |
| AT_lower_bound_ref = (0x0220|FORM_REF), |
| AT_lower_bound_data2 = (0x0220|FORM_DATA2), |
| AT_lower_bound_data4 = (0x0220|FORM_DATA4), |
| AT_lower_bound_data8 = (0x0220|FORM_DATA8), |
| AT_private = (0x0240|FORM_STRING), |
| AT_producer = (0x0250|FORM_STRING), |
| AT_program = (0x0230|FORM_STRING), |
| AT_protected = (0x0260|FORM_STRING), |
| AT_prototyped = (0x0270|FORM_STRING), |
| AT_public = (0x0280|FORM_STRING), |
| AT_pure_virtual = (0x0290|FORM_STRING), |
| AT_return_addr = (0x02a0|FORM_BLOCK2), |
| AT_abstract_origin = (0x02b0|FORM_REF), |
| AT_start_scope = (0x02c0|FORM_DATA4), |
| AT_stride_size = (0x02e0|FORM_DATA4), |
| AT_upper_bound_ref = (0x02f0|FORM_REF), |
| AT_upper_bound_data2 = (0x02f0|FORM_DATA2), |
| AT_upper_bound_data4 = (0x02f0|FORM_DATA4), |
| AT_upper_bound_data8 = (0x02f0|FORM_DATA8), |
| AT_virtual = (0x0300|FORM_STRING), |
| |
| /* GNU extensions. */ |
| |
| AT_sf_names = (0x8000|FORM_DATA4), |
| AT_src_info = (0x8010|FORM_DATA4), |
| AT_mac_info = (0x8020|FORM_DATA4), |
| AT_src_coords = (0x8030|FORM_DATA4), |
| AT_body_begin = (0x8040|FORM_ADDR), |
| AT_body_end = (0x8050|FORM_ADDR) |
| }; |
| |
| /* end of enums taken from gdb-6.0 sources */ |
| |
| void VG_(read_debuginfo_dwarf1) ( |
| SegInfo* si, |
| UChar* dwarf1d, Int dwarf1d_sz, |
| UChar* dwarf1l, Int dwarf1l_sz ) |
| { |
| UInt stmt_list; |
| Bool stmt_list_found; |
| Int die_offset, die_szb, at_offset; |
| UShort die_kind, at_kind; |
| UChar* at_base; |
| UChar* src_filename; |
| |
| if (0) |
| VG_(printf)("read_debuginfo_dwarf1 ( %p, %d, %p, %d )\n", |
| dwarf1d, dwarf1d_sz, dwarf1l, dwarf1l_sz ); |
| |
| /* This loop scans the DIEs. */ |
| die_offset = 0; |
| while (True) { |
| if (die_offset >= dwarf1d_sz) break; |
| |
| die_szb = *(Int*)(dwarf1d + die_offset); |
| die_kind = *(UShort*)(dwarf1d + die_offset + 4); |
| |
| /* We're only interested in compile_unit DIEs; ignore others. */ |
| if (die_kind != TAG_compile_unit) { |
| die_offset += die_szb; |
| continue; |
| } |
| |
| if (0) |
| VG_(printf)("compile-unit DIE: offset %d, tag 0x%x, size %d\n", |
| die_offset, (Int)die_kind, die_szb ); |
| |
| /* We've got a compile_unit DIE starting at (dwarf1d + |
| die_offset+6). Try and find the AT_name and AT_stmt_list |
| attributes. Then, finally, we can read the line number info |
| for this source file. */ |
| |
| /* The next 3 are set as we find the relevant attrs. */ |
| src_filename = NULL; |
| stmt_list_found = False; |
| stmt_list = 0; |
| |
| /* This loop scans the Attrs inside compile_unit DIEs. */ |
| at_base = dwarf1d + die_offset + 6; |
| at_offset = 0; |
| while (True) { |
| if (at_offset >= die_szb-6) break; |
| |
| at_kind = *(UShort*)(at_base + at_offset); |
| if (0) VG_(printf)("atoffset %d, attag 0x%x\n", |
| at_offset, (Int)at_kind ); |
| at_offset += 2; /* step over the attribute itself */ |
| /* We have to examine the attribute to figure out its |
| length. */ |
| switch (at_kind) { |
| case AT_stmt_list: |
| case AT_language: |
| case AT_sibling: |
| if (at_kind == AT_stmt_list) { |
| stmt_list_found = True; |
| stmt_list = *(Int*)(at_base+at_offset); |
| } |
| at_offset += 4; break; |
| case AT_high_pc: |
| case AT_low_pc: |
| at_offset += sizeof(void*); break; |
| case AT_name: |
| case AT_producer: |
| case AT_comp_dir: |
| /* Zero terminated string, step over it. */ |
| if (at_kind == AT_name) |
| src_filename = at_base + at_offset; |
| while (at_offset < die_szb-6 && at_base[at_offset] != 0) |
| at_offset++; |
| at_offset++; |
| break; |
| default: |
| VG_(printf)("Unhandled DWARF-1 attribute 0x%x\n", |
| (Int)at_kind ); |
| VG_(core_panic)("Unhandled DWARF-1 attribute"); |
| } /* switch (at_kind) */ |
| } /* looping over attributes */ |
| |
| /* So, did we find the required stuff for a line number table in |
| this DIE? If yes, read it. */ |
| if (stmt_list_found /* there is a line number table */ |
| && src_filename != NULL /* we know the source filename */ |
| ) { |
| /* Table starts: |
| Length: |
| 4 bytes, includes the entire table |
| Base address: |
| unclear (4? 8?), assuming native pointer size here. |
| Then a sequence of triples |
| (source line number -- 32 bits |
| source line column -- 16 bits |
| address delta -- 32 bits) |
| */ |
| Addr base; |
| Int len; |
| Char* curr_filenm; |
| UChar* ptr; |
| UInt prev_line, prev_delta; |
| |
| curr_filenm = VG_(addStr) ( si, src_filename, -1 ); |
| prev_line = prev_delta = 0; |
| |
| ptr = dwarf1l + stmt_list; |
| len = *(Int*)ptr; ptr += sizeof(Int); |
| base = (Addr)(*(void**)ptr); ptr += sizeof(void*); |
| len -= (sizeof(Int) + sizeof(void*)); |
| while (len > 0) { |
| UInt line; |
| UShort col; |
| UInt delta; |
| line = *(UInt*)ptr; ptr += sizeof(UInt); |
| col = *(UShort*)ptr; ptr += sizeof(UShort); |
| delta = *(UShort*)ptr; ptr += sizeof(UInt); |
| if (0) VG_(printf)("line %d, col %d, delta %d\n", |
| line, (Int)col, delta ); |
| len -= (sizeof(UInt) + sizeof(UShort) + sizeof(UInt)); |
| |
| if (delta > 0 && prev_line > 0) { |
| if (0) VG_(printf) (" %d %d-%d\n", |
| prev_line, prev_delta, delta-1); |
| VG_(addLineInfo) ( si, curr_filenm, |
| base + prev_delta, base + delta, |
| prev_line, 0 ); |
| } |
| prev_line = line; |
| prev_delta = delta; |
| } |
| } |
| |
| /* Move on the the next DIE. */ |
| die_offset += die_szb; |
| |
| } /* Looping over DIEs */ |
| |
| } |
| |
| |
| /*------------------------------------------------------------*/ |
| /*--- Read call-frame info from an .eh_frame section ---*/ |
| /*------------------------------------------------------------*/ |
| |
| /* Useful info .. |
| |
| In general: |
| gdb-6.3/gdb/dwarf2-frame.c |
| |
| gdb-6.3/gdb/i386-tdep.c: |
| |
| DWARF2/GCC uses the stack address *before* the function call as a |
| frame's CFA. [jrs: I presume this means %esp before the call as |
| the CFA]. |
| |
| JRS: on amd64, the dwarf register numbering is, as per |
| gdb-6.3/gdb/tdep-amd64.c and also amd64-abi-0.95.pdf: |
| |
| 0 1 2 3 4 5 6 7 |
| RAX RDX RCX RBX RSI RDI RBP RSP |
| |
| 8 ... 15 |
| R8 ... R15 |
| |
| 16 is the return address (RIP) |
| |
| This is pretty strange given this not the encoding scheme for |
| registers used in amd64 code. |
| |
| On x86 I cannot find any documentation. It _appears_ to be the |
| actual instruction encoding, viz: |
| |
| 0 1 2 3 4 5 6 7 |
| EAX ECX EDX EBX ESP EBP ESI EDI |
| |
| 8 is the return address (EIP) */ |
| |
| |
| /* ------------ Deal with summary-info records ------------ */ |
| |
| void VG_(ppCfiSI) ( CfiSI* si ) |
| { |
| # define SHOW_HOW(_how, _off) \ |
| do { \ |
| if (_how == CFIR_UNKNOWN) { \ |
| VG_(printf)("Unknown"); \ |
| } else \ |
| if (_how == CFIR_SAME) { \ |
| VG_(printf)("Same"); \ |
| } else \ |
| if (_how == CFIR_CFAREL) { \ |
| VG_(printf)("cfa+%d", _off); \ |
| } else \ |
| if (_how == CFIR_MEMCFAREL) { \ |
| VG_(printf)("*(cfa+%d)", _off); \ |
| } else { \ |
| VG_(printf)("???"); \ |
| } \ |
| } while (0) |
| |
| VG_(printf)("[%p .. %p]: ", si->base, |
| si->base + (UWord)si->len - 1); |
| VG_(printf)("let cfa=%s+%d", |
| si->cfa_sprel ? "oldSP" : "oldFP", si->cfa_off); |
| VG_(printf)(" in RA="); |
| SHOW_HOW(si->ra_how, si->ra_off); |
| VG_(printf)(" SP="); |
| SHOW_HOW(si->sp_how, si->sp_off); |
| VG_(printf)(" FP="); |
| SHOW_HOW(si->fp_how, si->fp_off); |
| VG_(printf)("\n"); |
| |
| # undef SHOW_HOW |
| } |
| |
| static void initCfiSI ( CfiSI* si ) |
| { |
| si->base = 0; |
| si->len = 0; |
| si->cfa_sprel = False; |
| si->ra_how = 0; |
| si->sp_how = 0; |
| si->fp_how = 0; |
| si->cfa_off = 0; |
| si->ra_off = 0; |
| si->sp_off = 0; |
| si->fp_off = 0; |
| } |
| |
| |
| /* --------------- Decls --------------- */ |
| |
| #if defined(VGP_x86_linux) |
| #define FP_COL 5 |
| #define SP_COL 4 |
| #define RA_COL 8 |
| #elif defined(VGP_amd64_linux) |
| #define FP_COL 6 |
| #define SP_COL 7 |
| #define RA_COL 16 |
| #endif |
| |
| /* the number of regs we are prepared to unwind */ |
| #define N_CFI_REGS 20 |
| |
| /* Instructions for the automaton */ |
| enum dwarf_cfa_primary_ops |
| { |
| DW_CFA_use_secondary = 0, |
| DW_CFA_advance_loc = 1, |
| DW_CFA_offset = 2, |
| DW_CFA_restore = 3 |
| }; |
| |
| enum dwarf_cfa_secondary_ops |
| { |
| DW_CFA_nop = 0x00, |
| DW_CFA_set_loc = 0x01, |
| DW_CFA_advance_loc1 = 0x02, |
| DW_CFA_advance_loc2 = 0x03, |
| DW_CFA_advance_loc4 = 0x04, |
| DW_CFA_offset_extended = 0x05, |
| DW_CFA_restore_extended = 0x06, |
| DW_CFA_undefined = 0x07, |
| DW_CFA_same_value = 0x08, |
| DW_CFA_register = 0x09, |
| DW_CFA_remember_state = 0x0a, |
| DW_CFA_restore_state = 0x0b, |
| DW_CFA_def_cfa = 0x0c, |
| DW_CFA_def_cfa_register = 0x0d, |
| DW_CFA_def_cfa_offset = 0x0e, |
| DW_CFA_offset_extended_sf = 0x11, /* DWARF3 only */ |
| DW_CFA_lo_user = 0x1c, |
| DW_CFA_GNU_args_size = 0x2e, |
| DW_CFA_hi_user = 0x3f |
| }; |
| |
| #define DW_EH_PE_absptr 0x00 |
| #define DW_EH_PE_omit 0xff |
| |
| #define DW_EH_PE_uleb128 0x01 |
| #define DW_EH_PE_udata2 0x02 |
| #define DW_EH_PE_udata4 0x03 |
| #define DW_EH_PE_udata8 0x04 |
| #define DW_EH_PE_sleb128 0x09 |
| #define DW_EH_PE_sdata2 0x0A |
| #define DW_EH_PE_sdata4 0x0B |
| #define DW_EH_PE_sdata8 0x0C |
| #define DW_EH_PE_signed 0x08 |
| |
| #define DW_EH_PE_pcrel 0x10 |
| #define DW_EH_PE_textrel 0x20 |
| #define DW_EH_PE_datarel 0x30 |
| #define DW_EH_PE_funcrel 0x40 |
| #define DW_EH_PE_aligned 0x50 |
| |
| #define DW_EH_PE_indirect 0x80 |
| |
| |
| /* RegRule and UnwindContext are used temporarily to do the unwinding. |
| The result is then summarised into a CfiSI, if possible. */ |
| |
| typedef |
| struct { |
| enum { RR_Undef, RR_Same, RR_CFAoff, RR_Reg, RR_Arch } tag; |
| |
| /* Note, .coff and .reg are never both in use. Therefore could |
| merge them into one. */ |
| |
| /* CFA offset if tag==RR_CFAoff */ |
| Int coff; |
| |
| /* reg, if tag==RR_Reg */ |
| Int reg; |
| } |
| RegRule; |
| |
| static void ppRegRule ( RegRule* reg ) |
| { |
| switch (reg->tag) { |
| case RR_Undef: VG_(printf)("u "); break; |
| case RR_Same: VG_(printf)("s "); break; |
| case RR_CFAoff: VG_(printf)("c%d ", reg->coff); break; |
| case RR_Reg: VG_(printf)("r%d ", reg->reg); break; |
| case RR_Arch: VG_(printf)("a "); break; |
| default: VG_(core_panic)("ppRegRule"); |
| } |
| } |
| |
| |
| typedef |
| struct { |
| /* Read-only fields. */ |
| Int code_a_f; |
| Int data_a_f; |
| Addr initloc; |
| /* The rest of these fields can be modifed by |
| run_CF_instruction. */ |
| /* The LOC entry */ |
| Addr loc; |
| /* The CFA entry */ |
| Int cfa_reg; |
| Int cfa_offset; /* in bytes */ |
| /* register unwind rules */ |
| RegRule reg[N_CFI_REGS]; |
| } |
| UnwindContext; |
| |
| static void ppUnwindContext ( UnwindContext* ctx ) |
| { |
| Int i; |
| VG_(printf)("0x%llx: ", (ULong)ctx->loc); |
| VG_(printf)("%d(r%d) ", ctx->cfa_offset, ctx->cfa_reg); |
| for (i = 0; i < N_CFI_REGS; i++) |
| ppRegRule(&ctx->reg[i]); |
| VG_(printf)("\n"); |
| } |
| |
| static void initUnwindContext ( /*OUT*/UnwindContext* ctx ) |
| { |
| Int i; |
| ctx->code_a_f = 0; |
| ctx->data_a_f = 0; |
| ctx->loc = 0; |
| ctx->cfa_reg = 0; |
| ctx->cfa_offset = 0; |
| for (i = 0; i < N_CFI_REGS; i++) { |
| ctx->reg[i].tag = RR_Undef; |
| ctx->reg[i].coff = 0; |
| ctx->reg[i].reg = 0; |
| } |
| } |
| |
| |
| /* --------------- Summarisation --------------- */ |
| |
| /* Summarise ctx into si, if possible. Returns True if successful. |
| This is taken to be just after ctx's loc advances; hence the |
| summary is up to but not including the current loc. This works |
| on both x86 and amd64. |
| */ |
| static Bool summarise_context( /*OUT*/CfiSI* si, |
| Addr loc_start, |
| UnwindContext* ctx ) |
| { |
| Int why = 0; |
| initCfiSI(si); |
| |
| /* How to generate the CFA */ |
| if (ctx->cfa_reg == SP_COL) { |
| si->cfa_sprel = True; |
| si->cfa_off = ctx->cfa_offset; |
| } else |
| if (ctx->cfa_reg == FP_COL) { |
| si->cfa_sprel = False; |
| si->cfa_off = ctx->cfa_offset; |
| } else { |
| why = 1; |
| goto failed; |
| } |
| |
| # define SUMMARISE_HOW(_how, _off, _ctxreg) \ |
| switch (_ctxreg.tag) { \ |
| case RR_Undef: _how = CFIR_UNKNOWN; _off = 0; break; \ |
| case RR_Same: _how = CFIR_SAME; _off = 0; break; \ |
| case RR_CFAoff: _how = CFIR_MEMCFAREL; _off = _ctxreg.coff; break; \ |
| default: { why = 2; goto failed; } /* otherwise give up */ \ |
| } |
| |
| SUMMARISE_HOW(si->ra_how, si->ra_off, ctx->reg[RA_COL] ); |
| SUMMARISE_HOW(si->fp_how, si->fp_off, ctx->reg[FP_COL] ); |
| |
| # undef SUMMARISE_HOW |
| |
| /* on x86/amd64, it seems the old %{e,r}sp value before the call is |
| always the same as the CFA. Therefore ... */ |
| si->sp_how = CFIR_CFAREL; |
| si->sp_off = 0; |
| |
| /* also, gcc says "Undef" for %{e,r}bp when it is unchanged. So |
| .. */ |
| if (ctx->reg[FP_COL].tag == RR_Undef) |
| si->fp_how = CFIR_SAME; |
| |
| /* knock out some obviously stupid cases */ |
| if (si->ra_how == CFIR_SAME) |
| { why = 3; goto failed; } |
| |
| /* bogus looking range? Note, we require that the difference is |
| representable in 32 bits. */ |
| if (loc_start >= ctx->loc) |
| { why = 4; goto failed; } |
| if (ctx->loc - loc_start > 10000000 /* let's say */) |
| { why = 5; goto failed; } |
| |
| si->base = loc_start + ctx->initloc; |
| si->len = (UInt)(ctx->loc - loc_start); |
| |
| return True; |
| |
| failed: |
| if (VG_(clo_verbosity) > 1) { |
| VG_(message)(Vg_DebugMsg, |
| "summarise_context(loc_start = %p)" |
| ": cannot summarise(why=%d): ", loc_start, why); |
| ppUnwindContext(ctx); |
| } |
| return False; |
| } |
| |
| static void ppUnwindContext_summary ( UnwindContext* ctx ) |
| { |
| VG_(printf)("0x%llx-1: ", (ULong)ctx->loc); |
| |
| if (ctx->cfa_reg == SP_COL) { |
| VG_(printf)("SP/CFA=%d+SP ", ctx->cfa_offset); |
| } else |
| if (ctx->cfa_reg == FP_COL) { |
| VG_(printf)("SP/CFA=%d+FP ", ctx->cfa_offset); |
| } else { |
| VG_(printf)("SP/CFA=unknown ", ctx->cfa_offset); |
| } |
| |
| VG_(printf)("RA="); |
| ppRegRule( &ctx->reg[RA_COL] ); |
| |
| VG_(printf)("FP="); |
| ppRegRule( &ctx->reg[FP_COL] ); |
| VG_(printf)("\n"); |
| } |
| |
| |
| /* ------------ Pick apart DWARF2 byte streams ------------ */ |
| |
| static inline Bool host_is_little_endian ( void ) |
| { |
| UInt x = 0x76543210; |
| UChar* p = (UChar*)(&x); |
| return toBool(*p == 0x10); |
| } |
| |
| static Short read_Short ( UChar* data ) |
| { |
| vg_assert(host_is_little_endian()); |
| Short r = 0; |
| r = data[0] |
| | ( ((UInt)data[1]) << 8 ); |
| return r; |
| } |
| |
| static Int read_Int ( UChar* data ) |
| { |
| vg_assert(host_is_little_endian()); |
| Int r = 0; |
| r = data[0] |
| | ( ((UInt)data[1]) << 8 ) |
| | ( ((UInt)data[2]) << 16 ) |
| | ( ((UInt)data[3]) << 24 ); |
| return r; |
| } |
| |
| static Long read_Long ( UChar* data ) |
| { |
| vg_assert(host_is_little_endian()); |
| Long r = 0; |
| r = data[0] |
| | ( ((ULong)data[1]) << 8 ) |
| | ( ((ULong)data[2]) << 16 ) |
| | ( ((ULong)data[3]) << 24 ) |
| | ( ((ULong)data[4]) << 32 ) |
| | ( ((ULong)data[5]) << 40 ) |
| | ( ((ULong)data[6]) << 48 ) |
| | ( ((ULong)data[7]) << 56 ); |
| return r; |
| } |
| |
| static UShort read_UShort ( UChar* data ) |
| { |
| vg_assert(host_is_little_endian()); |
| UInt r = 0; |
| r = data[0] |
| | ( ((UInt)data[1]) << 8 ); |
| return r; |
| } |
| |
| static UInt read_UInt ( UChar* data ) |
| { |
| vg_assert(host_is_little_endian()); |
| UInt r = 0; |
| r = data[0] |
| | ( ((UInt)data[1]) << 8 ) |
| | ( ((UInt)data[2]) << 16 ) |
| | ( ((UInt)data[3]) << 24 ); |
| return r; |
| } |
| |
| static ULong read_ULong ( UChar* data ) |
| { |
| vg_assert(host_is_little_endian()); |
| ULong r = 0; |
| r = data[0] |
| | ( ((ULong)data[1]) << 8 ) |
| | ( ((ULong)data[2]) << 16 ) |
| | ( ((ULong)data[3]) << 24 ) |
| | ( ((ULong)data[4]) << 32 ) |
| | ( ((ULong)data[5]) << 40 ) |
| | ( ((ULong)data[6]) << 48 ) |
| | ( ((ULong)data[7]) << 56 ); |
| return r; |
| } |
| |
| static Addr read_Addr ( UChar* data ) |
| { |
| # if VG_WORDSIZE == 4 |
| return read_UInt(data); |
| # else |
| return read_ULong(data); |
| # endif |
| } |
| |
| static UChar read_UChar ( UChar* data ) |
| { |
| return data[0]; |
| } |
| |
| static UChar default_Addr_encoding () |
| { |
| switch (sizeof(Addr)) { |
| case 4: return DW_EH_PE_udata4; |
| case 8: return DW_EH_PE_udata8; |
| default: vg_assert(0); |
| } |
| } |
| |
| static UInt size_of_encoded_Addr ( UChar encoding ) |
| { |
| if (encoding == DW_EH_PE_omit) |
| return 0; |
| |
| switch (encoding & 0x07) { |
| case DW_EH_PE_absptr: return sizeof(Addr); |
| case DW_EH_PE_udata2: return sizeof(UShort); |
| case DW_EH_PE_udata4: return sizeof(UInt); |
| case DW_EH_PE_udata8: return sizeof(ULong); |
| default: vg_assert(0); |
| } |
| } |
| |
| static Addr read_encoded_Addr ( UChar* data, UChar encoding, Int *nbytes, |
| UChar* ehframe, Addr ehframe_addr ) |
| { |
| Addr base; |
| Int offset; |
| |
| vg_assert((encoding & DW_EH_PE_indirect) == 0); |
| |
| *nbytes = 0; |
| |
| switch (encoding & 0x70) { |
| case DW_EH_PE_absptr: |
| base = 0; |
| break; |
| case DW_EH_PE_pcrel: |
| base = ehframe_addr + ( data - ehframe ); |
| break; |
| case DW_EH_PE_datarel: |
| vg_assert(0); |
| base = /* data base address */ 0; |
| break; |
| case DW_EH_PE_textrel: |
| vg_assert(0); |
| base = /* text base address */ 0; |
| break; |
| case DW_EH_PE_funcrel: |
| base = 0; |
| break; |
| case DW_EH_PE_aligned: |
| base = 0; |
| offset = data - ehframe; |
| if ((offset % sizeof(Addr)) != 0) { |
| *nbytes = sizeof(Addr) - (offset % sizeof(Addr)); |
| data += *nbytes; |
| } |
| break; |
| default: |
| vg_assert(0); |
| } |
| |
| if ((encoding & 0x07) == 0x00) |
| encoding |= default_Addr_encoding(); |
| |
| switch (encoding & 0x0f) { |
| case DW_EH_PE_udata2: |
| *nbytes += sizeof(UShort); |
| return base + read_UShort(data); |
| case DW_EH_PE_udata4: |
| *nbytes += sizeof(UInt); |
| return base + read_UInt(data); |
| case DW_EH_PE_udata8: |
| *nbytes += sizeof(ULong); |
| return base + read_ULong(data); |
| case DW_EH_PE_sdata2: |
| *nbytes += sizeof(Short); |
| return base + read_Short(data); |
| case DW_EH_PE_sdata4: |
| *nbytes += sizeof(Int); |
| return base + read_Int(data); |
| case DW_EH_PE_sdata8: |
| *nbytes += sizeof(Long); |
| return base + read_Long(data); |
| default: |
| vg_assert2(0, "read encoded address %d\n", encoding & 0x0f); |
| } |
| } |
| |
| |
| /* ------------ Run/show CFI instructions ------------ */ |
| |
| /* Run a CFI instruction, and also return its length. |
| Returns 0 if the instruction could not be executed. |
| */ |
| static Int run_CF_instruction ( /*MOD*/UnwindContext* ctx, |
| UChar* instr, |
| UnwindContext* restore_ctx ) |
| { |
| Int off, reg, reg2, nleb; |
| UInt delta; |
| Int i = 0; |
| UChar hi2 = (instr[i] >> 6) & 3; |
| UChar lo6 = instr[i] & 0x3F; |
| i++; |
| |
| if (hi2 == DW_CFA_advance_loc) { |
| delta = (UInt)lo6; |
| ctx->loc += delta; |
| return i; |
| } |
| |
| if (hi2 == DW_CFA_offset) { |
| /* Set rule for reg 'lo6' to CFAoffset(off * data_af) */ |
| off = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| reg = (Int)lo6; |
| if (reg < 0 || reg >= N_CFI_REGS) |
| return 0; /* fail */ |
| ctx->reg[reg].tag = RR_CFAoff; |
| ctx->reg[reg].coff = off * ctx->data_a_f; |
| return i; |
| } |
| |
| if (hi2 == DW_CFA_restore) { |
| reg = (Int)lo6; |
| if (reg < 0 || reg >= N_CFI_REGS) |
| return 0; /* fail */ |
| if (restore_ctx == NULL) |
| return 0; /* fail */ |
| ctx->reg[reg] = restore_ctx->reg[reg]; |
| return i; |
| } |
| |
| vg_assert(hi2 == DW_CFA_use_secondary); |
| |
| switch (lo6) { |
| case DW_CFA_nop: |
| break; |
| case DW_CFA_set_loc: |
| ctx->loc = read_Addr(&instr[i]) - ctx->initloc; i+= sizeof(Addr); |
| break; |
| case DW_CFA_advance_loc1: |
| delta = (UInt)read_UChar(&instr[i]); i+= sizeof(UChar); |
| ctx->loc += delta; |
| break; |
| case DW_CFA_advance_loc2: |
| delta = (UInt)read_UShort(&instr[i]); i+= sizeof(UShort); |
| ctx->loc += delta; |
| break; |
| case DW_CFA_advance_loc4: |
| delta = (UInt)read_UInt(&instr[i]); i+= sizeof(UInt); |
| ctx->loc += delta; |
| break; |
| |
| case DW_CFA_def_cfa: |
| reg = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| off = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| if (reg < 0 || reg >= N_CFI_REGS) |
| return 0; /* fail */ |
| ctx->cfa_reg = reg; |
| ctx->cfa_offset = off; |
| break; |
| |
| case DW_CFA_register: |
| reg = read_leb128( &instr[i], &nleb, 0); |
| i += nleb; |
| reg2 = read_leb128( &instr[i], &nleb, 0); |
| i += nleb; |
| if (reg < 0 || reg >= N_CFI_REGS) |
| return 0; /* fail */ |
| if (reg2 < 0 || reg2 >= N_CFI_REGS) |
| return 0; /* fail */ |
| ctx->reg[reg].tag = RR_Reg; |
| ctx->reg[reg].reg = reg2; |
| break; |
| |
| case DW_CFA_offset_extended_sf: |
| reg = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| off = read_leb128( &instr[i], &nleb, 1 ); |
| i += nleb; |
| if (reg < 0 || reg >= N_CFI_REGS) |
| return 0; /* fail */ |
| ctx->reg[reg].tag = RR_CFAoff; |
| ctx->reg[reg].coff = off * ctx->data_a_f; |
| break; |
| |
| case DW_CFA_def_cfa_register: |
| reg = read_leb128( &instr[i], &nleb, 0); |
| i += nleb; |
| if (reg < 0 || reg >= N_CFI_REGS) |
| return 0; /* fail */ |
| ctx->cfa_reg = reg; |
| break; |
| |
| case DW_CFA_def_cfa_offset: |
| off = read_leb128( &instr[i], &nleb, 0); |
| i += nleb; |
| ctx->cfa_offset = off; |
| break; |
| |
| case DW_CFA_GNU_args_size: |
| /* No idea what is supposed to happen. gdb-6.3 simply |
| ignores these. */ |
| off = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| break; |
| |
| default: |
| VG_(message)(Vg_DebugMsg, "DWARF2 CFI reader: unhandled CFI " |
| "instruction 0:%d", (Int)lo6); |
| i = 0; |
| break; |
| } |
| |
| return i; |
| } |
| |
| |
| /* Show a CFI instruction, and also return its length. */ |
| |
| static Int show_CF_instruction ( UChar* instr ) |
| { |
| UInt delta; |
| Int off, reg, reg2, nleb; |
| Addr loc; |
| Int i = 0; |
| UChar hi2 = (instr[i] >> 6) & 3; |
| UChar lo6 = instr[i] & 0x3F; |
| i++; |
| |
| if (0) VG_(printf)("raw:%x/%x:%x:%x:%x:%x:%x:%x:%x:%x\n", |
| hi2, lo6, |
| instr[i+0], instr[i+1], instr[i+2], instr[i+3], |
| instr[i+4], instr[i+5], instr[i+6], instr[i+7] ); |
| |
| if (hi2 == DW_CFA_advance_loc) { |
| VG_(printf)("DW_CFA_advance_loc(%d)\n", (Int)lo6); |
| return i; |
| } |
| |
| if (hi2 == DW_CFA_offset) { |
| off = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| VG_(printf)("DW_CFA_offset(r%d + %d x data_af)\n", (Int)lo6, off); |
| return i; |
| } |
| |
| if (hi2 == DW_CFA_restore) { |
| VG_(printf)("DW_CFA_restore(%d)\n", (Int)lo6); |
| return i; |
| } |
| |
| vg_assert(hi2 == DW_CFA_use_secondary); |
| |
| switch (lo6) { |
| |
| case DW_CFA_nop: |
| VG_(printf)("DW_CFA_nop\n"); |
| break; |
| |
| case DW_CFA_set_loc: |
| loc = read_Addr(&instr[i]); i+= sizeof(Addr); |
| VG_(printf)("DW_CFA_set_loc(%p)\n", loc); |
| break; |
| |
| case DW_CFA_advance_loc1: |
| delta = (UInt)read_UChar(&instr[i]); i+= sizeof(UChar); |
| VG_(printf)("DW_CFA_advance_loc1(%d)\n", delta); |
| break; |
| |
| case DW_CFA_advance_loc2: |
| delta = (UInt)read_UShort(&instr[i]); i+= sizeof(UShort); |
| VG_(printf)("DW_CFA_advance_loc2(%d)\n", delta); |
| break; |
| |
| case DW_CFA_advance_loc4: |
| delta = (UInt)read_UInt(&instr[i]); i+= sizeof(UInt); |
| VG_(printf)("DW_CFA_advance_loc4(%d)\n", delta); |
| break; |
| |
| case DW_CFA_def_cfa: |
| reg = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| off = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| VG_(printf)("DW_CFA_def_cfa(r%d, off %d)\n", reg, off); |
| break; |
| |
| case DW_CFA_register: |
| reg = read_leb128( &instr[i], &nleb, 0); |
| i += nleb; |
| reg2 = read_leb128( &instr[i], &nleb, 0); |
| i += nleb; |
| VG_(printf)("DW_CFA_register(r%d, r%d)\n", reg, reg2); |
| break; |
| |
| case DW_CFA_def_cfa_register: |
| reg = read_leb128( &instr[i], &nleb, 0); |
| i += nleb; |
| VG_(printf)("DW_CFA_def_cfa_register(r%d)\n", reg); |
| break; |
| |
| case DW_CFA_def_cfa_offset: |
| off = read_leb128( &instr[i], &nleb, 0); |
| i += nleb; |
| VG_(printf)("DW_CFA_def_cfa_offset(%d)\n", off); |
| break; |
| |
| case DW_CFA_GNU_args_size: |
| off = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| VG_(printf)("DW_CFA_GNU_args_size(%d)\n", off ); |
| break; |
| |
| default: |
| VG_(printf)("0:%d\n", (Int)lo6); |
| break; |
| } |
| |
| return i; |
| } |
| |
| |
| static void show_CF_instructions ( UChar* instrs, Int ilen ) |
| { |
| Int i = 0; |
| while (True) { |
| if (i >= ilen) break; |
| i += show_CF_instruction( &instrs[i] ); |
| } |
| } |
| |
| /* Run the CF instructions in instrs[0 .. ilen-1], until the end is |
| reached, or until there is a failure. Return True iff success. |
| */ |
| static |
| Bool run_CF_instructions ( SegInfo* si, |
| UnwindContext* ctx, UChar* instrs, Int ilen, |
| UWord fde_arange, |
| UnwindContext* restore_ctx ) |
| { |
| CfiSI cfisi; |
| Bool summ_ok; |
| Int j, i = 0; |
| Addr loc_prev; |
| if (0) ppUnwindContext(ctx); |
| if (0) ppUnwindContext_summary(ctx); |
| while (True) { |
| loc_prev = ctx->loc; |
| if (i >= ilen) break; |
| if (0) (void)show_CF_instruction( &instrs[i] ); |
| j = run_CF_instruction( ctx, &instrs[i], restore_ctx ); |
| if (j == 0) |
| return False; /* execution failed */ |
| i += j; |
| if (0) ppUnwindContext(ctx); |
| if (loc_prev != ctx->loc && si) { |
| summ_ok = summarise_context ( &cfisi, loc_prev, ctx ); |
| if (summ_ok) { |
| VG_(addCfiSI)(si, &cfisi); |
| if (VG_(clo_trace_cfi)) |
| VG_(ppCfiSI)(&cfisi); |
| } |
| } |
| } |
| if (ctx->loc < fde_arange) { |
| loc_prev = ctx->loc; |
| ctx->loc = fde_arange; |
| if (si) { |
| summ_ok = summarise_context ( &cfisi, loc_prev, ctx ); |
| if (summ_ok) { |
| VG_(addCfiSI)(si, &cfisi); |
| if (VG_(clo_trace_cfi)) |
| VG_(ppCfiSI)(&cfisi); |
| } |
| } |
| } |
| return True; |
| } |
| |
| |
| /* ------------ Main entry point for CFI reading ------------ */ |
| |
| void VG_(read_callframe_info_dwarf2) |
| ( /*OUT*/SegInfo* si, |
| UChar* ehframe, Int ehframe_sz, Addr ehframe_addr ) |
| { |
| UnwindContext ctx, restore_ctx; |
| Int nbytes; |
| HChar* how = NULL; |
| Int cie_codeaf = 0; |
| Int cie_dataaf = 0; |
| Bool ok; |
| |
| UChar* current_cie = NULL; |
| UChar* data = ehframe; |
| |
| UChar* cie_instrs = NULL; |
| Int cie_ilen = 0; |
| Bool saw_z_augmentation = False; |
| UChar address_encoding = default_Addr_encoding(); |
| |
| if (VG_(clo_trace_cfi)) { |
| VG_(printf)("\n-----------------------------------------------\n"); |
| VG_(printf)("CFI info: ehframe %p, ehframe_sz %d\n", |
| ehframe, ehframe_sz ); |
| VG_(printf)("CFI info: name %s\n", |
| si->filename ); |
| } |
| |
| /* Loop over CIEs/FDEs */ |
| |
| while (True) { |
| |
| /* Are we done? */ |
| if (data == ehframe + ehframe_sz) |
| return; |
| |
| /* Overshot the end? Means something is wrong */ |
| if (data > ehframe + ehframe_sz) { |
| how = "overran the end of .eh_frame"; |
| goto bad; |
| } |
| |
| /* Ok, we must be looking at the start of a new CIE or FDE. |
| Figure out which it is. */ |
| |
| UChar* ciefde_start = data; |
| if (VG_(clo_trace_cfi)) |
| VG_(printf)("\ncie/fde.start = %p (ehframe + 0x%x)\n", |
| ciefde_start, ciefde_start - ehframe); |
| |
| UInt ciefde_len = read_UInt(data); data += sizeof(UInt); |
| if (VG_(clo_trace_cfi)) |
| VG_(printf)("cie/fde.length = %d\n", ciefde_len); |
| |
| /* Apparently, if the .length field is zero, we are at the end |
| of the sequence. ?? Neither the DWARF2 spec not the AMD64 |
| ABI spec say this, though. */ |
| if (ciefde_len == 0) { |
| if (data == ehframe + ehframe_sz) |
| return; |
| how = "zero-sized CIE/FDE but not at section end\n"; |
| goto bad; |
| } |
| |
| UInt cie_pointer = read_UInt(data); data += sizeof(UInt); |
| if (VG_(clo_trace_cfi)) |
| VG_(printf)("cie.pointer = %d\n", cie_pointer); |
| |
| /* If cie_pointer is zero, we've got a CIE; else it's an FDE. */ |
| if (cie_pointer == 0) { |
| |
| /* Remember the start proper of the current CIE */ |
| current_cie = ciefde_start + sizeof(UInt); |
| |
| /* --------- CIE --------- */ |
| if (VG_(clo_trace_cfi)) |
| VG_(printf)("------ new CIE ------\n"); |
| |
| UChar cie_version = read_UChar(data); data += sizeof(UChar); |
| if (VG_(clo_trace_cfi)) |
| VG_(printf)("cie.version = %d\n", (Int)cie_version); |
| if (cie_version != 1) { |
| how = "unexpected CIE version (not 1)"; |
| goto bad; |
| } |
| |
| UChar* cie_augmentation = data; |
| data += 1 + VG_(strlen)(cie_augmentation); |
| if (VG_(clo_trace_cfi)) |
| VG_(printf)("cie.augment = \"%s\"\n", cie_augmentation); |
| |
| if (cie_augmentation[0] == 'e' && cie_augmentation[1] == 'h') { |
| data += sizeof(Addr); |
| cie_augmentation += 2; |
| } |
| |
| cie_codeaf = read_leb128( data, &nbytes, 0); |
| data += nbytes; |
| if (VG_(clo_trace_cfi)) |
| VG_(printf)("cie.code_af = %d\n", cie_codeaf); |
| |
| cie_dataaf = read_leb128( data, &nbytes, 1); |
| data += nbytes; |
| if (VG_(clo_trace_cfi)) |
| VG_(printf)("cie.data_af = %d\n", cie_dataaf); |
| |
| UChar cie_rareg = read_UChar(data); data += sizeof(UChar); |
| if (VG_(clo_trace_cfi)) |
| VG_(printf)("cie.ra_reg = %d\n", (Int)cie_rareg); |
| if (cie_rareg != RA_COL) { |
| how = "cie.ra_reg does not match RA_COL"; |
| goto bad; |
| } |
| |
| saw_z_augmentation = *cie_augmentation == 'z'; |
| if (saw_z_augmentation) { |
| UInt length = read_leb128( data, &nbytes, 0); |
| data += nbytes; |
| cie_instrs = data + length; |
| cie_augmentation++; |
| } else { |
| cie_instrs = NULL; |
| } |
| |
| address_encoding = default_Addr_encoding(); |
| |
| while (*cie_augmentation) { |
| switch (*cie_augmentation) { |
| case 'L': |
| data++; |
| cie_augmentation++; |
| break; |
| case 'R': |
| address_encoding = read_UChar(data); data += sizeof(UChar); |
| cie_augmentation++; |
| break; |
| case 'P': |
| data += size_of_encoded_Addr( read_UChar(data) ); |
| data++; |
| cie_augmentation++; |
| break; |
| default: |
| if (cie_instrs == NULL) { |
| how = "unhandled cie.augmentation"; |
| goto bad; |
| } |
| data = cie_instrs; |
| goto done_augmentation; |
| } |
| } |
| |
| done_augmentation: |
| |
| if (VG_(clo_trace_cfi)) |
| VG_(printf)("cie.encoding = 0x%x\n", address_encoding); |
| |
| cie_instrs = data; |
| cie_ilen = ciefde_start + ciefde_len + sizeof(UInt) - data; |
| if (VG_(clo_trace_cfi)) { |
| VG_(printf)("cie.instrs = %p\n", cie_instrs); |
| VG_(printf)("cie.ilen = %d\n", (Int)cie_ilen); |
| } |
| |
| if (cie_ilen < 0 || cie_ilen > ehframe_sz) { |
| how = "implausible # cie initial insns"; |
| goto bad; |
| } |
| |
| data += cie_ilen; |
| |
| if (VG_(clo_trace_cfi)) |
| show_CF_instructions(cie_instrs, cie_ilen); |
| |
| } else { |
| |
| /* --------- FDE --------- */ |
| |
| /* Ensure that (1) we have a valid CIE, and (2) that it is |
| indeed the CIE referred to by this FDE. */ |
| if (current_cie == NULL) { |
| how = "FDE with no preceding CIE"; |
| goto bad; |
| } |
| if (cie_pointer != data - current_cie) { |
| how = "FDE does not refer to preceding CIE"; |
| goto bad; |
| } |
| |
| Addr fde_initloc |
| = read_encoded_Addr(data, address_encoding, |
| &nbytes, ehframe, ehframe_addr); |
| data += nbytes; |
| if (VG_(clo_trace_cfi)) |
| VG_(printf)("fde.initloc = %p\n", (void*)fde_initloc); |
| |
| UWord fde_arange |
| = read_encoded_Addr(data, address_encoding & 0xf, |
| &nbytes, ehframe, ehframe_addr); |
| data += nbytes; |
| if (VG_(clo_trace_cfi)) |
| VG_(printf)("fde.arangec = %p\n", (void*)fde_arange); |
| |
| if (saw_z_augmentation) { |
| data += read_leb128( data, &nbytes, 0); |
| data += nbytes; |
| } |
| |
| UChar* fde_instrs = data; |
| Int fde_ilen = ciefde_start + ciefde_len + sizeof(UInt) - data; |
| if (VG_(clo_trace_cfi)) { |
| VG_(printf)("fde.instrs = %p\n", fde_instrs); |
| VG_(printf)("fde.ilen = %d\n", (Int)fde_ilen); |
| } |
| |
| if (fde_ilen < 0 || fde_ilen > ehframe_sz) { |
| how = "implausible # fde insns"; |
| goto bad; |
| } |
| |
| data += fde_ilen; |
| |
| if (VG_(clo_trace_cfi)) |
| show_CF_instructions(fde_instrs, fde_ilen); |
| |
| initUnwindContext(&ctx); |
| ctx.code_a_f = cie_codeaf; |
| ctx.data_a_f = cie_dataaf; |
| ctx.initloc = fde_initloc; |
| |
| initUnwindContext(&restore_ctx); |
| |
| ok = run_CF_instructions( |
| NULL, &ctx, cie_instrs, cie_ilen, 0, NULL); |
| if (ok) { |
| restore_ctx = ctx; |
| ok = run_CF_instructions( |
| si, &ctx, fde_instrs, fde_ilen, fde_arange, |
| &restore_ctx); |
| } |
| } |
| } |
| |
| return; |
| |
| bad: |
| VG_(message)(Vg_UserMsg, "Warning: %s in DWARF2 CFI reading", how); |
| return; |
| } |
| |
| |
| /*--------------------------------------------------------------------*/ |
| /*--- end vg_dwarf.c ---*/ |
| /*--------------------------------------------------------------------*/ |