| |
| /*--------------------------------------------------------------------*/ |
| /*--- Read DWARF1/2/3 debug info. readdwarf.c ---*/ |
| /*--------------------------------------------------------------------*/ |
| |
| /* |
| This file is part of Valgrind, a dynamic binary instrumentation |
| framework. |
| |
| Copyright (C) 2000-2008 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. |
| */ |
| /* |
| Stabs reader greatly improved by Nick Nethercote, Apr 02. |
| This module was also extensively hacked on by Jeremy Fitzhardinge |
| and Tom Hughes. |
| */ |
| |
| #include "pub_core_basics.h" |
| #include "pub_core_libcbase.h" |
| #include "pub_core_libcassert.h" |
| #include "pub_core_libcprint.h" |
| #include "pub_core_options.h" |
| #include "pub_core_xarray.h" |
| #include "priv_misc.h" /* dinfo_zalloc/free/strdup */ |
| #include "priv_d3basics.h" |
| #include "priv_tytypes.h" |
| #include "priv_storage.h" |
| #include "priv_readdwarf.h" /* self */ |
| |
| |
| /*------------------------------------------------------------*/ |
| /*--- ---*/ |
| /*--- Read line number and CFI info from DWARF1, DWARF2 ---*/ |
| /*--- and to some extent DWARF3 sections. ---*/ |
| /*--- ---*/ |
| /*------------------------------------------------------------*/ |
| |
| /*------------------------------------------------------------*/ |
| /*--- Expanding arrays of words, for holding file name and ---*/ |
| /*--- directory name arrays. ---*/ |
| /*------------------------------------------------------------*/ |
| |
| typedef |
| struct { |
| Word* tab; |
| UInt tab_size; |
| UInt tab_used; |
| } |
| WordArray; |
| |
| static void init_WordArray ( WordArray* wa ) |
| { |
| wa->tab = NULL; |
| wa->tab_size = 0; |
| wa->tab_used = 0; |
| } |
| |
| static void free_WordArray ( WordArray* wa ) |
| { |
| if (wa->tab) { |
| vg_assert(wa->tab_size > 0); |
| ML_(dinfo_free)(wa->tab); |
| } |
| init_WordArray(wa); |
| } |
| |
| static void addto_WordArray ( WordArray* wa, Word w ) |
| { |
| UInt new_size, i; |
| Word* new_tab; |
| |
| if (0) VG_(printf)("<<ADD %p (new sz = %d) >>\n", |
| (HChar*)w, wa->tab_used+1); |
| |
| if (wa->tab_used < wa->tab_size) { |
| /* fine */ |
| } else { |
| /* expand array */ |
| if (0) VG_(printf)("EXPAND ARRAY from %d\n", wa->tab_size); |
| vg_assert(wa->tab_used == wa->tab_size); |
| vg_assert( (wa->tab_size == 0 && wa->tab == NULL) |
| || (wa->tab_size != 0 && wa->tab != NULL) ); |
| new_size = wa->tab_size == 0 ? 8 : 2 * wa->tab_size; |
| new_tab = ML_(dinfo_zalloc)("di.aWA.1", new_size * sizeof(Word)); |
| vg_assert(new_tab != NULL); |
| for (i = 0; i < wa->tab_used; i++) |
| new_tab[i] = wa->tab[i]; |
| wa->tab_size = new_size; |
| if (wa->tab) |
| ML_(dinfo_free)(wa->tab); |
| wa->tab = new_tab; |
| } |
| |
| vg_assert(wa->tab_used < wa->tab_size); |
| vg_assert(wa->tab_size > 0); |
| wa->tab[wa->tab_used] = w; |
| wa->tab_used++; |
| } |
| |
| static Word index_WordArray ( /*OUT*/Bool* inRange, WordArray* wa, Int i ) |
| { |
| vg_assert(inRange); |
| if (i >= 0 && i < wa->tab_used) { |
| *inRange = True; |
| return wa->tab[i]; |
| } else { |
| *inRange = False; |
| return 0; |
| } |
| } |
| |
| |
| /*------------------------------------------------------------*/ |
| /*--- Read DWARF2 format line number info. ---*/ |
| /*------------------------------------------------------------*/ |
| |
| /* Structure holding info extracted from the a .debug_line |
| section. */ |
| typedef struct |
| { |
| ULong li_length; |
| UShort li_version; |
| ULong li_header_length; |
| UChar li_min_insn_length; |
| UChar li_default_is_stmt; |
| Int li_line_base; |
| UChar li_line_range; |
| UChar li_opcode_base; |
| } |
| DebugLineInfo; |
| |
| /* Structure holding additional infos found from a .debug_info |
| * compilation unit block */ |
| typedef struct |
| { |
| /* Feel free to add more members here if you need ! */ |
| Char* compdir; /* Compilation directory - points to .debug_info */ |
| Char* name; /* Main file name - points to .debug_info */ |
| ULong stmt_list; /* Offset in .debug_line */ |
| Bool dw64; /* 64-bit Dwarf? */ |
| } |
| UnitInfo; |
| |
| /* 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 |
| { |
| /* 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; |
| } LineSMR; |
| |
| |
| /* FIXME: duplicated in readdwarf3.c */ |
| static |
| ULong read_leb128 ( UChar* data, Int* length_return, Int sign ) |
| { |
| ULong result = 0; |
| UInt num_read = 0; |
| Int shift = 0; |
| UChar byte; |
| |
| vg_assert(sign == 0 || sign == 1); |
| |
| do |
| { |
| byte = * data ++; |
| num_read ++; |
| |
| result |= ((ULong)(byte & 0x7f)) << shift; |
| |
| shift += 7; |
| |
| } |
| while (byte & 0x80); |
| |
| if (length_return != NULL) |
| * length_return = num_read; |
| |
| if (sign && (shift < 64) && (byte & 0x40)) |
| result |= -(1ULL << shift); |
| |
| return result; |
| } |
| |
| /* Small helper functions easier to use |
| * value is returned and the given pointer is |
| * moved past end of leb128 data */ |
| /* FIXME: duplicated in readdwarf3.c */ |
| static ULong read_leb128U( UChar **data ) |
| { |
| Int len; |
| ULong val = read_leb128( *data, &len, 0 ); |
| *data += len; |
| return val; |
| } |
| |
| /* Same for signed data */ |
| /* FIXME: duplicated in readdwarf3.c */ |
| static Long read_leb128S( UChar **data ) |
| { |
| Int len; |
| ULong val = read_leb128( *data, &len, 1 ); |
| *data += len; |
| return (Long)val; |
| } |
| |
| /* Read what the DWARF3 spec calls an "initial length field". This |
| uses up either 4 or 12 bytes of the input and produces a 32-bit or |
| 64-bit number respectively. |
| |
| Read 32-bit value from p. If it is 0xFFFFFFFF, instead read a |
| 64-bit bit value from p+4. This is used in 64-bit dwarf to encode |
| some table lengths. |
| |
| XXX this is a hack: the endianness of the initial length field is |
| specified by the DWARF we're reading. This happens to work only |
| because we don't do cross-arch jitting, hence this code runs on a |
| platform of the same endianness as the DWARF it is reading. Same |
| applies for initial lengths for CIE/FDEs and probably in zillions |
| of other places -- to be precise, exactly the places where |
| binutils/dwarf.c calls byte_get(). |
| */ |
| static ULong read_initial_length_field ( UChar* p_img, /*OUT*/Bool* is64 ) |
| { |
| UInt w32 = *((UInt*)p_img); |
| if (w32 == 0xFFFFFFFF) { |
| *is64 = True; |
| return *((ULong*)(p_img+4)); |
| } else { |
| *is64 = False; |
| return (ULong)w32; |
| } |
| } |
| |
| |
| static LineSMR state_machine_regs; |
| |
| static |
| void reset_state_machine ( Int is_stmt ) |
| { |
| if (0) VG_(printf)("smr.a := %p (reset)\n", NULL ); |
| 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; |
| } |
| |
| /* Look up a directory name, or return NULL if unknown. */ |
| static |
| Char* lookupDir ( Int filename_index, |
| WordArray* fnidx2dir, |
| WordArray* dirnames ) |
| { |
| Bool inRange; |
| Word diridx, dirname; |
| |
| diridx = index_WordArray( &inRange, fnidx2dir, filename_index ); |
| if (!inRange) goto bad; |
| |
| dirname = index_WordArray( &inRange, dirnames, (Int)diridx ); |
| if (!inRange) goto bad; |
| |
| return (Char*)dirname; |
| bad: |
| return NULL; |
| } |
| |
| //////////////////////////////////////////////////////////////////// |
| //////////////////////////////////////////////////////////////////// |
| |
| /* Handled an extended line op starting at 'data'. Returns the number |
| of bytes that 'data' should be advanced by. */ |
| static |
| Word process_extended_line_op( struct _DebugInfo* di, |
| WordArray* filenames, |
| WordArray* dirnames, |
| WordArray* fnidx2dir, |
| 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, |
| "Warning: DWARF2 reader: " |
| "Badly formed extended line op encountered"); |
| return (Word)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 %#lx, smr.a %#lx\n", |
| di->text_bias, state_machine_regs.address ); |
| /* JRS: added for compliance with spec; is pointless due to |
| reset_state_machine below */ |
| state_machine_regs.end_sequence = 1; |
| |
| if (state_machine_regs.is_stmt) { |
| if (state_machine_regs.last_address) { |
| Bool inRange = False; |
| Char* filename |
| = (Char*)index_WordArray( &inRange, filenames, |
| state_machine_regs.last_file); |
| if (!inRange || !filename) |
| filename = "???"; |
| ML_(addLineInfo) ( |
| di, |
| filename, |
| lookupDir( state_machine_regs.last_file, |
| fnidx2dir, dirnames ), |
| di->text_bias + state_machine_regs.last_address, |
| di->text_bias + state_machine_regs.address, |
| state_machine_regs.last_line, 0 |
| ); |
| } |
| } |
| reset_state_machine (is_stmt); |
| if (di->ddump_line) |
| VG_(printf)(" Extended opcode %d: End of Sequence\n\n", |
| (Int)op_code); |
| break; |
| |
| case DW_LNE_set_address: |
| adr = *((Addr *)data); |
| state_machine_regs.address = adr; |
| if (di->ddump_line) |
| VG_(printf)(" Extended opcode %d: set Address to 0x%lx\n", |
| (Int)op_code, (Addr)adr); |
| break; |
| |
| case DW_LNE_define_file: |
| name = data; |
| addto_WordArray( filenames, (Word)ML_(addStr)(di,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); |
| if (di->ddump_line) |
| VG_(printf)(" DWARF2-line: set_address\n"); |
| break; |
| |
| default: |
| if (di->ddump_line) |
| VG_(printf)("process_extended_line_op:default\n"); |
| break; |
| } |
| |
| return (Word)len; |
| } |
| |
| //////////////////////////////////////////////////////////////////// |
| //////////////////////////////////////////////////////////////////// |
| |
| /* read a .debug_line section block for a compilation unit |
| * |
| * Input: - theBlock must point to the start of the block |
| * for the given compilation unit |
| * - ui contains additional info like the compilation dir |
| * for this unit |
| * |
| * Output: - si debug info structures get updated |
| */ |
| static |
| void read_dwarf2_lineblock ( struct _DebugInfo* di, |
| UnitInfo* ui, |
| UChar* theBlock, /* IMAGE */ |
| Int noLargerThan ) |
| { |
| Int i; |
| DebugLineInfo info; |
| UChar* standard_opcodes; |
| UChar* end_of_sequence; |
| Bool is64; |
| WordArray filenames; |
| WordArray dirnames; |
| WordArray fnidx2dir; |
| |
| UChar* external = theBlock; |
| UChar* data = theBlock; |
| |
| /* filenames is an array of file names harvested from the DWARF2 |
| info. Entry [0] is NULL and is never referred to by the state |
| machine. |
| |
| Similarly, dirnames is an array of directory names. Entry [0] |
| is also NULL and denotes "we don't know what the path is", since |
| that is different from "the path is the empty string". Unlike |
| the file name table, the state machine does refer to entry [0], |
| which basically means "." ("the current directory of the |
| compilation", whatever that means, according to the DWARF3 |
| spec.) |
| |
| fnidx2dir is an array of indexes into the dirnames table. |
| (confused yet?) filenames[] and fnidx2dir[] are indexed |
| together. That is, for some index i in the filename table, then |
| |
| the filename is filenames[i] |
| the directory is dirnames[ fnidx2dir[i] ] */ |
| |
| /* Fails due to gcc padding ... |
| vg_assert(sizeof(DWARF2_External_LineInfo) |
| == sizeof(DWARF2_Internal_LineInfo)); |
| */ |
| |
| init_WordArray(&filenames); |
| init_WordArray(&dirnames); |
| init_WordArray(&fnidx2dir); |
| |
| /* DWARF2 starts numbering filename entries at 1, so we need to |
| add a dummy zeroth entry to the table. The zeroth dirnames |
| entry denotes 'current directory of compilation' so we might |
| as well make the fnidx2dir zeroth entry denote that. |
| */ |
| addto_WordArray( &filenames, (Word)NULL ); |
| |
| if (ui->compdir) |
| addto_WordArray( &dirnames, (Word)ML_(addStr)(di, ui->compdir, -1) ); |
| else |
| addto_WordArray( &dirnames, (Word)ML_(addStr)(di, ".", -1) ); |
| |
| addto_WordArray( &fnidx2dir, (Word)0 ); /* compilation dir */ |
| |
| info.li_length = read_initial_length_field( external, &is64 ); |
| external += is64 ? 12 : 4; |
| if (di->ddump_line) |
| VG_(printf)(" Length: %llu\n", |
| info.li_length); |
| |
| /* Check the length of the block. */ |
| if (info.li_length > noLargerThan) { |
| ML_(symerr)(di, True, |
| "DWARF line info appears to be corrupt " |
| "- the section is too small"); |
| goto out; |
| } |
| |
| /* Check its version number. */ |
| info.li_version = * ((UShort *)external); |
| external += 2; |
| if (di->ddump_line) |
| VG_(printf)(" DWARF Version: %d\n", |
| (Int)info.li_version); |
| |
| if (info.li_version != 2) { |
| ML_(symerr)(di, True, |
| "Only DWARF version 2 line info " |
| "is currently supported."); |
| goto out; |
| } |
| |
| info.li_header_length = ui->dw64 ? *((ULong*)external) |
| : (ULong)(*((UInt*)external)); |
| external += ui->dw64 ? 8 : 4; |
| if (di->ddump_line) |
| VG_(printf)(" Prologue Length: %llu\n", |
| info.li_header_length); |
| |
| info.li_min_insn_length = * ((UChar *)external); |
| external += 1; |
| if (di->ddump_line) |
| VG_(printf)(" Minimum Instruction Length: %d\n", |
| (Int)info.li_min_insn_length); |
| |
| info.li_default_is_stmt = * ((UChar *)external); |
| external += 1; |
| if (di->ddump_line) |
| VG_(printf)(" Initial value of 'is_stmt': %d\n", |
| (Int)info.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. |
| |
| Therefore: */ |
| info.li_default_is_stmt = True; |
| |
| /* JRS: changed (UInt*) to (UChar*) */ |
| info.li_line_base = * ((UChar *)external); |
| info.li_line_base = (Int)(signed char)info.li_line_base; |
| external += 1; |
| if (di->ddump_line) |
| VG_(printf)(" Line Base: %d\n", |
| info.li_line_base); |
| |
| info.li_line_range = * ((UChar *)external); |
| external += 1; |
| if (di->ddump_line) |
| VG_(printf)(" Line Range: %d\n", |
| (Int)info.li_line_range); |
| |
| info.li_opcode_base = * ((UChar *)external); |
| external += 1; |
| if (di->ddump_line) |
| VG_(printf)(" Opcode Base: %d\n\n", |
| info.li_opcode_base); |
| |
| if (0) VG_(printf)("dwarf2: line base: %d, range %d, opc base: %d\n", |
| (Int)info.li_line_base, |
| (Int)info.li_line_range, |
| (Int)info.li_opcode_base); |
| |
| end_of_sequence = data + info.li_length |
| + (is64 ? 12 : 4); |
| |
| reset_state_machine (info.li_default_is_stmt); |
| |
| /* Read the contents of the Opcodes table. */ |
| standard_opcodes = external; |
| if (di->ddump_line) { |
| VG_(printf)(" Opcodes:\n"); |
| for (i = 1; i < (Int)info.li_opcode_base; i++) { |
| VG_(printf)(" Opcode %d has %d args\n", |
| i, (Int)standard_opcodes[i-1]); |
| } |
| VG_(printf)("\n"); |
| } |
| |
| /* Read the contents of the Directory table. */ |
| data = standard_opcodes + info.li_opcode_base - 1; |
| |
| if (di->ddump_line) |
| VG_(printf)(" The Directory Table%s\n", |
| *data == 0 ? " is empty." : ":" ); |
| |
| while (* data != 0) { |
| |
| # define NBUF 4096 |
| static Char buf[NBUF]; |
| |
| if (di->ddump_line) |
| VG_(printf)(" %s\n", data); |
| |
| /* If data[0] is '/', then 'data' is an absolute path and we |
| don't mess with it. Otherwise, if we can, construct the |
| 'path ui->compdir' ++ "/" ++ 'data'. */ |
| |
| if (*data != '/' |
| /* not an absolute path */ |
| && ui->compdir != NULL |
| /* actually got something sensible for compdir */ |
| && VG_(strlen)(ui->compdir) + VG_(strlen)(data) + 5/*paranoia*/ < NBUF |
| /* it's short enough to concatenate */) |
| { |
| buf[0] = 0; |
| VG_(strcat)(buf, ui->compdir); |
| VG_(strcat)(buf, "/"); |
| VG_(strcat)(buf, data); |
| vg_assert(VG_(strlen)(buf) < NBUF); |
| addto_WordArray( &dirnames, (Word)ML_(addStr)(di,buf,-1) ); |
| if (0) VG_(printf)("rel path %s\n", buf); |
| } else { |
| /* just use 'data'. */ |
| addto_WordArray( &dirnames, (Word)ML_(addStr)(di,data,-1) ); |
| if (0) VG_(printf)("abs path %s\n", data); |
| } |
| |
| data += VG_(strlen)(data) + 1; |
| |
| # undef NBUF |
| } |
| |
| if (di->ddump_line) |
| VG_(printf)("\n"); |
| |
| if (*data != 0) { |
| ML_(symerr)(di, True, |
| "can't find NUL at end of DWARF2 directory table"); |
| goto out; |
| } |
| data ++; |
| |
| /* Read the contents of the File Name table. This produces a bunch |
| of file names, and for each, an index to the corresponding |
| directory name entry. */ |
| if (di->ddump_line) { |
| VG_(printf)(" The File Name Table:\n"); |
| VG_(printf)(" Entry Dir Time Size Name\n"); |
| } |
| |
| i = 1; |
| while (* data != 0) { |
| UChar* name; |
| Int bytes_read, diridx; |
| Int uu_time, uu_size; /* unused, and a guess */ |
| name = data; |
| data += VG_(strlen) ((Char *) data) + 1; |
| |
| diridx = read_leb128 (data, & bytes_read, 0); |
| data += bytes_read; |
| uu_time = read_leb128 (data, & bytes_read, 0); |
| data += bytes_read; |
| uu_size = read_leb128 (data, & bytes_read, 0); |
| data += bytes_read; |
| |
| addto_WordArray( &filenames, (Word)ML_(addStr)(di,name,-1) ); |
| addto_WordArray( &fnidx2dir, (Word)diridx ); |
| if (0) VG_(printf)("file %s diridx %d\n", name, diridx ); |
| if (di->ddump_line) |
| VG_(printf)(" %d\t%d\t%d\t%d\t%s\n", |
| i, diridx, uu_time, uu_size, name); |
| i++; |
| } |
| |
| if (di->ddump_line) |
| VG_(printf)("\n"); |
| |
| if (*data != 0) { |
| ML_(symerr)(di, True, |
| "can't find NUL at end of DWARF2 file name table"); |
| goto out; |
| } |
| data ++; |
| |
| if (di->ddump_line) |
| VG_(printf)(" Line Number Statements:\n"); |
| |
| /* 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 += %#x\n", adv ); |
| adv = (op_code % info.li_line_range) + info.li_line_base; |
| if (0) VG_(printf)("1002: di->o %#lx, smr.a %#lx\n", |
| di->text_bias, state_machine_regs.address ); |
| state_machine_regs.line += adv; |
| |
| if (di->ddump_line) |
| VG_(printf)(" Special opcode %d: advance Address by %d " |
| "to 0x%lx and Line by %d to %d\n", |
| (Int)op_code, advAddr, state_machine_regs.address, |
| (Int)adv, (Int)state_machine_regs.line ); |
| |
| if (state_machine_regs.is_stmt) { |
| /* only add a statement if there was a previous boundary */ |
| if (state_machine_regs.last_address) { |
| Bool inRange = False; |
| Char* filename |
| = (Char*)index_WordArray( &inRange, &filenames, |
| state_machine_regs.last_file); |
| if (!inRange || !filename) |
| filename = "???"; |
| ML_(addLineInfo)( |
| di, |
| filename, |
| lookupDir( state_machine_regs.last_file, |
| &fnidx2dir, &dirnames ), |
| di->text_bias + state_machine_regs.last_address, |
| di->text_bias + 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 { /* ! (op_code >= info.li_opcode_base) */ |
| |
| switch (op_code) { |
| case DW_LNS_extended_op: |
| data += process_extended_line_op ( |
| di, &filenames, &dirnames, &fnidx2dir, |
| data, info.li_default_is_stmt); |
| break; |
| |
| case DW_LNS_copy: |
| if (0) VG_(printf)("1002: di->o %#lx, smr.a %#lx\n", |
| di->text_bias, 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) { |
| Bool inRange = False; |
| Char* filename |
| = (Char*)index_WordArray( &inRange, &filenames, |
| state_machine_regs.last_file ); |
| if (!inRange || !filename) |
| filename = "???"; |
| ML_(addLineInfo)( |
| di, |
| filename, |
| lookupDir( state_machine_regs.last_file, |
| &fnidx2dir, &dirnames ), |
| di->text_bias + state_machine_regs.last_address, |
| di->text_bias + 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 */ |
| if (di->ddump_line) |
| VG_(printf)(" Copy\n"); |
| 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 += %#x\n", adv ); |
| if (di->ddump_line) |
| VG_(printf)(" Advance PC by %d to 0x%lx\n", |
| (Int)adv, state_machine_regs.address); |
| break; |
| |
| case DW_LNS_advance_line: |
| adv = read_leb128 (data, & bytes_read, 1); |
| data += bytes_read; |
| state_machine_regs.line += adv; |
| if (di->ddump_line) |
| VG_(printf)(" Advance Line by %d to %d\n", |
| (Int)adv, (Int)state_machine_regs.line); |
| break; |
| |
| case DW_LNS_set_file: |
| adv = read_leb128 (data, & bytes_read, 0); |
| data += bytes_read; |
| state_machine_regs.file = adv; |
| if (di->ddump_line) |
| VG_(printf)(" Set File Name to entry %d in the File Name Table\n", |
| (Int)adv); |
| break; |
| |
| case DW_LNS_set_column: |
| adv = read_leb128 (data, & bytes_read, 0); |
| data += bytes_read; |
| state_machine_regs.column = adv; |
| if (di->ddump_line) |
| VG_(printf)(" DWARF2-line: set_column\n"); |
| break; |
| |
| case DW_LNS_negate_stmt: |
| adv = state_machine_regs.is_stmt; |
| adv = ! adv; |
| state_machine_regs.is_stmt = adv; |
| if (di->ddump_line) |
| VG_(printf)(" DWARF2-line: negate_stmt\n"); |
| break; |
| |
| case DW_LNS_set_basic_block: |
| state_machine_regs.basic_block = 1; |
| if (di->ddump_line) |
| VG_(printf)(" DWARF2-line: set_basic_block\n"); |
| 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 += %#x\n", adv ); |
| if (di->ddump_line) |
| VG_(printf)(" Advance PC by constant %d to 0x%lx\n", |
| (Int)adv, (Addr)state_machine_regs.address); |
| 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 += %#x\n", adv ); |
| if (di->ddump_line) |
| VG_(printf)(" DWARF2-line: fixed_advance_pc\n"); |
| break; |
| |
| case DW_LNS_set_prologue_end: |
| if (di->ddump_line) |
| VG_(printf)(" DWARF2-line: set_prologue_end\n"); |
| break; |
| |
| case DW_LNS_set_epilogue_begin: |
| if (di->ddump_line) |
| VG_(printf)(" DWARF2-line: set_epilogue_begin\n"); |
| break; |
| |
| case DW_LNS_set_isa: |
| adv = read_leb128 (data, & bytes_read, 0); |
| data += bytes_read; |
| if (di->ddump_line) |
| VG_(printf)(" DWARF2-line: set_isa\n"); |
| break; |
| |
| default: { |
| Int j; |
| for (j = standard_opcodes[op_code - 1]; j > 0 ; --j) { |
| read_leb128 (data, &bytes_read, 0); |
| data += bytes_read; |
| } |
| if (di->ddump_line) |
| VG_(printf)(" Unknown opcode %d\n", (Int)op_code); |
| break; |
| } |
| } /* switch (op_code) */ |
| |
| } /* if (op_code >= info.li_opcode_base) */ |
| |
| } /* while (data < end_of_sequence) */ |
| |
| if (di->ddump_line) |
| VG_(printf)("\n"); |
| |
| out: |
| free_WordArray(&filenames); |
| free_WordArray(&dirnames); |
| free_WordArray(&fnidx2dir); |
| } |
| |
| //////////////////////////////////////////////////////////////////// |
| //////////////////////////////////////////////////////////////////// |
| |
| /* Return abbrev for given code |
| * Returned pointer points to the tag |
| * */ |
| static UChar* lookup_abbrev( UChar* p, UInt acode ) |
| { |
| UInt code; |
| UInt name; |
| for( ; ; ) { |
| code = read_leb128U( &p ); |
| if ( code == acode ) |
| return p; |
| read_leb128U( &p ); /* skip tag */ |
| p++; /* skip has_children flag */ |
| do { |
| name = read_leb128U( &p ); /* name */ |
| read_leb128U( &p ); /* form */ |
| } |
| while( name != 0 ); /* until name == form == 0 */ |
| } |
| return NULL; |
| } |
| |
| /* Read general information for a particular compile unit block in |
| * the .debug_info section. |
| * |
| * Input: - unitblock is the start of a compilation |
| * unit block in .debuginfo section |
| * - debugabbrev is start of .debug_abbrev section |
| * - debugstr is start of .debug_str section |
| * |
| * Output: Fill members of ui pertaining to the compilation unit: |
| * - ui->name is the name of the compilation unit |
| * - ui->compdir is the compilation unit directory |
| * - ui->stmt_list is the offset in .debug_line section |
| * for the dbginfos of this compilation unit |
| * |
| * Note : the output strings are not allocated and point |
| * directly to the memory-mapped section. |
| */ |
| static |
| void read_unitinfo_dwarf2( /*OUT*/UnitInfo* ui, |
| UChar* unitblock_img, |
| UChar* debugabbrev_img, |
| UChar* debugstr_img, |
| struct _DebugInfo* di ) |
| { |
| UInt acode, abcode; |
| ULong atoffs, blklen; |
| Int level; |
| UShort ver; |
| |
| UChar addr_size; |
| UChar* p = unitblock_img; |
| UChar* end_img; |
| UChar* abbrev_img; |
| |
| VG_(memset)( ui, 0, sizeof( UnitInfo ) ); |
| ui->stmt_list = -1LL; |
| |
| /* Read the compilation unit header in .debug_info section - See p 70 */ |
| |
| /* This block length */ |
| blklen = read_initial_length_field( p, &ui->dw64 ); |
| p += ui->dw64 ? 12 : 4; |
| |
| /* version should be 2 */ |
| ver = *((UShort*)p); |
| p += 2; |
| |
| /* get offset in abbrev */ |
| atoffs = ui->dw64 ? *((ULong*)p) : (ULong)(*((UInt*)p)); |
| p += ui->dw64 ? 8 : 4; |
| |
| /* Address size */ |
| addr_size = *p; |
| p += 1; |
| |
| end_img = unitblock_img |
| + blklen + (ui->dw64 ? 12 : 4); /* End of this block */ |
| level = 0; /* Level in the abbrev tree */ |
| abbrev_img = debugabbrev_img |
| + atoffs; /* Abbreviation data for this block */ |
| |
| /* Read the compilation unit entries */ |
| while ( p < end_img ) { |
| Bool has_child; |
| UInt tag; |
| |
| acode = read_leb128U( &p ); /* abbreviation code */ |
| if ( acode == 0 ) { |
| /* NULL entry used for padding - or last child for a sequence |
| - see para 7.5.3 */ |
| level--; |
| continue; |
| } |
| |
| /* Read abbreviation header */ |
| abcode = read_leb128U( &abbrev_img ); /* abbreviation code */ |
| if ( acode != abcode ) { |
| /* We are in in children list, and must rewind to a |
| * previously declared abbrev code. This code works but is |
| * not triggered since we shortcut the parsing once we have |
| * read the compile_unit block. This should only occur when |
| * level > 0 */ |
| abbrev_img = lookup_abbrev( debugabbrev_img + atoffs, acode ); |
| } |
| |
| tag = read_leb128U( &abbrev_img ); |
| has_child = *(abbrev_img++) == 1; /* DW_CHILDREN_yes */ |
| |
| if ( has_child ) |
| level++; |
| |
| /* And loop on entries */ |
| for ( ; ; ) { |
| /* Read entry definition */ |
| UInt name, form; |
| ULong cval = -1LL; /* Constant value read */ |
| Char *sval = NULL; /* String value read */ |
| name = read_leb128U( &abbrev_img ); |
| form = read_leb128U( &abbrev_img ); |
| if ( name == 0 ) |
| break; |
| |
| /* Read data */ |
| /* Attributes encoding explained p 71 */ |
| if ( form == 0x16 /* FORM_indirect */ ) |
| form = read_leb128U( &p ); |
| /* Decode form. For most kinds, Just skip the amount of data since |
| we don't use it for now */ |
| /* JRS 9 Feb 06: This now handles 64-bit DWARF too. In |
| 64-bit DWARF, lineptr (and loclistptr,macptr,rangelistptr |
| classes) use FORM_data8, not FORM_data4. Also, |
| FORM_ref_addr and FORM_strp are 64-bit values, not 32-bit |
| values. */ |
| switch( form ) { |
| /* Those cases extract the data properly */ |
| case 0x05: /* FORM_data2 */ cval = *((UShort*)p); p +=2; break; |
| case 0x06: /* FORM_data4 */ cval = *((UInt*)p);p +=4; break; |
| case 0x0e: /* FORM_strp */ /* pointer in .debug_str */ |
| /* 2006-01-01: only generate a value if |
| debugstr is non-NULL (which means that a |
| debug_str section was found) */ |
| if (debugstr_img && !ui->dw64) |
| sval = debugstr_img + *((UInt*)p); |
| if (debugstr_img && ui->dw64) |
| sval = debugstr_img + *((ULong*)p); |
| p += ui->dw64 ? 8 : 4; |
| break; |
| case 0x08: /* FORM_string */ sval = (Char*)p; |
| p += VG_(strlen)((Char*)p) + 1; break; |
| case 0x0b: /* FORM_data1 */ cval = *p; p++; break; |
| |
| /* TODO : Following ones just skip data - implement if you need */ |
| case 0x01: /* FORM_addr */ p += addr_size; break; |
| case 0x03: /* FORM_block2 */ p += *((UShort*)p) + 2; break; |
| case 0x04: /* FORM_block4 */ p += *((UInt*)p) + 4; break; |
| case 0x07: /* FORM_data8 */ if (ui->dw64) cval = *((ULong*)p); |
| p += 8; break; |
| /* perhaps should assign unconditionally to cval? */ |
| case 0x09: /* FORM_block */ p += read_leb128U( &p ); break; |
| case 0x0a: /* FORM_block1 */ p += *p + 1; break; |
| case 0x0c: /* FORM_flag */ p++; break; |
| case 0x0d: /* FORM_sdata */ read_leb128S( &p ); break; |
| case 0x0f: /* FORM_udata */ read_leb128U( &p ); break; |
| case 0x10: /* FORM_ref_addr */ p += ui->dw64 ? 8 : 4; break; |
| case 0x11: /* FORM_ref1 */ p++; break; |
| case 0x12: /* FORM_ref2 */ p += 2; break; |
| case 0x13: /* FORM_ref4 */ p += 4; break; |
| case 0x14: /* FORM_ref8 */ p += 8; break; |
| case 0x15: /* FORM_ref_udata */ read_leb128U( &p ); break; |
| |
| default: |
| VG_(printf)( "### unhandled dwarf2 abbrev form code 0x%x\n", form ); |
| break; |
| } |
| |
| /* Now store the members we need in the UnitInfo structure */ |
| if ( tag == 0x0011 /*TAG_compile_unit*/ ) { |
| if ( name == 0x03 ) ui->name = sval; /* DW_AT_name */ |
| else if ( name == 0x1b ) ui->compdir = sval; /* DW_AT_compdir */ |
| else if ( name == 0x10 ) ui->stmt_list = cval; /* DW_AT_stmt_list */ |
| } |
| } |
| /* Shortcut the parsing once we have read the compile_unit block |
| * That's enough info for us, and we are not gdb ! */ |
| if ( tag == 0x0011 /*TAG_compile_unit*/ ) |
| break; |
| } /* Loop on each sub block */ |
| |
| /* This test would be valid if we were not shortcutting the parsing |
| if (level != 0) |
| VG_(printf)( "#### Exiting debuginfo block at level %d !!!\n", level ); |
| */ |
| } |
| |
| |
| //////////////////////////////////////////////////////////////////// |
| //////////////////////////////////////////////////////////////////// |
| |
| /* Collect the debug info from DWARF3 debugging sections |
| * of a given module. |
| * |
| * Inputs: given .debug_xxx sections |
| * Output: update di to contain all the DWARF3 debug infos |
| */ |
| void ML_(read_debuginfo_dwarf3) |
| ( struct _DebugInfo* di, |
| UChar* debug_info_img, Word debug_info_sz, /* .debug_info */ |
| UChar* debug_abbv_img, Word debug_abbv_sz, /* .debug_abbrev */ |
| UChar* debug_line_img, Word debug_line_sz, /* .debug_line */ |
| UChar* debug_str_img, Word debug_str_sz ) /* .debug_str */ |
| { |
| UnitInfo ui; |
| UShort ver; |
| UChar* block_img; |
| UChar* end1_img; |
| ULong blklen; |
| Bool blklen_is_64; |
| Int blklen_len; |
| |
| end1_img = debug_info_img + debug_info_sz; |
| blklen_len = 0; |
| |
| /* Make sure we at least have a header for the first block */ |
| if (debug_info_sz < 4) { |
| ML_(symerr)( di, True, |
| "Last block truncated in .debug_info; ignoring" ); |
| return; |
| } |
| |
| /* Iterate on all the blocks we find in .debug_info */ |
| for ( block_img = debug_info_img; |
| block_img < end1_img - 4; |
| block_img += blklen + blklen_len ) { |
| |
| /* Read the compilation unit header in .debug_info section - See |
| p 70 */ |
| /* This block length */ |
| blklen = read_initial_length_field( block_img, &blklen_is_64 ); |
| blklen_len = blklen_is_64 ? 12 : 4; |
| if ( block_img + blklen + blklen_len > end1_img ) { |
| ML_(symerr)( di, True, |
| "Last block truncated in .debug_info; ignoring" ); |
| return; |
| } |
| |
| /* version should be 2 */ |
| ver = *((UShort*)( block_img + blklen_len )); |
| if ( ver != 2 ) { |
| ML_(symerr)( di, True, |
| "Ignoring non-dwarf2 block in .debug_info" ); |
| continue; |
| } |
| |
| /* Fill ui with offset in .debug_line and compdir */ |
| if (0) |
| VG_(printf)( "Reading UnitInfo at 0x%lx.....\n", |
| block_img - debug_info_img + 0UL ); |
| read_unitinfo_dwarf2( &ui, block_img, |
| debug_abbv_img, debug_str_img, di ); |
| if (0) |
| VG_(printf)( " => LINES=0x%llx NAME=%s DIR=%s\n", |
| ui.stmt_list, ui.name, ui.compdir ); |
| |
| /* Ignore blocks with no .debug_line associated block */ |
| if ( ui.stmt_list == -1LL ) |
| continue; |
| |
| if (0) |
| VG_(printf)("debug_line_sz %ld, ui.stmt_list %lld %s\n", |
| debug_line_sz, ui.stmt_list, ui.name ); |
| /* Read the .debug_line block for this compile unit */ |
| read_dwarf2_lineblock( |
| di, &ui, debug_line_img + ui.stmt_list, |
| debug_line_sz - ui.stmt_list ); |
| } |
| } |
| |
| |
| //////////////////////////////////////////////////////////////////// |
| //////////////////////////////////////////////////////////////////// |
| |
| /*------------------------------------------------------------*/ |
| /*--- 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 ML_(read_debuginfo_dwarf1) ( |
| struct _DebugInfo* di, |
| 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 = ML_(addStr) ( di, 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); |
| ML_(addLineInfo) ( di, curr_filenm, NULL, |
| 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 ---*/ |
| /*------------------------------------------------------------*/ |
| |
| /* Sources of info: |
| |
| The DWARF3 spec, available from http://www.dwarfstd.org/Download.php |
| |
| This describes how to read CFA data from .debug_frame sections. |
| So as to maximise everybody's annoyance and confusion, .eh_frame |
| sections are almost the same as .debug_frame sections, but differ |
| in a few subtle and ill documented but important aspects. |
| |
| Generic ELF Specification, sections 7.5 (DWARF Extensions) and 7.6 |
| (Exception Frames), available from |
| |
| http://www.linux-foundation.org/spec/book/ELF-generic/ELF-generic.html |
| |
| This really does describe .eh_frame, at least the aspects that |
| differ from standard DWARF3. It's better than guessing, and |
| (marginally) more fun than reading the gdb source code. |
| */ |
| |
| /* 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/amd64-tdep.c and also amd64-abi-0.98.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) |
| "The table defines Return Address to have a register number, |
| even though the address is stored in 0(%rsp) and not in a |
| physical register." |
| |
| 17 ... 24 |
| XMM0 ... XMM7 |
| |
| 25 ... 32 |
| XMM8 ... XMM15 |
| |
| 33 ... 40 |
| ST0 ... ST7 |
| |
| 41 ... 48 |
| MM0 ... MM7 |
| |
| 49 RFLAGS |
| 50,51,52,53,54,55 ES,CS,SS,DS,FS,GS |
| 58 FS.BASE (what's that?) |
| 59 GS.BASE (what's that?) |
| 62 TR (task register) |
| 63 LDTR (LDT register) |
| 64 MXCSR |
| 65 FCW (x87 control word) |
| 66 FSW (x86 status word) |
| |
| 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) */ |
| |
| |
| /* Comments re DW_CFA_set_loc, 16 Nov 06. |
| |
| JRS: |
| Someone recently sent me a libcrypto.so.0.9.8 as distributed with |
| Ubuntu of some flavour, compiled with gcc 4.1.2 on amd64. It |
| causes V's CF reader to complain a lot: |
| |
| >> --19976-- DWARF2 CFI reader: unhandled CFI instruction 0:24 |
| >> --19976-- DWARF2 CFI reader: unhandled CFI instruction 0:24 |
| >> --19976-- DWARF2 CFI reader: unhandled CFI instruction 0:24 |
| >> --19976-- DWARF2 CFI reader: unhandled CFI instruction 0:24 |
| >> --19976-- DWARF2 CFI reader: unhandled CFI instruction 0:48 |
| >> --19976-- DWARF2 CFI reader: unhandled CFI instruction 0:24 |
| |
| After chasing this around a bit it seems that the CF bytecode |
| parser lost sync at a DW_CFA_set_loc, which has a single argument |
| denoting an address. |
| |
| As it stands that address is extracted by read_Addr(). On amd64 |
| that just fetches 8 bytes regardless of anything else. |
| |
| read_encoded_Addr() is more sophisticated. This appears to take |
| into account some kind of encoding flag. When I replace the uses |
| of read_Addr by read_encoded_Addr for DW_CFA_set_loc, the |
| complaints go away, there is no loss of sync, and the parsed CF |
| instructions are the same as shown by readelf --debug-dump=frames. |
| |
| So it seems a plausible fix. The problem is I looked in the DWARF3 |
| spec and completely failed to figure out whether or not the arg to |
| DW_CFA_set_loc is supposed to be encoded in a way suitable for |
| read_encoded_Addr, nor for that matter any description of what it |
| is that read_encoded_Addr is really decoding. |
| |
| TomH: |
| The problem is that the encoding is not standard - the eh_frame |
| section uses the same encoding as the dwarf_frame section except |
| for a few small changes, and this is one of them. So this is not |
| something the DWARF standard covers. |
| |
| There is an augmentation string to indicate what is going on though |
| so that programs can recognise it. |
| |
| What we are doing seems to match what gdb 6.5 and libdwarf 20060614 |
| do though. I'm not sure about readelf though. |
| |
| (later): Well dwarfdump barfs on it: |
| |
| dwarfdump ERROR: dwarf_get_fde_info_for_reg: |
| DW_DLE_DF_FRAME_DECODING_ERROR(193) (193) |
| |
| I've looked at binutils as well now, and the code in readelf agrees |
| with your patch - ie it treats set_loc as having an encoded address |
| if there is a zR augmentation indicating an encoding. |
| |
| Quite why gdb and libdwarf don't understand this is an interesting |
| question... |
| |
| Final outcome: all uses of read_Addr were replaced by |
| read_encoded_Addr. A new type AddressDecodingInfo was added to |
| make it relatively clean to plumb through the extra info needed by |
| read_encoded_Addr. |
| */ |
| |
| /* More badness re address encoding, 12 Jan 07. |
| |
| Most gcc provided CIEs have a "zR" augmentation, which means they |
| supply their own address encoding, and that works fine. However, |
| some icc9 supplied CIEs have no augmentation, which means they use |
| the default_Addr_encoding(). That says to use a machine-word sized |
| value, literally unmodified. |
| |
| Since .so's are, in general, relocated when loaded, having absolute |
| addresses in the CFI data makes no sense when read_encoded_Addr is |
| used to find the initial location for a FDE. The resulting saga: |
| |
| TomH: |
| > I'm chasing a stack backtrace failure for an amd64 .so which was |
| > created I believe by icc 9.1. After a while I wound up looking at |
| > this: (readdwarf.c) |
| > |
| > 5083 tom static UChar default_Addr_encoding ( void ) |
| > 3584 tom { |
| > 3584 tom switch (sizeof(Addr)) { |
| > 3584 tom case 4: return DW_EH_PE_udata4; |
| > 3584 tom case 8: return DW_EH_PE_udata8; |
| > 3584 tom default: vg_assert(0); |
| > 3584 tom } |
| > 3584 tom } |
| > |
| > If a CIE does not have an "augmentation string" (typically "zR") then |
| > addresses are decoded as described by default_Addr_encoding. If there |
| > is an 'R' in the augmentation string then the encoding to use |
| > is specified by the CIE itself, which works fine with GCC compiled code |
| > since that always appears to specify zR. |
| |
| Correct. |
| |
| > Problem is this .so has no augmentation string and so uses the |
| > default encoding, viz DW_EH_PE_udata8. That appears to mean |
| > "read a 64 bit number" and use that as-is (for the starting value |
| > of the program counter when running the CFA program). |
| |
| Strictly speaking the default is DW_EH_PE_absptr, but that amounts |
| to either udata4 or udata8 depending on the platform's pointer size |
| which is a shortcut I used. |
| |
| > For this .so that gives nonsense (very small) PCs which are later |
| > rejected by the sanity check which ensures PC ranges fall inside |
| > the mapped text segment. It seems like the .so expects to have the |
| > start VMA of the text segment added on. This would correspond to |
| > |
| > static UChar default_Addr_encoding ( void ) |
| > { |
| > switch (sizeof(Addr)) { |
| > case 4: return DW_EH_PE_textrel + DW_EH_PE_udata4; |
| > case 8: return DW_EH_PE_textrel + DW_EH_PE_udata8; |
| > default: vg_assert(0); |
| > } |
| > } |
| |
| The problem you're seeing is that you have absolute pointers inside |
| a shared library, which obviously makes little sense on the face of |
| things as how would the linker know where the library will be |
| loaded? |
| |
| The answer of course is that it doesn't, so if it points absolute |
| pointers in the frame unwind data is has to include relocations for |
| them, and I'm betting that if you look at the relocations in the |
| library you will there are some for that data. |
| |
| That is fine of course when ld.so maps the library - it will |
| relocate the eh_frame data as it maps it (or prelinking will |
| already have done so) and when the g++ exception code kicks in and |
| unwinds the stack it will see relocated data. |
| |
| We of course are mapping the section from the ELF file ourselves |
| and are not applying the relocations, hence the problem you are |
| seeing. |
| |
| Strictly speaking we should apply the relocations but the cheap |
| solution is essentially to do what you've done - strictly speaking |
| you should adjust by the difference between the address the library |
| was linked for and the address it has been loaded at, but a shared |
| library will normally be linked for address zero I believe. It's |
| possible that prelinking might change that though? |
| |
| JRS: |
| That all syncs with what I am seeing. |
| |
| So what I am inclined to do is: |
| |
| - Leave default_Addr_encoding as it is |
| |
| - Change read_encoded_Addr's handling of "case DW_EH_PE_absptr" so |
| it sets base to, as you say, the difference between the address |
| the library was linked for and the address it has been loaded at |
| (== the SegInfo's text_bias) |
| |
| Does that sound sane? I think it should even handle the prelinked |
| case. |
| |
| (JRS, later) |
| |
| Hmm. Plausible as it sounds, it doesn't work. It now produces |
| bogus backtraces for locations inside the (statically linked) |
| memcheck executable. |
| |
| Besides, there are a couple of other places where read_encoded_Addr |
| is used -- one of which is used to establish the length of the |
| address range covered by the current FDE: |
| |
| fde_arange = read_encoded_Addr(&nbytes, &adi, data); |
| |
| and it doesn't seem to make any sense for read_encoded_Addr to add |
| on the text segment bias in that context. The DWARF3 spec says |
| that both the initial_location and address_range (length) fields |
| are encoded the same way ("target address"), so it is unclear at |
| what stage in the process it would be appropriate to relocate the |
| former but not the latter. |
| |
| One unprincipled kludge that does work is the following: just |
| before handing one of the address range fragments off to |
| ML_(addDiCfSI) for permanent storage, check its start address. If |
| that is very low (less than 2 M), and is far below the mapped text |
| segment, and adding the text bias would move the fragment entirely |
| inside the mapped text segment, then do so. A kind of kludged |
| last-minute relocation, if you like. |
| |
| 12 Jan 07: committing said kludge (see kludge_then_addDiCfSI). If |
| the situation clarifies, it can easily enough be backed out and |
| replaced by a better fix. |
| */ |
| |
| /* --------------- Decls --------------- */ |
| |
| #if defined(VGP_x86_linux) |
| # define FP_REG 5 |
| # define SP_REG 4 |
| # define RA_REG_DEFAULT 8 |
| #elif defined(VGP_amd64_linux) |
| # define FP_REG 6 |
| # define SP_REG 7 |
| # define RA_REG_DEFAULT 16 |
| #elif defined(VGP_ppc32_linux) |
| # define FP_REG 1 |
| # define SP_REG 1 |
| # define RA_REG_DEFAULT 8 // CAB: What's a good default ? |
| #elif defined(VGP_ppc64_linux) |
| # define FP_REG 1 |
| # define SP_REG 1 |
| # define RA_REG_DEFAULT 8 // CAB: What's a good default ? |
| #else |
| # error "Unknown platform" |
| #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_def_cfa_expression = 0x0f, /* DWARF3 only */ |
| DW_CFA_expression = 0x10, /* DWARF3 only */ |
| DW_CFA_offset_extended_sf = 0x11, /* DWARF3 only */ |
| DW_CFA_def_cfa_sf = 0x12, /* DWARF3 only */ |
| DW_CFA_def_cfa_offset_sf = 0x13, /* DWARF3 only */ |
| DW_CFA_val_offset = 0x14, /* DWARF3 only */ |
| DW_CFA_val_offset_sf = 0x15, /* DWARF3 only */ |
| DW_CFA_val_expression = 0x16, /* DWARF3 only */ |
| DW_CFA_lo_user = 0x1c, |
| DW_CFA_GNU_window_save = 0x2d, /* GNU extension */ |
| DW_CFA_GNU_args_size = 0x2e, /* GNU extension */ |
| DW_CFA_GNU_negative_offset_extended = 0x2f, /* GNU extension */ |
| 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 sequence of CfiSIs, if |
| possible. UnwindContext effectively holds the state of the |
| abstract machine whilst it is running. |
| |
| The CFA can either be a signed offset from a register, |
| or an expression: |
| |
| CFA = cfa_reg + cfa_off when UnwindContext.cfa_is_regoff==True |
| | [[ cfa_expr_id ]] |
| |
| When .cfa_is_regoff == True, cfa_expr_id must be zero |
| When .cfa_is_regoff == False, cfa_reg must be zero |
| and cfa_off must be zero |
| |
| RegRule describes, for each register, how to get its |
| value in the previous frame, where 'cfa' denotes the cfa |
| for the frame as a whole: |
| |
| RegRule = RR_Undef -- undefined |
| | RR_Same -- same as in previous frame |
| | RR_CFAOff arg -- is at * ( cfa + arg ) |
| | RR_CFAValOff arg -- is ( cfa + arg ) |
| | RR_Reg arg -- is in register 'arg' |
| | RR_Expr arg -- is at * [[ arg ]] |
| | RR_ValExpr arg -- is [[ arg ]] |
| | RR_Arch -- dunno |
| |
| Note that RR_Expr is redundant since the same can be represented |
| using RR_ValExpr with an explicit dereference (CfiExpr_Deref) at |
| the outermost level. |
| |
| All expressions are stored in exprs in the containing |
| UnwindContext. Since the UnwindContext gets reinitialised for each |
| new FDE, summarise_context needs to copy out any expressions it |
| wants to keep into the cfsi_exprs field of the containing SegInfo. |
| */ |
| typedef |
| struct { |
| enum { RR_Undef, RR_Same, RR_CFAOff, RR_CFAValOff, |
| RR_Reg, /*RR_Expr,*/ RR_ValExpr, RR_Arch } tag; |
| /* meaning: int offset for CFAoff/CFAValOff |
| reg # for Reg |
| expr index for Expr/ValExpr */ |
| Int arg; |
| } |
| RegRule; |
| |
| static void ppRegRule ( XArray* exprs, RegRule* rrule ) |
| { |
| vg_assert(exprs); |
| switch (rrule->tag) { |
| case RR_Undef: VG_(printf)("u "); break; |
| case RR_Same: VG_(printf)("s "); break; |
| case RR_CFAOff: VG_(printf)("c%d ", rrule->arg); break; |
| case RR_CFAValOff: VG_(printf)("v%d ", rrule->arg); break; |
| case RR_Reg: VG_(printf)("r%d ", rrule->arg); break; |
| case RR_ValExpr: VG_(printf)("ve{"); |
| ML_(ppCfiExpr)( exprs, rrule->arg ); |
| VG_(printf)("} "); |
| break; |
| case RR_Arch: VG_(printf)("a "); break; |
| default: VG_(core_panic)("ppRegRule"); |
| } |
| } |
| |
| |
| typedef |
| struct { |
| /* Read-only fields (set by the CIE) */ |
| Int code_a_f; |
| Int data_a_f; |
| Addr initloc; |
| Int ra_reg; |
| /* The rest of these fields can be modifed by |
| run_CF_instruction. */ |
| /* The LOC entry */ |
| Addr loc; |
| /* The CFA entry. This can be either reg+/-offset or an expr. */ |
| Bool cfa_is_regoff; /* True=>is reg+offset; False=>is expr */ |
| Int cfa_reg; |
| Int cfa_off; /* in bytes */ |
| Int cfa_expr_ix; /* index into cfa_exprs */ |
| /* register unwind rules */ |
| RegRule reg[N_CFI_REGS]; |
| /* array of CfiExpr, shared by reg[] and cfa_expr_ix */ |
| XArray* exprs; |
| } |
| UnwindContext; |
| |
| static void ppUnwindContext ( UnwindContext* ctx ) |
| { |
| Int i; |
| VG_(printf)("0x%llx: ", (ULong)ctx->loc); |
| if (ctx->cfa_is_regoff) { |
| VG_(printf)("%d(r%d) ", ctx->cfa_off, ctx->cfa_reg); |
| } else { |
| vg_assert(ctx->exprs); |
| VG_(printf)("{"); |
| ML_(ppCfiExpr)( ctx->exprs, ctx->cfa_expr_ix ); |
| VG_(printf)("} "); |
| } |
| for (i = 0; i < N_CFI_REGS; i++) |
| ppRegRule(ctx->exprs, &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->initloc = 0; |
| ctx->ra_reg = RA_REG_DEFAULT; |
| ctx->loc = 0; |
| ctx->cfa_is_regoff = True; |
| ctx->cfa_reg = 0; |
| ctx->cfa_off = 0; |
| ctx->cfa_expr_ix = 0; |
| ctx->exprs = NULL; |
| for (i = 0; i < N_CFI_REGS; i++) { |
| ctx->reg[i].tag = RR_Undef; |
| ctx->reg[i].arg = 0; |
| } |
| } |
| |
| |
| /* A structure which holds information needed by read_encoded_Addr(). |
| */ |
| typedef |
| struct { |
| UChar encoding; |
| UChar* ehframe_image; |
| Addr ehframe_avma; |
| Addr text_bias; |
| } |
| AddressDecodingInfo; |
| |
| |
| /* ------------ Deal with summary-info records ------------ */ |
| |
| static void initCfiSI ( DiCfSI* si ) |
| { |
| si->base = 0; |
| si->len = 0; |
| si->cfa_how = 0; |
| 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; |
| } |
| |
| |
| /* --------------- Summarisation --------------- */ |
| |
| /* Forward */ |
| static |
| Int copy_convert_CfiExpr_tree ( XArray* dst, |
| UnwindContext* srcuc, |
| Int nd ); |
| |
| /* 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*/DiCfSI* si, |
| Addr loc_start, |
| UnwindContext* ctx, |
| struct _DebugInfo* debuginfo ) |
| { |
| Int why = 0; |
| initCfiSI(si); |
| |
| /* How to generate the CFA */ |
| if (!ctx->cfa_is_regoff) { |
| /* it was set by DW_CFA_def_cfa_expression; try to convert */ |
| XArray *src, *dst; |
| Int conv; |
| src = ctx->exprs; |
| dst = debuginfo->cfsi_exprs; |
| if (src && (VG_(sizeXA)(src) > 0) && (!dst)) { |
| dst = VG_(newXA)( ML_(dinfo_zalloc), "di.ccCt.1", ML_(dinfo_free), |
| sizeof(CfiExpr) ); |
| vg_assert(dst); |
| debuginfo->cfsi_exprs = dst; |
| } |
| conv = copy_convert_CfiExpr_tree |
| ( dst, ctx, ctx->cfa_expr_ix ); |
| vg_assert(conv >= -1); |
| if (conv == -1) { why = 6; goto failed; } |
| si->cfa_how = CFIC_EXPR; |
| si->cfa_off = conv; |
| if (0 && debuginfo->ddump_frames) |
| ML_(ppCfiExpr)(dst, conv); |
| } else |
| if (ctx->cfa_is_regoff && ctx->cfa_reg == SP_REG) { |
| si->cfa_how = CFIC_SPREL; |
| si->cfa_off = ctx->cfa_off; |
| } else |
| if (ctx->cfa_is_regoff && ctx->cfa_reg == FP_REG) { |
| si->cfa_how = CFIC_FPREL; |
| si->cfa_off = ctx->cfa_off; |
| } 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.arg; break; \ |
| case RR_CFAValOff: \ |
| _how = CFIR_CFAREL; _off = _ctxreg.arg; break; \ |
| case RR_ValExpr: { \ |
| XArray *src, *dst; \ |
| Int conv; \ |
| src = ctx->exprs; \ |
| dst = debuginfo->cfsi_exprs; \ |
| if (src && (VG_(sizeXA)(src) > 0) && (!dst)) { \ |
| dst = VG_(newXA)( ML_(dinfo_zalloc), \ |
| "di.ccCt.2", \ |
| ML_(dinfo_free), \ |
| sizeof(CfiExpr) ); \ |
| vg_assert(dst); \ |
| debuginfo->cfsi_exprs = dst; \ |
| } \ |
| conv = copy_convert_CfiExpr_tree \ |
| ( dst, ctx, _ctxreg.arg ); \ |
| vg_assert(conv >= -1); \ |
| if (conv == -1) { why = 7; goto failed; } \ |
| _how = CFIR_EXPR; \ |
| _off = conv; \ |
| if (0 && debuginfo->ddump_frames) \ |
| ML_(ppCfiExpr)(dst, conv); \ |
| break; \ |
| } \ |
| default: \ |
| why = 2; goto failed; /* otherwise give up */ \ |
| } |
| |
| SUMMARISE_HOW(si->ra_how, si->ra_off, ctx->reg[ctx->ra_reg] ); |
| SUMMARISE_HOW(si->fp_how, si->fp_off, ctx->reg[FP_REG] ); |
| |
| # 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_REG].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) > 2 || debuginfo->trace_cfi) { |
| VG_(message)(Vg_DebugMsg, |
| "summarise_context(loc_start = %#lx)" |
| ": cannot summarise(why=%d): ", loc_start, why); |
| ppUnwindContext(ctx); |
| } |
| return False; |
| } |
| |
| /* Copy the tree rooted at srcuc->exprs node srcix to dstxa, on the |
| way converting any DwReg regs (regs numbered using the Dwarf scheme |
| defined by each architecture's ABI) into CfiRegs, which are |
| platform independent. If the conversion isn't possible because |
| there is no equivalent register, return -1. This has the |
| undesirable side effect of de-dagifying the input; oh well. */ |
| static Int copy_convert_CfiExpr_tree ( XArray* dstxa, |
| UnwindContext* srcuc, |
| Int srcix ) |
| { |
| CfiExpr* src; |
| Int cpL, cpR, cpA, dwreg; |
| XArray* srcxa = srcuc->exprs; |
| vg_assert(srcxa); |
| vg_assert(dstxa); |
| vg_assert(srcix >= 0 && srcix < VG_(sizeXA)(srcxa)); |
| |
| src = VG_(indexXA)( srcxa, srcix ); |
| switch (src->tag) { |
| case Cex_Undef: |
| return ML_(CfiExpr_Undef)( dstxa ); |
| case Cex_Deref: |
| cpA = copy_convert_CfiExpr_tree( dstxa, srcuc, src->Cex.Deref.ixAddr ); |
| if (cpA == -1) |
| return -1; /* propagate failure */ |
| return ML_(CfiExpr_Deref)( dstxa, cpA ); |
| case Cex_Const: |
| return ML_(CfiExpr_Const)( dstxa, src->Cex.Const.con ); |
| case Cex_Binop: |
| cpL = copy_convert_CfiExpr_tree( dstxa, srcuc, src->Cex.Binop.ixL ); |
| cpR = copy_convert_CfiExpr_tree( dstxa, srcuc, src->Cex.Binop.ixR ); |
| vg_assert(cpL >= -1 && cpR >= -1); |
| if (cpL == -1 || cpR == -1) |
| return -1; /* propagate failure */ |
| return ML_(CfiExpr_Binop)( dstxa, src->Cex.Binop.op, cpL, cpR ); |
| case Cex_CfiReg: |
| /* should not see these in input (are created only by this |
| conversion step!) */ |
| VG_(core_panic)("copy_convert_CfiExpr_tree: CfiReg in input"); |
| case Cex_DwReg: |
| /* This is the only place where the conversion can fail. */ |
| dwreg = src->Cex.DwReg.reg; |
| if (dwreg == SP_REG) |
| return ML_(CfiExpr_CfiReg)( dstxa, Creg_SP ); |
| if (dwreg == FP_REG) |
| return ML_(CfiExpr_CfiReg)( dstxa, Creg_FP ); |
| if (dwreg == srcuc->ra_reg) |
| return ML_(CfiExpr_CfiReg)( dstxa, Creg_IP ); /* correct? */ |
| /* else we must fail - can't represent the reg */ |
| return -1; |
| default: |
| VG_(core_panic)("copy_convert_CfiExpr_tree: default"); |
| } |
| } |
| |
| |
| static void ppUnwindContext_summary ( UnwindContext* ctx ) |
| { |
| VG_(printf)("0x%llx-1: ", (ULong)ctx->loc); |
| |
| if (ctx->cfa_reg == SP_REG) { |
| VG_(printf)("SP/CFA=%d+SP ", ctx->cfa_off); |
| } else |
| if (ctx->cfa_reg == FP_REG) { |
| VG_(printf)("SP/CFA=%d+FP ", ctx->cfa_off); |
| } else { |
| VG_(printf)("SP/CFA=unknown "); |
| } |
| |
| VG_(printf)("RA="); |
| ppRegRule( ctx->exprs, &ctx->reg[ctx->ra_reg] ); |
| |
| VG_(printf)("FP="); |
| ppRegRule( ctx->exprs, &ctx->reg[FP_REG] ); |
| 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 ) |
| { |
| Short r = 0; |
| vg_assert(host_is_little_endian()); |
| r = data[0] |
| | ( ((UInt)data[1]) << 8 ); |
| return r; |
| } |
| |
| static Int read_Int ( UChar* data ) |
| { |
| Int r = 0; |
| vg_assert(host_is_little_endian()); |
| r = data[0] |
| | ( ((UInt)data[1]) << 8 ) |
| | ( ((UInt)data[2]) << 16 ) |
| | ( ((UInt)data[3]) << 24 ); |
| return r; |
| } |
| |
| static Long read_Long ( UChar* data ) |
| { |
| Long r = 0; |
| vg_assert(host_is_little_endian()); |
| 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 ) |
| { |
| UInt r = 0; |
| vg_assert(host_is_little_endian()); |
| r = data[0] |
| | ( ((UInt)data[1]) << 8 ); |
| return r; |
| } |
| |
| static UInt read_UInt ( UChar* data ) |
| { |
| UInt r = 0; |
| vg_assert(host_is_little_endian()); |
| r = data[0] |
| | ( ((UInt)data[1]) << 8 ) |
| | ( ((UInt)data[2]) << 16 ) |
| | ( ((UInt)data[3]) << 24 ); |
| return r; |
| } |
| |
| static ULong read_ULong ( UChar* data ) |
| { |
| ULong r = 0; |
| vg_assert(host_is_little_endian()); |
| 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 UChar read_UChar ( UChar* data ) |
| { |
| return data[0]; |
| } |
| |
| static ULong read_le_u_encoded_literal ( UChar* data, UInt size ) |
| { |
| switch (size) { |
| case 8: return (ULong)read_ULong( data ); |
| case 4: return (ULong)read_UInt( data ); |
| case 2: return (ULong)read_UShort( data ); |
| case 1: return (ULong)read_UChar( data ); |
| default: vg_assert(0); /*NOTREACHED*/ return 0; |
| } |
| } |
| |
| static Long read_le_s_encoded_literal ( UChar* data, UInt size ) |
| { |
| Long s64 = read_le_u_encoded_literal( data, size ); |
| switch (size) { |
| case 8: break; |
| case 4: s64 <<= 32; s64 >>= 32; break; |
| case 2: s64 <<= 48; s64 >>= 48; break; |
| case 1: s64 <<= 56; s64 >>= 56; break; |
| default: vg_assert(0); /*NOTREACHED*/ return 0; |
| } |
| return s64; |
| } |
| |
| static UChar default_Addr_encoding ( void ) |
| { |
| 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 ( /*OUT*/Int* nbytes, |
| AddressDecodingInfo* adi, |
| UChar* data ) |
| { |
| /* Regarding the handling of DW_EH_PE_absptr. DWARF3 says this |
| denotes an absolute address, hence you would think 'base' is |
| zero. However, that is nonsensical (unless relocations are to |
| be applied to the unwind data before reading it, which sounds |
| unlikely). My interpretation is that DW_EH_PE_absptr indicates |
| an address relative to where the object was loaded (technically, |
| relative to its stated load VMA, hence the use of text_bias |
| rather than text_avma). Hmm, should we use text_bias or |
| text_avma here? Not sure. |
| |
| This view appears to be supported by DWARF3 spec sec 7.3 |
| "Executable Objects and Shared Objects": |
| |
| This requirement makes the debugging information for shared |
| objects position independent. Virtual addresses in a shared |
| object may be calculated by adding the offset to the base |
| address at which the object was attached. This offset is |
| available in the run-time linker's data structures. |
| */ |
| Addr base; |
| Word offset; |
| UChar encoding = adi->encoding; |
| UChar* ehframe_image = adi->ehframe_image; |
| Addr ehframe_avma = adi->ehframe_avma; |
| |
| vg_assert((encoding & DW_EH_PE_indirect) == 0); |
| |
| *nbytes = 0; |
| |
| switch (encoding & 0x70) { |
| case DW_EH_PE_absptr: |
| base = adi->text_bias; |
| break; |
| case DW_EH_PE_pcrel: |
| base = ehframe_avma + ( data - ehframe_image ); |
| 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_image; |
| 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 DWARF3 expressions ---------- */ |
| |
| /* Convert the DWARF3 expression in expr[0 .. exprlen-1] into a dag |
| (of CfiExprs) stored in ctx->exprs, and return the index in |
| ctx->exprs of the root node. Or fail in which case return -1. */ |
| /* IMPORTANT: when adding expression forms here, also remember to |
| add suitable evaluation code in evalCfiExpr in debuginfo.c. */ |
| static Int dwarfexpr_to_dag ( UnwindContext* ctx, |
| UChar* expr, Int exprlen, |
| Bool push_cfa_at_start, |
| Bool ddump_frames ) |
| { |
| # define N_EXPR_STACK 20 |
| |
| # define PUSH(_arg) \ |
| do { \ |
| vg_assert(sp >= -1 && sp < N_EXPR_STACK); \ |
| if (sp == N_EXPR_STACK-1) \ |
| return -1; \ |
| sp++; \ |
| stack[sp] = (_arg); \ |
| } while (0) |
| |
| # define POP(_lval) \ |
| do { \ |
| vg_assert(sp >= -1 && sp < N_EXPR_STACK); \ |
| if (sp == -1) \ |
| return -1; \ |
| _lval = stack[sp]; \ |
| sp--; \ |
| } while (0) |
| |
| Int ix, ix2, reg; |
| UChar opcode; |
| Word sw; |
| UWord uw; |
| CfiOp op; |
| HChar* opname; |
| |
| Int sp; /* # of top element: valid is -1 .. N_EXPR_STACK-1 */ |
| Int stack[N_EXPR_STACK]; /* indices into ctx->exprs */ |
| |
| XArray* dst = ctx->exprs; |
| UChar* limit = expr + exprlen; |
| |
| vg_assert(dst); |
| vg_assert(exprlen >= 0); |
| |
| sp = -1; /* empty */ |
| |
| /* Synthesise the CFA as a CfiExpr */ |
| if (push_cfa_at_start) { |
| if (ctx->cfa_is_regoff) { |
| /* cfa is reg +/- offset */ |
| ix = ML_(CfiExpr_Binop)( dst, |
| Cop_Add, |
| ML_(CfiExpr_DwReg)( dst, ctx->cfa_reg ), |
| ML_(CfiExpr_Const)( dst, (UWord)(Word)ctx->cfa_off ) |
| ); |
| PUSH(ix); |
| } else { |
| /* CFA is already an expr; use its root node */ |
| PUSH(ctx->cfa_expr_ix); |
| } |
| } |
| |
| while (True) { |
| |
| vg_assert(sp >= -1 && sp < N_EXPR_STACK); |
| |
| if (expr > limit) |
| return -1; /* overrun - something's wrong */ |
| |
| if (expr == limit) { |
| /* end of expr - return expr on the top of stack. */ |
| if (sp == -1) |
| return -1; /* stack empty. Bad. */ |
| else |
| break; |
| } |
| |
| op = 0; opname = NULL; /* excessively conservative */ |
| |
| opcode = *expr++; |
| switch (opcode) { |
| |
| case DW_OP_lit0 ... DW_OP_lit31: |
| /* push: literal 0 .. 31 */ |
| sw = (Word)opcode - (Word)DW_OP_lit0; |
| vg_assert(sw >= 0 && sw <= 31); |
| PUSH( ML_(CfiExpr_Const)( dst, (UWord)sw ) ); |
| if (ddump_frames) |
| VG_(printf)("DW_OP_lit%ld", sw); |
| break; |
| |
| case DW_OP_breg0 ... DW_OP_breg31: |
| /* push: reg + sleb128 */ |
| reg = (Int)opcode - (Int)DW_OP_breg0; |
| vg_assert(reg >= 0 && reg <= 31); |
| sw = read_leb128S( &expr ); |
| ix = ML_(CfiExpr_Binop)( dst, |
| Cop_Add, |
| ML_(CfiExpr_DwReg)( dst, reg ), |
| ML_(CfiExpr_Const)( dst, (UWord)sw ) |
| ); |
| PUSH(ix); |
| if (ddump_frames) |
| VG_(printf)("DW_OP_breg%d: %ld", reg, sw); |
| break; |
| |
| case DW_OP_plus_uconst: |
| uw = read_leb128U( &expr ); |
| PUSH( ML_(CfiExpr_Const)( dst, uw ) ); |
| POP( ix ); |
| POP( ix2 ); |
| PUSH( ML_(CfiExpr_Binop)( dst, op, ix2, ix ) ); |
| if (ddump_frames) |
| VG_(printf)("DW_OP_plus_uconst: %lu", uw); |
| break; |
| |
| case DW_OP_const4s: |
| /* push: 32-bit signed immediate */ |
| sw = read_le_s_encoded_literal( expr, 4 ); |
| expr += 4; |
| PUSH( ML_(CfiExpr_Const)( dst, (UWord)sw ) ); |
| if (ddump_frames) |
| VG_(printf)("DW_OP_const4s: %ld", sw); |
| break; |
| |
| case DW_OP_minus: |
| op = Cop_Sub; opname = "minus"; goto binop; |
| case DW_OP_plus: |
| op = Cop_Add; opname = "plus"; goto binop; |
| case DW_OP_and: |
| op = Cop_And; opname = "and"; goto binop; |
| case DW_OP_mul: |
| op = Cop_Mul; opname = "mul"; goto binop; |
| binop: |
| POP( ix ); |
| POP( ix2 ); |
| PUSH( ML_(CfiExpr_Binop)( dst, op, ix2, ix ) ); |
| if (ddump_frames) |
| VG_(printf)("DW_OP_%s", opname); |
| break; |
| |
| case DW_OP_deref: |
| POP( ix ); |
| PUSH( ML_(CfiExpr_Deref)( dst, ix ) ); |
| if (ddump_frames) |
| VG_(printf)("DW_OP_deref"); |
| break; |
| |
| default: |
| if (!VG_(clo_xml)) |
| VG_(message)(Vg_DebugMsg, |
| "Warning: DWARF2 CFI reader: unhandled DW_OP_ " |
| "opcode 0x%x", (Int)opcode); |
| return -1; |
| } |
| |
| if (expr < limit && ddump_frames) |
| VG_(printf)("; "); |
| |
| } |
| |
| vg_assert(sp >= -1 && sp < N_EXPR_STACK); |
| if (sp == -1) |
| return -1; |
| |
| if (0 && ddump_frames) |
| ML_(ppCfiExpr)( dst, stack[sp] ); |
| return stack[sp]; |
| |
| # undef POP |
| # undef PUSH |
| # undef N_EXPR_STACK |
| } |
| |
| |
| /* ------------ 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, |
| AddressDecodingInfo* adi, |
| struct _DebugInfo* di ) |
| { |
| Int off, reg, reg2, nleb, len; |
| UInt delta; |
| UChar* expr; |
| Int j; |
| Int i = 0; |
| UChar hi2 = (instr[i] >> 6) & 3; |
| UChar lo6 = instr[i] & 0x3F; |
| Addr printing_bias = ((Addr)ctx->initloc) - ((Addr)di->text_bias); |
| i++; |
| |
| if (hi2 == DW_CFA_advance_loc) { |
| delta = (UInt)lo6; |
| ctx->loc += delta; |
| if (di->ddump_frames) |
| VG_(printf)(" DW_CFA_advance_loc: %d to %08lx\n", |
| (Int)delta, (Addr)ctx->loc + printing_bias); |
| return i; |
| } |
| |
| if (hi2 == DW_CFA_offset) { |
| /* Set rule for reg 'lo6' to CFAOff(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].arg = off * ctx->data_a_f; |
| if (di->ddump_frames) |
| VG_(printf)(" DW_CFA_offset: r%d at cfa%s%d\n", |
| (Int)reg, ctx->reg[reg].arg < 0 ? "" : "+", |
| (Int)ctx->reg[reg].arg ); |
| 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]; |
| if (di->ddump_frames) |
| VG_(printf)(" DW_CFA_restore: r%d\n", (Int)reg); |
| return i; |
| } |
| |
| vg_assert(hi2 == DW_CFA_use_secondary); |
| |
| switch (lo6) { |
| case DW_CFA_nop: |
| if (di->ddump_frames) |
| VG_(printf)(" DW_CFA_nop\n"); |
| break; |
| case DW_CFA_set_loc: |
| /* WAS: |
| ctx->loc = read_Addr(&instr[i]) - ctx->initloc; i+= sizeof(Addr); |
| Was this ever right? */ |
| /* 2007 Feb 23: No. binutils/dwarf.c treats it as an encoded |
| address and that appears to be in accordance with the |
| DWARF3 spec. */ |
| ctx->loc = read_encoded_Addr(&len, adi, &instr[i]); |
| i += len; |
| if (di->ddump_frames) |
| VG_(printf)(" rci:DW_CFA_set_loc\n"); |
| break; |
| case DW_CFA_advance_loc1: |
| delta = (UInt)read_UChar(&instr[i]); i+= sizeof(UChar); |
| ctx->loc += delta; |
| if (di->ddump_frames) |
| VG_(printf)(" DW_CFA_advance_loc1: %d to %08lx\n", |
| (Int)delta, (Addr)ctx->loc + printing_bias); |
| break; |
| case DW_CFA_advance_loc2: |
| delta = (UInt)read_UShort(&instr[i]); i+= sizeof(UShort); |
| ctx->loc += delta; |
| if (di->ddump_frames) |
| VG_(printf)(" DW_CFA_advance_loc2: %d to %08lx\n", |
| (Int)delta, (Addr)ctx->loc + printing_bias); |
| break; |
| case DW_CFA_advance_loc4: |
| delta = (UInt)read_UInt(&instr[i]); i+= sizeof(UInt); |
| ctx->loc += delta; |
| if (di->ddump_frames) |
| VG_(printf)(" DW_CFA_advance_loc4: %d to %08lx\n", |
| (Int)delta, (Addr)ctx->loc + printing_bias); |
| 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_is_regoff = True; |
| ctx->cfa_expr_ix = 0; |
| ctx->cfa_reg = reg; |
| ctx->cfa_off = off; |
| if (di->ddump_frames) |
| VG_(printf)(" DW_CFA_def_cfa: r%d ofs %d\n", (Int)reg, (Int)off); |
| break; |
| |
| case DW_CFA_def_cfa_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->cfa_is_regoff = True; |
| ctx->cfa_expr_ix = 0; |
| ctx->cfa_reg = reg; |
| ctx->cfa_off = off * ctx->data_a_f; |
| if (di->ddump_frames) |
| VG_(printf)(" rci:DW_CFA_def_cfa_sf\n"); |
| 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].arg = reg2; |
| if (di->ddump_frames) |
| VG_(printf)(" DW_CFA_register: r%d in r%d\n", |
| (Int)reg, (Int)reg2); |
| break; |
| |
| case DW_CFA_offset_extended: |
| 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->reg[reg].tag = RR_CFAOff; |
| ctx->reg[reg].arg = off * ctx->data_a_f; |
| if (di->ddump_frames) |
| VG_(printf)(" rci:DW_CFA_offset_extended\n"); |
| 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].arg = off * ctx->data_a_f; |
| if (di->ddump_frames) |
| VG_(printf)(" DW_CFA_offset_extended_sf: r%d at cfa%s%d\n", |
| reg, ctx->reg[reg].arg < 0 ? "" : "+", |
| (Int)ctx->reg[reg].arg); |
| break; |
| |
| case DW_CFA_GNU_negative_offset_extended: |
| 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->reg[reg].tag = RR_CFAOff; |
| ctx->reg[reg].arg = (-off) * ctx->data_a_f; |
| if (di->ddump_frames) |
| VG_(printf)(" rci:DW_CFA_GNU_negative_offset_extended\n"); |
| break; |
| |
| case DW_CFA_restore_extended: |
| reg = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| if (reg < 0 || reg >= N_CFI_REGS) |
| return 0; /* fail */ |
| if (restore_ctx == NULL) |
| return 0; /* fail */ |
| ctx->reg[reg] = restore_ctx->reg[reg]; |
| if (di->ddump_frames) |
| VG_(printf)(" rci:DW_CFA_restore_extended\n"); |
| break; |
| |
| case DW_CFA_val_offset: |
| 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->reg[reg].tag = RR_CFAValOff; |
| ctx->reg[reg].arg = off * ctx->data_a_f; |
| if (di->ddump_frames) |
| VG_(printf)(" rci:DW_CFA_val_offset\n"); |
| break; |
| |
| case DW_CFA_val_offset_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_CFAValOff; |
| ctx->reg[reg].arg = off * ctx->data_a_f; |
| if (di->ddump_frames) |
| VG_(printf)(" rci:DW_CFA_val_offset_sf\n"); |
| 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_is_regoff = True; |
| ctx->cfa_expr_ix = 0; |
| ctx->cfa_reg = reg; |
| /* ->cfa_off unchanged */ |
| if (di->ddump_frames) |
| VG_(printf)(" DW_CFA_def_cfa_reg: r%d\n", (Int)reg ); |
| break; |
| |
| case DW_CFA_def_cfa_offset: |
| off = read_leb128( &instr[i], &nleb, 0); |
| i += nleb; |
| ctx->cfa_is_regoff = True; |
| ctx->cfa_expr_ix = 0; |
| /* ->reg is unchanged */ |
| ctx->cfa_off = off; |
| if (di->ddump_frames) |
| VG_(printf)(" DW_CFA_def_cfa_offset: %d\n", (Int)off); |
| break; |
| |
| case DW_CFA_def_cfa_offset_sf: |
| off = read_leb128( &instr[i], &nleb, 1); |
| i += nleb; |
| ctx->cfa_is_regoff = True; |
| ctx->cfa_expr_ix = 0; |
| /* ->reg is unchanged */ |
| ctx->cfa_off = off * ctx->data_a_f; |
| if (di->ddump_frames) |
| VG_(printf)(" DW_CFA_def_cfa_offset_sf: %d\n", ctx->cfa_off); |
| break; |
| |
| case DW_CFA_undefined: |
| reg = read_leb128( &instr[i], &nleb, 0); |
| i += nleb; |
| if (reg < 0 || reg >= N_CFI_REGS) |
| return 0; /* fail */ |
| ctx->reg[reg].tag = RR_Undef; |
| ctx->reg[reg].arg = 0; |
| if (di->ddump_frames) |
| VG_(printf)(" rci:DW_CFA_undefined\n"); |
| 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; |
| if (di->ddump_frames) |
| VG_(printf)(" rci:DW_CFA_GNU_args_size (ignored)\n"); |
| break; |
| |
| case DW_CFA_expression: |
| /* Identical to DW_CFA_val_expression except that the value |
| computed is an address and so needs one final |
| dereference. */ |
| reg = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| len = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| expr = &instr[i]; |
| i += len; |
| if (reg < 0 || reg >= N_CFI_REGS) |
| return 0; /* fail */ |
| if (di->ddump_frames) |
| VG_(printf)(" DW_CFA_expression: r%d (", |
| (Int)reg); |
| /* Convert the expression into a dag rooted at ctx->exprs index j, |
| or fail. */ |
| j = dwarfexpr_to_dag ( ctx, expr, len, True/*push CFA at start*/, |
| di->ddump_frames); |
| if (di->ddump_frames) |
| VG_(printf)(")\n"); |
| vg_assert(j >= -1); |
| if (j >= 0) { |
| vg_assert(ctx->exprs); |
| vg_assert( j < VG_(sizeXA)(ctx->exprs) ); |
| } |
| if (j == -1) |
| return 0; /* fail */ |
| /* Add an extra dereference */ |
| j = ML_(CfiExpr_Deref)( ctx->exprs, j ); |
| ctx->reg[reg].tag = RR_ValExpr; |
| ctx->reg[reg].arg = j; |
| break; |
| |
| case DW_CFA_val_expression: |
| reg = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| len = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| expr = &instr[i]; |
| i += len; |
| if (reg < 0 || reg >= N_CFI_REGS) |
| return 0; /* fail */ |
| if (di->ddump_frames) |
| VG_(printf)(" DW_CFA_val_expression: r%d (", |
| (Int)reg); |
| /* Convert the expression into a dag rooted at ctx->exprs index j, |
| or fail. */ |
| j = dwarfexpr_to_dag ( ctx, expr, len, True/*push CFA at start*/, |
| di->ddump_frames); |
| if (di->ddump_frames) |
| VG_(printf)(")\n"); |
| vg_assert(j >= -1); |
| if (j >= 0) { |
| vg_assert(ctx->exprs); |
| vg_assert( j < VG_(sizeXA)(ctx->exprs) ); |
| } |
| if (j == -1) |
| return 0; /* fail */ |
| ctx->reg[reg].tag = RR_ValExpr; |
| ctx->reg[reg].arg = j; |
| break; |
| |
| case DW_CFA_def_cfa_expression: |
| len = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| expr = &instr[i]; |
| i += len; |
| if (di->ddump_frames) |
| VG_(printf)(" DW_CFA_def_cfa_expression ("); |
| /* Convert the expression into a dag rooted at ctx->exprs index j, |
| or fail. */ |
| j = dwarfexpr_to_dag ( ctx, expr, len, True/*push CFA at start*/, |
| di->ddump_frames); |
| if (di->ddump_frames) |
| VG_(printf)(")\n"); |
| ctx->cfa_is_regoff = False; |
| ctx->cfa_reg = 0; |
| ctx->cfa_off = 0; |
| ctx->cfa_expr_ix = j; |
| break; |
| |
| case DW_CFA_GNU_window_save: |
| /* Ignored. This appears to be sparc-specific; quite why it |
| turns up in SuSE-supplied x86 .so's beats me. */ |
| if (di->ddump_frames) |
| VG_(printf)("DW_CFA_GNU_window_save\n"); |
| break; |
| |
| default: |
| VG_(message)(Vg_DebugMsg, "DWARF2 CFI reader: unhandled CFI " |
| "instruction 0:%d", (Int)lo6); |
| if (di->ddump_frames) |
| VG_(printf)(" rci:run_CF_instruction:default\n"); |
| i = 0; |
| break; |
| } |
| |
| return i; |
| } |
| |
| |
| /* Show a CFI instruction, and also return its length. Show it as |
| close as possible (preferably identical) to how GNU binutils |
| readelf --debug-dump=frames would. */ |
| |
| static Int show_CF_instruction ( UChar* instr, |
| AddressDecodingInfo* adi, |
| Int code_a_f, Int data_a_f ) |
| { |
| UInt delta; |
| Int off, coff, reg, reg2, nleb, len; |
| 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)(" sci:DW_CFA_advance_loc(%d)\n", (Int)lo6); |
| return i; |
| } |
| |
| if (hi2 == DW_CFA_offset) { |
| off = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| coff = off * data_a_f; |
| VG_(printf)(" DW_CFA_offset: r%d at cfa%s%d\n", |
| (Int)lo6, coff < 0 ? "" : "+", (Int)coff ); |
| return i; |
| } |
| |
| if (hi2 == DW_CFA_restore) { |
| VG_(printf)(" sci:DW_CFA_restore(r%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: |
| /* WAS: loc = read_Addr(&instr[i]); i+= sizeof(Addr); |
| (now known to be incorrect -- the address is encoded) */ |
| loc = read_encoded_Addr(&len, adi, &instr[i]); |
| i += len; |
| VG_(printf)(" sci:DW_CFA_set_loc(%#lx)\n", loc); |
| break; |
| |
| case DW_CFA_advance_loc1: |
| delta = (UInt)read_UChar(&instr[i]); i+= sizeof(UChar); |
| VG_(printf)(" sci:DW_CFA_advance_loc1(%d)\n", delta); |
| break; |
| |
| case DW_CFA_advance_loc2: |
| delta = (UInt)read_UShort(&instr[i]); i+= sizeof(UShort); |
| VG_(printf)(" sci: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 ofs %d\n", (Int)reg, (Int)off); |
| break; |
| |
| case DW_CFA_def_cfa_sf: |
| reg = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| off = read_leb128( &instr[i], &nleb, 1 ); |
| i += nleb; |
| VG_(printf)(" DW_CFA_def_cfa_sf: r%d ofs %d\n", |
| (Int)reg, (Int)(off * data_a_f)); |
| 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)(" sci: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)(" sci: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)(" sci:DW_CFA_def_cfa_offset(%d)\n", off); |
| break; |
| |
| case DW_CFA_def_cfa_offset_sf: |
| off = read_leb128( &instr[i], &nleb, 1); |
| i += nleb; |
| VG_(printf)(" sci:DW_CFA_def_cfa_offset_sf(%d)\n", off); |
| break; |
| |
| case DW_CFA_restore_extended: |
| reg = read_leb128( &instr[i], &nleb, 0); |
| i += nleb; |
| VG_(printf)(" sci:DW_CFA_restore_extended(r%d)\n", reg); |
| break; |
| |
| case DW_CFA_undefined: |
| reg = read_leb128( &instr[i], &nleb, 0); |
| i += nleb; |
| VG_(printf)(" sci:DW_CFA_undefined(r%d)\n", reg); |
| break; |
| |
| case DW_CFA_same_value: |
| reg = read_leb128( &instr[i], &nleb, 0); |
| i += nleb; |
| VG_(printf)(" sci:DW_CFA_same_value(r%d)\n", reg); |
| break; |
| |
| case DW_CFA_remember_state: |
| VG_(printf)(" sci:DW_CFA_remember_state\n"); |
| break; |
| |
| case DW_CFA_restore_state: |
| VG_(printf)(" sci:DW_CFA_restore_state\n"); |
| break; |
| |
| case DW_CFA_GNU_args_size: |
| off = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| VG_(printf)(" sci:DW_CFA_GNU_args_size(%d)\n", off ); |
| break; |
| |
| case DW_CFA_def_cfa_expression: |
| len = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| i += len; |
| VG_(printf)(" sci:DW_CFA_def_cfa_expression(length %d)\n", len); |
| break; |
| |
| case DW_CFA_expression: |
| reg = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| len = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| i += len; |
| VG_(printf)(" sci:DW_CFA_expression(r%d, length %d)\n", reg, len); |
| break; |
| |
| case DW_CFA_val_expression: |
| reg = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| len = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| i += len; |
| VG_(printf)(" sci:DW_CFA_val_expression(r%d, length %d)\n", reg, len); |
| break; |
| |
| case DW_CFA_offset_extended: |
| reg = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| off = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| VG_(printf)(" sci:DW_CFA_offset_extended(r%d, " |
| "off %d x data_af)\n", reg, off); |
| 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; |
| coff = (Int)(off * data_a_f); |
| VG_(printf)(" DW_CFA_offset_extended_sf: r%d at cfa%s%d\n", |
| reg, coff < 0 ? "" : "+", coff); |
| break; |
| |
| case DW_CFA_GNU_negative_offset_extended: |
| reg = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| off = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| VG_(printf)(" sci:DW_CFA_GNU_negative_offset_extended" |
| "(r%d, off %d x data_af)\n", reg, -off); |
| break; |
| |
| case DW_CFA_val_offset: |
| reg = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| off = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| VG_(printf)(" sci:DW_CFA_val_offset(r%d, off %d x data_af)\n", |
| reg, off); |
| break; |
| |
| case DW_CFA_val_offset_sf: |
| reg = read_leb128( &instr[i], &nleb, 0 ); |
| i += nleb; |
| off = read_leb128( &instr[i], &nleb, 1 ); |
| i += nleb; |
| VG_(printf)(" sci:DW_CFA_val_offset_sf(r%d, off %d x data_af)\n", |
| reg, off); |
| break; |
| |
| case DW_CFA_GNU_window_save: |
| VG_(printf)(" sci:DW_CFA_GNU_window_save\n"); |
| break; |
| |
| default: |
| VG_(printf)(" sci:0:%d\n", (Int)lo6); |
| break; |
| } |
| |
| return i; |
| } |
| |
| |
| /* Show the instructions in instrs[0 .. ilen-1]. */ |
| static void show_CF_instructions ( UChar* instrs, Int ilen, |
| AddressDecodingInfo* adi, |
| Int code_a_f, Int data_a_f ) |
| { |
| Int i = 0; |
| while (True) { |
| if (i >= ilen) break; |
| i += show_CF_instruction( &instrs[i], adi, code_a_f, data_a_f ); |
| } |
| } |
| |
| |
| /* 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 ( struct _DebugInfo* di, |
| Bool record, |
| UnwindContext* ctx, UChar* instrs, Int ilen, |
| UWord fde_arange, |
| UnwindContext* restore_ctx, |
| AddressDecodingInfo* adi ) |
| { |
| DiCfSI cfsi; |
| 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], adi, |
| ctx->code_a_f, ctx->data_a_f ); |
| j = run_CF_instruction( ctx, &instrs[i], restore_ctx, adi, di ); |
| if (j == 0) |
| return False; /* execution failed */ |
| i += j; |
| if (0) ppUnwindContext(ctx); |
| if (record && loc_prev != ctx->loc) { |
| summ_ok = summarise_context ( &cfsi, loc_prev, ctx, di ); |
| if (summ_ok) { |
| ML_(addDiCfSI)(di, &cfsi); |
| if (di->trace_cfi) |
| ML_(ppDiCfSI)(di->cfsi_exprs, &cfsi); |
| } |
| } |
| } |
| if (ctx->loc < fde_arange) { |
| loc_prev = ctx->loc; |
| ctx->loc = fde_arange; |
| if (record) { |
| summ_ok = summarise_context ( &cfsi, loc_prev, ctx, di ); |
| if (summ_ok) { |
| ML_(addDiCfSI)(di, &cfsi); |
| if (di->trace_cfi) |
| ML_(ppDiCfSI)(di->cfsi_exprs, &cfsi); |
| } |
| } |
| } |
| return True; |
| } |
| |
| |
| /* ------------ Main entry point for CFI reading ------------ */ |
| |
| typedef |
| struct { |
| /* This gives the CIE an identity to which FDEs will refer. */ |
| ULong offset; |
| /* Code, data factors. */ |
| Int code_a_f; |
| Int data_a_f; |
| /* Return-address pseudo-register. */ |
| Int ra_reg; |
| UChar address_encoding; |
| /* Where are the instrs? Note, this are simply pointers back to |
| the transiently-mapped-in section. */ |
| UChar* instrs; |
| Int ilen; |
| /* God knows .. don't ask */ |
| Bool saw_z_augmentation; |
| } |
| CIE; |
| |
| static void init_CIE ( CIE* cie ) |
| { |
| cie->offset = 0; |
| cie->code_a_f = 0; |
| cie->data_a_f = 0; |
| cie->ra_reg = 0; |
| cie->address_encoding = 0; |
| cie->instrs = NULL; |
| cie->ilen = 0; |
| cie->saw_z_augmentation = False; |
| } |
| |
| #define N_CIEs 2000 |
| static CIE the_CIEs[N_CIEs]; |
| |
| |
| void ML_(read_callframe_info_dwarf3) |
| ( /*OUT*/struct _DebugInfo* di, UChar* ehframe_image ) |
| { |
| Int nbytes; |
| HChar* how = NULL; |
| Int n_CIEs = 0; |
| UChar* data = ehframe_image; |
| |
| # if defined(VGP_ppc32_linux) || defined(VGP_ppc64_linux) |
| /* These targets don't use CFI-based stack unwinding. */ |
| return; |
| # endif |
| |
| if (di->trace_cfi) { |
| VG_(printf)("\n-----------------------------------------------\n"); |
| VG_(printf)("CFI info: szB %ld, _avma %#lx, _image %p\n", |
| di->ehframe_size, di->ehframe_avma, |
| ehframe_image ); |
| VG_(printf)("CFI info: name %s\n", |
| di->filename ); |
| } |
| |
| /* Loop over CIEs/FDEs */ |
| |
| /* Conceptually, the frame info is a sequence of FDEs, one for each |
| function. Inside an FDE is a miniature program for a special |
| state machine, which, when run, produces the stack-unwinding |
| info for that function. |
| |
| Because the FDEs typically have much in common, and because the |
| DWARF designers appear to have been fanatical about space |
| saving, the common parts are factored out into so-called CIEs. |
| That means that what we traverse is a sequence of structs, each |
| of which is either a FDE (usually) or a CIE (occasionally). |
| Each FDE has a field indicating which CIE is the one pertaining |
| to it. |
| |
| The following loop traverses the sequence. FDEs are dealt with |
| immediately; once we harvest the useful info in an FDE, it is |
| then forgotten about. By contrast, CIEs are validated and |
| dumped into an array, because later FDEs may refer to any |
| previously-seen CIE. |
| */ |
| while (True) { |
| UChar* ciefde_start; |
| ULong ciefde_len; |
| ULong cie_pointer; |
| Bool dw64; |
| |
| /* Are we done? */ |
| if (data == ehframe_image + di->ehframe_size) |
| return; |
| |
| /* Overshot the end? Means something is wrong */ |
| if (data > ehframe_image + di->ehframe_size) { |
| 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. */ |
| |
| ciefde_start = data; |
| if (di->trace_cfi) |
| VG_(printf)("\ncie/fde.start = %p (ehframe_image + 0x%lx)\n", |
| ciefde_start, |
| ciefde_start - ehframe_image + 0UL); |
| |
| ciefde_len = (ULong) read_UInt(data); data += sizeof(UInt); |
| if (di->trace_cfi) |
| VG_(printf)("cie/fde.length = %lld\n", ciefde_len); |
| |
| /* Apparently, if the .length field is zero, we are at the end |
| of the sequence. This is stated in the Generic Elf |
| Specification (see comments far above here) and is one of the |
| places where .eh_frame and .debug_frame data differ. */ |
| if (ciefde_len == 0) { |
| if (di->ddump_frames) |
| VG_(printf)("%08lx ZERO terminator\n\n", |
| ((Addr)ciefde_start) - ((Addr)ehframe_image)); |
| return; |
| } |
| |
| /* If the .length field is 0xFFFFFFFF then we're dealing with |
| 64-bit DWARF, and the real length is stored as a 64-bit |
| number immediately following it. */ |
| dw64 = False; |
| if (ciefde_len == 0xFFFFFFFFUL) { |
| dw64 = True; |
| ciefde_len = read_ULong(data); data += sizeof(ULong); |
| } |
| |
| /* Now get the CIE ID, whose size depends on the DWARF 32 vs |
| 64-ness. */ |
| if (dw64) { |
| cie_pointer = read_ULong(data); |
| data += sizeof(ULong); /* XXX see XXX below */ |
| } else { |
| cie_pointer = (ULong)read_UInt(data); |
| data += sizeof(UInt); /* XXX see XXX below */ |
| } |
| |
| if (di->trace_cfi) |
| VG_(printf)("cie.pointer = %lld\n", cie_pointer); |
| |
| /* If cie_pointer is zero, we've got a CIE; else it's an FDE. */ |
| if (cie_pointer == 0) { |
| |
| Int this_CIE; |
| UChar cie_version; |
| UChar* cie_augmentation; |
| |
| /* --------- CIE --------- */ |
| if (di->trace_cfi) |
| VG_(printf)("------ new CIE (#%d of 0 .. %d) ------\n", |
| n_CIEs, N_CIEs - 1); |
| |
| /* Allocate a new CIE record. */ |
| vg_assert(n_CIEs >= 0 && n_CIEs <= N_CIEs); |
| if (n_CIEs == N_CIEs) { |
| how = "N_CIEs is too low. Increase and recompile."; |
| goto bad; |
| } |
| |
| this_CIE = n_CIEs; |
| n_CIEs++; |
| init_CIE( &the_CIEs[this_CIE] ); |
| |
| /* Record its offset. This is how we will find it again |
| later when looking at an FDE. */ |
| the_CIEs[this_CIE].offset = (ULong)(ciefde_start - ehframe_image); |
| |
| if (di->ddump_frames) |
| VG_(printf)("%08lx %08lx %08lx CIE\n", |
| ((Addr)ciefde_start) - ((Addr)ehframe_image), |
| (Addr)ciefde_len, |
| (Addr)(UWord)cie_pointer ); |
| |
| cie_version = read_UChar(data); data += sizeof(UChar); |
| if (di->trace_cfi) |
| VG_(printf)("cie.version = %d\n", (Int)cie_version); |
| if (di->ddump_frames) |
| VG_(printf)(" Version: %d\n", (Int)cie_version); |
| if (cie_version != 1) { |
| how = "unexpected CIE version (not 1)"; |
| goto bad; |
| } |
| |
| cie_augmentation = data; |
| data += 1 + VG_(strlen)(cie_augmentation); |
| if (di->trace_cfi) |
| VG_(printf)("cie.augment = \"%s\"\n", cie_augmentation); |
| if (di->ddump_frames) |
| VG_(printf)(" Augmentation: \"%s\"\n", cie_augmentation); |
| |
| if (cie_augmentation[0] == 'e' && cie_augmentation[1] == 'h') { |
| data += sizeof(Addr); |
| cie_augmentation += 2; |
| } |
| |
| the_CIEs[this_CIE].code_a_f = read_leb128( data, &nbytes, 0); |
| data += nbytes; |
| if (di->trace_cfi) |
| VG_(printf)("cie.code_af = %d\n", |
| the_CIEs[this_CIE].code_a_f); |
| if (di->ddump_frames) |
| VG_(printf)(" Code alignment factor: %d\n", |
| (Int)the_CIEs[this_CIE].code_a_f); |
| |
| the_CIEs[this_CIE].data_a_f = read_leb128( data, &nbytes, 1); |
| data += nbytes; |
| if (di->trace_cfi) |
| VG_(printf)("cie.data_af = %d\n", |
| the_CIEs[this_CIE].data_a_f); |
| if (di->ddump_frames) |
| VG_(printf)(" Data alignment factor: %d\n", |
| (Int)the_CIEs[this_CIE].data_a_f); |
| |
| the_CIEs[this_CIE].ra_reg = (Int)read_UChar(data); |
| data += sizeof(UChar); |
| if (di->trace_cfi) |
| VG_(printf)("cie.ra_reg = %d\n", |
| the_CIEs[this_CIE].ra_reg); |
| if (di->ddump_frames) |
| VG_(printf)(" Return address column: %d\n", |
| (Int)the_CIEs[this_CIE].ra_reg); |
| |
| if (the_CIEs[this_CIE].ra_reg < 0 |
| || the_CIEs[this_CIE].ra_reg >= N_CFI_REGS) { |
| how = "cie.ra_reg has implausible value"; |
| goto bad; |
| } |
| |
| the_CIEs[this_CIE].saw_z_augmentation |
| = *cie_augmentation == 'z'; |
| if (the_CIEs[this_CIE].saw_z_augmentation) { |
| UInt length = read_leb128( data, &nbytes, 0); |
| data += nbytes; |
| the_CIEs[this_CIE].instrs = data + length; |
| cie_augmentation++; |
| if (di->ddump_frames) { |
| UInt i; |
| VG_(printf)(" Augmentation data: "); |
| for (i = 0; i < length; i++) |
| VG_(printf)(" %02x", (UInt)data[i]); |
| VG_(printf)("\n"); |
| } |
| } else { |
| the_CIEs[this_CIE].instrs = NULL; |
| } |
| |
| the_CIEs[this_CIE].address_encoding = default_Addr_encoding(); |
| |
| while (*cie_augmentation) { |
| switch (*cie_augmentation) { |
| case 'L': |
| data++; |
| cie_augmentation++; |
| break; |
| case 'R': |
| the_CIEs[this_CIE].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; |
| case 'S': |
| cie_augmentation++; |
| break; |
| default: |
| if (the_CIEs[this_CIE].instrs == NULL) { |
| how = "unhandled cie.augmentation"; |
| goto bad; |
| } |
| data = the_CIEs[this_CIE].instrs; |
| goto done_augmentation; |
| } |
| } |
| |
| done_augmentation: |
| |
| if (di->trace_cfi) |
| VG_(printf)("cie.encoding = 0x%x\n", |
| the_CIEs[this_CIE].address_encoding); |
| |
| the_CIEs[this_CIE].instrs = data; |
| the_CIEs[this_CIE].ilen |
| = ciefde_start + ciefde_len + sizeof(UInt) - data; |
| if (di->trace_cfi) { |
| VG_(printf)("cie.instrs = %p\n", the_CIEs[this_CIE].instrs); |
| VG_(printf)("cie.ilen = %d\n", the_CIEs[this_CIE].ilen); |
| } |
| |
| if (the_CIEs[this_CIE].ilen < 0 |
| || the_CIEs[this_CIE].ilen > di->ehframe_size) { |
| how = "implausible # cie initial insns"; |
| goto bad; |
| } |
| |
| data += the_CIEs[this_CIE].ilen; |
| |
| /* Show the CIE's instructions (the preamble for each FDE |
| that uses this CIE). */ |
| if (di->ddump_frames) |
| VG_(printf)("\n"); |
| |
| if (di->trace_cfi || di->ddump_frames) { |
| AddressDecodingInfo adi; |
| adi.encoding = the_CIEs[this_CIE].address_encoding; |
| adi.ehframe_image = ehframe_image; |
| adi.ehframe_avma = di->ehframe_avma; |
| adi.text_bias = di->text_bias; |
| show_CF_instructions( the_CIEs[this_CIE].instrs, |
| the_CIEs[this_CIE].ilen, &adi, |
| the_CIEs[this_CIE].code_a_f, |
| the_CIEs[this_CIE].data_a_f ); |
| } |
| |
| if (di->ddump_frames) |
| VG_(printf)("\n"); |
| |
| } else { |
| |
| AddressDecodingInfo adi; |
| UnwindContext ctx, restore_ctx; |
| Int cie; |
| ULong look_for; |
| Bool ok; |
| Addr fde_initloc; |
| UWord fde_arange; |
| UChar* fde_instrs; |
| Int fde_ilen; |
| |
| /* --------- FDE --------- */ |
| |
| /* Find the relevant CIE. The CIE we want is located |
| cie_pointer bytes back from here. */ |
| |
| /* re sizeof(UInt) / sizeof(ULong), matches XXX above. */ |
| look_for = (data - (dw64 ? sizeof(ULong) : sizeof(UInt)) |
| - ehframe_image) |
| - cie_pointer; |
| |
| for (cie = 0; cie < n_CIEs; cie++) { |
| if (0) VG_(printf)("look for %lld %lld\n", |
| look_for, the_CIEs[cie].offset ); |
| if (the_CIEs[cie].offset == look_for) |
| break; |
| } |
| vg_assert(cie >= 0 && cie <= n_CIEs); |
| if (cie == n_CIEs) { |
| how = "FDE refers to not-findable CIE"; |
| goto bad; |
| } |
| |
| adi.encoding = the_CIEs[cie].address_encoding; |
| adi.ehframe_image = ehframe_image; |
| adi.ehframe_avma = di->ehframe_avma; |
| adi.text_bias = di->text_bias; |
| fde_initloc = read_encoded_Addr(&nbytes, &adi, data); |
| data += nbytes; |
| if (di->trace_cfi) |
| VG_(printf)("fde.initloc = %#lx\n", fde_initloc); |
| |
| adi.encoding = the_CIEs[cie].address_encoding & 0xf; |
| adi.ehframe_image = ehframe_image; |
| adi.ehframe_avma = di->ehframe_avma; |
| adi.text_bias = di->text_bias; |
| |
| /* WAS (incorrectly): |
| fde_arange = read_encoded_Addr(&nbytes, &adi, data); |
| data += nbytes; |
| The following corresponds to what binutils/dwarf.c does: |
| */ |
| { UInt ptr_size = size_of_encoded_Addr( adi.encoding ); |
| switch (ptr_size) { |
| case 8: case 4: case 2: case 1: |
| fde_arange |
| = (UWord)read_le_u_encoded_literal(data, ptr_size); |
| data += ptr_size; |
| break; |
| default: |
| how = "unknown arange field encoding in FDE"; |
| goto bad; |
| } |
| } |
| |
| if (di->trace_cfi) |
| VG_(printf)("fde.arangec = %#lx\n", fde_arange); |
| |
| if (di->ddump_frames) |
| VG_(printf)("%08lx %08lx %08lx FDE cie=%08lx pc=%08lx..%08lx\n", |
| ((Addr)ciefde_start) - ((Addr)ehframe_image), |
| (Addr)ciefde_len, |
| (Addr)(UWord)cie_pointer, |
| (Addr)look_for, |
| ((Addr)fde_initloc) - di->text_bias, |
| ((Addr)fde_initloc) - di->text_bias + fde_arange); |
| |
| if (the_CIEs[cie].saw_z_augmentation) { |
| UInt length = read_leb128( data, &nbytes, 0); |
| data += nbytes; |
| if (di->ddump_frames && (length > 0)) { |
| UInt i; |
| VG_(printf)(" Augmentation data: "); |
| for (i = 0; i < length; i++) |
| VG_(printf)(" %02x", (UInt)data[i]); |
| VG_(printf)("\n\n"); |
| } |
| data += length; |
| } |
| |
| fde_instrs = data; |
| fde_ilen = ciefde_start + ciefde_len + sizeof(UInt) - data; |
| if (di->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 > di->ehframe_size) { |
| how = "implausible # fde insns"; |
| goto bad; |
| } |
| |
| data += fde_ilen; |
| |
| adi.encoding = the_CIEs[cie].address_encoding; |
| adi.ehframe_image = ehframe_image; |
| adi.ehframe_avma = di->ehframe_avma; |
| adi.text_bias = di->text_bias; |
| |
| if (di->trace_cfi) |
| show_CF_instructions( fde_instrs, fde_ilen, &adi, |
| the_CIEs[cie].code_a_f, |
| the_CIEs[cie].data_a_f ); |
| |
| initUnwindContext(&ctx); |
| ctx.code_a_f = the_CIEs[cie].code_a_f; |
| ctx.data_a_f = the_CIEs[cie].data_a_f; |
| ctx.initloc = fde_initloc; |
| ctx.ra_reg = the_CIEs[cie].ra_reg; |
| ctx.exprs = VG_(newXA)( ML_(dinfo_zalloc), "di.rcid.1", |
| ML_(dinfo_free), |
| sizeof(CfiExpr) ); |
| vg_assert(ctx.exprs); |
| |
| /* Run the CIE's instructions. Ugly hack: if |
| --debug-dump=frames is in effect, suppress output for |
| these instructions since they will already have been shown |
| at the time the CIE was first encountered. Note, not |
| thread safe - if this reader is ever made threaded, should |
| fix properly. */ |
| { Bool hack = di->ddump_frames; |
| di->ddump_frames = False; |
| initUnwindContext(&restore_ctx); |
| ok = run_CF_instructions( |
| di, False, &ctx, the_CIEs[cie].instrs, |
| the_CIEs[cie].ilen, 0, NULL, &adi |
| ); |
| di->ddump_frames = hack; |
| } |
| /* And now run the instructions for the FDE, starting from |
| the state created by running the CIE preamble |
| instructions. */ |
| if (ok) { |
| restore_ctx = ctx; |
| ok = run_CF_instructions( |
| di, True, &ctx, fde_instrs, fde_ilen, fde_arange, |
| &restore_ctx, &adi |
| ); |
| if (di->ddump_frames) |
| VG_(printf)("\n"); |
| } |
| |
| VG_(deleteXA)( ctx.exprs ); |
| } |
| } |
| |
| return; |
| |
| bad: |
| if (!VG_(clo_xml) && VG_(clo_verbosity) > 1) |
| VG_(message)(Vg_UserMsg, "Warning: %s in DWARF2 CFI reading", how); |
| return; |
| } |
| |
| |
| /*--------------------------------------------------------------------*/ |
| /*--- end ---*/ |
| /*--------------------------------------------------------------------*/ |