https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=181390 2006-09-28 Jan Kratochvil * gdb/utils.c (paddress): Disable cutting of the printed addresses to the target's address bit size; user wants to see everything. * gdb/value.c (value_as_address_core): Original `value_as_address'. (value_as_address): New `value_as_address' wrapper - cut memory address to the target's address bit size, bugreport by John Reiser. 2008-03-02 Jan Kratochvil Port to GDB-6.8pre. New testcase `gdb.arch/amd64-i386-address.exp'. Index: gdb-6.7.50.20080227/gdb/utils.c =================================================================== --- gdb-6.7.50.20080227.orig/gdb/utils.c 2008-03-02 14:28:44.000000000 +0100 +++ gdb-6.7.50.20080227/gdb/utils.c 2008-03-02 14:35:09.000000000 +0100 @@ -2540,6 +2540,14 @@ paddr_nz (CORE_ADDR addr) const char * paddress (CORE_ADDR addr) { + /* Do not cut the address as the user should see all the information + available. Otherwise 64-bit gdb debugging 32-bit inferior would + report for `x/x 0xffffffffffffce70' error + `Cannot access memory at 0xffffce70' while the error occured just + because of the higher order bits 0xffffffff00000000 there. + This specific error no longer occurs as the address is now cut + during execution by `value_as_address'. */ +#if 0 /* Truncate address to the size of a target address, avoiding shifts larger or equal than the width of a CORE_ADDR. The local variable ADDR_BIT stops the compiler reporting a shift overflow @@ -2553,6 +2561,8 @@ paddress (CORE_ADDR addr) if (addr_bit < (sizeof (CORE_ADDR) * HOST_CHAR_BIT)) addr &= ((CORE_ADDR) 1 << addr_bit) - 1; +#endif + return hex_string (addr); } Index: gdb-6.7.50.20080227/gdb/value.c =================================================================== --- gdb-6.7.50.20080227.orig/gdb/value.c 2008-01-18 18:07:40.000000000 +0100 +++ gdb-6.7.50.20080227/gdb/value.c 2008-03-02 14:36:38.000000000 +0100 @@ -983,11 +983,9 @@ value_as_double (struct value *val) return foo; } -/* Extract a value as a C pointer. Does not deallocate the value. - Note that val's type may not actually be a pointer; value_as_long - handles all the cases. */ -CORE_ADDR -value_as_address (struct value *val) +/* See `value_as_address' below - core of value to C pointer extraction. */ +static CORE_ADDR +value_as_address_core (struct value *val) { /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure whether we want this to be true eventually. */ @@ -1087,6 +1085,34 @@ value_as_address (struct value *val) return unpack_long (value_type (val), value_contents (val)); #endif } + +/* Extract a value as a C pointer. Does not deallocate the value. + Note that val's type may not actually be a pointer; value_as_long + handles all the cases. */ +CORE_ADDR +value_as_address (struct value *val) +{ + CORE_ADDR addr; + int addr_bit; + + addr = value_as_address_core (val); + + /* Truncate address to the size of a target address, avoiding shifts + larger or equal than the width of a CORE_ADDR. The local + variable ADDR_BIT stops the compiler reporting a shift overflow + when it won't occur. */ + /* NOTE: This assumes that the significant address information is + kept in the least significant bits of ADDR - the upper bits were + either zero or sign extended. Should ADDRESS_TO_POINTER() or + some ADDRESS_TO_PRINTABLE() be used to do the conversion? */ + + addr_bit = gdbarch_addr_bit (current_gdbarch); + + if (addr_bit < (sizeof (CORE_ADDR) * HOST_CHAR_BIT)) + addr &= ((CORE_ADDR) 1 << addr_bit) - 1; + + return addr; +} /* Unpack raw data (copied from debugee, target byte order) at VALADDR as a long, or as a double, assuming the raw data is described --- /dev/null 2008-03-01 10:30:54.797374318 +0100 +++ gdb-6.7.50.20080227/gdb/testsuite/gdb.arch/amd64-i386-address.S 2008-03-02 12:47:06.000000000 +0100 @@ -0,0 +1,32 @@ +/* Copyright 2008 Free Software Foundation, Inc. + + 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 3 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, see . + + Please email any bugs, comments, and/or additions to this file to: + bug-gdb@gnu.org + + This file is part of the gdb testsuite. + + Test UNsigned extension of the 32-bit inferior address on a 64-bit host. + This file is based on the work by John Reiser. + This file was created by Jan Kratochvil . + https://bugzilla.redhat.com/show_bug.cgi?id=181390 */ + +_start: .globl _start + nop + int3 + movl %esp,%ebx + int3 # examining memory from $ebx fails, from $esp succeeds + nop + nop --- /dev/null 2008-03-01 10:30:54.797374318 +0100 +++ gdb-6.7.50.20080227/gdb/testsuite/gdb.arch/amd64-i386-address.exp 2008-03-02 12:57:11.000000000 +0100 @@ -0,0 +1,62 @@ +# Copyright 2008 Free Software Foundation, Inc. + +# 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 3 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, see . + +# Please email any bugs, comments, and/or additions to this file to: +# bug-gdb@gnu.org + +# This file is part of the gdb testsuite. + +# Test UNsigned extension of the 32-bit inferior address on a 64-bit host. +# This file is based on the work by John Reiser. +# This file was created by Jan Kratochvil . +# https://bugzilla.redhat.com/show_bug.cgi?id=181390 + +if {![istarget "x86_64-*-*"]} then { + verbose "Skipping amd64->i386 adress test." + return +} + +set testfile "amd64-i386-address" +set srcfile ${testfile}.S +set binfile ${objdir}/${subdir}/${testfile} + +if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable [list debug "additional_flags=-m32 -nostdlib"]] != "" } { + untested amd64-i386-address.exp + return -1 +} + +# Get things started. + +gdb_exit +gdb_start +gdb_reinitialize_dir $srcdir/$subdir +gdb_load ${binfile} + +gdb_run_cmd + +set test "trap stop" +gdb_test_multiple "" $test { + -re "Program received signal SIGTRAP,.*_start .*$gdb_prompt $" { + pass $test + } +} + +gdb_test "stepi" ".*_start .*int3.*" + +gdb_test "x/x \$esp" "0x\[0-9a-f\]*:\t0x0*1" + +# Failure case would be: +# 0xff8d7f00: Cannot access memory at address 0xff8d7f00 +gdb_test "x/x \$ebx" "0x\[0-9a-f\]*:\t0x0*1"