1# This testcase is part of GDB, the GNU debugger. 2 3# Copyright 2004, 2005, 2007, 2008, 2009, 2010, 2011 4# Free Software Foundation, Inc. 5 6# This program is free software; you can redistribute it and/or modify 7# it under the terms of the GNU General Public License as published by 8# the Free Software Foundation; either version 3 of the License, or 9# (at your option) any later version. 10# 11# This program is distributed in the hope that it will be useful, 12# but WITHOUT ANY WARRANTY; without even the implied warranty of 13# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14# GNU General Public License for more details. 15# 16# You should have received a copy of the GNU General Public License 17# along with this program. If not, see <http://www.gnu.org/licenses/>. 18 19# Check that GDB can trigger and backtrace SIGSEGV signal stacks 20# caused by both accessing (data) and executing (code) at address 21# zero. 22 23# On function descriptor architectures, a zero descriptor, instead of 24# a NULL pointer, is used. That way the NULL code test always 25# contains a zero code reference. 26 27# For recovery, sigjmp/longjmp are used. 28 29# This also tests backtrace/gdb1476. 30 31if [target_info exists gdb,nosignals] { 32 verbose "Skipping signull.exp because of nosignals." 33 continue 34} 35 36if $tracelevel { 37 strace $tracelevel 38} 39 40 41set testfile "signull" 42set srcfile ${testfile}.c 43set binfile ${objdir}/${subdir}/${testfile} 44if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } { 45 untested signull.exp 46 return -1 47} 48 49gdb_exit 50gdb_start 51gdb_reinitialize_dir $srcdir/$subdir 52gdb_load ${binfile} 53 54# 55# Run to `main' where we begin our tests. 56# 57 58if ![runto_main] then { 59 gdb_suppress_tests 60} 61 62# If we can examine what's at memory address 0, it is possible that we 63# could also execute it. This could probably make us run away, 64# executing random code, which could have all sorts of ill effects, 65# especially on targets without an MMU. Don't run the tests in that 66# case. 67 68gdb_test_multiple "x 0" "memory at address 0" { 69 -re "0x0:.*Cannot access memory at address 0x0.*$gdb_prompt $" { } 70 -re "0x0:.*Error accessing memory address 0x0.*$gdb_prompt $" { } 71 -re ".*$gdb_prompt $" { 72 untested "Memory at address 0 is possibly executable" 73 return 74 } 75} 76 77# If an attempt to call a NULL pointer leaves the inferior in main, 78# then function pointers are descriptors, probe this and remember the 79# result. 80 81gdb_test_no_output "set test = code_entry_point" \ 82 "set for function pointer probe" 83set test "probe function pointer" 84set function_pointer code_entry_point 85set signame "SIGSEGV" 86gdb_test_multiple "continue" "$test" { 87 -re "Program received signal SIGSEGV.*bowler .*$gdb_prompt $" { 88 set function_pointer code_descriptor 89 pass "$test (function descriptor)" 90 } 91 -re "Program received signal SIGSEGV.*0.*$gdb_prompt $" { 92 pass "$test (function entry-point)" 93 } 94 -re "Program received signal SIGBUS.*0.*$gdb_prompt $" { 95 set signame SIGBUS 96 pass "$test (function entry-point)" 97 } 98} 99 100# Re-start from scratch, breakpoint the bowler so that control is 101# regained after each test, and run up to that. 102rerun_to_main 103gdb_test "break bowler" 104gdb_test "break keeper" 105# By default Stop:Yes Print:Yes Pass:Yes 106gdb_test "handle SIGSEGV" "SIGSEGV.*Yes.*Yes.*Yes.*Segmentation fault" 107gdb_test "handle SIGBUS" "SIGBUS.*Yes.*Yes.*Yes.*Bus error" 108 109# For the given signal type, check that: the SIGSEGV occures; a 110# backtrace from the SEGV works; the sigsegv is delivered; a backtrace 111# through the SEGV works. 112 113proc test_segv { name tag bt_from_segv bt_from_keeper } { 114 global signame 115 gdb_test continue "Breakpoint.* bowler.*" "${name}; start with the bowler" 116 # NB: Don't use $tag in the testname - changes across systems. 117 gdb_test_no_output "set test = $tag" "${name}; select the pointer type" 118 gdb_test continue "Program received signal ${signame}.*" \ 119 "${name}; take the ${signame}" 120 gdb_test backtrace $bt_from_segv "${name}; backtrace from ${signame}" 121 gdb_test continue "Breakpoint.* keeper.*" "${name}; continue to the keeper" 122 gdb_test backtrace $bt_from_keeper "${name}; backtrace from keeper through ${signame}" 123} 124 125test_segv "data read" data_read \ 126 {#0 .* bowler .*#1 .* main .*} \ 127 {#0 .* keeper .*#1 .* handler .*#2 .* bowler .*#3 .* main .*} 128test_segv "data write" data_write \ 129 {#0 .* bowler .*#1 .* main .*} \ 130 {#0 .* keeper .*#1 .* handler .*#2 .* bowler .*#3 .* main .*} 131test_segv code $function_pointer \ 132 {#0 .* 0x0+ .*#1 .* bowler .*#2 .* main .*} \ 133 {#0 .* keeper .*#1 .* handler .*#2 .* 0x0+ .*#3 .* bowler .*#4 .* main .*} 134