gdb/testsuite/gdb.base/signull.exp

   1 # This testcase is part of GDB, the GNU debugger.
   2
   3 # Copyright 2004, 2005, 2007 Free Software Foundation, Inc.
   4
   5 # This program is free software; you can redistribute it and/or modify
   6 # it under the terms of the GNU General Public License as published by
   7 # the Free Software Foundation; either version 2 of the License, or
   8 # (at your option) any later version.
   9 #
  10 # This program is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 # GNU General Public License for more details.
  14 #
  15 # You should have received a copy of the GNU General Public License
  16 # along with this program; if not, write to the Free Software
  17 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  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
  31 if [target_info exists gdb,nosignals] {
  32     verbose "Skipping signull.exp because of nosignals."
  33     continue
  34 }
  35
  36 if $tracelevel {
  37     strace $tracelevel
  38 }
  39
  40 set prms_id 0
  41 set bug_id 0
  42
  43 set testfile "signull"
  44 set srcfile ${testfile}.c
  45 set binfile ${objdir}/${subdir}/${testfile}
  46 if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } {
  47     untested signull.exp
  48     return -1
  49 }
  50
  51 gdb_exit
  52 gdb_start
  53 gdb_reinitialize_dir $srcdir/$subdir
  54 gdb_load ${binfile}
  55
  56 #
  57 # Run to `main' where we begin our tests.
  58 #
  59
  60 if ![runto_main] then {
  61     gdb_suppress_tests
  62 }
  63
  64 # If we can examine what's at memory address 0, it is possible that we
  65 # could also execute it.  This could probably make us run away,
  66 # executing random code, which could have all sorts of ill effects,
  67 # especially on targets without an MMU.  Don't run the tests in that
  68 # case.
  69
  70 send_gdb "x 0\n"
  71 gdb_expect {
  72     -re "0x0:.*Cannot access memory at address 0x0.*$gdb_prompt $" { }
  73     -re "0x0:.*Error accessing memory address 0x0.*$gdb_prompt $" { }
  74     -re ".*$gdb_prompt $" {
  75         untested "Memory at address 0 is possibly executable"
  76         return
  77     }
  78 }
  79
  80 # If an attempt to call a NULL pointer leaves the inferior in main,
  81 # then function pointers are descriptors, probe this and remember the
  82 # result.
  83
  84 gdb_test "set test = code_entry_point" "" "set for function pointer probe"
  85 set test "probe function pointer"
  86 set function_pointer code_entry_point
  87 gdb_test_multiple "continue" "$test" {
  88     -re "Program received signal SIGSEGV.*bowler .*$gdb_prompt $" {
  89         set function_pointer code_descriptor
  90         pass "$test (function descriptor)"
  91     }
  92     -re "Program received signal SIGSEGV.*0.*$gdb_prompt $" {
  93         pass "$test (function entry-point)"
  94     }
  95 }
  96
  97 # Re-start from scratch, breakpoint the bowler so that control is
  98 # regained after each test, and run up to that.
  99 rerun_to_main
 100 gdb_test "break bowler"
 101 gdb_test "break keeper"
 102 # By default Stop:Yes Print:Yes Pass:Yes
 103 gdb_test "handle SIGSEGV" "SIGSEGV.*Yes.*Yes.*Yes.*Segmentation fault"
 104
 105 # For the given signal type, check that: the SIGSEGV occures; a
 106 # backtrace from the SEGV works; the sigsegv is delivered; a backtrace
 107 # through the SEGV works.
 108
 109 proc test_segv { name tag bt_from_segv bt_from_keeper } {
 110     gdb_test continue "Breakpoint.* bowler.*" "${name}; start with the bowler"
 111     # NB: Don't use $tag in the testname - changes across systems.
 112     gdb_test "set test = $tag" "" "${name}; select the pointer type"
 113     gdb_test continue "Program received signal SIGSEGV.*" \
 114         "${name}; take the SIGSEGV"
 115     gdb_test backtrace $bt_from_segv "${name}; backtrace from SIGSEGV"
 116     gdb_test continue "Breakpoint.* keeper.*" "${name}; continue to the keeper"
 117     gdb_test backtrace $bt_from_keeper "${name}; backtrace from keeper through SIGSEGV"
 118 }
 119
 120 test_segv "data read" data_read \
 121     {#0 .* bowler .*#1  .* main .*} \
 122     {#0 .* keeper .*#1  .* handler .*#2 .* bowler .*#3  .* main .*}
 123 test_segv "data write" data_write \
 124     {#0 .* bowler .*#1  .* main .*} \
 125     {#0 .* keeper .*#1  .* handler .*#2 .* bowler .*#3  .* main .*}
 126 test_segv code $function_pointer \
 127     {#0 .* 0x0+ .*#1 .* bowler .*#2  .* main .*} \
 128     {#0 .* keeper .*#1  .* handler .*#2 .* 0x0+ .*#3 .* bowler .*#4 .* main .*}