gdb/testsuite/gdb.base/signull.exp

   1 # This testcase is part of GDB, the GNU debugger.
   2
   3 # Copyright 2004, 2005, 2007, 2008 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 3 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, see <http://www.gnu.org/licenses/>.
  17
  18 # Check that GDB can trigger and backtrace SIGSEGV signal stacks
  19 # caused by both accessing (data) and executing (code) at address
  20 # zero.
  21
  22 # On function descriptor architectures, a zero descriptor, instead of
  23 # a NULL pointer, is used.  That way the NULL code test always
  24 # contains a zero code reference.
  25
  26 # For recovery, sigjmp/longjmp are used.
  27
  28 # This also tests backtrace/gdb1476.
  29
  30 if [target_info exists gdb,nosignals] {
  31     verbose "Skipping signull.exp because of nosignals."
  32     continue
  33 }
  34
  35 if $tracelevel {
  36     strace $tracelevel
  37 }
  38
  39 set prms_id 0
  40 set bug_id 0
  41
  42 set testfile "signull"
  43 set srcfile ${testfile}.c
  44 set binfile ${objdir}/${subdir}/${testfile}
  45 if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } {
  46     untested signull.exp
  47     return -1
  48 }
  49
  50 gdb_exit
  51 gdb_start
  52 gdb_reinitialize_dir $srcdir/$subdir
  53 gdb_load ${binfile}
  54
  55 #
  56 # Run to `main' where we begin our tests.
  57 #
  58
  59 if ![runto_main] then {
  60     gdb_suppress_tests
  61 }
  62
  63 # If we can examine what's at memory address 0, it is possible that we
  64 # could also execute it.  This could probably make us run away,
  65 # executing random code, which could have all sorts of ill effects,
  66 # especially on targets without an MMU.  Don't run the tests in that
  67 # case.
  68
  69 send_gdb "x 0\n"
  70 gdb_expect {
  71     -re "0x0:.*Cannot access memory at address 0x0.*$gdb_prompt $" { }
  72     -re "0x0:.*Error accessing memory address 0x0.*$gdb_prompt $" { }
  73     -re ".*$gdb_prompt $" {
  74         untested "Memory at address 0 is possibly executable"
  75         return
  76     }
  77 }
  78
  79 # If an attempt to call a NULL pointer leaves the inferior in main,
  80 # then function pointers are descriptors, probe this and remember the
  81 # result.
  82
  83 gdb_test "set test = code_entry_point" "" "set for function pointer probe"
  84 set test "probe function pointer"
  85 set function_pointer code_entry_point
  86 gdb_test_multiple "continue" "$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 }
  95
  96 # Re-start from scratch, breakpoint the bowler so that control is
  97 # regained after each test, and run up to that.
  98 rerun_to_main
  99 gdb_test "break bowler"
 100 gdb_test "break keeper"
 101 # By default Stop:Yes Print:Yes Pass:Yes
 102 gdb_test "handle SIGSEGV" "SIGSEGV.*Yes.*Yes.*Yes.*Segmentation fault"
 103
 104 # For the given signal type, check that: the SIGSEGV occures; a
 105 # backtrace from the SEGV works; the sigsegv is delivered; a backtrace
 106 # through the SEGV works.
 107
 108 proc test_segv { name tag bt_from_segv bt_from_keeper } {
 109     gdb_test continue "Breakpoint.* bowler.*" "${name}; start with the bowler"
 110     # NB: Don't use $tag in the testname - changes across systems.
 111     gdb_test "set test = $tag" "" "${name}; select the pointer type"
 112     gdb_test continue "Program received signal SIGSEGV.*" \
 113         "${name}; take the SIGSEGV"
 114     gdb_test backtrace $bt_from_segv "${name}; backtrace from SIGSEGV"
 115     gdb_test continue "Breakpoint.* keeper.*" "${name}; continue to the keeper"
 116     gdb_test backtrace $bt_from_keeper "${name}; backtrace from keeper through SIGSEGV"
 117 }
 118
 119 test_segv "data read" data_read \
 120     {#0 .* bowler .*#1  .* main .*} \
 121     {#0 .* keeper .*#1  .* handler .*#2 .* bowler .*#3  .* main .*}
 122 test_segv "data write" data_write \
 123     {#0 .* bowler .*#1  .* main .*} \
 124     {#0 .* keeper .*#1  .* handler .*#2 .* bowler .*#3  .* main .*}
 125 test_segv code $function_pointer \
 126     {#0 .* 0x0+ .*#1 .* bowler .*#2  .* main .*} \
 127     {#0 .* keeper .*#1  .* handler .*#2 .* 0x0+ .*#3 .* bowler .*#4 .* main .*}