gdb/testsuite/gdb.base/signull.exp

   1 # This testcase is part of GDB, the GNU debugger.
   2
   3 # Copyright 2004 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 $tracelevel {
  32     strace $tracelevel
  33 }
  34
  35 set prms_id 0
  36 set bug_id 0
  37
  38 set testfile "signull"
  39 set srcfile ${testfile}.c
  40 set binfile ${objdir}/${subdir}/${testfile}
  41 if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } {
  42     gdb_suppress_entire_file "Testcase compile failed, so all tests in this file will automatically fail."
  43 }
  44
  45 gdb_exit
  46 gdb_start
  47 gdb_reinitialize_dir $srcdir/$subdir
  48 gdb_load ${binfile}
  49
  50 #
  51 # Run to `main' where we begin our tests.
  52 #
  53
  54 if ![runto_main] then {
  55     gdb_suppress_tests
  56 }
  57
  58 # If we can examine what's at memory address 0, it is possible that we
  59 # could also execute it.  This could probably make us run away,
  60 # executing random code, which could have all sorts of ill effects,
  61 # especially on targets without an MMU.  Don't run the tests in that
  62 # case.
  63
  64 send_gdb "x 0\n"
  65 gdb_expect {
  66     -re "0x0:.*Cannot access memory at address 0x0.*$gdb_prompt $" { }
  67     -re "0x0:.*Error accessing memory address 0x0.*$gdb_prompt $" { }
  68     -re ".*$gdb_prompt $" {
  69         untested "Memory at address 0 is possibly executable"
  70         return
  71     }
  72 }
  73
  74 # If an attempt to call a NULL pointer leaves the inferior in main,
  75 # then function pointers are descriptors, probe this and remember the
  76 # result.
  77
  78 gdb_test "set test = code_entry_point" "" "set for function pointer probe"
  79 set test "probe function pointer"
  80 set function_pointer code_entry_point
  81 gdb_test_multiple "continue" "$test" {
  82     -re "Program received signal SIGSEGV.*bowler .*$gdb_prompt $" {
  83         set function_pointer code_descriptor
  84         pass "$test (function descriptor)"
  85     }
  86     -re "Program received signal SIGSEGV.*0.*$gdb_prompt $" {
  87         pass "$test (function entry-point)"
  88     }
  89 }
  90
  91 # Re-start from scratch, breakpoint the bowler so that control is
  92 # regained after each test, and run up to that.
  93 rerun_to_main
  94 gdb_test "break bowler"
  95 gdb_test "break keeper"
  96 # By default Stop:Yes Print:Yes Pass:Yes
  97 gdb_test "handle SIGSEGV" "SIGSEGV.*Yes.*Yes.*Yes.*Segmentation fault"
  98
  99 # For the given signal type, check that: the SIGSEGV occures; a
 100 # backtrace from the SEGV works; the sigsegv is delivered; a backtrace
 101 # through the SEGV works.
 102
 103 proc test_segv { name tag bt_from_segv bt_from_keeper } {
 104     gdb_test continue "Breakpoint.* bowler.*" "${name}; start with the bowler"
 105     # NB: Don't use $tag in the testname - changes across systems.
 106     gdb_test "set test = $tag" "" "${name}; select the pointer type"
 107     gdb_test continue "Program received signal SIGSEGV.*" \
 108         "${name}; take the SIGSEGV"
 109     gdb_test backtrace $bt_from_segv "${name}; backtrace from SIGSEGV"
 110     gdb_test continue "Breakpoint.* keeper.*" "${name}; continue to the keeper"
 111     gdb_test backtrace $bt_from_keeper "${name}; backtrace from keeper through SIGSEGV"
 112 }
 113
 114 test_segv "data read" data_read \
 115     {#0 .* bowler .*#1  .* main .*} \
 116     {#0 .* keeper .*#1  .* handler .*#2 .* bowler .*#3  .* main .*}
 117 test_segv "data write" data_write \
 118     {#0 .* bowler .*#1  .* main .*} \
 119     {#0 .* keeper .*#1  .* handler .*#2 .* bowler .*#3  .* main .*}
 120 test_segv code $function_pointer \
 121     {#0 .* 0x0+ .*#1 .* bowler .*#2  .* main .*} \
 122     {#0 .* keeper .*#1  .* handler .*#2 .* 0x0+ .*#3 .* bowler .*#4 .* main .*}