gdb/testsuite/gdb.base/signull.exp

   1 # This testcase is part of GDB, the GNU debugger.
   2
   3 # Copyright 2004-2020 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
  36 standard_testfile .c
  37
  38 if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } {
  39     untested "failed to compile"
  40     return -1
  41 }
  42
  43 clean_restart ${binfile}
  44
  45 #
  46 # Run to `main' where we begin our tests.
  47 #
  48
  49 if ![runto_main] then {
  50     fail "can't run to main"
  51     return 0
  52 }
  53
  54 # If we can examine what's at memory address 0, it is possible that we
  55 # could also execute it.  This could probably make us run away,
  56 # executing random code, which could have all sorts of ill effects,
  57 # especially on targets without an MMU.  Don't run the tests in that
  58 # case.
  59
  60 if { [is_address_zero_readable] } {
  61     untested "memory at address 0 is possibly executable"
  62     return
  63 }
  64
  65 # If an attempt to call a NULL pointer leaves the inferior in main,
  66 # then function pointers are descriptors, probe this and remember the
  67 # result.
  68
  69 gdb_test_no_output "set test = code_entry_point" \
  70     "set for function pointer probe"
  71 set test "probe function pointer"
  72 set function_pointer code_entry_point
  73 set signame "SIGSEGV"
  74 gdb_test_multiple "continue" "$test" {
  75     -re "Program received signal SIGSEGV.*bowler .*$gdb_prompt $" {
  76         set function_pointer code_descriptor
  77         pass "$test (function descriptor)"
  78     }
  79     -re "Program received signal SIGSEGV.*0.*$gdb_prompt $" {
  80         pass "$test (function entry-point)"
  81     }
  82     -re "Program received signal SIGBUS.*0.*$gdb_prompt $" {
  83         set signame SIGBUS
  84         pass "$test (function entry-point)"
  85     }
  86 }
  87
  88 # Re-start from scratch, breakpoint the bowler so that control is
  89 # regained after each test, and run up to that.
  90 rerun_to_main
  91 gdb_test "break bowler"
  92 gdb_test "break keeper"
  93 # By default Stop:Yes Print:Yes Pass:Yes
  94 gdb_test "handle SIGSEGV" "SIGSEGV.*Yes.*Yes.*Yes.*Segmentation fault"
  95 gdb_test "handle SIGBUS" "SIGBUS.*Yes.*Yes.*Yes.*Bus error"
  96
  97 # For the given signal type, check that: the SIGSEGV occures; a
  98 # backtrace from the SEGV works; the sigsegv is delivered; a backtrace
  99 # through the SEGV works.
 100
 101 proc test_segv { name tag bt_from_segv bt_from_keeper } {
 102     global signame
 103     gdb_test continue "Breakpoint.* bowler.*" "${name}; start with the bowler"
 104     # NB: Don't use $tag in the testname - changes across systems.
 105     gdb_test_no_output "set test = $tag" "${name}; select the pointer type"
 106     gdb_test continue "Program received signal ${signame}.*" \
 107         "${name}; take the ${signame}"
 108     gdb_test backtrace $bt_from_segv "${name}; backtrace from ${signame}"
 109     gdb_test continue "Breakpoint.* keeper.*" "${name}; continue to the keeper"
 110     gdb_test backtrace $bt_from_keeper "${name}; backtrace from keeper through ${signame}"
 111 }
 112
 113 test_segv "data read" data_read \
 114     {#0 .* bowler .*#1  .* main .*} \
 115     {#0 .* keeper .*#1  .* handler .*#2 .* bowler .*#3  .* main .*}
 116 test_segv "data write" data_write \
 117     {#0 .* bowler .*#1  .* main .*} \
 118     {#0 .* keeper .*#1  .* handler .*#2 .* bowler .*#3  .* main .*}
 119 test_segv code $function_pointer \
 120     {#0 .* 0x0+ .*#1 .* bowler .*#2  .* main .*} \
 121     {#0 .* keeper .*#1  .* handler .*#2 .* 0x0+ .*#3 .* bowler .*#4 .* main .*}