xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/testsuite/gdb.base/signull.exp (revision a04395531661c5e8d314125d5ae77d4cbedd5d73) 
1# This testcase is part of GDB, the GNU debugger.
2
3# Copyright 2004-2019 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
30if [target_info exists gdb,nosignals] {
31    verbose "Skipping signull.exp because of nosignals."
32    continue
33}
34
35
36standard_testfile .c
37
38if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } {
39    untested "failed to compile"
40    return -1
41}
42
43clean_restart ${binfile}
44
45#
46# Run to `main' where we begin our tests.
47#
48
49if ![runto_main] then {
50    fail "can't run to main"
51    return 0
52}
53
54# If we can examine what's at memory address 0, it is possible that we
55# could also execute it.  This could probably make us run away,
56# executing random code, which could have all sorts of ill effects,
57# especially on targets without an MMU.  Don't run the tests in that
58# case.
59
60if { [is_address_zero_readable] } {
61    untested "memory at address 0 is possibly executable"
62    return
63}
64
65# If an attempt to call a NULL pointer leaves the inferior in main,
66# then function pointers are descriptors, probe this and remember the
67# result.
68
69gdb_test_no_output "set test = code_entry_point" \
70    "set for function pointer probe"
71set test "probe function pointer"
72set function_pointer code_entry_point
73set signame "SIGSEGV"
74gdb_test_multiple "continue" "$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.
90rerun_to_main
91gdb_test "break bowler"
92gdb_test "break keeper"
93# By default Stop:Yes Print:Yes Pass:Yes
94gdb_test "handle SIGSEGV" "SIGSEGV.*Yes.*Yes.*Yes.*Segmentation fault"
95gdb_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
101proc 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
113test_segv "data read" data_read \
114    {#0 .* bowler .*#1  .* main .*} \
115    {#0 .* keeper .*#1  .* handler .*#2 .* bowler .*#3  .* main .*}
116test_segv "data write" data_write \
117    {#0 .* bowler .*#1  .* main .*} \
118    {#0 .* keeper .*#1  .* handler .*#2 .* bowler .*#3  .* main .*}
119test_segv code $function_pointer \
120    {#0 .* 0x0+ .*#1 .* bowler .*#2  .* main .*} \
121    {#0 .* keeper .*#1  .* handler .*#2 .* 0x0+ .*#3 .* bowler .*#4 .* main .*}
122