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45a83408 AC |
1 | # This testcase is part of GDB, the GNU debugger. |
2 | ||
b811d2c2 | 3 | # Copyright 2004-2020 Free Software Foundation, Inc. |
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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 | |
e22f8b7c | 7 | # the Free Software Foundation; either version 3 of the License, or |
45a83408 AC |
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 | |
e22f8b7c | 16 | # along with this program. If not, see <http://www.gnu.org/licenses/>. |
45a83408 AC |
17 | |
18 | # Check that GDB can and only executes single instructions when | |
19 | # stepping through a sequence of breakpoints interleaved by a signal | |
20 | # handler. | |
21 | ||
22 | # This test is known to tickle the following problems: kernel letting | |
23 | # the inferior execute both the system call, and the instruction | |
24 | # following, when single-stepping a system call; kernel failing to | |
25 | # propogate the single-step state when single-stepping the sigreturn | |
26 | # system call, instead resuming the inferior at full speed; GDB | |
27 | # doesn't know how to software single-step across a sigreturn | |
28 | # instruction. Since the kernel problems can be "fixed" using | |
29 | # software single-step this is KFAILed rather than XFAILed. | |
30 | ||
5f579bc5 | 31 | if [target_info exists gdb,nosignals] { |
446ab585 | 32 | verbose "Skipping sigbpt.exp because of nosignals." |
5f579bc5 NS |
33 | continue |
34 | } | |
35 | ||
45a83408 | 36 | |
0ab77f5f TT |
37 | standard_testfile |
38 | ||
5b362f04 | 39 | if {[prepare_for_testing "failed to prepare" $testfile $srcfile debug]} { |
b60f0898 | 40 | return -1 |
45a83408 AC |
41 | } |
42 | ||
45a83408 AC |
43 | # |
44 | # Run to `main' where we begin our tests. | |
45 | # | |
46 | ||
47 | if ![runto_main] then { | |
c8ee3f04 PW |
48 | fail "can't run to main" |
49 | return 0 | |
45a83408 AC |
50 | } |
51 | ||
52 | # If we can examine what's at memory address 0, it is possible that we | |
53 | # could also execute it. This could probably make us run away, | |
54 | # executing random code, which could have all sorts of ill effects, | |
55 | # especially on targets without an MMU. Don't run the tests in that | |
56 | # case. | |
57 | ||
20c6f1e1 | 58 | if { [is_address_zero_readable] } { |
bc6c7af4 | 59 | untested "memory at address 0 is possibly executable" |
20c6f1e1 | 60 | return |
45a83408 AC |
61 | } |
62 | ||
63 | gdb_test "break keeper" | |
64 | ||
65 | # Run to bowler, and then single step until there's a SIGSEGV. Record | |
66 | # the address of each single-step instruction (up to and including the | |
67 | # instruction that causes the SIGSEGV) in bowler_addrs, and the address | |
68 | # of the actual SIGSEGV in segv_addr. | |
aacd552b TG |
69 | # Note: this test detects which signal is received. Usually it is SIGSEGV |
70 | # (and we use SIGSEGV in comments) but on Darwin it is SIGBUS. | |
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71 | |
72 | set bowler_addrs bowler | |
d12371a9 | 73 | set segv_addr none |
45a83408 | 74 | gdb_test {display/i $pc} |
591a12a1 | 75 | gdb_test "advance bowler" "bowler.*" "advance to the bowler" |
aacd552b TG |
76 | set test "stepping to fault" |
77 | set signame "SIGSEGV" | |
45a83408 | 78 | gdb_test_multiple "stepi" "$test" { |
2b28d209 | 79 | -re "Program received signal (SIGBUS|SIGSEGV).*pc(\r\n| *) *=> (0x\[0-9a-f\]*).*$gdb_prompt $" { |
aacd552b TG |
80 | set signame $expect_out(1,string) |
81 | set segv_addr $expect_out(3,string) | |
45a83408 AC |
82 | pass "$test" |
83 | } | |
2b28d209 | 84 | -re " .*pc(\r\n| *)=> (0x\[0-9a-f\]*).*bowler.*$gdb_prompt $" { |
6a2eb474 | 85 | set bowler_addrs [concat $expect_out(2,string) $bowler_addrs] |
45a83408 AC |
86 | send_gdb "stepi\n" |
87 | exp_continue | |
88 | } | |
89 | } | |
90 | ||
91 | # Now record the address of the instruction following the faulting | |
92 | # instruction in bowler_addrs. | |
93 | ||
94 | set test "get insn after fault" | |
95 | gdb_test_multiple {x/2i $pc} "$test" { | |
2b28d209 | 96 | -re "=> (0x\[0-9a-f\]*).*bowler.*(0x\[0-9a-f\]*).*bowler.*$gdb_prompt $" { |
45a83408 AC |
97 | set bowler_addrs [concat $expect_out(2,string) $bowler_addrs] |
98 | pass "$test" | |
99 | } | |
100 | } | |
101 | ||
102 | # Procedures for returning the address of the instruction before, at | |
103 | # and after, the faulting instruction. | |
104 | ||
105 | proc before_segv { } { | |
106 | global bowler_addrs | |
107 | return [lindex $bowler_addrs 2] | |
108 | } | |
109 | ||
110 | proc at_segv { } { | |
111 | global bowler_addrs | |
112 | return [lindex $bowler_addrs 1] | |
113 | } | |
114 | ||
115 | proc after_segv { } { | |
116 | global bowler_addrs | |
117 | return [lindex $bowler_addrs 0] | |
118 | } | |
119 | ||
120 | # Check that the address table and SIGSEGV correspond. | |
121 | ||
bc6c7af4 | 122 | set test "verify that ${signame} occurs at the last STEPI insn" |
45a83408 AC |
123 | if {[string compare $segv_addr [at_segv]] == 0} { |
124 | pass "$test" | |
125 | } else { | |
126 | fail "$test ($segv_addr [at_segv])" | |
127 | } | |
128 | ||
129 | # Check that the inferior is correctly single stepped all the way back | |
130 | # to a faulting instruction. | |
131 | ||
132 | proc stepi_out { name args } { | |
133 | global gdb_prompt | |
aacd552b | 134 | global signame |
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135 | |
136 | # Set SIGSEGV to pass+nostop and then run the inferior all the way | |
137 | # through to the signal handler. With the handler is reached, | |
138 | # disable SIGSEGV, ensuring that further signals stop the | |
139 | # inferior. Stops a SIGSEGV infinite loop when a broke system | |
140 | # keeps re-executing the faulting instruction. | |
141 | rerun_to_main | |
f6978de9 | 142 | gdb_test "handle ${signame} nostop print pass" ".*" "${name}; pass ${signame}" |
1544280f | 143 | gdb_test "continue" "keeper.*" "${name}; continue to keeper" |
f6978de9 | 144 | gdb_test "handle ${signame} stop print nopass" ".*" "${name}; nopass ${signame}" |
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145 | |
146 | # Insert all the breakpoints. To avoid the need to step over | |
147 | # these instructions, this is delayed until after the keeper has | |
148 | # been reached. | |
149 | for {set i 0} {$i < [llength $args]} {incr i} { | |
150 | gdb_test "break [lindex $args $i]" "Breakpoint.*" \ | |
1544280f | 151 | "${name}; set breakpoint $i of [llength $args]" |
45a83408 AC |
152 | } |
153 | ||
154 | # Single step our way out of the keeper, through the signal | |
155 | # trampoline, and back to the instruction that faulted. | |
1544280f | 156 | set test "${name}; stepi out of handler" |
45a83408 | 157 | gdb_test_multiple "stepi" "$test" { |
8608915f | 158 | -re "Could not insert single-step breakpoint.*$gdb_prompt $" { |
a5b6e449 | 159 | setup_kfail gdb/8841 "sparc*-*-openbsd*" |
8608915f MK |
160 | fail "$test (could not insert single-step breakpoint)" |
161 | } | |
03346981 SL |
162 | -re "Cannot insert breakpoint.*Cannot access memory.*$gdb_prompt $" { |
163 | setup_kfail gdb/8841 "nios2*-*-linux*" | |
164 | fail "$test (could not insert single-step breakpoint)" | |
165 | } | |
45a83408 AC |
166 | -re "keeper.*$gdb_prompt $" { |
167 | send_gdb "stepi\n" | |
168 | exp_continue | |
169 | } | |
170 | -re "signal handler.*$gdb_prompt $" { | |
171 | send_gdb "stepi\n" | |
172 | exp_continue | |
173 | } | |
174 | -re "Program received signal SIGSEGV.*$gdb_prompt $" { | |
a5b6e449 | 175 | kfail gdb/8807 "$test (executed fault insn)" |
45a83408 | 176 | } |
6a2eb474 | 177 | -re "Breakpoint.*pc(\r\n| *)[at_segv] .*bowler.*$gdb_prompt $" { |
45a83408 AC |
178 | pass "$test (at breakpoint)" |
179 | } | |
6a2eb474 | 180 | -re "Breakpoint.*pc(\r\n| *)[after_segv] .*bowler.*$gdb_prompt $" { |
a5b6e449 | 181 | kfail gdb/8807 "$test (executed breakpoint)" |
45a83408 | 182 | } |
6a2eb474 | 183 | -re "pc(\r\n| *)[at_segv] .*bowler.*$gdb_prompt $" { |
45a83408 AC |
184 | pass "$test" |
185 | } | |
6a2eb474 | 186 | -re "pc(\r\n| *)[after_segv] .*bowler.*$gdb_prompt $" { |
a5b6e449 | 187 | kfail gdb/8807 "$test (skipped fault insn)" |
45a83408 | 188 | } |
2b28d209 | 189 | -re "pc(\r\n| *)=> 0x\[a-z0-9\]* .*bowler.*$gdb_prompt $" { |
a5b6e449 | 190 | kfail gdb/8807 "$test (corrupt pc)" |
56401cd5 | 191 | } |
45a83408 AC |
192 | } |
193 | ||
194 | # Clear any breakpoints | |
195 | for {set i 0} {$i < [llength $args]} {incr i} { | |
196 | gdb_test "clear [lindex $args $i]" "Deleted .*" \ | |
1544280f | 197 | "${name}; clear breakpoint $i of [llength $args]" |
45a83408 AC |
198 | } |
199 | } | |
200 | ||
201 | # Let a signal handler exit, returning to a breakpoint instruction | |
202 | # inserted at the original fault instruction. Check that the | |
203 | # breakpoint is hit, and that single stepping off that breakpoint | |
204 | # executes the underlying fault instruction causing a SIGSEGV. | |
205 | ||
206 | proc cont_out { name args } { | |
207 | global gdb_prompt | |
aacd552b | 208 | global signame |
45a83408 AC |
209 | |
210 | # Set SIGSEGV to pass+nostop and then run the inferior all the way | |
211 | # through to the signal handler. With the handler is reached, | |
212 | # disable SIGSEGV, ensuring that further signals stop the | |
213 | # inferior. Stops a SIGSEGV infinite loop when a broke system | |
214 | # keeps re-executing the faulting instruction. | |
215 | rerun_to_main | |
f6978de9 | 216 | gdb_test "handle ${signame} nostop print pass" ".*" "${name}; pass ${signame}" |
1544280f | 217 | gdb_test "continue" "keeper.*" "${name}; continue to keeper" |
f6978de9 | 218 | gdb_test "handle ${signame} stop print nopass" ".*" "${name}; nopass ${signame}" |
45a83408 AC |
219 | |
220 | # Insert all the breakpoints. To avoid the need to step over | |
221 | # these instructions, this is delayed until after the keeper has | |
222 | # been reached. Always set a breakpoint at the signal trampoline | |
223 | # instruction. | |
224 | set args [concat $args "*[at_segv]"] | |
225 | for {set i 0} {$i < [llength $args]} {incr i} { | |
226 | gdb_test "break [lindex $args $i]" "Breakpoint.*" \ | |
1544280f | 227 | "${name}; set breakpoint $i of [llength $args]" |
45a83408 AC |
228 | } |
229 | ||
230 | # Let the handler return, it should "appear to hit" the breakpoint | |
231 | # inserted at the faulting instruction. Note that the breakpoint | |
232 | # instruction wasn't executed, rather the inferior was SIGTRAPed | |
233 | # with the PC at the breakpoint. | |
2b28d209 | 234 | gdb_test "continue" "Breakpoint.*pc(\r\n| *)=> [at_segv] .*" \ |
1544280f | 235 | "${name}; continue to breakpoint at fault" |
45a83408 AC |
236 | |
237 | # Now single step the faulted instrction at that breakpoint. | |
238 | gdb_test "stepi" \ | |
2b28d209 | 239 | "Program received signal ${signame}.*pc(\r\n| *)=> [at_segv] .*" \ |
1544280f | 240 | "${name}; stepi fault" |
45a83408 AC |
241 | |
242 | # Clear any breakpoints | |
243 | for {set i 0} {$i < [llength $args]} {incr i} { | |
244 | gdb_test "clear [lindex $args $i]" "Deleted .*" \ | |
1544280f | 245 | "${name}; clear breakpoint $i of [llength $args]" |
45a83408 AC |
246 | } |
247 | ||
248 | } | |
249 | ||
250 | ||
251 | ||
252 | # Try to confuse DECR_PC_AFTER_BREAK architectures by scattering | |
253 | # breakpoints around the faulting address. In all cases the inferior | |
254 | # should single-step out of the signal trampoline halting (but not | |
255 | # executing) the fault instruction. | |
256 | ||
257 | stepi_out "stepi" | |
258 | stepi_out "stepi bp before segv" "*[before_segv]" | |
259 | stepi_out "stepi bp at segv" "*[at_segv]" | |
260 | stepi_out "stepi bp before and at segv" "*[at_segv]" "*[before_segv]" | |
261 | ||
262 | ||
263 | # Try to confuse DECR_PC_AFTER_BREAK architectures by scattering | |
264 | # breakpoints around the faulting address. In all cases the inferior | |
265 | # should exit the signal trampoline halting at the breakpoint that | |
266 | # replaced the fault instruction. | |
267 | cont_out "cont" | |
268 | cont_out "cont bp after segv" "*[before_segv]" | |
269 | cont_out "cont bp before and after segv" "*[before_segv]" "*[after_segv]" |