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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 and only executes single instructions when | |
20 | # stepping through a sequence of breakpoints interleaved by a signal | |
21 | # handler. | |
22 | ||
23 | # This test is known to tickle the following problems: kernel letting | |
24 | # the inferior execute both the system call, and the instruction | |
25 | # following, when single-stepping a system call; kernel failing to | |
26 | # propogate the single-step state when single-stepping the sigreturn | |
27 | # system call, instead resuming the inferior at full speed; GDB | |
28 | # doesn't know how to software single-step across a sigreturn | |
29 | # instruction. Since the kernel problems can be "fixed" using | |
30 | # software single-step this is KFAILed rather than XFAILed. | |
31 | ||
32 | if $tracelevel { | |
33 | strace $tracelevel | |
34 | } | |
35 | ||
36 | set prms_id 0 | |
37 | set bug_id 0 | |
38 | ||
39 | set testfile "sigbpt" | |
40 | set srcfile ${testfile}.c | |
41 | set binfile ${objdir}/${subdir}/${testfile} | |
42 | if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } { | |
43 | gdb_suppress_entire_file "Testcase compile failed, so all tests in this file will automatically fail." | |
44 | } | |
45 | ||
46 | gdb_exit | |
47 | gdb_start | |
48 | gdb_reinitialize_dir $srcdir/$subdir | |
49 | gdb_load ${binfile} | |
50 | ||
51 | # | |
52 | # Run to `main' where we begin our tests. | |
53 | # | |
54 | ||
55 | if ![runto_main] then { | |
56 | gdb_suppress_tests | |
57 | } | |
58 | ||
59 | # If we can examine what's at memory address 0, it is possible that we | |
60 | # could also execute it. This could probably make us run away, | |
61 | # executing random code, which could have all sorts of ill effects, | |
62 | # especially on targets without an MMU. Don't run the tests in that | |
63 | # case. | |
64 | ||
65 | send_gdb "x 0\n" | |
66 | gdb_expect { | |
67 | -re "0x0:.*Cannot access memory at address 0x0.*$gdb_prompt $" { } | |
68 | -re "0x0:.*Error accessing memory address 0x0.*$gdb_prompt $" { } | |
69 | -re ".*$gdb_prompt $" { | |
70 | untested "Memory at address 0 is possibly executable" | |
71 | return | |
72 | } | |
73 | } | |
74 | ||
75 | gdb_test "break keeper" | |
76 | ||
77 | # Run to bowler, and then single step until there's a SIGSEGV. Record | |
78 | # the address of each single-step instruction (up to and including the | |
79 | # instruction that causes the SIGSEGV) in bowler_addrs, and the address | |
80 | # of the actual SIGSEGV in segv_addr. | |
81 | ||
82 | set bowler_addrs bowler | |
83 | gdb_test {display/i $pc} | |
84 | gdb_test "advance *bowler" "bowler.*" "advance to the bowler" | |
85 | set test "stepping to SIGSEGV" | |
86 | gdb_test_multiple "stepi" "$test" { | |
87 | -re "Program received signal SIGSEGV.*pc *(0x\[0-9a-f\]*).*$gdb_prompt $" { | |
88 | set segv_addr $expect_out(1,string) | |
89 | pass "$test" | |
90 | } | |
91 | -re " .*pc *(0x\[0-9a-f\]*).*bowler.*$gdb_prompt $" { | |
92 | set bowler_addrs [concat $expect_out(1,string) $bowler_addrs] | |
93 | send_gdb "stepi\n" | |
94 | exp_continue | |
95 | } | |
96 | } | |
97 | ||
98 | # Now record the address of the instruction following the faulting | |
99 | # instruction in bowler_addrs. | |
100 | ||
101 | set test "get insn after fault" | |
102 | gdb_test_multiple {x/2i $pc} "$test" { | |
103 | -re "(0x\[0-9a-f\]*).*bowler.*(0x\[0-9a-f\]*).*bowler.*$gdb_prompt $" { | |
104 | set bowler_addrs [concat $expect_out(2,string) $bowler_addrs] | |
105 | pass "$test" | |
106 | } | |
107 | } | |
108 | ||
109 | # Procedures for returning the address of the instruction before, at | |
110 | # and after, the faulting instruction. | |
111 | ||
112 | proc before_segv { } { | |
113 | global bowler_addrs | |
114 | return [lindex $bowler_addrs 2] | |
115 | } | |
116 | ||
117 | proc at_segv { } { | |
118 | global bowler_addrs | |
119 | return [lindex $bowler_addrs 1] | |
120 | } | |
121 | ||
122 | proc after_segv { } { | |
123 | global bowler_addrs | |
124 | return [lindex $bowler_addrs 0] | |
125 | } | |
126 | ||
127 | # Check that the address table and SIGSEGV correspond. | |
128 | ||
129 | set test "Verify that SIGSEGV occurs at the last STEPI insn" | |
130 | if {[string compare $segv_addr [at_segv]] == 0} { | |
131 | pass "$test" | |
132 | } else { | |
133 | fail "$test ($segv_addr [at_segv])" | |
134 | } | |
135 | ||
136 | # Check that the inferior is correctly single stepped all the way back | |
137 | # to a faulting instruction. | |
138 | ||
139 | proc stepi_out { name args } { | |
140 | global gdb_prompt | |
141 | ||
142 | # Set SIGSEGV to pass+nostop and then run the inferior all the way | |
143 | # through to the signal handler. With the handler is reached, | |
144 | # disable SIGSEGV, ensuring that further signals stop the | |
145 | # inferior. Stops a SIGSEGV infinite loop when a broke system | |
146 | # keeps re-executing the faulting instruction. | |
147 | rerun_to_main | |
148 | gdb_test "handle SIGSEGV nostop print pass" "" "pass SIGSEGV; $name" | |
149 | gdb_test "continue" "keeper.*" "continue to keeper; $name" | |
150 | gdb_test "handle SIGSEGV stop print nopass" "" "nopass SIGSEGV; $name" | |
151 | ||
152 | # Insert all the breakpoints. To avoid the need to step over | |
153 | # these instructions, this is delayed until after the keeper has | |
154 | # been reached. | |
155 | for {set i 0} {$i < [llength $args]} {incr i} { | |
156 | gdb_test "break [lindex $args $i]" "Breakpoint.*" \ | |
157 | "set breakpoint $i of [llength $args]; $name" | |
158 | } | |
159 | ||
160 | # Single step our way out of the keeper, through the signal | |
161 | # trampoline, and back to the instruction that faulted. | |
162 | set test "stepi out of handler; $name" | |
163 | gdb_test_multiple "stepi" "$test" { | |
164 | -re "keeper.*$gdb_prompt $" { | |
165 | send_gdb "stepi\n" | |
166 | exp_continue | |
167 | } | |
168 | -re "signal handler.*$gdb_prompt $" { | |
169 | send_gdb "stepi\n" | |
170 | exp_continue | |
171 | } | |
172 | -re "Program received signal SIGSEGV.*$gdb_prompt $" { | |
173 | kfail gdb/1702 "$test (executed fault insn)" | |
174 | } | |
175 | -re "Breakpoint.*pc *[at_segv] .*bowler.*$gdb_prompt $" { | |
176 | pass "$test (at breakpoint)" | |
177 | } | |
178 | -re "Breakpoint.*pc *[after_segv] .*bowler.*$gdb_prompt $" { | |
179 | kfail gdb/1702 "$test (executed breakpoint)" | |
180 | } | |
181 | -re "pc *[at_segv] .*bowler.*$gdb_prompt $" { | |
182 | pass "$test" | |
183 | } | |
184 | -re "pc *[after_segv] .*bowler.*$gdb_prompt $" { | |
185 | kfail gdb/1702 "$test (skipped fault insn)" | |
186 | } | |
187 | } | |
188 | ||
189 | # Clear any breakpoints | |
190 | for {set i 0} {$i < [llength $args]} {incr i} { | |
191 | gdb_test "clear [lindex $args $i]" "Deleted .*" \ | |
192 | "clear breakpoint $i of [llength $args]; $name" | |
193 | } | |
194 | } | |
195 | ||
196 | # Let a signal handler exit, returning to a breakpoint instruction | |
197 | # inserted at the original fault instruction. Check that the | |
198 | # breakpoint is hit, and that single stepping off that breakpoint | |
199 | # executes the underlying fault instruction causing a SIGSEGV. | |
200 | ||
201 | proc cont_out { name args } { | |
202 | global gdb_prompt | |
203 | ||
204 | # Set SIGSEGV to pass+nostop and then run the inferior all the way | |
205 | # through to the signal handler. With the handler is reached, | |
206 | # disable SIGSEGV, ensuring that further signals stop the | |
207 | # inferior. Stops a SIGSEGV infinite loop when a broke system | |
208 | # keeps re-executing the faulting instruction. | |
209 | rerun_to_main | |
210 | gdb_test "handle SIGSEGV nostop print pass" "" "pass SIGSEGV; $name" | |
211 | gdb_test "continue" "keeper.*" "continue to keeper; $name" | |
212 | gdb_test "handle SIGSEGV stop print nopass" "" "nopass SIGSEGV; $name" | |
213 | ||
214 | # Insert all the breakpoints. To avoid the need to step over | |
215 | # these instructions, this is delayed until after the keeper has | |
216 | # been reached. Always set a breakpoint at the signal trampoline | |
217 | # instruction. | |
218 | set args [concat $args "*[at_segv]"] | |
219 | for {set i 0} {$i < [llength $args]} {incr i} { | |
220 | gdb_test "break [lindex $args $i]" "Breakpoint.*" \ | |
221 | "set breakpoint $i of [llength $args]; $name" | |
222 | } | |
223 | ||
224 | # Let the handler return, it should "appear to hit" the breakpoint | |
225 | # inserted at the faulting instruction. Note that the breakpoint | |
226 | # instruction wasn't executed, rather the inferior was SIGTRAPed | |
227 | # with the PC at the breakpoint. | |
228 | gdb_test "continue" "Breakpoint.*pc *[at_segv] .*" \ | |
229 | "continue to breakpoint at fault; $name" | |
230 | ||
231 | # Now single step the faulted instrction at that breakpoint. | |
232 | gdb_test "stepi" \ | |
233 | "Program received signal SIGSEGV.*pc *[at_segv] .*" \ | |
234 | "stepi fault; $name" | |
235 | ||
236 | # Clear any breakpoints | |
237 | for {set i 0} {$i < [llength $args]} {incr i} { | |
238 | gdb_test "clear [lindex $args $i]" "Deleted .*" \ | |
239 | "clear breakpoint $i of [llength $args]; $name" | |
240 | } | |
241 | ||
242 | } | |
243 | ||
244 | ||
245 | ||
246 | # Try to confuse DECR_PC_AFTER_BREAK architectures by scattering | |
247 | # breakpoints around the faulting address. In all cases the inferior | |
248 | # should single-step out of the signal trampoline halting (but not | |
249 | # executing) the fault instruction. | |
250 | ||
251 | stepi_out "stepi" | |
252 | stepi_out "stepi bp before segv" "*[before_segv]" | |
253 | stepi_out "stepi bp at segv" "*[at_segv]" | |
254 | stepi_out "stepi bp before and at segv" "*[at_segv]" "*[before_segv]" | |
255 | ||
256 | ||
257 | # Try to confuse DECR_PC_AFTER_BREAK architectures by scattering | |
258 | # breakpoints around the faulting address. In all cases the inferior | |
259 | # should exit the signal trampoline halting at the breakpoint that | |
260 | # replaced the fault instruction. | |
261 | cont_out "cont" | |
262 | cont_out "cont bp after segv" "*[before_segv]" | |
263 | cont_out "cont bp before and after segv" "*[before_segv]" "*[after_segv]" |