1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
|
# Copyright 2015-2021 Free Software Foundation, Inc.
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
# This testsuite is to test examining memory backward by specifying a negative
# number in the 'x' command.
standard_testfile
if { [prepare_for_testing "failed to prepare for examine-backward" \
${testfile} ${srcfile}] } {
return -1
}
if ![runto_main] {
untested "could not run to main"
return -1
}
proc get_first_mapped_address {} {
global gdb_prompt
set addr "0"
gdb_test_multiple "info proc mappings" "info proc mappings" {
-re "objfile\[\r\n\t \]+(0x\[0-9a-fA-F\]+).*\[\r\n\]*$gdb_prompt $" {
set addr $expect_out(1,string)
}
-re "$gdb_prompt $" {
unsupported "current target does not support 'info proc mappings'"
}
}
return ${addr}
}
with_test_prefix "invalid format" {
gdb_test "x/- 10xb main" "Invalid number \"10xb\"\." \
"a whitespace after a leading hyphen"
gdb_test "x/--10xb main" "Invalid number \"10xb\"\." \
"double hyphen"
gdb_test "x/-a10xb main" "Invalid number \"10xb\"\." \
"an alphabet after a leading hyphen"
gdb_test_no_output "x/-0i main" "zero with backward disassemble"
gdb_test_no_output "x/-0sh main" "zero with backward examine string"
}
with_test_prefix "memory page boundary" {
set boundary [get_first_mapped_address]
if {![is_address_zero_readable] && $boundary != 0} {
gdb_test_no_output "set print elements 0"
gdb_test_sequence "x/3s ${boundary}" "take 3 strings forward" {
"0x"
"0x"
"0x"
}
gdb_test_sequence "x/-4s" "take 4 strings backward" {
"Cannot access memory at address 0x"
"0x"
"0x"
"0x"
}
gdb_test_sequence "x/3s ${boundary}" "take 3 strings forward again" {
"0x"
"0x"
"0x"
}
gdb_test_sequence "x/-3s" "take 3 strings backward" {
"Cannot access memory at address 0x"
"0x"
"0x"
"0x"
}
}
}
with_test_prefix "address zero boundary" {
global gdb_prompt
set address_zero "0x0"
set byte "\t0x\[0-9a-f\]+"
set test "examine 3 bytes forward from ${address_zero}"
gdb_test_multiple "x/3xb ${address_zero}" "$test" {
-re "0x\[0-9a-f\]*0.*:${byte}${byte}${byte}\[\r\n\]*$gdb_prompt $" {
pass $test
}
-re "0x\[0-9a-f\]*0.*:\tCannot access memory at address 0x\[0-9a-f\]*0\[\r\n\]*$gdb_prompt $" {
# If we failed to read address 0 then this is fine, so
# long as we're not expecting to be able to read from
# address 0.
if {![is_address_zero_readable]} {
# The next test assumes that the last address examined
# would be 0x2. As we just failed to read address 0x0
# things are going to go wrong unless we now tell GDB
# to examine address 0x2. We assume here that if we
# can't read 0x0 we can't read 0x2 either.
gdb_test "x/3xb 0x2" "Cannot access memory at address 0x\[0-9a-f\]*2" \
"set last examined address to 0x2"
pass $test
} else {
fail $test
}
}
}
set test "examine 6 bytes backward"
gdb_test_multiple "x/-6x" "$test" {
-re "0x\[0-9a-f\]+fd.*:${byte}${byte}${byte}${byte}${byte}${byte}.*\[\r\n\]*$gdb_prompt $" {
pass $test
}
-re "0x\[0-9a-f\]+fd.*:\tCannot access memory at address 0x\[0-9a-f\]+fd.*\[\r\n\]*$gdb_prompt $" {
# We may, or may not have managed to read from address 0x0
# in the previous test, however, being able to read 0x0 is
# no guarantee that we can read from the other end of the
# address space. If we get an error about trying to read
# from the expected address then we count that as a pass,
# GDB did try to read the correct location, and this test
# is (mostly) about does GDB calculate the correct address
# when wrapping around.
pass $test
}
}
set test "examine 3 bytes backward from ${address_zero}"
gdb_test_multiple "x/-3x ${address_zero}" "$test" {
-re "0x\[0-9a-f\]+fd.*:${byte}${byte}${byte}.*\[\r\n\]*$gdb_prompt $" {
pass $test
}
-re "0x\[0-9a-f\]+fd.*:\tCannot access memory at address 0x\[0-9a-f\]+fd.*\[\r\n\]*$gdb_prompt $" {
# See previous test for why this is a pass.
pass $test
}
}
}
gdb_test_no_output "set charset ASCII"
with_test_prefix "char-width=1, print-max=20" {
gdb_test_no_output "set print elements 20"
gdb_test_sequence "x/6s &TestStrings" "take 6 strings forward" {
"\"ABCDEFGHIJKLMNOPQRST\"\.\.\."
"\"UVWXYZ\""
"\"\""
"\"\""
"\"[^\"]+\""
"\"01234567890123456789\"\.\.\."
}
gdb_test "x/-1xb" "0x39" "take 1 char backward"
gdb_test_sequence "x/-6s" "take 6 strings backward" {
"\"ABCDEFGHIJKLMNOPQRST\"\.\.\."
"\"UVWXYZ\""
"\"\""
"\"\""
"\"[^\"]+\""
"\"01234567890123456789\"\.\.\."
}
gdb_test_sequence "x/6s &TestStrings" "take 6 strings forward again" {
"\"ABCDEFGHIJKLMNOPQRST\"\.\.\."
"\"UVWXYZ\""
"\"\""
"\"\""
"\"[^\"]+\""
"\"01234567890123456789\"\.\.\."
}
gdb_test "x/-xb" "0x39" "take 1 char backward again"
gdb_test "x/-s" "\"01234567890123456789\"\.\.\." \
"take 1 string backward (1/6)"
gdb_test "x/-s" "\".+\"" \
"take 1 string backward (2/6)"
gdb_test "x/-s" "\"\"" \
"take 1 string backward (3/6)"
gdb_test "x/-s" "\"\"" \
"take 1 string backward (4/6)"
gdb_test "x/-s" "\"GHIJKLMNOPQRSTUVWXYZ\"" \
"take 1 string backward (5/6)"
gdb_test "x/-s" "\"ABCDEFGHIJKLMNOPQRST\"\.\.\." \
"take 1 string backward (6/6)"
}
with_test_prefix "char-width=2, print-max=20" {
gdb_test_no_output "set print elements 20"
gdb_test_sequence "x/6sh &TestStringsH" "take 6 strings forward" {
"u\"ABCDEFGHIJKLMNOPQRST\"\.\.\."
"u\"UVWXYZ\""
"u\"\""
"u\"\""
"u\"[^\"]+\""
"u\"01234567890123456789\"\.\.\."
}
gdb_test "x/-1xh" "0x0039" "take 1 char backward"
gdb_test_sequence "x/-6sh" "take 6 strings backward" {
"u\"ABCDEFGHIJKLMNOPQRST\"\.\.\."
"u\"UVWXYZ\""
"u\"\""
"u\"\""
"u\"[^\"]+\""
"u\"01234567890123456789\"\.\.\."
}
gdb_test_sequence "x/6sh &TestStringsH" "take 6 strings forward again" {
"u\"ABCDEFGHIJKLMNOPQRST\"\.\.\."
"u\"UVWXYZ\""
"u\"\""
"u\"\""
"u\"[^\"]+\""
"u\"01234567890123456789\"\.\.\."
}
gdb_test "x/-xh" "0x0039" "take 1 char backward again"
gdb_test "x/-sh" "u\"01234567890123456789\"\.\.\." \
"take 1 string backward (1/6)"
gdb_test "x/-sh" "u\".+\"" \
"take 1 string backward (2/6)"
gdb_test "x/-sh" "u\"\"" \
"take 1 string backward (3/6)"
gdb_test "x/-sh" "u\"\"" \
"take 1 string backward (4/6)"
gdb_test "x/-sh" "u\"GHIJKLMNOPQRSTUVWXYZ\"" \
"take 1 string backward (5/6)"
gdb_test "x/-sh" "u\"ABCDEFGHIJKLMNOPQRST\"\.\.\." \
"take 1 string backward (6/6)"
}
with_test_prefix "char-width=4, print-max=20" {
gdb_test_no_output "set print elements 20"
gdb_test_sequence "x/6sw &TestStringsW" "take 6 strings forward" {
"U\"ABCDEFGHIJKLMNOPQRST\"\.\.\."
"U\"UVWXYZ\""
"U\"\""
"U\"\""
"U\"[^\"]+\""
"U\"01234567890123456789\"\.\.\."
}
gdb_test "x/-1xw" "0x00000039" "take 1 char backward"
gdb_test_sequence "x/-6sw" "take 6 strings backward" {
"U\"ABCDEFGHIJKLMNOPQRST\"\.\.\."
"U\"UVWXYZ\""
"U\"\""
"U\"\""
"U\"[^\"]+\""
"U\"01234567890123456789\"\.\.\."
}
gdb_test_sequence "x/6sw &TestStringsW" "take 6 strings forward again" {
"U\"ABCDEFGHIJKLMNOPQRST\"\.\.\."
"U\"UVWXYZ\""
"U\"\""
"U\"\""
"U\"[^\"]+\""
"U\"01234567890123456789\"\.\.\."
}
gdb_test "x/-xw" "0x00000039" "take 1 char backward again"
gdb_test "x/-sw" "U\"01234567890123456789\"\.\.\." \
"take 1 string backward (1/6)"
gdb_test "x/-sw" "U\".+\"" \
"take 1 string backward (2/6)"
gdb_test "x/-sw" "U\"\"" \
"take 1 string backward (3/6)"
gdb_test "x/-sw" "U\"\"" \
"take 1 string backward (4/6)"
gdb_test "x/-sw" "U\"GHIJKLMNOPQRSTUVWXYZ\"" \
"take 1 string backward (5/6)"
gdb_test "x/-sw" "U\"ABCDEFGHIJKLMNOPQRST\"\.\.\." \
"take 1 string backward (6/6)"
}
with_test_prefix "char-width=2, print-max=0" {
gdb_test_no_output "set print elements 0"
gdb_test_sequence "x/6sh &TestStringsH" "take 6 strings forward" {
"u\"ABCDEFGHIJKLMNOPQRSTUVWXYZ\""
"u\"\""
"u\"\""
"u\"\\\\x307b\\\\x3052\\\\x307b\\\\x3052\""
"u\"012345678901234567890123456789\""
"u\"!!!!!!\""
}
gdb_test "x/-4xh" "0x0021\[\t \]+0x0021\[\t \]+0x0021\[\t \]+0x0000" \
"take 4 characters backward"
gdb_test_sequence "x/-6sh" "take 6 strings backward" {
"u\"ABCDEFGHIJKLMNOPQRSTUVWXYZ\""
"u\"\""
"u\"\""
"u\"[^\"]+\""
"u\"012345678901234567890123456789\""
"u\"!!!!!!\""
}
gdb_test_sequence "x/6sh &TestStringsH" "take 6 strings forward again" {
"u\"ABCDEFGHIJKLMNOPQRSTUVWXYZ\""
"u\"\""
"u\"\""
"u\"\\\\x307b\\\\x3052\\\\x307b\\\\x3052\""
"u\"012345678901234567890123456789\""
"u\"!!!!!!\""
}
gdb_test "x/-xh" "0x0000" "take 1 char backward"
gdb_test "x/-sh" "u\"!!!!!!\"" \
"take 1 string backward (1/6)"
gdb_test "x/-sh" "u\"012345678901234567890123456789\"" \
"take 1 string backward (2/6)"
gdb_test "x/-sh" "u\".+\"" \
"take 1 string backward (3/6)"
gdb_test "x/-sh" "u\"\"" \
"take 1 string backward (4/6)"
gdb_test "x/-sh" "u\"\"" \
"take 1 string backward (5/6)"
gdb_test "x/-sh" "u\"ABCDEFGHIJKLMNOPQRSTUVWXYZ\"" \
"take 1 string backward (6/6)"
}
with_test_prefix "char-width=1, print-max=4" {
gdb_test_no_output "set print elements 4"
gdb_test_sequence "x/9s &TestStrings" "take 9 strings forward" {
"\"ABCD\"\.\.\."
"\"EFGH\"\.\.\."
"\"IJKL\"\.\.\."
"\"MNOP\"\.\.\."
"\"QRST\"\.\.\."
"\"UVWX\"\.\.\."
"\"YZ\""
"\"\""
"\"\""
}
gdb_test "x/-xb" "0x00" "take 1 byte backward"
gdb_test_sequence "x/-4s" "take 4 strings backward (1/2)" {
"\"TUVW\"\.\.\."
"\"XYZ\""
"\"\""
"\"\""
}
gdb_test_sequence "x/-4s" "take 4 strings backward (2/2)" {
"\"CDEF\"\.\.\."
"\"GHIJ\"\.\.\."
"\"KLMN\"\.\.\."
"\"OPQR\"\.\.\."
}
}
with_test_prefix "backward disassemble general" {
set length_to_examine {1 2 3 4 10}
set disassmbly {}
gdb_test_no_output "set print asm-demangle on"
set main_re "main(\\(\\))?"
gdb_test "x/i main" "0x\[0-9a-fA-F\]+ <$main_re>:\t.*" \
"move the current position to main (x/i)"
gdb_test "x/-i" "0x\[0-9a-fA-F\]+ <$main_re>:\t.*" \
"move the current position to main (x/-i)"
for {set i 0} {$i < [llength $length_to_examine]} {incr i} {
set len [lindex $length_to_examine $i]
set instructions [capture_command_output "x/${len}i" ""]
lappend disassmbly $instructions
}
for {set i 0} {$i < [llength $length_to_examine]} {incr i} {
set idx [expr [llength $length_to_examine] - $i - 1]
set len [lindex $length_to_examine $idx]
set actual [capture_command_output "x/-${len}i" ""]
set expected [lindex $disassmbly $idx]
if {$actual == $expected} {
pass "inst:$idx"
} else {
fail "inst:$idx"
}
}
}
|
