gdb/testsuite/gdb.base/watchpoint-reuse-slot.exp

   1 # Copyright 2014-2023 Free Software Foundation, Inc.
   2
   3 # This program is free software; you can redistribute it and/or modify
   4 # it under the terms of the GNU General Public License as published by
   5 # the Free Software Foundation; either version 3 of the License, or
   6 # (at your option) any later version.
   7 #
   8 # This program is distributed in the hope that it will be useful,
   9 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 # GNU General Public License for more details.
  12 #
  13 # You should have received a copy of the GNU General Public License
  14 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15
  16 # Test alternating between watchpoint types, watching a sliding window
  17 # of addresses (thus alternating between aligned and unaligned
  18 # addresses).  Only a single watchpoint exists at any given time.  On
  19 # targets that only update the debug registers on resume, this
  20 # stresses the debug register setup code, both in GDB and in the
  21 # target/kernel as one watchpoint replaces the other in a single
  22 # operation.  (Note that we don't have any of these watchpoints
  23 # trigger.)
  24
  25 # The skip_hw_watchpoint_tests checks if watchpoints are supported by the
  26 # processor.  On PowerPC, the check runs a small test program under gdb
  27 # to determine if the Power processor supports HW watchpoints.  The check
  28 # must be done before starting the test so as to not disrupt the execution
  29 # of the actual test.
  30
  31 set skip_hw_watchpoint_tests_p [skip_hw_watchpoint_tests]
  32
  33 # starting the test.
  34
  35 standard_testfile
  36
  37 if {[prepare_for_testing "failed to prepare" $testfile $srcfile debug]} {
  38     return -1
  39 }
  40
  41 if {![runto_main]} {
  42     return 0
  43 }
  44
  45 # The line we'll be stepping.
  46 set srcline [gdb_get_line_number "stepi line"]
  47
  48 # The address the program is stopped at currently.
  49 set cur_addr ""
  50
  51 # Get the current PC.
  52
  53 proc get_pc {} {
  54     global hex gdb_prompt
  55
  56     set addr ""
  57     set test "get PC"
  58     gdb_test_multiple "p /x \$pc" "$test" {
  59         -re " = ($hex).*$gdb_prompt $" {
  60             set addr $expect_out(1,string)
  61             pass "$test"
  62         }
  63     }
  64
  65     return $addr
  66 }
  67
  68
  69 # Issue a stepi, and make sure the program advanced past the current
  70 # instruction (stored in the CUR_ADDR global).
  71
  72 proc stepi {} {
  73     global hex gdb_prompt cur_addr
  74
  75     set srcline "  for (i = 0; i < 100000; i++); /* stepi line */"
  76     set test "stepi advanced"
  77     gdb_test_multiple "stepi" $test {
  78         -re -wrap "[string_to_regexp $srcline]" {
  79             set addr [get_valueof "/x" "\$pc" "0"]
  80             if {$addr != $cur_addr} {
  81                 pass $test
  82             } else {
  83                 fail $test
  84             }
  85             set cur_addr $addr
  86         }
  87     }
  88 }
  89
  90 gdb_breakpoint $srcline
  91 gdb_continue_to_breakpoint "stepi line"
  92 set cur_addr [get_pc]
  93
  94 # The test tries various sequences of different types of watchpoints.
  95 # Probe for support first.
  96 proc build_cmds_list {} {
  97     global gdb_prompt
  98
  99     # So we get an immediate warning/error if the target doesn't support a
 100     # given watchpoint type.
 101     gdb_test_no_output "set breakpoint always-inserted on" \
 102         "Set breakpoints always inserted while building cmds list"
 103
 104     # The list of supported commands.  Below we'll probe for support and
 105     # add elements to this list.
 106     set cmds {}
 107
 108     foreach cmd {"watch" "awatch" "rwatch"} {
 109         set test $cmd
 110         gdb_test_multiple "$cmd buf.byte\[0\]" $test {
 111             -re "You may have requested too many.*$gdb_prompt $" {
 112                 unsupported $test
 113             }
 114             -re "Target does not support.*$gdb_prompt $" {
 115                 unsupported $test
 116             }
 117             -re "Can't set read/access watchpoint when hardware watchpoints are disabled.*$gdb_prompt $" {
 118                 unsupported $test
 119             }
 120             -re "$gdb_prompt $" {
 121                 pass $test
 122                 lappend cmds $cmd
 123             }
 124         }
 125
 126         delete_breakpoints
 127     }
 128
 129     set test "hbreak"
 130     gdb_test_multiple "hbreak -q main" $test {
 131         -re "You may have requested too many.*$gdb_prompt $" {
 132             unsupported $test
 133         }
 134         -re "No hardware breakpoint support.*$gdb_prompt $" {
 135             unsupported $test
 136         }
 137         -re "$gdb_prompt $" {
 138             pass $test
 139             lappend cmds "hbreak"
 140         }
 141     }
 142
 143     delete_breakpoints
 144
 145     return $cmds
 146 }
 147
 148 # Return true if the memory range [buf.byte + OFFSET, +WIDTH] can be
 149 # monitored by CMD, otherwise return false.
 150
 151 proc valid_addr_p {cmd offset width} {
 152
 153     if { [istarget "aarch64*-*-linux*"] } {
 154         # The aarch64 Linux kernel port only accepts 4-byte aligned addresses
 155         # for hardware breakpoints and 8-byte aligned addresses for hardware
 156         # watchpoints.  However, both GDB and GDBserver support unaligned
 157         # watchpoints by using more than one properly aligned watchpoint
 158         # registers to represent the whole unaligned region.  Breakpoint
 159         # addresses must still be aligned though.
 160         if {$cmd == "hbreak" } {
 161             if { [expr ($offset) % 4] != 0 } {
 162                 return 0
 163             }
 164         }
 165     } elseif { [istarget "arm*-*-linux*"] } {
 166         if { $cmd == "hbreak" } {
 167             # Breakpoints must be of length 2 (thumb) or 4 (ARM) bytes.
 168             if { $width != 2 && $width != 4 } {
 169                 return 0
 170             }
 171         } else {
 172             # Watchpoints can be of length 1, 2, 4 or 8 bytes.
 173             if { [expr $width % 2] != 0 } {
 174                 return 0
 175             }
 176         }
 177
 178         if { [expr ($offset) % 8] == 0 && $width == 8 } {
 179             # If WIDTH is 8 byte, the address should be 8-byte aligned.
 180             return 1
 181         } elseif { [expr ($offset) % 4] == 0 } {
 182             return 1
 183         } elseif { [expr ($offset) % 4] == 2 && $width == 2 } {
 184             # Halfword watchpoints and breakpoints.
 185             return 1
 186         } elseif { [expr ($offset) % 4] == 1 && $width == 1 && $cmd != "hbreak" } {
 187             # Single byte watchpoints.
 188             return 1
 189         } else {
 190             return 0
 191         }
 192     }
 193
 194     return 1
 195 }
 196
 197 # Watch WIDTH bytes at BASE + OFFSET.  CMD specifices the specific
 198 # type of watchpoint to use.  If CMD is "hbreak", WIDTH is ignored.
 199 # The HW_WP_P flag tells us if hardware watchpoints are enabled or
 200 # not.
 201
 202 proc watch_command {cmd base offset width hw_wp_p} {
 203     global srcfile srcline hex
 204
 205     if {$cmd == "hbreak"} {
 206         set expr "*(buf.byte + $base + $offset)"
 207         gdb_test "hbreak $expr" "Hardware assisted breakpoint \[0-9\]+ at $hex"
 208     } elseif {$cmd == "watch"} {
 209         set expr "*(buf.byte + $base + $offset)@$width"
 210
 211         if { ! $hw_wp_p } {
 212             set wp_prefix "Watchpoint"
 213         } else {
 214             set wp_prefix "Hardware watchpoint"
 215         }
 216
 217         gdb_test "$cmd $expr" \
 218             "${wp_prefix} \[0-9\]+: [string_to_regexp $expr]"
 219     } elseif {$cmd == "awatch"} {
 220         set expr "*(buf.byte + $base + $offset)@$width"
 221         gdb_test "$cmd $expr" \
 222             "Hardware access \\(read/write\\) watchpoint \[0-9\]+: [string_to_regexp $expr]"
 223     } elseif {$cmd == "rwatch"} {
 224         set expr "*(buf.byte + $base + $offset)@$width"
 225         gdb_test "$cmd $expr" \
 226             "Hardware read watchpoint \[0-9\]+: [string_to_regexp $expr]"
 227     }
 228 }
 229
 230 # Run the watchpoint tests (see the description at the top for details), the
 231 # HW_WP_P flag tells us if hardware watchpoints are enabled or not.
 232 proc run_watchpoints_tests {hw_wp_p} {
 233
 234     set cmds [build_cmds_list]
 235
 236     foreach always_inserted {"off" "on" } {
 237         gdb_test_no_output "set breakpoint always-inserted $always_inserted"
 238         foreach cmd1 $cmds {
 239             foreach cmd2 $cmds {
 240                 for {set width 1} {$width < 4} {incr width} {
 241
 242                     if {$cmd1 == "hbreak" && $cmd2 == "hbreak" \
 243                             && $width > 1} {
 244                         # hbreak ignores WIDTH, no use testing more than
 245                         # once.
 246                         continue
 247                     }
 248
 249                     for {set x 0} {$x < 4} {incr x} {
 250
 251                         if { ![valid_addr_p $cmd1 $x $width]
 252                              || ![valid_addr_p $cmd2 $x+1 $width] } {
 253                             # Skip tests if requested address or length
 254                             # of breakpoint or watchpoint don't meet
 255                             # target or kernel requirements.
 256                             continue
 257                         }
 258
 259                         set prefix "always-inserted $always_inserted: "
 260                         append prefix "$cmd1 x $cmd2: "
 261                         with_test_prefix "$prefix: width $width, iter $x" {
 262                             with_test_prefix "base + 0" {
 263                                 watch_command $cmd1 $x 0 $width $hw_wp_p
 264                                 stepi
 265                                 gdb_test_no_output "delete \$bpnum"
 266                             }
 267                             with_test_prefix "base + 1" {
 268                                 watch_command $cmd2 $x 1 $width $hw_wp_p
 269                                 stepi
 270                                 gdb_test_no_output "delete \$bpnum"
 271                             }
 272                         }
 273                     }
 274                 }
 275             }
 276         }
 277     }
 278 }
 279
 280 # Based on HW_WP_P set whether hardware watchpoints can be used or
 281 # not, then call RUN_WATCHPOINTS_TESTS.
 282 proc setup_and_run_watchpoints_tests { hw_wp_p } {
 283     if {$hw_wp_p} {
 284         set prefix "hw-watch"
 285     } else {
 286         set prefix "sw-watch"
 287     }
 288
 289     with_test_prefix $prefix {
 290         gdb_test_no_output "set can-use-hw-watchpoints ${hw_wp_p}"
 291
 292         run_watchpoints_tests $hw_wp_p
 293     }
 294 }
 295
 296 # Run tests with hardware watchpoints disabled, then again with them
 297 # enabled (if this target supports hardware watchpoints).
 298 if { !$skip_hw_watchpoint_tests_p } {
 299     # Run test with H/W enabled.
 300     setup_and_run_watchpoints_tests 1
 301 }
 302
 303 # Run test with H/W disabled
 304 setup_and_run_watchpoints_tests 0