old-cross-binutils/gdb/testsuite/gdb.base/sss-bp-on-user-bp.exp

66 lines
2.2 KiB
Text
Raw Normal View History

# Copyright 2014-2015 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/>.
# Test that removing a single-step breakpoint that is placed at the
# same address as another regular breakpoint leaves the regular
# breakpoint inserted.
standard_testfile
set executable ${testfile}
if {[prepare_for_testing "failed to prepare" $testfile $srcfile debug]} {
return -1
}
if ![runto_main] then {
fail "Can't run to main"
return 0
}
gdb_breakpoint [gdb_get_line_number "set foo break here"]
gdb_continue_to_breakpoint "first breakpoint" ".* set foo break here .*"
# Get the address of the next instruction and set a breakpoint there.
set next_insn_addr ""
set test "disassemble main"
gdb_test_multiple $test $test {
-re ".*=> $hex <\\+$decimal>:\[^\r\n\]+\r\n ($hex) .*$gdb_prompt $" {
set next_insn_addr $expect_out(1,string)
pass $test
}
}
if { $next_insn_addr == "" } {
return -1
}
gdb_test "b *$next_insn_addr" "Breakpoint .*"
# So that GDB doesn't try to remove the regular breakpoint when the
# step finishes.
gdb_test_no_output "set breakpoint always-inserted on"
# On software single-step targets, this step will want to momentarily
# place a single-step breakpoint over the bar breakpoint, and then
# remove it. But, a regular breakpoint is planted there already, and
# with always-inserted on, should remain planted when the step
# finishes.
gdb_test "si" "Breakpoint .*"
# If the breakpoint is still correctly inserted, then this jump should
# re-trigger it. Otherwise, GDB will lose control and the program
User breakpoint ignored if software-single-step at same location with the following code... 12 Nested; -- break #1 13 return I; -- break #2 14 end; (line 12 is a call to function Nested) ... we have noticed the following errorneous behavior on ppc-aix, where, after having inserted a breakpoint at line 12 and line 13, and continuing from the breakpoint at line 12, the program never stops at line 13, running away until the program terminates: % gdb -q func (gdb) b func.adb:12 Breakpoint 1 at 0x10000a24: file func.adb, line 12. (gdb) b func.adb:13 Breakpoint 2 at 0x10000a28: file func.adb, line 13. (gdb) run Starting program: /[...]/func Breakpoint 1, func () at func.adb:12 12 Nested; -- break #1 (gdb) c Continuing. [Inferior 1 (process 4128872) exited with code 02] When resuming from the first breakpoint, GDB first tries to step out of that first breakpoint. We rely on software single-stepping on this platform, and it just so happens that the address of the first software single-step breakpoint is the same as the user's breakpoint #2 (0x10000a28). So, with infrun and target traces turned on (but uninteresting traces snip'ed off), the "continue" operation looks like this: (gdb) c ### First, we insert the user breakpoints (the second one is an internal ### breakpoint on __pthread_init). The first user breakpoint is not ### inserted as we need to step out of it first. target_insert_breakpoint (0x0000000010000a28, xxx) = 0 target_insert_breakpoint (0x00000000d03f3800, xxx) = 0 ### Then we proceed with the step-out-of-breakpoint... infrun: resume (step=1, signal=GDB_SIGNAL_0), trap_expected=1, current thread [process 15335610] at 0x10000a24 ### That's when we insert the SSS breakpoints... target_insert_breakpoint (0x0000000010000a28, xxx) = 0 target_insert_breakpoint (0x00000000100009ac, xxx) = 0 ### ... then let the inferior resume... target_resume (15335610, continue, 0) infrun: wait_for_inferior () target_wait (-1, status, options={}) = 15335610, status->kind = stopped, signal = GDB_SIGNAL_TRAP infrun: target_wait (-1, status) = infrun: 15335610 [process 15335610], infrun: status->kind = stopped, signal = GDB_SIGNAL_TRAP infrun: infwait_normal_state infrun: TARGET_WAITKIND_STOPPED infrun: stop_pc = 0x100009ac ### At this point, we stopped at the second SSS breakpoint... target_stopped_by_watchpoint () = 0 ### We remove the SSS breakpoints... target_remove_breakpoint (0x0000000010000a28, xxx) = 0 target_remove_breakpoint (0x00000000100009ac, xxx) = 0 target_stopped_by_watchpoint () = 0 ### We find that we're not done, so we resume.... infrun: no stepping, continue ### And thus insert the user breakpoints again, except we're not ### inserting the second breakpoint?!? target_insert_breakpoint (0x0000000010000a24, xxx) = 0 infrun: resume (step=0, signal=GDB_SIGNAL_0), trap_expected=0, current thread [process 15335610] at 0x100009ac target_resume (-1, continue, 0) infrun: prepare_to_wait target_wait (-1, status, options={}) = 15335610, status->kind = exited, status = 2 What happens is that the removal of the software single-step breakpoints effectively removed the breakpoint instruction from inferior memory. But because such breakpoints are inserted directly as raw breakpoints rather than through the normal chain of breakpoints, we fail to notice that one of the user breakpoints points to the same address and that this user breakpoint is therefore effectively un-inserted. When resuming after the single-step, GDB thinks that the user breakpoint is still inserted and therefore does not need to insert it again. This patch teaches the insert and remove routines of both regular and raw breakpoints to be aware of each other. Special care needs to be applied in case the target supports evaluation of breakpoint conditions or commands. gdb/ChangeLog: PR breakpoints/17000 * breakpoint.c (find_non_raw_software_breakpoint_inserted_here): New function, extracted from software_breakpoint_inserted_here_p. (software_breakpoint_inserted_here_p): Replace factored out code by call to find_non_raw_software_breakpoint_inserted_here. (bp_target_info_copy_insertion_state): New function. (bkpt_insert_location): Handle the case of a single-step breakpoint already inserted at the same address. (bkpt_remove_location): Handle the case of a single-step breakpoint still inserted at the same address. (deprecated_insert_raw_breakpoint): Handle the case of non-raw breakpoint already inserted at the same address. (deprecated_remove_raw_breakpoint): Handle the case of a non-raw breakpoint still inserted at the same address. (find_single_step_breakpoint): New function, extracted from single_step_breakpoint_inserted_here_p. (find_single_step_breakpoint): New function, factored out from single_step_breakpoint_inserted_here_p. (single_step_breakpoint_inserted_here_p): Reimplement. gdb/testsuite/ChangeLog: PR breakpoints/17000 * gdb.base/sss-bp-on-user-bp.exp: Remove kfail. * gdb.base/sss-bp-on-user-bp-2.exp: Remove kfail. Tested on ppc-aix with AdaCore's testsuite. Tested on x86_64-linux, (native and gdbserver) with the official testsuite. Also tested on x86_64-linux through Pedro's branch enabling software single-stepping on that platform (native and gdbserver).
2014-06-03 16:42:19 +00:00
# will exit. See PR breakpoints/17000.
gdb_test "jump *\$pc" "Breakpoint .*"