This applies the second part of GDB's End of Year Procedure, which
updates the copyright year range in all of GDB's files.
gdb/ChangeLog:
Update copyright year range in all GDB files.
sss-bp-on-user-bp.c has an assumption that write to integer can be
compiled to a single instruction, which isn't true on some arch, such
as arm. This test requires setting two breakpoints on two consecutive
instructions, so this patch is to get the address of the next
instruction via disassemble and set the 2nd breakpoint there. This
approach is portable.
This patch fixes the fails in sss-bp-on-user-bp.exp on arm-none-abi
target. There is no change in x86 test results. I also revert the
patch to PR breakpoints/17000, and verified that the patched
sss-bp-on-user-bp.exp still trigger the fail on
x86-with-software-single-step.
gdb/testsuite:
2014-06-04 Yao Qi <yao@codesourcery.com>
* gdb.base/sss-bp-on-user-bp.c (main): Remove comments.
* gdb.base/sss-bp-on-user-bp.exp: Don't set breakpoint on
"set bar break here". Get the next instruction address and
set breakpoint there. Remove "bar break" from the regexp
patterns.
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).
GDB gets confused when removing a software single-step breakpoint that
is at the same address as another breakpoint. Add a kfailed test.
gdb/testsuite/
2014-05-30 Pedro Alves <palves@redhat.com>
PR breakpoints/17000
* gdb.base/sss-bp-on-user-bp.c: New file.
* gdb.base/sss-bp-on-user-bp.exp: New file.
Joel Brobecker
Luis Machado
Yao Qi
Pedro Alves