Re: [PATCH v2] Fix inconsistent breakpoint kinds between breakpoints and tracepoints in GDBServer.

[Antoine Tremblay <antoine.tremblay@ericsson.com>]

On 10/22/2015 12:04 PM, Pedro Alves wrote:
> On 10/22/2015 05:03 PM, Antoine Tremblay wrote:
>>
>>
>> On 10/22/2015 11:58 AM, Pedro Alves wrote:
>>> On 10/22/2015 04:56 PM, Antoine Tremblay wrote:
>>>> This patch fixes a regression introduced by :
>>>> https://sourceware.org/ml/gdb-patches/2015-10/msg00369.html
>>>>
>>>> Tests : gdb.trace/trace-break.exp and gdb.trace/trace-mt.exp would fail on x86
>>>> with gdbserver-{native,extended}.
>>>>
>>>> Before this patch, the breakpoint kind set by GDB with a Z packet and the one
>>>> set in the case of a tracepoint would be inconsistent on targets that did not
>>>> implement breakpoint_kind_from_pc. On x86 for example a breakpoint set by GDB
>>>> would have a kind of 1 but a breakpoint set by a tracepoint would have a kind of
>>>> 0.
>>>>
>>>> This created a missmatch when trying to insert a tracepoint and a breakpoint at
>>>> the same location. One of the two breakpoints would be removed with debug
>>>> message : "Inconsistent breakpoint kind".
>>>>
>>>> This patch fixes the issue by changing the default 0 breakpoint kind to be
>>>> the size of the breakpoint according to sw_breakpoint_from_kind.
>>>>
>>>> The default breakpoint kind must be the breakpoint length to keep consistency
>>>> between breakpoints set via GDB and the ones set internally by GDBServer.
>>>>
>>>> No regression on Ubuntu 14.04 x86-64 with gdbserver-{native-extended}
>>>>
>>>> gdb/gdbserver/ChangeLog:
>>>>
>>>> 	* linux-low.c (default_breakpoint_kind_from_pc): New function.
>>>> 	(linux_breakpoint_kind_from_pc): Use default_breakpoint_kind_from_pc for
>>>> 	the default breakpoint kind.
>>>
>>> OK.
>>>
>>
>> I forgot to set the function default_breakpoint_kind_from_pc static, ok
>> with that change ?
>
> Sure.
>
> (I think you'll need to move the function to target.c to
> fix !Linux ports, but I'm OK with doing that as a separate step.)
>

I don't think so since I fix !linux ports like so :

/* Implementation of the target_ops method "breakpoint_kind_from_pc".  */

static int
win32_breakpoint_kind_from_pc (CORE_ADDR *pcptr)
{
   return the_low_target.breakpoint_len;
}

/* Implementation of the target_ops method "sw_breakpoint_from_kind".  */

static const gdb_byte *
win32_sw_breakpoint_from_kind (int kind, int *size)
{
   *size = the_low_target.breakpoint_len;
   return the_low_target.breakpoint;
}

?