Re: [PATCH v8 5/7] Support software single step on ARM in GDBServer

[Antoine Tremblay <antoine dot tremblay at ericsson dot com>]

On 01/06/2016 09:22 AM, Yao Qi wrote:
> Antoine Tremblay <antoine.tremblay@ericsson.com> writes:
>
> Hi Antoine,
>
> > --- a/gdb/gdbserver/linux-aarch32-low.h
> > +++ b/gdb/gdbserver/linux-aarch32-low.h
> > @@ -15,6 +15,27 @@
> >      You should have received a copy of the GNU General Public License
> >      along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
> >
> > +/* Correct in either endianness.  */
> > +#define arm_abi_breakpoint 0xef9f0001UL
> > +
> > +/* For new EABI binaries.  We recognize it regardless of which ABI
> > +   is used for gdbserver, so single threaded debugging should work
> > +   OK, but for multi-threaded debugging we only insert the current
> > +   ABI's breakpoint instruction.  For now at least.  */
> > +#define arm_eabi_breakpoint 0xe7f001f0UL
> > +
> > +#ifndef __ARM_EABI__
> > +static const unsigned long arm_breakpoint = arm_abi_breakpoint;
> > +#else
> > +static const unsigned long arm_breakpoint = arm_eabi_breakpoint;
> > +#endif
> > +
> > +#define arm_breakpoint_len 4
> > +static const unsigned short thumb_breakpoint = 0xde01;
> > +#define thumb_breakpoint_len 2
> > +static const unsigned short thumb2_breakpoint[] = { 0xf7f0, 0xa000 };
> > +#define thumb2_breakpoint_len 4
> > +
>
> This change causes GDBserver build errors on both ARM and AArch64, which
> are shown in the commit log of the patch below.

Strange I did not see those at all with arm-linux-gnueabihf-gcc 
(Ubuntu/Linaro 4.8.2-16ubuntu4) 4.8.2

Ideas on why you see those and I would not ?

Looking forward to your follow up patches about the issues revealed...

Thanks,
Antoine