Re: [Qemu-stable] [Qemu-devel] [PATCH v2 2/2] target/lm32: hold BQL in gdbstub

[Michael Walle]

Am 2018-05-21 14:25, schrieb Peter Maydell:
> On 21 May 2018 at 13:21, Michael Walle <address@hidden> wrote:
> > Changing the IP/IM registers may cause interrupts, so hold the BQL.
> >
> > Cc: address@hidden
> > Signed-off-by: Michael Walle <address@hidden>
> > ---
> >  target/lm32/gdbstub.c | 5 +++++
> >  1 file changed, 5 insertions(+)
> >
> > diff --git a/target/lm32/gdbstub.c b/target/lm32/gdbstub.c
> > index cf929dd392..dac9418a2b 100644
> > --- a/target/lm32/gdbstub.c
> > +++ b/target/lm32/gdbstub.c
> > @@ -18,6 +18,7 @@
> >   * License along with this library; if not, see 
> > <http://www.gnu.org/licenses/>.
> >   */
> >  #include "qemu/osdep.h"
> > +#include "qemu/main-loop.h"
> >  #include "qemu-common.h"
> >  #include "cpu.h"
> >  #include "exec/gdbstub.h"
> > @@ -82,10 +83,14 @@ int lm32_cpu_gdb_write_register(CPUState *cs, 
> > uint8_t *mem_buf, int n)
> >              env->ie = tmp;
> >              break;
> >          case 37:
> > +            qemu_mutex_lock_iothread();
> >              lm32_pic_set_im(env->pic_state, tmp);
> > +            qemu_mutex_unlock_iothread();
> >              break;
> >          case 38:
> > +            qemu_mutex_lock_iothread();
> >              lm32_pic_set_ip(env->pic_state, tmp);
> > +            qemu_mutex_unlock_iothread();
> >              break;
> >          }
> >      }
>
> Are you sure this is necessary? I would have expected the gdbstub to
> be operating under the qemu lock anyway.


You're right. The gdbstub is already holding the lock. So i'll drop this 
and send the pull request right now.

-michael