RE: [PATCH v4 1/1] gdb: avoid conversion of SIGSEGV to SIGTRAP on user breakpoints

AMD General

Hi Andrew,

Kindly pinging for a re-approval.

Regards,
-Baris

On Friday, July 17, 2026 3:25 PM, Gerlicher, Klaus wrote:
> Thank you, Baris.
>
>  I discovered this too *after* I posted. I'll make sure it's updated once Andrew
> approves again.
>
> Thanks
> Klaus
>
> > -----Original Message-----
> > From: Aktemur, Baris <[email protected]>
> > Sent: Friday, July 17, 2026 11:17 AM
> > To: Gerlicher, Klaus <[email protected]>; gdb-
> > [email protected]
> > Cc: [email protected]
> > Subject: RE: [PATCH v4 1/1] gdb: avoid conversion of SIGSEGV to SIGTRAP on
> > user breakpoints
> >
> > AMD General
> >
> > Hi Klaus,
> >
> > On Friday, July 17, 2026 9:45 AM, Klaus Gerlicher wrote:
> > > GDB converts signals GDB_SIGNAL_ILL, GDB_SIGNAL_SEGV and
> > GDB_SIGNAL_EMT to
> > > GDB_SIGNAL_TRAP if a breakpoint is inserted at the fault location.  If, due
> > > to imprecise page fault reporting, a breakpoint is at the same address as
> > > the fault address, this signal would always be reported as
> > GDB_SIGNAL_TRAP.
> > >
> > > Add a new gdbarch function, imprecise_pagefault_reporting, that allows the
> > > signal conversion from GDB_SIGNAL_SEGV to GDB_SIGNAL_TRAP to be
> > skipped for
> > > an architecture.  The default is false (conversion enabled), preserving
> > > existing behavior.
> >
> > It seems gdbarch.py has been updated since the last time you generated
> > gdbarch files.
> > Re-generating gives the diff below.  The patch LGTM with that fixed.
> >
> > Reviewed-By: Tankut Baris Aktemur <[email protected]>
> >
> > Thank you.
> > -Baris
> >
> >
> > diff --git a/gdb/gdbarch-gen.c b/gdb/gdbarch-gen.c
> > index d9bb3e7078c..0b815296261 100644
> > --- a/gdb/gdbarch-gen.c
> > +++ b/gdb/gdbarch-gen.c
> > @@ -5295,8 +5295,8 @@ set_gdbarch_get_shadow_stack_pointer (struct
> > gdbarch *gdbarch,
> >  bool
> >  gdbarch_imprecise_pagefault_reporting (struct gdbarch *gdbarch)
> >  {
> > -  gdb_assert (gdbarch != NULL);
> > -  gdb_assert (gdbarch->imprecise_pagefault_reporting != NULL);
> > +  gdb_assert (gdbarch != nullptr);
> > +  gdb_assert (gdbarch->imprecise_pagefault_reporting != nullptr);
> >    if (gdbarch_debug >= 2)
> >      gdb_printf (gdb_stdlog, "gdbarch_imprecise_pagefault_reporting
> > called\n");
> >    return gdbarch->imprecise_pagefault_reporting ();
> > diff --git a/gdb/gdbarch-gen.h b/gdb/gdbarch-gen.h
> > index bb95df25eb6..a96692c206c 100644
> > --- a/gdb/gdbarch-gen.h
> > +++ b/gdb/gdbarch-gen.h
> > @@ -1756,6 +1756,6 @@ void set_gdbarch_get_shadow_stack_pointer
> > (struct gdbarch *gdbarch, gdbarch_get_
> >  /* Returns true if architecture has imprecise pagefault reporting.  This is
> >     used in conversion of SIGSEGV to SIGTRAP for an architecture. */
> >
> > -typedef bool (gdbarch_imprecise_pagefault_reporting_ftype) ();
> > -extern bool gdbarch_imprecise_pagefault_reporting (struct gdbarch
> > *gdbarch);
> > -extern void set_gdbarch_imprecise_pagefault_reporting (struct gdbarch
> > *gdbarch, gdbarch_imprecise_pagefault_reporting_ftype
> > *imprecise_pagefault_reporting);
> > +using gdbarch_imprecise_pagefault_reporting_ftype = bool ();
> > +bool gdbarch_imprecise_pagefault_reporting (struct gdbarch *gdbarch);
> > +void set_gdbarch_imprecise_pagefault_reporting (struct gdbarch *gdbarch,
> > gdbarch_imprecise_pagefault_reporting_ftype
> > *imprecise_pagefault_reporting);
> >
>
> Intel Deutschland GmbH
>
> Registered Address: Dornacher Strasse 1, 85622 Feldkirchen, Germany
> Tel: +49 89 991 430, www.intel.de
> Managing Directors: Harry Demas, Jeffrey Schneiderman, Yin Chong Sorrell
> Chairperson of the Supervisory Board: Nicole Lau
> Registered Seat: Munich
> Commercial Register: Amtsgericht Muenchen HRB 186928