Re: [PATCH] tree-optimization/111736 - avoid address sanitizing of __seg_gs

[Richard Biener <rguenther@suse.de>]

On Thu, 21 Mar 2024, Jakub Jelinek wrote:

> On Thu, Mar 21, 2024 at 10:25:24AM +0100, Richard Biener wrote:
> > The following more thoroughly avoids address sanitizing accesses
> > to non-generic address-spaces.
> > 
> > Bootstrapped and tested on x86_64-unknown-linux-gnu.
> > 
> > OK?
> > 
> > Thanks,
> > Richard.
> > 
> > 	PR tree-optimization/111736
> > 	* asan.cc (instrument_derefs): Do not instrument accesses
> > 	to non-generic address-spaces.
> > 
> > 	* gcc.target/i386/pr111736.c: New testcase.
> > ---
> >  gcc/asan.cc                              |  4 ++++
> >  gcc/testsuite/gcc.target/i386/pr111736.c | 23 +++++++++++++++++++++++
> >  2 files changed, 27 insertions(+)
> >  create mode 100644 gcc/testsuite/gcc.target/i386/pr111736.c
> > 
> > diff --git a/gcc/asan.cc b/gcc/asan.cc
> > index cfe83106460..04caf8802e2 100644
> > --- a/gcc/asan.cc
> > +++ b/gcc/asan.cc
> > @@ -2755,6 +2755,10 @@ instrument_derefs (gimple_stmt_iterator *iter, tree t,
> >    if (VAR_P (inner) && DECL_HARD_REGISTER (inner))
> >      return;
> >  
> > +  /* Accesses to non-generic address-spaces are not handled.  */
> 
> I'd say s/are not handled/should not be instrumented/

Fixed and pushed.  I suppose for address-spaces nested within the
generic address space we could instrument the address converted to
the generic address space value.

Richard.

> > +  if (!ADDR_SPACE_GENERIC_P (TYPE_ADDR_SPACE (TREE_TYPE (inner))))
> > +    return;
> > +
> 
> Otherwise LGTM.
> 
> >    poly_int64 decl_size;
> >    if ((VAR_P (inner)
> >         || (TREE_CODE (inner) == RESULT_DECL
> > diff --git a/gcc/testsuite/gcc.target/i386/pr111736.c b/gcc/testsuite/gcc.target/i386/pr111736.c
> > new file mode 100644
> > index 00000000000..231fdd07e80
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.target/i386/pr111736.c
> > @@ -0,0 +1,23 @@
> > +/* { dg-do compile } */
> > +/* { dg-options "-O2 -fsanitize=address" } */
> > +
> > +int __seg_gs m;
> > +
> > +int foo (void)
> > +{
> > +  return m;
> > +}
> > +
> > +extern int  __seg_gs n;
> > +
> > +int bar (void)
> > +{
> > +  return n;
> > +}
> > +
> > +int baz (int __seg_gs *o)
> > +{
> > +  return *o;
> > +}
> > +
> > +/* { dg-final { scan-assembler-not "asan_report_load" } } */
> > -- 
> > 2.35.3
> 
> 	Jakub
> 
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE Software Solutions Germany GmbH,
Frankenstrasse 146, 90461 Nuernberg, Germany;
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