[PATCH v2] aarch64: Fix error messages for GCS and BTI incompatible modules

[Andreas K. Huettel]

Am Dienstag, 6. Januar 2026, 15:53:03 Mitteleuropäische Normalzeit schrieb Adhemerval Zanella Netto:
> 
> On 06/01/26 08:17, Yury Khrustalev wrote:
> > When either program path of module name is empty, don't print an
> > empty string followed by a colon.
> > 
> > Also fix-up test for a static BTI binary to check error message
> > for this case.
> 
> LGTM, thanks.
> 
> Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
> 
> PS: CCing Andreas to give the final ack to install it.

OK

> 
> > ---
> >  sysdeps/aarch64/Makefile               |  1 +
> >  sysdeps/aarch64/dl-bti.c               | 20 +++++++++++++++-----
> >  sysdeps/aarch64/dl-gcs.c               | 19 ++++++++++++++-----
> >  sysdeps/aarch64/tst-bti-abort-static.c |  4 ++++
> >  4 files changed, 34 insertions(+), 10 deletions(-)
> > 
> > diff --git a/sysdeps/aarch64/Makefile b/sysdeps/aarch64/Makefile
> > index b939bcfc11..ee3981e3f6 100644
> > --- a/sysdeps/aarch64/Makefile
> > +++ b/sysdeps/aarch64/Makefile
> > @@ -90,6 +90,7 @@ ifeq (yes,$(have-test-bti))
> >  
> >  tests += \
> >    tst-bti-abort-imm \
> > +  tst-bti-abort-static \
> >    tst-bti-abort-transitive \
> >    tst-bti-abort-unprot \
> >    tst-bti-dep-prot \
> > diff --git a/sysdeps/aarch64/dl-bti.c b/sysdeps/aarch64/dl-bti.c
> > index 5d743e775f..1301ce2e73 100644
> > --- a/sysdeps/aarch64/dl-bti.c
> > +++ b/sysdeps/aarch64/dl-bti.c
> > @@ -66,13 +66,23 @@ _dl_bti_protect (struct link_map *map, int fd)
> >  static void
> >  bti_failed (struct link_map *l, const char *program)
> >  {
> > -  if (program)
> > -    _dl_fatal_printf ("%s: %s: failed to turn on BTI protection\n",
> > -		      program, l->l_name);
> > +  if (program != NULL)
> > +    {
> > +      if (program[0] != '\0' && l->l_name[0] != '\0')
> > +	/* A program's dependency is not BTI compatible.  */
> > +	_dl_fatal_printf ("%s: %s: failed to turn on BTI protection\n",
> > +			  program, l->l_name);
> > +      if (program[0] != '\0')
> > +	/* The program itself is not BTI compatible.  */
> > +	_dl_fatal_printf ("%s: failed to turn on BTI protection\n", program);
> > +      /* For static binaries, program will be an empty string.  */
> > +      _dl_fatal_printf ("error: failed to turn on BTI protection\n");
> > +    }
> >    else
> > -    /* Note: the errno value is not available any more.  */
> > +    /* If program is NULL, we are processing a dlopen operation.
> > +       Note: the errno value is not available any more.  */
> >      _dl_signal_error (0, l->l_name, "dlopen",
> > -		      N_("failed to turn on BTI protection"));
> > +		      "failed to turn on BTI protection");
> >  }
> >  
> >  
> > diff --git a/sysdeps/aarch64/dl-gcs.c b/sysdeps/aarch64/dl-gcs.c
> > index 7a80e14933..1c6944562d 100644
> > --- a/sysdeps/aarch64/dl-gcs.c
> > +++ b/sysdeps/aarch64/dl-gcs.c
> > @@ -33,18 +33,27 @@
> >  static void
> >  fail (struct link_map *l, const char *program)
> >  {
> > -  if (program && program[0])
> > -    _dl_fatal_printf ("%s: %s: %s\n", program, l->l_name, "not GCS compatible");
> > -  else if (program)
> > -    _dl_fatal_printf ("%s\n", "not GCS compatible");
> > +    if (program != NULL)
> > +    {
> > +      if (program[0] != '\0' && l->l_name[0] != '\0')
> > +	/* A program's dependency is not GCS compatible.  */
> > +	_dl_fatal_printf ("%s: %s: not GCS compatible\n", program, l->l_name);
> > +      if (program[0] != '\0')
> > +	/* The program itself is not GCS compatible.  */
> > +	_dl_fatal_printf ("%s: not GCS compatible\n", program);
> > +      /* For static binaries, program will be an empty string.  */
> > +      _dl_fatal_printf ("error: not GCS compatible\n");
> > +    }
> >    else
> > +    /* If program is NULL, we are processing a dlopen operation.
> > +       Note: the errno value is not available any more.  */
> >      _dl_signal_error (0, l->l_name, "dlopen", "not GCS compatible");
> >  }
> >  
> >  static void
> >  unsupported (void)
> >  {
> > -  _dl_fatal_printf ("%s\n", "unsupported GCS policy");
> > +  _dl_fatal_printf ("unsupported GCS policy\n");
> >  }
> >  
> >  /* This function is called only when binary markings are not
> > diff --git a/sysdeps/aarch64/tst-bti-abort-static.c b/sysdeps/aarch64/tst-bti-abort-static.c
> > index 83871b1fdb..6385e41c65 100644
> > --- a/sysdeps/aarch64/tst-bti-abort-static.c
> > +++ b/sysdeps/aarch64/tst-bti-abort-static.c
> > @@ -22,6 +22,7 @@
> >  #include <stddef.h>
> >  #include <stdint.h>
> >  #include <string.h>
> > +#include <sys/auxv.h>
> >  
> >  #include <support/check.h>
> >  #include <support/support.h>
> > @@ -30,6 +31,9 @@
> >  static int
> >  do_test (void)
> >  {
> > +  unsigned long hwcap2 = getauxval (AT_HWCAP2);
> > +  if ((hwcap2 & HWCAP2_BTI) == 0)
> > +    FAIL_UNSUPPORTED ("BTI is not supported by this system");
> >    return 0;
> >  }
> >  
> 
> 


-- 
Andreas K. Hüttel
dilfridge@gentoo.org
Gentoo Linux developer 
(council, comrel, toolchain, base-system, perl, libreoffice)
https://wiki.gentoo.org/wiki/User:Dilfridge
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