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

[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.

> ---
>  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;
>  }
>