elf: Implement DT_AUDIT, DT_DEPAUDIT support [BZ #24943]

  binutils ld has supported --audit, --depaudit for a long time,
only support in glibc has been missing.

[Rebased &repost of an old, unreviewed patch.]

-----
 NEWS                    |  3 ++
 elf/Makefile            | 22 ++++++++++++--
 elf/rtld.c              | 78 +++++++++++++++++++++++++++++++++++++++++++++----
 elf/tst-audit14.c       | 46 +++++++++++++++++++++++++++++
 elf/tst-audit15.c       | 50 +++++++++++++++++++++++++++++++
 elf/tst-audit16.c       | 54 ++++++++++++++++++++++++++++++++++
 elf/tst-auditlogmod-1.c | 27 +++++++++++++++++
 elf/tst-auditlogmod-2.c | 27 +++++++++++++++++
 elf/tst-auditlogmod-3.c | 27 +++++++++++++++++
 support/Makefile        |  1 +
 support/xgetline.c      | 39 +++++++++++++++++++++++++
 support/xstdio.h        |  6 ++++
 12 files changed, 373 insertions(+), 7 deletions(-)
  

On 2/17/20 11:02 AM, Florian Weimer wrote:
> binutils ld has supported --audit, --depaudit for a long time,
> only support in glibc has been missing.
> 
> [Rebased &repost of an old, unreviewed patch.]

OK for master.

Includes tests of DT_AUDIT, and DT_DEPAUDIT for a variable number
of audit libraries.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

> -----
>  NEWS                    |  3 ++
>  elf/Makefile            | 22 ++++++++++++--
>  elf/rtld.c              | 78 +++++++++++++++++++++++++++++++++++++++++++++----
>  elf/tst-audit14.c       | 46 +++++++++++++++++++++++++++++
>  elf/tst-audit15.c       | 50 +++++++++++++++++++++++++++++++
>  elf/tst-audit16.c       | 54 ++++++++++++++++++++++++++++++++++
>  elf/tst-auditlogmod-1.c | 27 +++++++++++++++++
>  elf/tst-auditlogmod-2.c | 27 +++++++++++++++++
>  elf/tst-auditlogmod-3.c | 27 +++++++++++++++++
>  support/Makefile        |  1 +
>  support/xgetline.c      | 39 +++++++++++++++++++++++++
>  support/xstdio.h        |  6 ++++
>  12 files changed, 373 insertions(+), 7 deletions(-)
> 
> diff --git a/NEWS b/NEWS
> index 77631ca707..3d75d6cfc6 100644
> --- a/NEWS
> +++ b/NEWS
> @@ -11,6 +11,9 @@ Major new features:
>  
>    * New locale added: ckb_IQ (Kurdish/Sorani spoken in Iraq)
>  
> +* The GNU C Library now loads audit modules listed in the DT_AUDIT and
> +  DT_DEPAUDIT dynamic section entries of the main executable.
> +
>  Deprecated and removed features, and other changes affecting compatibility:
>  
>    [Add deprecations, removals and changes affecting compatibility here]
> diff --git a/elf/Makefile b/elf/Makefile
> index a137143db7..12c505f3b7 100644
> --- a/elf/Makefile
> +++ b/elf/Makefile
> @@ -202,7 +202,8 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \
>  	 tst-sonamemove-link tst-sonamemove-dlopen tst-dlopen-tlsmodid \
>  	 tst-dlopen-self tst-auditmany tst-initfinilazyfail tst-dlopenfail \
>  	 tst-dlopenfail-2 \
> -	 tst-filterobj tst-filterobj-dlopen tst-auxobj tst-auxobj-dlopen
> +	 tst-filterobj tst-filterobj-dlopen tst-auxobj tst-auxobj-dlopen \
> +	 tst-audit14 tst-audit15 tst-audit16
>  #	 reldep9
>  tests-internal += loadtest unload unload2 circleload1 \
>  	 neededtest neededtest2 neededtest3 neededtest4 \
> @@ -314,7 +315,8 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \
>  		tst-initlazyfailmod tst-finilazyfailmod \
>  		tst-dlopenfailmod1 tst-dlopenfaillinkmod tst-dlopenfailmod2 \
>  		tst-dlopenfailmod3 tst-ldconfig-ld-mod \
> -		tst-filterobj-flt tst-filterobj-aux tst-filterobj-filtee
> +		tst-filterobj-flt tst-filterobj-aux tst-filterobj-filtee \
> +		tst-auditlogmod-1 tst-auditlogmod-2 tst-auditlogmod-3
>  # Most modules build with _ISOMAC defined, but those filtered out
>  # depend on internal headers.
>  modules-names-tests = $(filter-out ifuncmod% tst-libc_dlvsym-dso tst-tlsmod%,\
> @@ -1491,6 +1493,22 @@ $(objpfx)tst-auditmany.out: $(objpfx)tst-auditmanymod1.so \
>  tst-auditmany-ENV = \
>    LD_AUDIT=tst-auditmanymod1.so:tst-auditmanymod2.so:tst-auditmanymod3.so:tst-auditmanymod4.so:tst-auditmanymod5.so:tst-auditmanymod6.so:tst-auditmanymod7.so:tst-auditmanymod8.so:tst-auditmanymod9.so
>  
> +LDFLAGS-tst-audit14 = -Wl,--audit=tst-auditlogmod-1.so
> +$(objpfx)tst-auditlogmod-1.so: $(libsupport)
> +$(objpfx)tst-audit14.out: $(objpfx)tst-auditlogmod-1.so
> +LDFLAGS-tst-audit15 = \
> +  -Wl,--audit=tst-auditlogmod-1.so,--depaudit=tst-auditlogmod-2.so
> +$(objpfx)tst-auditlogmod-2.so: $(libsupport)
> +$(objpfx)tst-audit15.out: \
> +  $(objpfx)tst-auditlogmod-1.so $(objpfx)tst-auditlogmod-2.so
> +LDFLAGS-tst-audit16 = \
> +  -Wl,--audit=tst-auditlogmod-1.so:tst-auditlogmod-2.so \
> +  -Wl,--depaudit=tst-auditlogmod-3.so
> +$(objpfx)tst-auditlogmod-3.so: $(libsupport)
> +$(objpfx)tst-audit16.out: \
> +  $(objpfx)tst-auditlogmod-1.so $(objpfx)tst-auditlogmod-2.so \
> +  $(objpfx)tst-auditlogmod-3.so
> +
>  # tst-sonamemove links against an older implementation of the library.
>  LDFLAGS-tst-sonamemove-linkmod1.so = \
>    -Wl,--version-script=tst-sonamemove-linkmod1.map \
> diff --git a/elf/rtld.c b/elf/rtld.c
> index 51dfaf966a..167da48def 100644
> --- a/elf/rtld.c
> +++ b/elf/rtld.c
> @@ -188,6 +188,15 @@ static struct audit_list
>    struct audit_list *next;
>  } *audit_list;
>  
> +/* State flag for hte struct audit_list_iter iterator.  */
> +enum audit_iter_list_state
> +  {
> +    audit_iter_list_in_string,
> +    audit_iter_list_in_dt_audit,
> +    audit_iter_list_in_dt_depaudit,
> +    audit_iter_list_in_list,
> +  };
> +
>  /* Iterator for audit_list_string followed by audit_list.  */
>  struct audit_list_iter
>  {
> @@ -198,6 +207,9 @@ struct audit_list_iter
>       the first element.  */
>    struct audit_list *previous;
>  
> +  /* One of the enum audit_iter_list_state values.  */
> +  unsigned char state;
> +
>    /* Scratch buffer for returning a name which is part of
>       audit_list_string.  */
>    char fname[SECURE_NAME_LIMIT];
> @@ -209,14 +221,66 @@ audit_list_iter_init (struct audit_list_iter *iter)
>  {
>    iter->audit_list_tail = audit_list_string;
>    iter->previous = NULL;
> +  iter->state = audit_iter_list_in_string;
> +}
> +
> +/* Look up the INDEX of a dynamic tag in MAIN_MAP and store it in
> +   ITER->audit_list_tail if it exists.  */
> +static void
> +audit_list_iter_fetch_index (struct audit_list_iter *iter,
> +			     struct link_map *main_map, size_t index)
> +{
> +  if (main_map->l_info[index] != NULL)
> +    iter->audit_list_tail
> +      = ((const char *) D_PTR (main_map, l_info[DT_STRTAB])
> +	 +  main_map->l_info[index]->d_un.d_val);
> +}
> +
> +/* Advance ITER->state and put the next string into
> +   ITER->audit_list_tail.  */
> +static void
> +audit_list_iter_fetch_string (struct audit_list_iter *iter,
> +			      struct link_map *main_map)
> +{
> +  /* Advance the state.  */
> +  ++iter->state;
> +  assert (iter->state <= audit_iter_list_in_list);
> +
> +  /* Default to a missing string.  */
> +  iter->audit_list_tail = NULL;
> +
> +  /* Determine the next string.  */
> +  switch ((enum audit_iter_list_state) iter->state)
> +    {
> +    case audit_iter_list_in_string:
> +      /* Not possible because state was advanced.  */
> +      __builtin_unreachable ();
> +    case audit_iter_list_in_dt_audit:
> +      audit_list_iter_fetch_index (iter, main_map, ADDRIDX (DT_AUDIT));
> +      break;
> +    case audit_iter_list_in_dt_depaudit:
> +      audit_list_iter_fetch_index (iter, main_map, ADDRIDX (DT_DEPAUDIT));
> +      break;
> +    case audit_iter_list_in_list:
> +      /* No DT_* tag left to process.  */
> +      return;
> +    }
>  }
>  
>  /* Iterate through both audit_list_string and audit_list.  */
>  static const char *
> -audit_list_iter_next (struct audit_list_iter *iter)
> +audit_list_iter_next (struct audit_list_iter *iter, struct link_map *main_map)
>  {
> -  if (iter->audit_list_tail != NULL)
> +  while (iter->state != audit_iter_list_in_list)
>      {
> +      /* If the current string is missing or exhausted, fetch the next
> +	 string.  This advances iter->state.  */
> +      if (iter->audit_list_tail == NULL || *iter->audit_list_tail == '\0')
> +	{
> +	  audit_list_iter_fetch_string (iter, main_map);
> +	  continue;
> +	}
> +
>        /* First iterate over audit_list_string.  */
>        while (*iter->audit_list_tail != '\0')
>  	{
> @@ -241,7 +305,9 @@ audit_list_iter_next (struct audit_list_iter *iter)
>  	    return iter->fname;
>  	  /* Otherwise, wrap around and try the next name.  */
>  	}
> -      /* Fall through to the procesing of audit_list.  */
> +
> +      /* Fetch the next audit string, or fall through to linked list
> +	 processing below.  */
>      }
>  
>    if (iter->previous == NULL)
> @@ -1070,7 +1136,7 @@ load_audit_modules (struct link_map *main_map)
>  
>    while (true)
>      {
> -      const char *name = audit_list_iter_next (&al_iter);
> +      const char *name = audit_list_iter_next (&al_iter, main_map);
>        if (name == NULL)
>  	break;
>        load_audit_module (name, &last_audit);
> @@ -1620,7 +1686,9 @@ ERROR: '%s': cannot process note segment.\n", _dl_argv[0]);
>    /* If we have auditing DSOs to load, do it now.  */
>    bool need_security_init = true;
>    if (__glibc_unlikely (audit_list != NULL)
> -      || __glibc_unlikely (audit_list_string != NULL))
> +      || __glibc_unlikely (audit_list_string != NULL)
> +      || __glibc_unlikely (main_map->l_info[ADDRIDX (DT_AUDIT)] != NULL)
> +      || __glibc_unlikely (main_map->l_info[ADDRIDX (DT_DEPAUDIT)] != NULL))

OK.

>      {
>        /* Since we start using the auditing DSOs right away we need to
>  	 initialize the data structures now.  */
> diff --git a/elf/tst-audit14.c b/elf/tst-audit14.c
> new file mode 100644
> index 0000000000..73e6634e35
> --- /dev/null
> +++ b/elf/tst-audit14.c
> @@ -0,0 +1,46 @@
> +/* Main program with DT_AUDIT.  One audit module.
> +   Copyright (C) 2020 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <stdlib.h>
> +#include <string.h>
> +#include <support/check.h>
> +#include <support/xstdio.h>
> +
> +static int
> +do_test (void)
> +{
> +  /* Verify what the audit module has written.  This test assumes that
> +     standard output has been redirected to a regular file.  */
> +  FILE *fp = xfopen ("/dev/stdout", "r");
> +
> +  char *buffer = NULL;
> +  size_t buffer_length = 0;
> +  size_t line_length = xgetline (&buffer, &buffer_length, fp);
> +  const char *message = "info: tst-auditlogmod-1.so loaded\n";

OK.

> +  TEST_COMPARE_BLOB (message, strlen (message), buffer, line_length);
> +
> +  /* No more audit module output.  */
> +  line_length = xgetline (&buffer, &buffer_length, fp);
> +  TEST_COMPARE_BLOB ("", 0, buffer, line_length);
> +
> +  free (buffer);
> +  xfclose (fp);
> +  return 0;
> +}
> +
> +#include <support/test-driver.c>
> diff --git a/elf/tst-audit15.c b/elf/tst-audit15.c
> new file mode 100644
> index 0000000000..3d6a31c242
> --- /dev/null
> +++ b/elf/tst-audit15.c
> @@ -0,0 +1,50 @@
> +/* Main program with DT_AUDIT and DT_DEPAUDIT.  Two audit modules.
> +   Copyright (C) 2020 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <stdlib.h>
> +#include <string.h>
> +#include <support/check.h>
> +#include <support/xstdio.h>
> +
> +static int
> +do_test (void)
> +{
> +  /* Verify what the audit modules have written.  This test assumes
> +     that standard output has been redirected to a regular file.  */
> +  FILE *fp = xfopen ("/dev/stdout", "r");
> +
> +  char *buffer = NULL;
> +  size_t buffer_length = 0;
> +  size_t line_length = xgetline (&buffer, &buffer_length, fp);
> +  const char *message = "info: tst-auditlogmod-1.so loaded\n";
> +  TEST_COMPARE_BLOB (message, strlen (message), buffer, line_length);
> +
> +  line_length = xgetline (&buffer, &buffer_length, fp);
> +  message = "info: tst-auditlogmod-2.so loaded\n";
> +  TEST_COMPARE_BLOB (message, strlen (message), buffer, line_length);
> +
> +  /* No more audit module output.  */
> +  line_length = xgetline (&buffer, &buffer_length, fp);
> +  TEST_COMPARE_BLOB ("", 0, buffer, line_length);
> +
> +  free (buffer);
> +  xfclose (fp);
> +  return 0;
> +}
> +
> +#include <support/test-driver.c>
> diff --git a/elf/tst-audit16.c b/elf/tst-audit16.c
> new file mode 100644
> index 0000000000..1a7d6eee5e
> --- /dev/null
> +++ b/elf/tst-audit16.c
> @@ -0,0 +1,54 @@
> +/* Main program with DT_AUDIT and DT_DEPAUDIT.  Three audit modules.
> +   Copyright (C) 2020 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <stdlib.h>
> +#include <string.h>
> +#include <support/check.h>
> +#include <support/xstdio.h>
> +
> +static int
> +do_test (void)
> +{
> +  /* Verify what the audit modules have written.  This test assumes
> +     that standard output has been redirected to a regular file.  */
> +  FILE *fp = xfopen ("/dev/stdout", "r");
> +
> +  char *buffer = NULL;
> +  size_t buffer_length = 0;
> +  size_t line_length = xgetline (&buffer, &buffer_length, fp);
> +  const char *message = "info: tst-auditlogmod-1.so loaded\n";
> +  TEST_COMPARE_BLOB (message, strlen (message), buffer, line_length);
> +
> +  line_length = xgetline (&buffer, &buffer_length, fp);
> +  message = "info: tst-auditlogmod-2.so loaded\n";
> +  TEST_COMPARE_BLOB (message, strlen (message), buffer, line_length);
> +
> +  line_length = xgetline (&buffer, &buffer_length, fp);
> +  message = "info: tst-auditlogmod-3.so loaded\n";
> +  TEST_COMPARE_BLOB (message, strlen (message), buffer, line_length);
> +
> +  /* No more audit module output.  */
> +  line_length = xgetline (&buffer, &buffer_length, fp);
> +  TEST_COMPARE_BLOB ("", 0, buffer, line_length);
> +
> +  free (buffer);
> +  xfclose (fp);
> +  return 0;
> +}
> +
> +#include <support/test-driver.c>
> diff --git a/elf/tst-auditlogmod-1.c b/elf/tst-auditlogmod-1.c
> new file mode 100644
> index 0000000000..e6b8cd9094
> --- /dev/null
> +++ b/elf/tst-auditlogmod-1.c
> @@ -0,0 +1,27 @@
> +/* Audit module which logs that it was loaded.  Variant 1.
> +   Copyright (C) 2020 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <link.h>
> +#include <support/support.h>
> +
> +unsigned int
> +la_version (unsigned int v)
> +{
> +  write_message ("info: tst-auditlogmod-1.so loaded\n");
> +  return LAV_CURRENT;
> +}

OK.

> diff --git a/elf/tst-auditlogmod-2.c b/elf/tst-auditlogmod-2.c
> new file mode 100644
> index 0000000000..9e7f0acabc
> --- /dev/null
> +++ b/elf/tst-auditlogmod-2.c
> @@ -0,0 +1,27 @@
> +/* Audit module which logs that it was loaded.  Variant 2.
> +   Copyright (C) 2020 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <link.h>
> +#include <support/support.h>
> +
> +unsigned int
> +la_version (unsigned int v)
> +{
> +  write_message ("info: tst-auditlogmod-2.so loaded\n");
> +  return LAV_CURRENT;
> +}

OK.

> diff --git a/elf/tst-auditlogmod-3.c b/elf/tst-auditlogmod-3.c
> new file mode 100644
> index 0000000000..c4c1a58145
> --- /dev/null
> +++ b/elf/tst-auditlogmod-3.c
> @@ -0,0 +1,27 @@
> +/* Audit module which logs that it was loaded.  Variant 3.
> +   Copyright (C) 2020 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <link.h>
> +#include <support/support.h>
> +
> +unsigned int
> +la_version (unsigned int v)
> +{
> +  write_message ("info: tst-auditlogmod-3.so loaded\n");
> +  return LAV_CURRENT;
> +}

OK.

> diff --git a/support/Makefile b/support/Makefile
> index a0304e6def..0c1e622286 100644
> --- a/support/Makefile
> +++ b/support/Makefile
> @@ -95,6 +95,7 @@ libsupport-routines = \
>    xfopen \
>    xfork \
>    xftruncate \
> +  xgetline \
>    xgetsockname \
>    xlisten \
>    xlseek \
> diff --git a/support/xgetline.c b/support/xgetline.c
> new file mode 100644
> index 0000000000..50326a44cd
> --- /dev/null
> +++ b/support/xgetline.c
> @@ -0,0 +1,39 @@
> +/* getline with error checking.
> +   Copyright (C) 2020 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <support/check.h>
> +#include <support/xstdio.h>
> +
> +size_t
> +xgetline (char **buffer, size_t *length,  FILE *fp)
> +{
> +  TEST_VERIFY (!ferror (fp));
> +  ssize_t ret = getline (buffer, length, fp);
> +  if (ferror (fp))
> +    {
> +      TEST_VERIFY (ret < 0);
> +      FAIL_EXIT1 ("getline: %m");
> +    }
> +  if (feof (fp))
> +    {
> +      TEST_VERIFY (ret <= 0);
> +      return 0;
> +    }
> +  TEST_VERIFY (ret > 0);
> +  return ret;
> +}

OK.

> diff --git a/support/xstdio.h b/support/xstdio.h
> index b62267a2a2..de32a8fe1d 100644
> --- a/support/xstdio.h
> +++ b/support/xstdio.h
> @@ -19,6 +19,7 @@
>  #ifndef SUPPORT_XSTDIO_H
>  #define SUPPORT_XSTDIO_H
>  
> +#include <stddef.h>
>  #include <stdio.h>
>  #include <sys/cdefs.h>
>  
> @@ -27,6 +28,11 @@ __BEGIN_DECLS
>  FILE *xfopen (const char *path, const char *mode);
>  void xfclose (FILE *);
>  
> +/* Read a line from FP, using getline.  *BUFFER must be NULL, or a
> +   heap-allocated pointer of *LENGTH bytes.  Return the number of bytes
> +   in the line if a line was read, or 0 on EOF.  */
> +size_t xgetline (char **buffer, size_t *length,  FILE *fp);

OK.

> +
>  __END_DECLS
>  
>  #endif /* SUPPORT_XSTDIO_H */
>
  

On 17/02/2020 13:02, Florian Weimer wrote:
> diff --git a/elf/rtld.c b/elf/rtld.c
> index 51dfaf966a..167da48def 100644
> --- a/elf/rtld.c
> +++ b/elf/rtld.c
> @@ -188,6 +188,15 @@ static struct audit_list
>    struct audit_list *next;
>  } *audit_list;
>  
> +/* State flag for hte struct audit_list_iter iterator.  */
> +enum audit_iter_list_state
> +  {
> +    audit_iter_list_in_string,
> +    audit_iter_list_in_dt_audit,
> +    audit_iter_list_in_dt_depaudit,
> +    audit_iter_list_in_list,
> +  };
> +
>  /* Iterator for audit_list_string followed by audit_list.  */
>  struct audit_list_iter
>  {
> @@ -198,6 +207,9 @@ struct audit_list_iter
>       the first element.  */
>    struct audit_list *previous;
>  
> +  /* One of the enum audit_iter_list_state values.  */
> +  unsigned char state;

Why not use enum audit_iter_list_state as the type?

Rest looks ok, thanks.
  

* Adhemerval Zanella via Libc-alpha:

> On 17/02/2020 13:02, Florian Weimer wrote:
>> diff --git a/elf/rtld.c b/elf/rtld.c
>> index 51dfaf966a..167da48def 100644
>> --- a/elf/rtld.c
>> +++ b/elf/rtld.c
>> @@ -188,6 +188,15 @@ static struct audit_list
>>    struct audit_list *next;
>>  } *audit_list;
>>  
>> +/* State flag for hte struct audit_list_iter iterator.  */
>> +enum audit_iter_list_state
>> +  {
>> +    audit_iter_list_in_string,
>> +    audit_iter_list_in_dt_audit,
>> +    audit_iter_list_in_dt_depaudit,
>> +    audit_iter_list_in_list,
>> +  };
>> +
>>  /* Iterator for audit_list_string followed by audit_list.  */
>>  struct audit_list_iter
>>  {
>> @@ -198,6 +207,9 @@ struct audit_list_iter
>>       the first element.  */
>>    struct audit_list *previous;
>>  
>> +  /* One of the enum audit_iter_list_state values.  */
>> +  unsigned char state;
>
> Why not use enum audit_iter_list_state as the type?

It avoids increasing the size of struct audit_list_iter.

Thanks,
Florian
  

On 02/04/2020 05:46, Florian Weimer wrote:
> * Adhemerval Zanella via Libc-alpha:
> 
>> On 17/02/2020 13:02, Florian Weimer wrote:
>>> diff --git a/elf/rtld.c b/elf/rtld.c
>>> index 51dfaf966a..167da48def 100644
>>> --- a/elf/rtld.c
>>> +++ b/elf/rtld.c
>>> @@ -188,6 +188,15 @@ static struct audit_list
>>>    struct audit_list *next;
>>>  } *audit_list;
>>>  
>>> +/* State flag for hte struct audit_list_iter iterator.  */
>>> +enum audit_iter_list_state
>>> +  {
>>> +    audit_iter_list_in_string,
>>> +    audit_iter_list_in_dt_audit,
>>> +    audit_iter_list_in_dt_depaudit,
>>> +    audit_iter_list_in_list,
>>> +  };
>>> +
>>>  /* Iterator for audit_list_string followed by audit_list.  */
>>>  struct audit_list_iter
>>>  {
>>> @@ -198,6 +207,9 @@ struct audit_list_iter
>>>       the first element.  */
>>>    struct audit_list *previous;
>>>  
>>> +  /* One of the enum audit_iter_list_state values.  */
>>> +  unsigned char state;
>>
>> Why not use enum audit_iter_list_state as the type?
> 
> It avoids increasing the size of struct audit_list_iter.

But do we care for this specific usage?
  

* Adhemerval Zanella:

> On 02/04/2020 05:46, Florian Weimer wrote:
>> * Adhemerval Zanella via Libc-alpha:
>> 
>>> On 17/02/2020 13:02, Florian Weimer wrote:
>>>> diff --git a/elf/rtld.c b/elf/rtld.c
>>>> index 51dfaf966a..167da48def 100644
>>>> --- a/elf/rtld.c
>>>> +++ b/elf/rtld.c
>>>> @@ -188,6 +188,15 @@ static struct audit_list
>>>>    struct audit_list *next;
>>>>  } *audit_list;
>>>>  
>>>> +/* State flag for hte struct audit_list_iter iterator.  */
>>>> +enum audit_iter_list_state
>>>> +  {
>>>> +    audit_iter_list_in_string,
>>>> +    audit_iter_list_in_dt_audit,
>>>> +    audit_iter_list_in_dt_depaudit,
>>>> +    audit_iter_list_in_list,
>>>> +  };
>>>> +
>>>>  /* Iterator for audit_list_string followed by audit_list.  */
>>>>  struct audit_list_iter
>>>>  {
>>>> @@ -198,6 +207,9 @@ struct audit_list_iter
>>>>       the first element.  */
>>>>    struct audit_list *previous;
>>>>  
>>>> +  /* One of the enum audit_iter_list_state values.  */
>>>> +  unsigned char state;
>>>
>>> Why not use enum audit_iter_list_state as the type?
>> 
>> It avoids increasing the size of struct audit_list_iter.
>
> But do we care for this specific usage? 

No, not really.

I looked at this again from a larger view and will use a simple
stack-allocated array for all string lists.  It turns out that all list
strings use ':' as a separator, so there is no reason to handle
individual strings differently.

Thanks,
Florian