Re: [PATCH v13 1/4] elf: Add la_activity during application exit

[Carlos O'Donell <carlos@redhat.com>]

On 2/1/22 09:46, Adhemerval Zanella wrote:
> la_activity is not called during application exit, even though
> la_objclose is.

OK for glibc 2.35. Please push.

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

 
> Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu.
> ---
>  elf/Makefile         |   7 ++
>  elf/dl-fini.c        |   8 ++
>  elf/tst-audit23.c    | 239 +++++++++++++++++++++++++++++++++++++++++++
>  elf/tst-audit23mod.c |  23 +++++
>  elf/tst-auditmod23.c |  74 ++++++++++++++
>  5 files changed, 351 insertions(+)
>  create mode 100644 elf/tst-audit23.c
>  create mode 100644 elf/tst-audit23mod.c
>  create mode 100644 elf/tst-auditmod23.c
> 
> diff --git a/elf/Makefile b/elf/Makefile
> index 1fa1a519a5..ddd0e84afc 100644
> --- a/elf/Makefile
> +++ b/elf/Makefile
> @@ -378,6 +378,7 @@ tests += \
>    tst-audit19b \
>    tst-audit20 \
>    tst-audit22 \
> +  tst-audit23 \
>    tst-auditmany \
>    tst-auxobj \
>    tst-auxobj-dlopen \
> @@ -674,6 +675,7 @@ modules-names = \
>    tst-audit13mod1 \
>    tst-audit18mod \
>    tst-audit19bmod \
> +  tst-audit23mod \
>    tst-auditlogmod-1 \
>    tst-auditlogmod-2 \
>    tst-auditlogmod-3 \
> @@ -696,6 +698,7 @@ modules-names = \
>    tst-auditmod19b \
>    tst-auditmod20 \
>    tst-auditmod22 \
> +  tst-auditmod23 \
>    tst-auxvalmod \
>    tst-big-note-lib \
>    tst-deep1mod1 \
> @@ -2139,6 +2142,10 @@ tst-audit20-ENV = LD_AUDIT=$(objpfx)tst-auditmod20.so
>  $(objpfx)tst-audit22.out: $(objpfx)tst-auditmod22.so
>  tst-audit22-ARGS = -- $(host-test-program-cmd)
>  
> +$(objpfx)tst-audit23.out: $(objpfx)tst-auditmod23.so \
> +			  $(objpfx)tst-audit23mod.so
> +tst-audit23-ARGS = -- $(host-test-program-cmd)
> +
>  # 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/dl-fini.c b/elf/dl-fini.c
> index de8eb1b3c9..030b1fcbcd 100644
> --- a/elf/dl-fini.c
> +++ b/elf/dl-fini.c
> @@ -64,6 +64,10 @@ _dl_fini (void)
>  	__rtld_lock_unlock_recursive (GL(dl_load_lock));
>        else
>  	{
> +#ifdef SHARED
> +	  _dl_audit_activity_nsid (ns, LA_ACT_DELETE);
> +#endif
> +
>  	  /* Now we can allocate an array to hold all the pointers and
>  	     copy the pointers in.  */
>  	  struct link_map *maps[nloaded];
> @@ -153,6 +157,10 @@ _dl_fini (void)
>  	      /* Correct the previous increment.  */
>  	      --l->l_direct_opencount;
>  	    }
> +
> +#ifdef SHARED
> +	  _dl_audit_activity_nsid (ns, LA_ACT_CONSISTENT);
> +#endif
>  	}
>      }
>  
> diff --git a/elf/tst-audit23.c b/elf/tst-audit23.c
> new file mode 100644
> index 0000000000..4904cf1340
> --- /dev/null
> +++ b/elf/tst-audit23.c
> @@ -0,0 +1,239 @@
> +/* Check for expected la_objopen and la_objeclose for all objects.
> +   Copyright (C) 2022 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
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#include <array_length.h>
> +#include <errno.h>
> +#include <getopt.h>
> +#include <link.h>
> +#include <limits.h>
> +#include <inttypes.h>
> +#include <gnu/lib-names.h>
> +#include <string.h>
> +#include <stdlib.h>
> +#include <support/capture_subprocess.h>
> +#include <support/check.h>
> +#include <support/xstdio.h>
> +#include <support/xdlfcn.h>
> +#include <support/support.h>
> +
> +static int restart;
> +#define CMDLINE_OPTIONS \
> +  { "restart", no_argument, &restart, 1 },
> +
> +static int
> +handle_restart (void)
> +{
> +  xdlopen ("tst-audit23mod.so", RTLD_NOW);
> +  xdlmopen (LM_ID_NEWLM, LIBC_SO, RTLD_NOW);
> +
> +  return 0;
> +}
> +
> +static inline bool
> +startswith (const char *str, const char *pre)
> +{
> +  size_t lenpre = strlen (pre);
> +  size_t lenstr = strlen (str);
> +  return lenstr >= lenpre && memcmp (pre, str, lenpre) == 0;
> +}
> +
> +static inline bool
> +is_vdso (const char *str)
> +{
> +  return startswith (str, "linux-gate")
> +	 || startswith (str, "linux-vdso");
> +}
> +
> +static int
> +do_test (int argc, char *argv[])
> +{
> +  /* We must have either:
> +     - One or four parameters left if called initially:
> +       + path to ld.so         optional
> +       + "--library-path"      optional
> +       + the library path      optional
> +       + the application name  */
> +  if (restart)
> +    return handle_restart ();
> +
> +  char *spargv[9];
> +  TEST_VERIFY_EXIT (((argc - 1) + 3) < array_length (spargv));
> +  int i = 0;
> +  for (; i < argc - 1; i++)
> +    spargv[i] = argv[i + 1];
> +  spargv[i++] = (char *) "--direct";
> +  spargv[i++] = (char *) "--restart";
> +  spargv[i] = NULL;
> +
> +  setenv ("LD_AUDIT", "tst-auditmod23.so", 0);
> +  struct support_capture_subprocess result
> +    = support_capture_subprogram (spargv[0], spargv);
> +  support_capture_subprocess_check (&result, "tst-audit22", 0, sc_allow_stderr);
> +
> +  /* The expected la_objopen/la_objclose:
> +     1. executable
> +     2. loader
> +     3. libc.so
> +     4. tst-audit23mod.so
> +     5. libc.so (LM_ID_NEWLM).
> +     6. vdso (optional and ignored).  */
> +  enum { max_objs = 6 };
> +  struct la_obj_t
> +  {
> +    char *lname;
> +    uintptr_t laddr;
> +    Lmid_t lmid;
> +    bool closed;
> +  } objs[max_objs] = { [0 ... max_objs-1] = { .closed = false } };
> +  size_t nobjs = 0;
> +
> +  /* The expected namespaces are one for the audit module, one for the
> +     application, and another for the dlmopen on handle_restart.  */
> +  enum { max_ns = 3 };
> +  uintptr_t acts[max_ns] = { 0 };
> +  size_t nacts = 0;
> +  int last_act = -1;
> +  uintptr_t last_act_cookie = -1;
> +  bool seen_first_objclose = false;
> +
> +  FILE *out = fmemopen (result.err.buffer, result.err.length, "r");
> +  TEST_VERIFY (out != NULL);
> +  char *buffer = NULL;
> +  size_t buffer_length = 0;
> +  while (xgetline (&buffer, &buffer_length, out))
> +    {
> +      if (startswith (buffer, "la_activity: "))
> +	{
> +	  uintptr_t cookie;
> +	  int this_act;
> +	  int r = sscanf (buffer, "la_activity: %d %"SCNxPTR"", &this_act,
> +			  &cookie);
> +	  TEST_COMPARE (r, 2);
> +
> +	  /* The cookie identifies the object at the head of the link map,
> +	     so we only add a new namespace if it changes from the previous
> +	     one.  This works since dlmopen is the last in the test body.  */
> +	  if (cookie != last_act_cookie && last_act_cookie != -1)
> +	    TEST_COMPARE (last_act, LA_ACT_CONSISTENT);
> +
> +	  if (this_act == LA_ACT_ADD && acts[nacts] != cookie)
> +	    {
> +	      acts[nacts++] = cookie;
> +	      last_act_cookie = cookie;
> +	    }
> +	  /* The LA_ACT_DELETE is called in the reverse order of LA_ACT_ADD
> +	     at program termination (if the tests adds a dlclose or a library
> +	     with extra dependencies this will need to be adapted).  */
> +	  else if (this_act == LA_ACT_DELETE)
> +	    {
> +	      last_act_cookie = acts[--nacts];
> +	      TEST_COMPARE (acts[nacts], cookie);
> +	      acts[nacts] = 0;
> +	    }
> +	  else if (this_act == LA_ACT_CONSISTENT)
> +	    {
> +	      TEST_COMPARE (cookie, last_act_cookie);
> +
> +	      /* LA_ACT_DELETE must always be followed by an la_objclose.  */
> +	      if (last_act == LA_ACT_DELETE)
> +		TEST_COMPARE (seen_first_objclose, true);
> +	      else
> +		TEST_COMPARE (last_act, LA_ACT_ADD);
> +	    }
> +
> +	  last_act = this_act;
> +	  seen_first_objclose = false;
> +	}
> +      else if (startswith (buffer, "la_objopen: "))
> +	{
> +	  char *lname;
> +	  uintptr_t laddr;
> +	  Lmid_t lmid;
> +	  uintptr_t cookie;
> +	  int r = sscanf (buffer, "la_objopen: %"SCNxPTR"  %ms %"SCNxPTR" %ld",
> +			  &cookie, &lname, &laddr, &lmid);
> +	  TEST_COMPARE (r, 4);
> +
> +	  /* la_objclose is not triggered by vDSO because glibc does not
> +	     unload it.  */
> +	  if (is_vdso (lname))
> +	    continue;
> +	  if (nobjs == max_objs)
> +	    FAIL_EXIT1 ("non expected la_objopen: %s %"PRIxPTR" %ld",
> +			lname, laddr, lmid);
> +	  objs[nobjs].lname = lname;
> +	  objs[nobjs].laddr = laddr;
> +	  objs[nobjs].lmid = lmid;
> +	  objs[nobjs].closed = false;
> +	  nobjs++;
> +
> +	  /* This indirectly checks that la_objopen always comes before
> +	     la_objclose btween la_activity calls.  */
> +	  seen_first_objclose = false;
> +	}
> +      else if (startswith (buffer, "la_objclose: "))
> +	{
> +	  char *lname;
> +	  uintptr_t laddr;
> +	  Lmid_t lmid;
> +	  uintptr_t cookie;
> +	  int r = sscanf (buffer, "la_objclose: %"SCNxPTR" %ms %"SCNxPTR" %ld",
> +			  &cookie, &lname, &laddr, &lmid);
> +	  TEST_COMPARE (r, 4);
> +
> +	  for (size_t i = 0; i < nobjs; i++)
> +	    {
> +	      if (strcmp (lname, objs[i].lname) == 0 && lmid == objs[i].lmid)
> +		{
> +		  TEST_COMPARE (objs[i].closed, false);
> +		  objs[i].closed = true;
> +		  break;
> +		}
> +	    }
> +
> +	  /* la_objclose should be called after la_activity(LA_ACT_DELETE) for
> +	     the closed object's namespace.  */
> +	  TEST_COMPARE (last_act, LA_ACT_DELETE);
> +	  if (!seen_first_objclose)
> +	    {
> +	      TEST_COMPARE (last_act_cookie, cookie);
> +	      seen_first_objclose = true;
> +	    }
> +	}
> +    }
> +
> +  for (size_t i = 0; i < nobjs; i++)
> +    {
> +      TEST_COMPARE (objs[i].closed, true);
> +      free (objs[i].lname);
> +    }
> +
> +  /* la_activity(LA_ACT_CONSISTENT) should be the last callback received.
> +     Since only one link map may be not-CONSISTENT at a time, this also
> +     ensures la_activity(LA_ACT_CONSISTENT) is the last callback received
> +     for every namespace.  */
> +  TEST_COMPARE (last_act, LA_ACT_CONSISTENT);
> +
> +  free (buffer);
> +  xfclose (out);
> +
> +  return 0;
> +}
> +
> +#define TEST_FUNCTION_ARGV do_test
> +#include <support/test-driver.c>
> diff --git a/elf/tst-audit23mod.c b/elf/tst-audit23mod.c
> new file mode 100644
> index 0000000000..3031568703
> --- /dev/null
> +++ b/elf/tst-audit23mod.c
> @@ -0,0 +1,23 @@
> +/* Extra module for tst-audit23
> +   Copyright (C) 2022 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
> +   <https://www.gnu.org/licenses/>.  */
> +
> +int
> +foo (void)
> +{
> +  return 0;
> +}
> diff --git a/elf/tst-auditmod23.c b/elf/tst-auditmod23.c
> new file mode 100644
> index 0000000000..d7c60d7a5c
> --- /dev/null
> +++ b/elf/tst-auditmod23.c
> @@ -0,0 +1,74 @@
> +/* Audit module loaded by tst-audit23.
> +   Copyright (C) 2022 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
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#include <link.h>
> +#include <inttypes.h>
> +#include <stdlib.h>
> +#include <stdio.h>
> +#include <string.h>
> +#include <sys/auxv.h>
> +
> +unsigned int
> +la_version (unsigned int version)
> +{
> +  return LAV_CURRENT;
> +}
> +
> +struct map_desc_t
> +{
> +  char *lname;
> +  uintptr_t laddr;
> +  Lmid_t lmid;
> +};
> +
> +void
> +la_activity (uintptr_t *cookie, unsigned int flag)
> +{
> +  fprintf (stderr, "%s: %d %"PRIxPTR"\n", __func__, flag, (uintptr_t) cookie);
> +}
> +
> +unsigned int
> +la_objopen (struct link_map *map, Lmid_t lmid, uintptr_t *cookie)
> +{
> +  const char *l_name = map->l_name[0] == '\0' ? "mainapp" : map->l_name;
> +  fprintf (stderr, "%s: %"PRIxPTR" %s %"PRIxPTR" %ld\n", __func__,
> +	   (uintptr_t) cookie, l_name, map->l_addr, lmid);
> +
> +  struct map_desc_t *map_desc = malloc (sizeof (struct map_desc_t));
> +  if (map_desc == NULL)
> +    abort ();
> +
> +  map_desc->lname = strdup (l_name);
> +  map_desc->laddr = map->l_addr;
> +  map_desc->lmid = lmid;
> +
> +  *cookie = (uintptr_t) map_desc;
> +
> +  return 0;
> +}
> +
> +unsigned int
> +la_objclose (uintptr_t *cookie)
> +{
> +  struct map_desc_t *map_desc = (struct map_desc_t *) *cookie;
> +  fprintf (stderr, "%s: %"PRIxPTR" %s %"PRIxPTR" %ld\n", __func__,
> +	   (uintptr_t) cookie, map_desc->lname, map_desc->laddr,
> +	   map_desc->lmid);
> +
> +  return 0;
> +}


-- 
Cheers,
Carlos.