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From: Florian Weimer <fweimer@redhat.com>
To: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Cc: libc-alpha@sourceware.org,  John Mellor-Crummey <johnmc@rice.edu>,
	 Ben Woodard <woodard@redhat.com>
Subject: Re: [PATCH v6 04/20] elf: Add _dl_audit_objsearch
Date: Fri, 17 Dec 2021 13:21:13 +0100	[thread overview]
Message-ID: <87pmpvmngm.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <20211115183734.531155-5-adhemerval.zanella@linaro.org> (Adhemerval Zanella's message of "Mon, 15 Nov 2021 15:37:18 -0300")

* Adhemerval Zanella:

> diff --git a/elf/dl-audit.c b/elf/dl-audit.c
> index 5fbc76a36c..de85ef1ddd 100644
> --- a/elf/dl-audit.c
> +++ b/elf/dl-audit.c
> @@ -42,6 +42,43 @@ _dl_audit_activity_nsid (Lmid_t nsid, int action)
>    _dl_audit_activity_map (head, action);
>  }
>  
> +bool
> +_dl_audit_objsearch (const char **name, const char **origname,
> +		     struct link_map *l, unsigned int code)
> +{
> +  if (__glibc_likely (GLRO(dl_naudit) == 0)
> +      || l == NULL || l->l_auditing
> +      || code == 0)
> +    return true;
> +
> +  struct audit_ifaces *afct = GLRO(dl_audit);
> +  for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
> +    {
> +      if (afct->objsearch != NULL)
> +	{
> +	  const char *before = *name;
> +	  struct auditstate *state = link_map_audit_state (l, cnt);
> +	  *name = afct->objsearch (*name, &state->cookie, code);
> +	  if (*name == NULL)
> +	    return false;
> +
> +	  if (origname != NULL && before != *name
> +	      && strcmp (before, *name) != 0)
> +	    {
> +	      if (__glibc_unlikely (GLRO(dl_debug_mask) & DL_DEBUG_FILES))
> +		_dl_debug_printf ("audit changed filename %s -> %s\n",
> +				  before, *name);
> +
> +	      if (*origname == NULL)
> +		*origname = before;
> +	    }
> +	}
> +      afct = afct->next;
> +   }
> +
> +  return true;
> +}

Sorry, I find the interface rather confusing.  *name is an in-out
parameter, and *origname is an out parameter.  This is not really clear
from their names.

I looked at the rest of elf/dl-load.c, and origname appears to be solely
used as an optimization, to avoid having to call add_name_to_object
twice.  (add_name_to_object already filters out duplicate names.)

I think this interface should work:

  const char *_dl_audit_objsearch (const char *name, struct link_map *l,
                                   unsigned int code);

Callers need to check for NULL return values and stop loading the
object.  Otherwise they have to register both names with
add_name_to_object.

What do you think?

Thanks,
Florian


  reply	other threads:[~2021-12-17 12:21 UTC|newest]

Thread overview: 89+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-15 18:37 [PATCH v6 00/20] Multiple rtld-audit fixes Adhemerval Zanella
2021-11-15 18:37 ` [PATCH v6 01/20] elf: Suppress audit calls when a (new) namespace is empty (BZ #28062) Adhemerval Zanella
2021-11-15 19:01   ` Florian Weimer
2021-11-16 13:14     ` Adhemerval Zanella
2021-11-16 13:15       ` Florian Weimer
2021-11-16 13:45       ` Andreas Schwab
2021-11-16 13:48         ` Florian Weimer
2021-11-16 14:16           ` Andreas Schwab
2021-11-18 19:58             ` Adhemerval Zanella
2021-11-15 18:37 ` [PATCH v6 02/20] elf: Add _dl_audit_objopen Adhemerval Zanella
2021-12-10 12:40   ` Florian Weimer
2021-12-10 12:48     ` Florian Weimer
2021-12-10 13:45       ` Adhemerval Zanella
2021-12-10 14:11         ` Adhemerval Zanella
2021-12-10 14:15           ` Florian Weimer
2021-12-10 14:41             ` Adhemerval Zanella
2021-11-15 18:37 ` [PATCH v6 03/20] elf: Add _dl_audit_activity_map and _dl_audit_activity_nsid Adhemerval Zanella
2021-12-10 13:54   ` Florian Weimer
2021-12-10 14:58     ` Adhemerval Zanella
2021-11-15 18:37 ` [PATCH v6 04/20] elf: Add _dl_audit_objsearch Adhemerval Zanella
2021-12-17 12:21   ` Florian Weimer [this message]
2021-12-17 16:09     ` Adhemerval Zanella
2021-12-17 16:12       ` Florian Weimer
2021-12-17 16:33         ` Adhemerval Zanella
2021-11-15 18:37 ` [PATCH v6 05/20] elf: Add _dl_audit_objclose Adhemerval Zanella
2021-12-17 16:29   ` Florian Weimer
2021-12-17 16:39     ` Adhemerval Zanella
2021-11-15 18:37 ` [PATCH v6 06/20] elf: Add _dl_audit_symbind_alt and _dl_audit_symbind Adhemerval Zanella
2021-12-17 16:50   ` Florian Weimer
2021-12-17 18:46     ` Adhemerval Zanella
2021-11-15 18:37 ` [PATCH v6 07/20] elf: Add _dl_audit_preinit Adhemerval Zanella
2021-12-17 17:13   ` Florian Weimer
2021-12-17 18:54     ` Adhemerval Zanella
2021-11-15 18:37 ` [PATCH v6 08/20] elf: Add _dl_audit_pltenter Adhemerval Zanella
2021-12-17 17:21   ` Florian Weimer
2021-11-15 18:37 ` [PATCH v6 09/20] elf: Add _dl_audit_pltexit Adhemerval Zanella
2021-12-17 17:43   ` Florian Weimer
2021-12-17 19:02     ` Adhemerval Zanella
2021-11-15 18:37 ` [PATCH v6 10/20] elf: Avoid unnecessary slowdown from profiling with audit (BZ#15533) Adhemerval Zanella
2021-12-18 18:45   ` Florian Weimer
2021-12-20 12:10     ` Adhemerval Zanella
2021-11-15 18:37 ` [PATCH v6 11/20] elf: Add audit tests for modules with TLSDESC Adhemerval Zanella
2021-12-18 18:53   ` Florian Weimer
2021-12-20 12:23     ` Adhemerval Zanella
2021-11-15 18:37 ` [PATCH v6 12/20] elf: Do not fail for failed dlmopen on audit modules (BZ #28061) Adhemerval Zanella
2021-12-18 18:59   ` Florian Weimer
2021-12-20 12:24     ` Adhemerval Zanella
2021-11-15 18:37 ` [PATCH v6 13/20] elf: Fix initial-exec TLS access on audit modules (BZ #28096) Adhemerval Zanella
2021-12-18 18:01   ` Florian Weimer
2021-12-20 13:25     ` Adhemerval Zanella
2021-11-15 18:37 ` [PATCH v6 14/20] elf: Issue audit la_objopen() for vDSO Adhemerval Zanella
2021-12-18 20:00   ` Florian Weimer
2021-12-20 12:50     ` Adhemerval Zanella
2021-12-20 13:18       ` Florian Weimer
2021-11-15 18:37 ` [PATCH v6 15/20] elf: Run constructors if executable has a soname of a dependency Adhemerval Zanella
2021-12-18 20:08   ` Florian Weimer
2021-12-20 16:49     ` Adhemerval Zanella
2021-12-20 16:52       ` Florian Weimer
2021-12-20 16:55         ` Adhemerval Zanella
2021-11-15 18:37 ` [PATCH v6 16/20] elf: Add main application on main_map l_name Adhemerval Zanella
2021-12-20 13:32   ` Florian Weimer
2021-12-20 18:04     ` Adhemerval Zanella
2021-11-15 18:37 ` [PATCH v6 17/20] elf: Add la_activity during application exit Adhemerval Zanella
2021-12-20 13:34   ` Florian Weimer
2021-12-20 19:46     ` Adhemerval Zanella
2021-11-15 18:37 ` [PATCH v6 18/20] elf: Issue la_symbind() for bind-now (BZ #23734) Adhemerval Zanella
2021-12-20 19:18   ` Florian Weimer
2021-12-20 20:43     ` Adhemerval Zanella
2021-12-20 21:04       ` Florian Weimer
2021-12-20 21:09         ` Adhemerval Zanella
2021-11-15 18:37 ` [PATCH v6 19/20] elf: Fix runtime linker auditing on aarch64 (BZ #26643) Adhemerval Zanella
2021-12-20 21:32   ` Florian Weimer
2021-12-21 14:33     ` Adhemerval Zanella
2021-12-21 14:44       ` Florian Weimer
2021-12-21 14:48         ` Adhemerval Zanella
2021-12-21 14:54           ` Florian Weimer
2021-12-21 17:03             ` Adhemerval Zanella
2021-12-21 17:22               ` Florian Weimer
2021-12-21 17:38                 ` Adhemerval Zanella
2021-12-21 18:11                   ` Florian Weimer
2021-12-21 18:19                     ` Adhemerval Zanella
2021-12-20 21:34   ` Florian Weimer
2021-12-21 17:47   ` Szabolcs Nagy
2021-12-21 17:49     ` Adhemerval Zanella
2021-11-15 18:37 ` [PATCH v6 20/20] elf: Add SVE support for aarch64 rtld-audit Adhemerval Zanella
2021-12-21 14:27   ` Florian Weimer
2021-12-21 14:37     ` Adhemerval Zanella
2021-12-21 16:45     ` Szabolcs Nagy
2021-12-21 17:08       ` Adhemerval Zanella

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