[v6,03/20] elf: Add _dl_audit_activity_map and _dl_audit_activity_nsid
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Description |
dj/TryBot-apply_patch |
success
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Patch applied to master at the time it was sent
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Commit Message
It consolidates the code required to call la_activity() audit
callback.
Also for a new Lmid_t the namespace link_map list are empty, so it
requires to check if before using it. This can happen for when audit
module is used along with dlmopen.
Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu.
---
elf/dl-audit.c | 23 ++++++++++++++++
elf/dl-close.c | 54 +++++++-------------------------------
elf/dl-load.c | 20 +-------------
elf/dl-open.c | 20 +-------------
elf/rtld.c | 31 ++--------------------
sysdeps/generic/ldsodefs.h | 7 +++++
6 files changed, 43 insertions(+), 112 deletions(-)
Comments
* Adhemerval Zanella:
> diff --git a/elf/dl-close.c b/elf/dl-close.c
> index 4f5cfcc1c3..79dbb41094 100644
> --- a/elf/dl-close.c
> +++ b/elf/dl-close.c
> + /* Auditing checkpoint: we have deleted all objects. If head is NULL, the
> + namespace has become empty, and the audit interface does not give us a
> + way to signal LA_ACT_CONSISTENT for it because the first loaded module
> + is used to identify the namespace.
> +
> + Furthermore, do not notify auditors of the cleanup of a failed audit
> + module loading attempt. */
> + _dl_audit_activity_nsid (nsid, LA_ACT_CONSISTENT);
> #endif
The comment is not really well-placed here. I think it belongs to the
head == NULL check in _dl_audit_activity_nsid.
>
> if (__builtin_expect (ns->_ns_loaded == NULL, 0)
> diff --git a/elf/dl-load.c b/elf/dl-load.c
> index 907ab8f5f7..848d3e08eb 100644
> --- a/elf/dl-load.c
> +++ b/elf/dl-load.c
> @@ -1483,25 +1483,7 @@ cannot enable executable stack as shared object requires");
> if (r->r_state == RT_CONSISTENT)
> {
> #ifdef SHARED
> - /* Auditing checkpoint: we are going to add new objects. */
> - if ((mode & __RTLD_AUDIT) == 0
> - && __glibc_unlikely (GLRO(dl_naudit) > 0))
The mode & __RTLD_AUDIT check is not included in
_dl_audit_activity_nsid.
> diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
> index dec592bf53..ea481cbe84 100644
> --- a/sysdeps/generic/ldsodefs.h
> +++ b/sysdeps/generic/ldsodefs.h
> @@ -1392,6 +1392,13 @@ link_map_audit_state (struct link_map *l, size_t index)
> }
> }
>
> +/* Call the la_activity() from the audit modules from the link map L
> + and issues the ACTION argument. */
> +void _dl_audit_activity_map (struct link_map *l, int action)
> + attribute_hidden;
> +/* Call the la_activity() from the audit modules from the link map
> + from the namespace NSSID and issues the ACTION argument. */
> +void _dl_audit_activity_nsid (Lmid_t nsid, int action);
(), typo: NS[S]ID. Maybe we should have a general comment here that
these notifications are skipped for auditing namespaces?
Thanks,
Florian
On 10/12/2021 10:54, Florian Weimer wrote:
> * Adhemerval Zanella:
>
>> diff --git a/elf/dl-close.c b/elf/dl-close.c
>> index 4f5cfcc1c3..79dbb41094 100644
>> --- a/elf/dl-close.c
>> +++ b/elf/dl-close.c
>
>> + /* Auditing checkpoint: we have deleted all objects. If head is NULL, the
>> + namespace has become empty, and the audit interface does not give us a
>> + way to signal LA_ACT_CONSISTENT for it because the first loaded module
>> + is used to identify the namespace.
>> +
>> + Furthermore, do not notify auditors of the cleanup of a failed audit
>> + module loading attempt. */
>> + _dl_audit_activity_nsid (nsid, LA_ACT_CONSISTENT);
>> #endif
>
> The comment is not really well-placed here. I think it belongs to the
> head == NULL check in _dl_audit_activity_nsid.
>
Ack.
>>
>> if (__builtin_expect (ns->_ns_loaded == NULL, 0)
>> diff --git a/elf/dl-load.c b/elf/dl-load.c
>> index 907ab8f5f7..848d3e08eb 100644
>> --- a/elf/dl-load.c
>> +++ b/elf/dl-load.c
>> @@ -1483,25 +1483,7 @@ cannot enable executable stack as shared object requires");
>> if (r->r_state == RT_CONSISTENT)
>> {
>> #ifdef SHARED
>> - /* Auditing checkpoint: we are going to add new objects. */
>> - if ((mode & __RTLD_AUDIT) == 0
>> - && __glibc_unlikely (GLRO(dl_naudit) > 0))
>
> The mode & __RTLD_AUDIT check is not included in
> _dl_audit_activity_nsid.
Ack, I have reinstated it on _dl_map_object_from_fd.
>
>> diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
>> index dec592bf53..ea481cbe84 100644
>> --- a/sysdeps/generic/ldsodefs.h
>> +++ b/sysdeps/generic/ldsodefs.h
>> @@ -1392,6 +1392,13 @@ link_map_audit_state (struct link_map *l, size_t index)
>> }
>> }
>>
>> +/* Call the la_activity() from the audit modules from the link map L
>> + and issues the ACTION argument. */
>> +void _dl_audit_activity_map (struct link_map *l, int action)
>> + attribute_hidden;
>> +/* Call the la_activity() from the audit modules from the link map
>> + from the namespace NSSID and issues the ACTION argument. */
>> +void _dl_audit_activity_nsid (Lmid_t nsid, int action);
>
> (), typo: NS[S]ID. Maybe we should have a general comment here that
> these notifications are skipped for auditing namespaces?
Ack. Yeah I think mention auditing namespaces is worth here.
>
> Thanks,
> Florian
>
@@ -19,6 +19,29 @@
#include <ldsodefs.h>
#ifdef SHARED
+void
+_dl_audit_activity_map (struct link_map *l, int action)
+{
+ struct audit_ifaces *afct = GLRO(dl_audit);
+ for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
+ {
+ if (afct->activity != NULL)
+ afct->activity (&link_map_audit_state (l, cnt)->cookie, action);
+ afct = afct->next;
+ }
+}
+
+void
+_dl_audit_activity_nsid (Lmid_t nsid, int action)
+{
+ struct link_map *head = GL(dl_ns)[nsid]._ns_loaded;
+ if (__glibc_likely (GLRO(dl_naudit) == 0)
+ || head == NULL || head->l_auditing)
+ return;
+
+ _dl_audit_activity_map (head, action);
+}
+
void
_dl_audit_objopen (struct link_map *l, Lmid_t nsid, bool check_audit)
{
@@ -472,25 +472,7 @@ _dl_close_worker (struct link_map *map, bool force)
#ifdef SHARED
/* Auditing checkpoint: we will start deleting objects. */
- if (__glibc_unlikely (do_audit))
- {
- struct link_map *head = ns->_ns_loaded;
- struct audit_ifaces *afct = GLRO(dl_audit);
- /* Do not call the functions for any auditing object. */
- if (head->l_auditing == 0)
- {
- for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
- {
- if (afct->activity != NULL)
- {
- struct auditstate *state = link_map_audit_state (head, cnt);
- afct->activity (&state->cookie, LA_ACT_DELETE);
- }
-
- afct = afct->next;
- }
- }
- }
+ _dl_audit_activity_nsid (nsid, LA_ACT_DELETE);
#endif
/* Notify the debugger we are about to remove some loaded objects. */
@@ -785,32 +767,14 @@ _dl_close_worker (struct link_map *map, bool force)
__rtld_lock_unlock_recursive (GL(dl_load_tls_lock));
#ifdef SHARED
- /* Auditing checkpoint: we have deleted all objects. */
- if (__glibc_unlikely (do_audit))
- {
- struct link_map *head = ns->_ns_loaded;
- /* If head is NULL, the namespace has become empty, and the
- audit interface does not give us a way to signal
- LA_ACT_CONSISTENT for it because the first loaded module is
- used to identify the namespace.
-
- Furthermore, do not notify auditors of the cleanup of a
- failed audit module loading attempt. */
- if (head != NULL && head->l_auditing == 0)
- {
- struct audit_ifaces *afct = GLRO(dl_audit);
- for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
- {
- if (afct->activity != NULL)
- {
- struct auditstate *state = link_map_audit_state (head, cnt);
- afct->activity (&state->cookie, LA_ACT_CONSISTENT);
- }
-
- afct = afct->next;
- }
- }
- }
+ /* Auditing checkpoint: we have deleted all objects. If head is NULL, the
+ namespace has become empty, and the audit interface does not give us a
+ way to signal LA_ACT_CONSISTENT for it because the first loaded module
+ is used to identify the namespace.
+
+ Furthermore, do not notify auditors of the cleanup of a failed audit
+ module loading attempt. */
+ _dl_audit_activity_nsid (nsid, LA_ACT_CONSISTENT);
#endif
if (__builtin_expect (ns->_ns_loaded == NULL, 0)
@@ -1483,25 +1483,7 @@ cannot enable executable stack as shared object requires");
if (r->r_state == RT_CONSISTENT)
{
#ifdef SHARED
- /* Auditing checkpoint: we are going to add new objects. */
- if ((mode & __RTLD_AUDIT) == 0
- && __glibc_unlikely (GLRO(dl_naudit) > 0))
- {
- struct link_map *head = GL(dl_ns)[nsid]._ns_loaded;
- /* Do not call the functions for any auditing object. */
- if (head->l_auditing == 0)
- {
- struct audit_ifaces *afct = GLRO(dl_audit);
- for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
- {
- if (afct->activity != NULL)
- afct->activity (&link_map_audit_state (head, cnt)->cookie,
- LA_ACT_ADD);
-
- afct = afct->next;
- }
- }
- }
+ _dl_audit_activity_nsid (nsid, LA_ACT_ADD);
#endif
/* Notify the debugger we have added some objects. We need to
@@ -611,25 +611,7 @@ dl_open_worker_begin (void *a)
#ifdef SHARED
/* Auditing checkpoint: we have added all objects. */
- if (__glibc_unlikely (GLRO(dl_naudit) > 0))
- {
- struct link_map *head = GL(dl_ns)[new->l_ns]._ns_loaded;
- /* Do not call the functions for any auditing object. */
- if (head->l_auditing == 0)
- {
- struct audit_ifaces *afct = GLRO(dl_audit);
- for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
- {
- if (afct->activity != NULL)
- {
- struct auditstate *state = link_map_audit_state (head, cnt);
- afct->activity (&state->cookie, LA_ACT_CONSISTENT);
- }
-
- afct = afct->next;
- }
- }
- }
+ _dl_audit_activity_nsid (new->l_ns, LA_ACT_CONSISTENT);
#endif
/* Notify the debugger all new objects are now ready to go. */
@@ -1759,18 +1759,7 @@ dl_main (const ElfW(Phdr) *phdr,
/* Auditing checkpoint: we are ready to signal that the initial map
is being constructed. */
- if (__glibc_unlikely (GLRO(dl_naudit) > 0))
- {
- struct audit_ifaces *afct = GLRO(dl_audit);
- for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
- {
- if (afct->activity != NULL)
- afct->activity (&link_map_audit_state (main_map, cnt)->cookie,
- LA_ACT_ADD);
-
- afct = afct->next;
- }
- }
+ _dl_audit_activity_map (main_map, LA_ACT_ADD);
/* We have two ways to specify objects to preload: via environment
variable and via the file /etc/ld.so.preload. The latter can also
@@ -2451,23 +2440,7 @@ dl_main (const ElfW(Phdr) *phdr,
#ifdef SHARED
/* Auditing checkpoint: we have added all objects. */
- if (__glibc_unlikely (GLRO(dl_naudit) > 0))
- {
- struct link_map *head = GL(dl_ns)[LM_ID_BASE]._ns_loaded;
- /* Do not call the functions for any auditing object. */
- if (head->l_auditing == 0)
- {
- struct audit_ifaces *afct = GLRO(dl_audit);
- for (unsigned int cnt = 0; cnt < GLRO(dl_naudit); ++cnt)
- {
- if (afct->activity != NULL)
- afct->activity (&link_map_audit_state (head, cnt)->cookie,
- LA_ACT_CONSISTENT);
-
- afct = afct->next;
- }
- }
- }
+ _dl_audit_activity_nsid (LM_ID_BASE, LA_ACT_CONSISTENT);
#endif
/* Notify the debugger all new objects are now ready to go. We must re-get
@@ -1392,6 +1392,13 @@ link_map_audit_state (struct link_map *l, size_t index)
}
}
+/* Call the la_activity() from the audit modules from the link map L
+ and issues the ACTION argument. */
+void _dl_audit_activity_map (struct link_map *l, int action)
+ attribute_hidden;
+/* Call the la_activity() from the audit modules from the link map
+ from the namespace NSSID and issues the ACTION argument. */
+void _dl_audit_activity_nsid (Lmid_t nsid, int action);
/* Call the la_objopen() from the audit modules for the link_map L on the
namespace identification NSID. If CHECK_AUDIT is set it will also check
if main mapping of the namespace is a audit modules. */