* systemtap broken by USER_NS for now
@ 2013-05-22 14:00 Alexander Y. Fomichev
2013-05-22 21:40 ` David Smith
0 siblings, 1 reply; 3+ messages in thread
From: Alexander Y. Fomichev @ 2013-05-22 14:00 UTC (permalink / raw)
To: systemtap
[-- Attachment #1: Type: text/plain, Size: 1324 bytes --]
Hi
for now user_ns unconditionally requires
CONFIG_UIDGID_STRICT_TYPE_CHECKS and the latter in turn breaks things
this way:
typedef struct {
uid_t val;
} kuid_t;
and so:
stap # ./probe.stp
In file included from /usr/share/systemtap/runtime/linux/task_finder.c:17:0,
from /usr/share/systemtap/runtime/linux/runtime.h:188,
from /usr/share/systemtap/runtime/runtime.h:24,
from
/tmp/.private/root/stap7M7WmA/stap_6ce999ddb8d32c70dcbe287153f6957f_16537_src.c:22:
/usr/share/systemtap/runtime/linux/task_finder2.c: In function
'__stp_utrace_attach_match_filename':
/usr/share/systemtap/runtime/linux/task_finder2.c:816:11: error:
incompatible types when assigning to type 'uid_t' from type 'kuid_t'
tsk_euid = task_euid(tsk);
^
.....................................................................
It seems like fix is straightforward - just use from_kuid_munged to
get euid if CONFIG_UIDGID_STRICT_TYPE_CHECKS is defined. (really it
always works on latest kernels but breaks older ones). I've attached a
simple patch and it works for 3.9 (both with and without
STRICT_TYPE_CHECKS) but i'm not systemtap guy so i could be completely
wrong. Feel free to throw it out without reading :)
--
Best regards.
Alexander Y. Fomichev <git.user@gmail.com>
[-- Attachment #2: uidgid_strict_type_check.patch --]
[-- Type: application/octet-stream, Size: 5734 bytes --]
diff -urNp a/runtime/linux/task_finder.c b/runtime/linux/task_finder.c
--- a/runtime/linux/task_finder.c 2013-05-21 15:51:55.000000000 +0400
+++ b/runtime/linux/task_finder.c 2013-05-21 16:45:47.634899524 +0400
@@ -23,6 +23,10 @@
#ifndef STAPCONF_TASK_UID
#include <linux/cred.h>
#endif
+#ifdef CONFIG_UIDGID_STRICT_TYPE_CHECKS
+#include <linux/cred.h>
+#include <linux/uidgid.h>
+#endif
#include "syscall.h"
#include "utrace_compatibility.h"
#include "task_finder_map.c"
@@ -851,8 +855,12 @@ __stp_utrace_attach_match_filename(struc
#ifdef STAPCONF_TASK_UID
tsk_euid = tsk->euid;
#else
+#ifdef CONFIG_UIDGID_STRICT_TYPE_CHECKS
+ tsk_euid = from_kuid_munged(current_user_ns(), task_euid(tsk));
+#else
tsk_euid = task_euid(tsk);
#endif
+#endif
filelen = strlen(filename);
list_for_each(tgt_node, &__stp_task_finder_list) {
int rc;
@@ -1660,8 +1668,12 @@ stap_start_task_finder(void)
#ifdef STAPCONF_TASK_UID
tsk_euid = tsk->euid;
#else
+#ifdef CONFIG_UIDGID_STRICT_TYPE_CHECKS
+ tsk_euid = from_kuid_munged(current_user_ns(), task_euid(tsk));
+#else
tsk_euid = task_euid(tsk);
#endif
+#endif
mmpathlen = strlen(mmpath);
list_for_each(tgt_node, &__stp_task_finder_list) {
struct stap_task_finder_target *tgt;
diff -urNp a/runtime/linux/task_finder2.c b/runtime/linux/task_finder2.c
--- a/runtime/linux/task_finder2.c 2013-05-21 15:51:55.000000000 +0400
+++ b/runtime/linux/task_finder2.c 2013-05-21 16:45:47.638232907 +0400
@@ -9,6 +9,10 @@
#ifndef STAPCONF_TASK_UID
#include <linux/cred.h>
#endif
+#ifdef CONFIG_UIDGID_STRICT_TYPE_CHECKS
+#include <linux/cred.h>
+#include <linux/uidgid.h>
+#endif
#include "syscall.h"
#include "task_finder_map.c"
#include "task_finder_vma.c"
@@ -813,8 +817,12 @@ __stp_utrace_attach_match_filename(struc
#ifdef STAPCONF_TASK_UID
tsk_euid = tsk->euid;
#else
+#ifdef CONFIG_UIDGID_STRICT_TYPE_CHECKS
+ tsk_euid = from_kuid_munged(current_user_ns(), task_euid(tsk));
+#else
tsk_euid = task_euid(tsk);
#endif
+#endif
filelen = strlen(filename);
list_for_each(tgt_node, &__stp_task_finder_list) {
int rc;
@@ -1699,8 +1707,12 @@ stap_start_task_finder(void)
#ifdef STAPCONF_TASK_UID
tsk_euid = tsk->euid;
#else
+#ifdef CONFIG_UIDGID_STRICT_TYPE_CHECKS
+ tsk_euid = from_kuid_munged(current_user_ns(), task_euid(tsk));
+#else
tsk_euid = task_euid(tsk);
#endif
+#endif
mmpathlen = strlen(mmpath);
list_for_each(tgt_node, &__stp_task_finder_list) {
struct stap_task_finder_target *tgt;
diff -urNp a/runtime/transport/control.c b/runtime/transport/control.c
--- a/runtime/transport/control.c 2013-05-21 15:51:54.000000000 +0400
+++ b/runtime/transport/control.c 2013-05-21 16:45:47.638232907 +0400
@@ -14,6 +14,10 @@
#include "symbols.c"
#include <linux/delay.h>
#include <linux/poll.h>
+#ifdef CONFIG_UIDGID_STRICT_TYPE_CHECKS
+#include <linux/cred.h>
+#include <linux/uidgid.h>
+#endif
static _stp_mempool_t *_stp_pool_q;
static struct list_head _stp_ctl_ready_q;
@@ -34,8 +38,12 @@ static ssize_t _stp_ctl_write_cmd(struct
#ifdef STAPCONF_TASK_UID
uid_t euid = current->euid;
#else
+#ifdef CONFIG_UIDGID_STRICT_TYPE_CHECKS
+ uid_t euid = from_kuid_munged(current_user_ns(), current_euid());
+#else
uid_t euid = current_euid();
#endif
+#endif
if (count < sizeof(u32))
return 0;
diff -urNp a/runtime/transport/debugfs.c b/runtime/transport/debugfs.c
--- a/runtime/transport/debugfs.c 2013-05-21 15:51:54.000000000 +0400
+++ b/runtime/transport/debugfs.c 2013-05-21 16:45:47.638232907 +0400
@@ -48,8 +48,8 @@ static int _stp_register_ctl_channel_fs(
return -1;
}
- _stp_cmd_file->d_inode->i_uid = _stp_uid;
- _stp_cmd_file->d_inode->i_gid = _stp_gid;
+ _stp_cmd_file->d_inode->i_uid = KUIDT_INIT(_stp_uid);
+ _stp_cmd_file->d_inode->i_gid = KGIDT_INIT(_stp_gid);
return 0;
}
diff -urNp a/runtime/transport/relay_v2.c b/runtime/transport/relay_v2.c
--- a/runtime/transport/relay_v2.c 2013-05-21 15:51:54.000000000 +0400
+++ b/runtime/transport/relay_v2.c 2013-05-21 16:45:47.638232907 +0400
@@ -234,8 +234,8 @@ __stp_relay_create_buf_file_callback(con
file = NULL;
}
else if (file) {
- file->d_inode->i_uid = _stp_uid;
- file->d_inode->i_gid = _stp_gid;
+ file->d_inode->i_uid = KUIDT_INIT(_stp_uid);
+ file->d_inode->i_gid = KGIDT_INIT(_stp_gid);
}
return file;
}
@@ -303,8 +303,8 @@ static int _stp_transport_data_fs_init(v
goto err;
}
- _stp_relay_data.dropped_file->d_inode->i_uid = _stp_uid;
- _stp_relay_data.dropped_file->d_inode->i_gid = _stp_gid;
+ _stp_relay_data.dropped_file->d_inode->i_uid = KUIDT_INIT(_stp_uid);
+ _stp_relay_data.dropped_file->d_inode->i_gid = KGIDT_INIT(_stp_gid);
/* Create "trace" file. */
npages = _stp_subbuf_size * _stp_nsubbufs;
diff -urNp a/runtime/transport/transport.c b/runtime/transport/transport.c
--- a/runtime/transport/transport.c 2013-05-21 15:51:54.000000000 +0400
+++ b/runtime/transport/transport.c 2013-05-21 16:45:47.638232907 +0400
@@ -20,6 +20,10 @@
#include <linux/namei.h>
#include <linux/delay.h>
#include <linux/mutex.h>
+#ifdef CONFIG_UIDGID_STRICT_TYPE_CHECKS
+#include <linux/cred.h>
+#include <linux/uidgid.h>
+#endif
static int _stp_exit_flag = 0;
@@ -336,9 +340,14 @@ static int _stp_transport_init(void)
_stp_uid = current->uid;
_stp_gid = current->gid;
#else
+#ifdef CONFIG_UIDGID_STRICT_TYPE_CHECKS
+ _stp_uid = from_kuid_munged(current_user_ns(), current_uid());
+ _stp_gid = from_kgid_munged(current_user_ns(), current_gid());
+#else
_stp_uid = current_uid();
_stp_gid = current_gid();
#endif
+#endif
/* PR13489, missing inode-uprobes symbol-export workaround */
#if !defined(STAPCONF_TASK_USER_REGSET_VIEW_EXPORTED) && !defined(STAPCONF_UTRACE_REGSET) /* RHEL5 era utrace */
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: systemtap broken by USER_NS for now
2013-05-22 14:00 systemtap broken by USER_NS for now Alexander Y. Fomichev
@ 2013-05-22 21:40 ` David Smith
2013-05-31 19:49 ` David Smith
0 siblings, 1 reply; 3+ messages in thread
From: David Smith @ 2013-05-22 21:40 UTC (permalink / raw)
To: Alexander Y. Fomichev; +Cc: systemtap
On 05/22/2013 09:00 AM, Alexander Y. Fomichev wrote:
> Hi
>
> for now user_ns unconditionally requires
> CONFIG_UIDGID_STRICT_TYPE_CHECKS and the latter in turn breaks things
> this way:
>
> typedef struct {
> uid_t val;
> } kuid_t;
>
> and so:
>
> stap # ./probe.stp
> In file included from /usr/share/systemtap/runtime/linux/task_finder.c:17:0,
> from /usr/share/systemtap/runtime/linux/runtime.h:188,
> from /usr/share/systemtap/runtime/runtime.h:24,
> from
> /tmp/.private/root/stap7M7WmA/stap_6ce999ddb8d32c70dcbe287153f6957f_16537_src.c:22:
> /usr/share/systemtap/runtime/linux/task_finder2.c: In function
> '__stp_utrace_attach_match_filename':
> /usr/share/systemtap/runtime/linux/task_finder2.c:816:11: error:
> incompatible types when assigning to type 'uid_t' from type 'kuid_t'
> tsk_euid = task_euid(tsk);
> ^
> .....................................................................
>
> It seems like fix is straightforward - just use from_kuid_munged to
> get euid if CONFIG_UIDGID_STRICT_TYPE_CHECKS is defined. (really it
> always works on latest kernels but breaks older ones). I've attached a
> simple patch and it works for 3.9 (both with and without
> STRICT_TYPE_CHECKS) but i'm not systemtap guy so i could be completely
> wrong. Feel free to throw it out without reading :)
>
> --
> Best regards.
> Alexander Y. Fomichev <git.user@gmail.com>
>
Hmm, thanks for finding this and developing the patch. The tricky part
here will be supporting 3.9 without breaking some of the earliest
kernels we support (like RHEL4's 2.6.9).
I'll look into your patch. I'm also wondering if some of the procfs
fixes I just put in will work with CONFIG_UIDGID_STRICT_TYPE_CHECKS.
I'll send out an update when I've figured something out.
--
David Smith
dsmith@redhat.com
Red Hat
http://www.redhat.com
256.217.0141 (direct)
256.837.0057 (fax)
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: systemtap broken by USER_NS for now
2013-05-22 21:40 ` David Smith
@ 2013-05-31 19:49 ` David Smith
0 siblings, 0 replies; 3+ messages in thread
From: David Smith @ 2013-05-31 19:49 UTC (permalink / raw)
To: Alexander Y. Fomichev; +Cc: systemtap
On 05/22/2013 04:40 PM, David Smith wrote:
> On 05/22/2013 09:00 AM, Alexander Y. Fomichev wrote:
>> Hi
>>
>> for now user_ns unconditionally requires
>> CONFIG_UIDGID_STRICT_TYPE_CHECKS and the latter in turn breaks things
>> this way:
>>
>> typedef struct {
>> uid_t val;
>> } kuid_t;
>>
>> and so:
>>
>> stap # ./probe.stp
>> In file included from /usr/share/systemtap/runtime/linux/task_finder.c:17:0,
>> from /usr/share/systemtap/runtime/linux/runtime.h:188,
>> from /usr/share/systemtap/runtime/runtime.h:24,
>> from
>> /tmp/.private/root/stap7M7WmA/stap_6ce999ddb8d32c70dcbe287153f6957f_16537_src.c:22:
>> /usr/share/systemtap/runtime/linux/task_finder2.c: In function
>> '__stp_utrace_attach_match_filename':
>> /usr/share/systemtap/runtime/linux/task_finder2.c:816:11: error:
>> incompatible types when assigning to type 'uid_t' from type 'kuid_t'
>> tsk_euid = task_euid(tsk);
>> ^
>> .....................................................................
>>
>> It seems like fix is straightforward - just use from_kuid_munged to
>> get euid if CONFIG_UIDGID_STRICT_TYPE_CHECKS is defined. (really it
>> always works on latest kernels but breaks older ones). I've attached a
>> simple patch and it works for 3.9 (both with and without
>> STRICT_TYPE_CHECKS) but i'm not systemtap guy so i could be completely
>> wrong. Feel free to throw it out without reading :)
>>
>> --
>> Best regards.
>> Alexander Y. Fomichev <git.user@gmail.com>
>>
>
> Hmm, thanks for finding this and developing the patch. The tricky part
> here will be supporting 3.9 without breaking some of the earliest
> kernels we support (like RHEL4's 2.6.9).
>
> I'll look into your patch. I'm also wondering if some of the procfs
> fixes I just put in will work with CONFIG_UIDGID_STRICT_TYPE_CHECKS.
>
> I'll send out an update when I've figured something out.
I've checked your (a bit modified) work in as commit 8571631. As I
feared, I had to tweak it a bit to handle old kernels.
Thanks again.
--
David Smith
dsmith@redhat.com
Red Hat
http://www.redhat.com
256.217.0141 (direct)
256.837.0057 (fax)
^ permalink raw reply [flat|nested] 3+ messages in thread
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2013-05-22 21:40 ` David Smith
2013-05-31 19:49 ` David Smith
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