From: Jens Axboe <[email protected]>
To: Jann Horn <[email protected]>
Cc: Stefan Metzmacher <[email protected]>,
io-uring <[email protected]>,
Linux API Mailing List <[email protected]>,
Pavel Begunkov <[email protected]>
Subject: Re: IORING_REGISTER_CREDS[_UPDATE]() and credfd_create()?
Date: Wed, 29 Jan 2020 20:18:33 -0700 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
On 1/29/20 7:20 PM, Jens Axboe wrote:
> On 1/29/20 6:08 PM, Jens Axboe wrote:
>> On 1/29/20 10:34 AM, Jens Axboe wrote:
>>> On 1/29/20 7:59 AM, Jann Horn wrote:
>>>> On Tue, Jan 28, 2020 at 8:42 PM Jens Axboe <[email protected]> wrote:
>>>>> On 1/28/20 11:04 AM, Jens Axboe wrote:
>>>>>> On 1/28/20 10:19 AM, Jens Axboe wrote:
>>>> [...]
>>>>>>> #1 adds support for registering the personality of the invoking task,
>>>>>>> and #2 adds support for IORING_OP_USE_CREDS. Right now it's limited to
>>>>>>> just having one link, it doesn't support a chain of them.
>>>> [...]
>>>>> I didn't like it becoming a bit too complicated, both in terms of
>>>>> implementation and use. And the fact that we'd have to jump through
>>>>> hoops to make this work for a full chain.
>>>>>
>>>>> So I punted and just added sqe->personality and IOSQE_PERSONALITY.
>>>>> This makes it way easier to use. Same branch:
>>>>>
>>>>> https://git.kernel.dk/cgit/linux-block/log/?h=for-5.6/io_uring-vfs-creds
>>>>>
>>>>> I'd feel much better with this variant for 5.6.
>>>>
>>>> Some general feedback from an inspectability/debuggability perspective:
>>>>
>>>> At some point, it might be nice if you could add a .show_fdinfo
>>>> handler to the io_uring_fops that makes it possible to get a rough
>>>> overview over the state of the uring by reading /proc/$pid/fdinfo/$fd,
>>>> just like e.g. eventfd (see eventfd_show_fdinfo()). It might be
>>>> helpful for debugging to be able to see information about the fixed
>>>> files and buffers that have been registered. Same for the
>>>> personalities; that information might also be useful when someone is
>>>> trying to figure out what privileges a running process actually has.
>>>
>>> Agree, that would be a very useful addition. I'll take a look at it.
>>
>> Jann, how much info are you looking for? Here's a rough start, just
>> shows the number of registered files and buffers, and lists the
>> personalities registered. We could also dump the buffer info for
>> each of them, and ditto for the files. Not sure how much verbosity
>> is acceptable in fdinfo?
>>
>> Here's the test app for personality:
>>
>> # cat 3
>> pos: 0
>> flags: 02000002
>> mnt_id: 14
>> user-files: 0
>> user-bufs: 0
>> personalities:
>> 1: uid=0/gid=0
>
> Here's one that adds the registered buffers and files as well. So
> essentially this shows any info on the registered parts.
Output of this version, using t/io_uring from fio:
# cat /proc/338/fdinfo/4
pos: 0
flags: 02000002
mnt_id: 14
user-files: 1
0: nvme0n1p2
user-bufs: 128
0: 55ea44b52000/4096
1: 55ea44b54000/4096
2: 55ea44b56000/4096
3: 55ea44b58000/4096
4: 55ea44b5a000/4096
5: 55ea44b5c000/4096
6: 55ea44b5e000/4096
7: 55ea44b60000/4096
8: 55ea44b62000/4096
9: 55ea44b64000/4096
10: 55ea44b66000/4096
11: 55ea44b68000/4096
12: 55ea44b6a000/4096
13: 55ea44b6c000/4096
14: 55ea44b6e000/4096
15: 55ea44b70000/4096
16: 55ea44b72000/4096
17: 55ea44b74000/4096
18: 55ea44b76000/4096
19: 55ea44b78000/4096
20: 55ea44b7a000/4096
21: 55ea44b7c000/4096
22: 55ea44b7e000/4096
23: 55ea44b80000/4096
24: 55ea44b82000/4096
25: 55ea44b84000/4096
26: 55ea44b86000/4096
27: 55ea44b88000/4096
28: 55ea44b8a000/4096
29: 55ea44b8c000/4096
30: 55ea44b8e000/4096
31: 55ea44b90000/4096
32: 55ea44b92000/4096
33: 55ea44b94000/4096
34: 55ea44b96000/4096
35: 55ea44b98000/4096
36: 55ea44b9a000/4096
37: 55ea44b9c000/4096
38: 55ea44b9e000/4096
39: 55ea44ba0000/4096
40: 55ea44ba2000/4096
41: 55ea44ba4000/4096
42: 55ea44ba6000/4096
43: 55ea44ba8000/4096
44: 55ea44baa000/4096
45: 55ea44bac000/4096
46: 55ea44bae000/4096
47: 55ea44bb0000/4096
48: 55ea44bb2000/4096
49: 55ea44bb4000/4096
50: 55ea44bb6000/4096
51: 55ea44bb8000/4096
52: 55ea44bba000/4096
53: 55ea44bbc000/4096
54: 55ea44bbe000/4096
55: 55ea44bc0000/4096
56: 55ea44bc2000/4096
57: 55ea44bc4000/4096
58: 55ea44bc6000/4096
59: 55ea44bc8000/4096
60: 55ea44bca000/4096
61: 55ea44bcc000/4096
62: 55ea44bce000/4096
63: 55ea44bd0000/4096
64: 55ea44bd2000/4096
65: 55ea44bd4000/4096
66: 55ea44bd6000/4096
67: 55ea44bd8000/4096
68: 55ea44bda000/4096
69: 55ea44bdc000/4096
70: 55ea44bde000/4096
71: 55ea44be0000/4096
72: 55ea44be2000/4096
73: 55ea44be4000/4096
74: 55ea44be6000/4096
75: 55ea44be8000/4096
76: 55ea44bea000/4096
77: 55ea44bec000/4096
78: 55ea44bee000/4096
79: 55ea44bf0000/4096
80: 55ea44bf2000/4096
81: 55ea44bf4000/4096
82: 55ea44bf6000/4096
83: 55ea44bf8000/4096
84: 55ea44bfa000/4096
85: 55ea44bfc000/4096
86: 55ea44bfe000/4096
87: 55ea44c00000/4096
88: 55ea44c02000/4096
89: 55ea44c04000/4096
90: 55ea44c06000/4096
91: 55ea44c08000/4096
92: 55ea44c0a000/4096
93: 55ea44c0c000/4096
94: 55ea44c0e000/4096
95: 55ea44c10000/4096
96: 55ea44c12000/4096
97: 55ea44c14000/4096
98: 55ea44c16000/4096
99: 55ea44c18000/4096
100: 55ea44c1a000/4096
101: 55ea44c1c000/4096
102: 55ea44c1e000/4096
103: 55ea44c20000/4096
104: 55ea44c22000/4096
105: 55ea44c24000/4096
106: 55ea44c26000/4096
107: 55ea44c28000/4096
108: 55ea44c2a000/4096
109: 55ea44c2c000/4096
110: 55ea44c2e000/4096
111: 55ea44c30000/4096
112: 55ea44c32000/4096
113: 55ea44c34000/4096
114: 55ea44c36000/4096
115: 55ea44c38000/4096
116: 55ea44c3a000/4096
117: 55ea44c3c000/4096
118: 55ea44c3e000/4096
119: 55ea44c40000/4096
120: 55ea44c42000/4096
121: 55ea44c44000/4096
122: 55ea44c46000/4096
123: 55ea44c48000/4096
124: 55ea44c4a000/4096
125: 55ea44c4c000/4096
126: 55ea44c4e000/4096
127: 55ea44c50000/4096
--
Jens Axboe
next prev parent reply other threads:[~2020-01-30 3:18 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-28 10:18 IORING_REGISTER_CREDS[_UPDATE]() and credfd_create()? Stefan Metzmacher
2020-01-28 16:10 ` Jens Axboe
2020-01-28 16:17 ` Stefan Metzmacher
2020-01-28 16:19 ` Jens Axboe
2020-01-28 17:19 ` Jens Axboe
2020-01-28 18:04 ` Jens Axboe
2020-01-28 19:42 ` Jens Axboe
2020-01-28 20:16 ` Pavel Begunkov
2020-01-28 20:19 ` Jens Axboe
2020-01-28 20:50 ` Pavel Begunkov
2020-01-28 20:56 ` Jens Axboe
2020-01-28 21:25 ` Christian Brauner
2020-01-28 22:38 ` Pavel Begunkov
2020-01-28 23:36 ` Pavel Begunkov
2020-01-28 23:40 ` Jens Axboe
2020-01-28 23:51 ` Jens Axboe
2020-01-29 0:10 ` Pavel Begunkov
2020-01-29 0:15 ` Jens Axboe
2020-01-29 0:18 ` Jens Axboe
2020-01-29 0:20 ` Jens Axboe
2020-01-29 0:21 ` Pavel Begunkov
2020-01-29 0:24 ` Jens Axboe
2020-01-29 0:54 ` Jens Axboe
2020-01-29 10:17 ` Pavel Begunkov
2020-01-29 13:11 ` Stefan Metzmacher
2020-01-29 13:41 ` Pavel Begunkov
2020-01-29 13:56 ` Stefan Metzmacher
2020-01-29 14:23 ` Pavel Begunkov
2020-01-29 14:27 ` Stefan Metzmacher
2020-01-29 14:34 ` Pavel Begunkov
2020-01-29 17:34 ` Jens Axboe
2020-01-29 17:42 ` Jens Axboe
2020-01-29 20:09 ` Stefan Metzmacher
2020-01-29 20:48 ` Jens Axboe
2020-01-29 17:46 ` Pavel Begunkov
2020-01-29 14:59 ` Jann Horn
2020-01-29 17:34 ` Jens Axboe
2020-01-30 1:08 ` Jens Axboe
2020-01-30 2:20 ` Jens Axboe
2020-01-30 3:18 ` Jens Axboe [this message]
2020-01-30 6:53 ` Stefan Metzmacher
2020-01-30 10:11 ` Jann Horn
2020-01-30 10:26 ` Christian Brauner
2020-01-30 14:11 ` Jens Axboe
2020-01-30 14:47 ` Stefan Metzmacher
2020-01-30 15:34 ` Jens Axboe
2020-01-30 15:13 ` Christian Brauner
2020-01-30 15:29 ` Jens Axboe
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