I am trying to run `strace` against kworker, but I cannot attach strace despite havingset ptrace_scope=0 and being root.
Here is the proof:
# echo 1 > /proc/sys/kernel/yama/ptrace_scope root@rasal:/home/me# whoami root root@rasal:/home/me# cat /proc/sys/kernel/yama/ptrace_scope 0 root@rasal:/home/me# ps ax | grep kworker 5 ? S< 0:00 [kworker/0:0H] 31 ? S< 0:00 [kworker/1:0H] 35 ? S 0:00 [kworker/2:0] 36 ? S< 0:00 [kworker/2:0H] 41 ? S< 0:00 [kworker/3:0H] 58 ? S 0:00 [kworker/1:1] 76 ? S 0:00 [kworker/3:1] 78 ? S 0:00 [kworker/1:2] 79 ? S 0:00 [kworker/2:1] 149 ? S 0:00 [kworker/0:1] 162 ? S 0:00 [kworker/u16:3] 163 ? S 0:00 [kworker/u16:4] 164 ? S 0:00 [kworker/u16:5] 448 ? S< 0:00 [kworker/3:1H] 449 ? S< 0:00 [kworker/1:1H] 451 ? S< 0:00 [kworker/2:1H] 452 ? S< 0:00 [kworker/0:1H] 560 ? S 0:00 [kworker/3:2] 604 ? S 0:00 [kworker/0:2] 1006 ? S< 0:00 [kworker/u17:0] 1017 ? S< 0:00 [kworker/u17:1] 4222 ? S 0:00 [kworker/3:0] 4249 pts/4 S+ 0:00 grep --color=auto kworker root@rasal:/home/me# strace -p 4222 strace: attach: ptrace(PTRACE_ATTACH, ...): Operation not permitted Could not attach to process. If your uid matches the uid of the target process, check the setting of /proc/sys/kernel/yama/ptrace_scope, or try again as the root user. For more details, see /etc/sysctl.d/10-ptrace.conf root@rasal:/home/me# uname -a Linux rasal 3.16.0-49-generic #65~14.04.1-Ubuntu SMP Wed Sep 9 10:03:23 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
Any info on this?
ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: linux-image-3.16.0-49-generic 3.16.0-49.65~14.04.1 ProcVersionSignature: Ubuntu 3.16.0-49.65~14.04.1-generic 3.16.7-ckt15 Uname: Linux 3.16.0-49-generic x86_64 ApportVersion: 2.14.1-0ubuntu3.13 Architecture: amd64 CurrentDesktop: KDE Date: Tue Sep 15 00:01:12 2015 InstallationDate: Installed on 2014-05-05 (497 days ago) InstallationMedia: Kubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140416.1) SourcePackage: linux-lts-utopic UpgradeStatus: Upgraded to trusty on 2014-11-21 (297 days ago)
I am trying to run `strace` against kworker, but I cannot attach strace despite havingset ptrace_scope=0 and being root.
Here is the proof:
# echo 1 > /proc/sys/ kernel/ yama/ptrace_ scope /home/me# whoami /home/me# cat /proc/sys/ kernel/ yama/ptrace_ scope /home/me# ps ax | grep kworker /home/me# strace -p 4222 PTRACE_ ATTACH, ...): Operation not permitted kernel/ yama/ptrace_ scope, or try d/10-ptrace. conf /home/me# uname -a
root@rasal:
root
root@rasal:
0
root@rasal:
5 ? S< 0:00 [kworker/0:0H]
31 ? S< 0:00 [kworker/1:0H]
35 ? S 0:00 [kworker/2:0]
36 ? S< 0:00 [kworker/2:0H]
41 ? S< 0:00 [kworker/3:0H]
58 ? S 0:00 [kworker/1:1]
76 ? S 0:00 [kworker/3:1]
78 ? S 0:00 [kworker/1:2]
79 ? S 0:00 [kworker/2:1]
149 ? S 0:00 [kworker/0:1]
162 ? S 0:00 [kworker/u16:3]
163 ? S 0:00 [kworker/u16:4]
164 ? S 0:00 [kworker/u16:5]
448 ? S< 0:00 [kworker/3:1H]
449 ? S< 0:00 [kworker/1:1H]
451 ? S< 0:00 [kworker/2:1H]
452 ? S< 0:00 [kworker/0:1H]
560 ? S 0:00 [kworker/3:2]
604 ? S 0:00 [kworker/0:2]
1006 ? S< 0:00 [kworker/u17:0]
1017 ? S< 0:00 [kworker/u17:1]
4222 ? S 0:00 [kworker/3:0]
4249 pts/4 S+ 0:00 grep --color=auto kworker
root@rasal:
strace: attach: ptrace(
Could not attach to process. If your uid matches the uid of the target
process, check the setting of /proc/sys/
again as the root user. For more details, see /etc/sysctl.
root@rasal:
Linux rasal 3.16.0-49-generic #65~14.04.1-Ubuntu SMP Wed Sep 9 10:03:23 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
Any info on this?
ProblemType: Bug 3.16.0- 49-generic 3.16.0- 49.65~14. 04.1 ature: Ubuntu 3.16.0- 49.65~14. 04.1-generic 3.16.7-ckt15
DistroRelease: Ubuntu 14.04
Package: linux-image-
ProcVersionSign
Uname: Linux 3.16.0-49-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.13
Architecture: amd64
CurrentDesktop: KDE
Date: Tue Sep 15 00:01:12 2015
InstallationDate: Installed on 2014-05-05 (497 days ago)
InstallationMedia: Kubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140416.1)
SourcePackage: linux-lts-utopic
UpgradeStatus: Upgraded to trusty on 2014-11-21 (297 days ago)