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lttng-modules may trigger deadlock in the timekeeping subsystem with Linux <= 3.10.13, <= 3.11.2

DISCUSSION Woegerer, Paul 4 participants 6 messages Oct 14, 2013 – Oct 15, 2013

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#0 lore raw

Hi,

looking at the following commits shows that the current version of lttng-modules 2.3.x can trigger a deadlock in the timekeeping subsystem of Linux.

http://git.lttng.org/?p=lttng-modules.git;a=commit;h=fc8216ae9ec5d18172d8227d179475e7cc1fb45c
http://git.lttng.org/?p=lttng-modules.git;a=commit;h=9998f5216f4641a79e158135c4c1658dcc6cd2d8
http://git.lttng.org/?p=lttng-modules.git;a=commit;h=e14bf96416c39675a5f785b032d1c5279020b93d

This is caused by a bug in the kernel that was introduced in 3.10. The problem is already fixed in Linux 3.10.14, 3.11.3 and 3.12. See:
http://marc.info/?l=linux-kernel&m=137894350929349

lttng-modules 2.3.2 contains preprocessor-code that makes sure that building of lttng-modules fails for the unlucky combinations of kernel and lttng-modules. The problem is when we update our lttng-modules 2.3.0 to 2.3.2 then we would have lttng-modules failing to build for our qemu* MACHINEs.

Any recommendations on how we should address this ?

Many thanks,
Paul

Signature · 3 lines
Paul Woegerer, SW Development Engineer
Sourcery Analyzer <http://go.mentor.com/sourceryanalyzer>
Mentor Graphics, Embedded Software Division
#1 lore raw
Quoted 14 lines · Paul

Hi,

looking at the following commits shows that the current version of lttng-modules 2.3.x can trigger a deadlock in the timekeeping subsystem of Linux.

http://git.lttng.org/?p=lttng-modules.git;a=commit;h=fc8216ae9ec5d18172d8227d179475e7cc1fb45c
http://git.lttng.org/?p=lttng-modules.git;a=commit;h=9998f5216f4641a79e158135c4c1658dcc6cd2d8
http://git.lttng.org/?p=lttng-modules.git;a=commit;h=e14bf96416c39675a5f785b032d1c5279020b93d

This is caused by a bug in the kernel that was introduced in 3.10. The problem is already fixed in Linux 3.10.14, 3.11.3 and 3.12. See:
http://marc.info/?l=linux-kernel&m=137894350929349

Quoted 8 lines

lttng-modules 2.3.2 contains preprocessor-code that makes sure that building of lttng-modules fails for the unlucky combinations of kernel and lttng-modules. The problem is when we update our lttng-modules 2.3.0 to 2.3.2 then we would have lttng-modules failing to build for our qemu* MACHINEs.

Any recommendations on how we should address this ?

Probably just get Bruce to update linux-yocto-3.10 to 3.10.14, or pull the specific commit that fixes it in.

Tom

Quoted 3 lines

Many thanks,
Paul

#2 lore raw
Quoted 21 lines · Tom Zanussi
Quoted 20 lines · Paul

Hi,

looking at the following commits shows that the current version of lttng-modules 2.3.x can trigger a deadlock in the timekeeping subsystem of Linux.

http://git.lttng.org/?p=lttng-modules.git;a=commit;h=fc8216ae9ec5d18172d8227d179475e7cc1fb45c
http://git.lttng.org/?p=lttng-modules.git;a=commit;h=9998f5216f4641a79e158135c4c1658dcc6cd2d8
http://git.lttng.org/?p=lttng-modules.git;a=commit;h=e14bf96416c39675a5f785b032d1c5279020b93d

This is caused by a bug in the kernel that was introduced in 3.10. The problem is already fixed in Linux 3.10.14, 3.11.3 and 3.12. See:
http://marc.info/?l=linux-kernel&m=137894350929349

lttng-modules 2.3.2 contains preprocessor-code that makes sure that building of lttng-modules fails for the unlucky combinations of kernel and lttng-modules. The problem is when we update our lttng-modules 2.3.0 to 2.3.2 then we would have lttng-modules failing to build for our qemu* MACHINEs.

Quoted 6 lines
Quoted 2 lines

Any recommendations on how we should address this ?

Probably just get Bruce to update linux-yocto-3.10 to 3.10.14, or pull the specific commit that fixes it in.

Adding Bruce to Cc:

Tom

Quoted 6 lines

Tom

Quoted 3 lines

Many thanks,
Paul

#3 lore raw
In reply to Tom Zanussi
Quoted 21 lines · Tom Zanussi
Quoted 20 lines · Paul

Hi,

looking at the following commits shows that the current version of lttng-modules 2.3.x can trigger a deadlock in the timekeeping subsystem of Linux.

http://git.lttng.org/?p=lttng-modules.git;a=commit;h=fc8216ae9ec5d18172d8227d179475e7cc1fb45c
http://git.lttng.org/?p=lttng-modules.git;a=commit;h=9998f5216f4641a79e158135c4c1658dcc6cd2d8
http://git.lttng.org/?p=lttng-modules.git;a=commit;h=e14bf96416c39675a5f785b032d1c5279020b93d

This is caused by a bug in the kernel that was introduced in 3.10. The problem is already fixed in Linux 3.10.14, 3.11.3 and 3.12. See:
http://marc.info/?l=linux-kernel&m=137894350929349

lttng-modules 2.3.2 contains preprocessor-code that makes sure that building of lttng-modules fails for the unlucky combinations of kernel and lttng-modules. The problem is when we update our lttng-modules 2.3.0 to 2.3.2 then we would have lttng-modules failing to build for our qemu* MACHINEs.

Quoted 5 lines
Quoted 2 lines

Any recommendations on how we should address this ?

Probably just get Bruce to update linux-yocto-3.10 to 3.10.14, or pull the specific commit that fixes it in.

Precisely. And I already have all the -stable updates queued, it just needs to be 1.5.1, since I stopped sending updates to 3.10 for 1.5 proper a few weeks ago.

This isn't severe enough to warrant any special handling outside of getting the -stable update into 1.5.1.

Cheers,

Bruce

Quoted 12 lines

Tom

Quoted 3 lines

Many thanks,
Paul

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#4 lore raw
Quoted 23 lines · Bruce Ashfield
Quoted 21 lines · Tom Zanussi
Quoted 20 lines · Paul

Hi,

looking at the following commits shows that the current version of lttng-modules 2.3.x can trigger a deadlock in the timekeeping subsystem of Linux.

http://git.lttng.org/?p=lttng-modules.git;a=commit;h=fc8216ae9ec5d18172d8227d179475e7cc1fb45c
http://git.lttng.org/?p=lttng-modules.git;a=commit;h=9998f5216f4641a79e158135c4c1658dcc6cd2d8
http://git.lttng.org/?p=lttng-modules.git;a=commit;h=e14bf96416c39675a5f785b032d1c5279020b93d

This is caused by a bug in the kernel that was introduced in 3.10. The problem is already fixed in Linux 3.10.14, 3.11.3 and 3.12. See:
http://marc.info/?l=linux-kernel&m=137894350929349

lttng-modules 2.3.2 contains preprocessor-code that makes sure that building of lttng-modules fails for the unlucky combinations of kernel and lttng-modules. The problem is when we update our lttng-modules 2.3.0 to 2.3.2 then we would have lttng-modules failing to build for our qemu* MACHINEs.

Quoted 7 lines
Quoted 4 lines
Quoted 2 lines

Any recommendations on how we should address this ?

Probably just get Bruce to update linux-yocto-3.10 to 3.10.14, or pull the specific commit that fixes it in.

Precisely. And I already have all the -stable updates queued, it just needs to be 1.5.1, since I stopped sending updates to 3.10 for 1.5 proper a few weeks ago.

Bruce, as soon as you have updated linux-yocto-3.10 to 3.10.14 (or later) I will send the patch that updates lttng-modules from 2.3.0 to 2.3.2. This will ensure we will have the checks from 2.3.2 in, so that users of other bsps will get a compile time error if they are tring to build a fatal combination of lttng-modules and kernel.

Thanks,
Paul

Quoted 20 lines

This isn't severe enough to warrant any special handling outside of getting the -stable update into 1.5.1.

Cheers,

Bruce

Quoted 10 lines

Tom

Quoted 3 lines

Many thanks,
Paul

_______________________________________________
Openembedded-core mailing list
[email protected]
http://lists.openembedded.org/mailman/listinfo/openembedded-core

Signature · 3 lines
Paul Woegerer, SW Development Engineer
Sourcery Analyzer <http://go.mentor.com/sourceryanalyzer>
Mentor Graphics, Embedded Software Division
#5 lore raw
In reply to Tom Zanussi
Quoted 9 lines · Tom Zanussi
Quoted 7 lines · Paul

lttng-modules 2.3.2 contains preprocessor-code that makes sure that building of lttng-modules fails for the unlucky combinations of kernel and lttng-modules. The problem is when we update our lttng-modules 2.3.0 to 2.3.2 then we would have lttng-modules failing to build for our qemu* MACHINEs.

Any recommendations on how we should address this ?

Probably just get Bruce to update linux-yocto-3.10 to 3.10.14,

That would be the ideal solution.

--
Paul

Quoted 7 lines

Tom

Quoted 3 lines

Many thanks,
Paul

Signature · 3 lines
Paul Woegerer, SW Development Engineer
Sourcery Analyzer <http://go.mentor.com/sourceryanalyzer>
Mentor Graphics, Embedded Software Division