Ubuntu
linux package

'perf record' fails with "Perf session creation failed"

Bug #1375441 reported by bugproxy
8
This bug affects 1 person
Affects Status Importance Assigned to Milestone
linux (Ubuntu)
Fix Released
Undecided
Tim Gardner
Utopic
Fix Released
Undecided
Tim Gardner

Bug Description

---Problem Description---
When run as normal user, 'perf record ls' fails with:

  Perf session creation failed.

The command runs successfully when run as root.

---uname output---
Linux ubuntu 3.16.0-16-generic #22-Ubuntu SMP Wed Sep 17 18:45:43 UTC 2014 ppc64le ppc64le ppc64le GNU/Linux

Machine Type = POWER8E pvr 004b 0201

> Maynard,
>
> Can you check if /proc/sys/kernel/kptr_restrict has 1 in it on your
> system ?

Yes, the value is '1'.

>
> On my system it does have 1 and I can repro. Following seems to
> fix:
> echo 0 > /proc/sys/kernel/kptr_restrict

Yes, changing it to '0' does "fix" it, although that shouldn't be necessary, as you know. So something is broken.

I am able to repro with 3.17.0-rc4 based mainline perf tool.

I suspect that the change in behavior was introduced unintentionally by
this upstream commit. machine__create_kernel_maps() now calls
 machine__get_kernel_start_addr() which checks the kptr_restrict state.

---

commit a93f0e551af9e194db38bfe16001e17a3a1d189a
Author: Simon Que <email address hidden>
Date: Mon Jun 16 11:32:09 2014 -0700

    perf symbols: Get kernel start address by symbol name

This is being fixed by a recent upstream commit:

    https://lkml.org/lkml/2014/9/27/26

Will Ubuntu pick that fix up automatically ?

bugproxy (bugproxy)
tags: added: architecture-ppc64le bugnameltc-116381 severity-medium targetmilestone-inin---
Luciano Chavez (lnx1138)
affects: ubuntu → linux (Ubuntu)
Changed in linux (Ubuntu):
status: New → Confirmed
bugproxy (bugproxy)
tags: added: targetmilestone-inin1410
removed: targetmilestone-inin---
Joseph Salisbury (jsalisbury)
tags: added: kernel-da-key
Revision history for this message
Tim Gardner (timg-tpi) wrote :

I applied http://git.kernel.org/cgit/linux/kernel/git/tip/tip.git/patch/?id=a5c2a4c9561cbbd374231bd341936dae716df9dd for now. If this had been marked for stable it would likely have trickled down automatically.

Changed in linux (Ubuntu Utopic):
assignee: nobody → Tim Gardner (timg-tpi)
status: Confirmed → Fix Committed
Revision history for this message
Launchpad Janitor (janitor) wrote :

This bug was fixed in the package linux - 3.16.0-20.27

---------------
linux (3.16.0-20.27) utopic; urgency=low

  [ Tim Gardner ]

  * [Config] CONFIG_CXL=m
  * Release Tracking Bug
    - LP: #1376354

  [ Andi Kleen ]

  * SAUCE: perf tools: Fix perf record as non root with kptr_restrict == 1
    - LP: #1375441

  [ Chris J Arges ]

  * SAUCE: Revert "sd: don't use scsi_setup_blk_pc_cmnd for flush requests"
    - LP: #1375452

  [ Ian Munsie ]

  * SAUCE: (no-up) powerpc/cell: Move spu_handle_mm_fault() out of cell platform
  * SAUCE: (no-up) powerpc/cell: Move data segment faulting code out of cell platform
  * SAUCE: (no-up) powerpc/msi: Improve IRQ bitmap allocator
  * SAUCE: (no-up) powerpc/mm: Export mmu_kernel_ssize and mmu_linear_psize
  * SAUCE: (no-up) powerpc/powernv: Split out set MSI IRQ chip code
  * SAUCE: (no-up) cxl: Add new header for call backs and structs
  * SAUCE: (no-up) powerpc/powerpc: Add new PCIe functions for allocating cxl interrupts
  * SAUCE: (no-up) powerpc/mm: Add new hash_page_mm()
  * SAUCE: (no-up) powerpc/opal: Add PHB to cxl mode call
  * SAUCE: (no-up) powerpc/mm: Add hooks for cxl
  * SAUCE: (no-up) cxl: Add base builtin support
  * SAUCE: (no-up) cxl: Driver code for powernv PCIe based cards for userspace access
  * SAUCE: (no-up) cxl: Userspace header file.
  * SAUCE: (no-up) cxl: Add driver to Kbuild and Makefiles
  * SAUCE: (no-up) cxl: Add documentation for userspace APIs
 -- Tim Gardner <email address hidden> Tue, 30 Sep 2014 13:05:27 -0600

Changed in linux (Ubuntu Utopic):
status: Fix Committed → Fix Released
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