StacktraceAddressSignature is missing

This happens for stack traces whose first 15 frames consist of more than 20% unresolvable addresses, i. e. addresses which do not belong into any known range in /proc/pid/maps. For example, an xeyes stack trace without debug symbols looks like this:

#0 0x00007fa41cf4b430 in __poll_nocancel () at ../sysdeps/unix/syscall-template.S:81
#1 0x00007fa41da94458 in _XtWaitForSomething () from /usr/lib/x86_64-linux-gnu/libXt.so.6
#2 0x00007fa41da95df3 in XtAppProcessEvent () from /usr/lib/x86_64-linux-gnu/libXt.so.6
#3 0x00007fa41da8a4bd in XtAppMainLoop () from /usr/lib/x86_64-linux-gnu/libXt.so.6
#4 0x00000000004018e7 in ?? ()
#5 0x00007fa41ce81c15 in __libc_start_main (main=0x401760, argc=1, ubp_av=0x7fff260180a8, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fff26018098) at libc-start.c:227
        result = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {0, -7013435209680200018, 4200756, 140733831020704, 0, 0, 7013522814131723950, 7053617805804002990}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x403030, 0x7fff260180a8}, data = {prev = 0x0, cleanup = 0x0, canceltype = 4206640}}}
        not_first_call = <optimized out>
#6 0x000000000040195d in ?? ()
#7 0x00007fff26018098 in ?? ()
#8 0x000000000000001c in ?? ()
#9 0x0000000000000001 in ?? ()
#10 0x00007fff26019776 in ?? ()
#11 0x0000000000000000 in ?? ()

Note the very low addresses in frames 8, 9, and 11. These are absolutely impossible as under Unix the first page (i. e. everything up to 0xFFF) is always unallocated memory. So these look like gdb artifacts. With x11-apps-dbgsym, these are gone and it looks much cleaner:

#0 0x00007fa41cf4b430 in __poll_nocancel () at ../sysdeps/unix/syscall-template.S:81
#1 0x00007fa41da94458 in _XtWaitForSomething () from /usr/lib/x86_64-linux-gnu/libXt.so.6
#2 0x00007fa41da95df3 in XtAppProcessEvent () from /usr/lib/x86_64-linux-gnu/libXt.so.6
#3 0x00007fa41da8a4bd in XtAppMainLoop () from /usr/lib/x86_64-linux-gnu/libXt.so.6
#4 0x00000000004018e7 in main (argc=1, argv=<optimized out>) at ../xeyes/xeyes.c:137
        app_context = 0xd0b0e0
        toplevel = <optimized out>
        arg = {{name = 0x604792 <XtShellStrings+18> "iconPixmap", value = 67108865}, {name = 0x6047be <XtShellStrings+62> "iconMask", value = 67108867}}
        i = 2

So as a first and very safe measure, we can ignore frames with addresses < 0x1000. Also, by now I have grown quite a lot of confidence in our StackAddressSignature approach, so I'm inclined to remove the current safety heuristics of "at most 20% frames without resolvable offsets" and just ignore frames with unresolvable offsets instead. We still keep the minimum length requirement.

We should soon have the ability to count how many reports we are receiving that don't have a SAS field. After discussing and thinking about it again, I'm going to go with the small and 100% safe solution first to ignore addresses < 0x1000, but keep the error counting for unresolvable "high" addresses. If we keep getting those, then something else is wrong.

Fixed in trunk: http://bazaar.launchpad.net/~apport-hackers/apport/trunk/revision/2541

This bug was fixed in the package apport - 2.6.3-0ubuntu1

---------------
apport (2.6.3-0ubuntu1) raring; urgency=low

  * New upstream release. Changes since our previous snapshot:
    - debian.py: Only reject reports with useless stack traces if the report
      actually has a stack trace at all.
    - debian.py: Fix UTF-8 string handling. Thanks Ritesh Raj Sarraf.
    - debian.py: Fix crash on broken "Package" fields, as generated by current
      Debian/Ubuntu dkms package.
    - data/apport: Call fsync when writing upstart crash reports.
    - report.py, add_gdb_info(): Handle libnih's assertion messages.
      (LP: #997359)
    - apport-gtk, apport-kde: Don't provide an option to restart a crashed
      application when the crash occurred in a thread (LP: #1033902).
    - apport-retrace: Disallow option -C without option -S. Thanks Kyle
      Nitzsche.
    - fileutils.py, mark_report_upload(): Refresh the .upload stamps if a
      previous version of the report was already uploaded, but another
      instance of the problem happened since then. Thanks Brian Murray. (LP:
      #1084296)
    - Ignore implausibly low addresses when computing
      StacktraceAddressSignature. These are usually artifacts from gdb when
      not having debug symbols, and having too many of them prevents proper
      client-side duplicate detection and proper bucketing in daisy.
      (LP: #1084996)
    - fileutils.py: Ignore .desktop files with NoDisplay=true. (LP: #1048524)
  * debian/tests/control: Run tests as root, just like before switching our
    autopkgtests to run as user "ubuntu" by default. This enables a couple of
    extra tests, and avoids some confusion because the distro and the user
    name are identical.
  * data/package-hooks/source_linux-nexus7.py: Fix PEP-8 error.
 -- Martin Pitt <email address hidden> Fri, 30 Nov 2012 18:00:01 +0100

I uploaded precise and quantal SRUs for this to the review queue.

Hello Martin, or anyone else affected,

Accepted apport into quantal-proposed. The package will build now and be available at http://launchpad.net/ubuntu/+source/apport/2.6.1-0ubuntu8 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please change the bug tag from verification-needed to verification-done. If it does not, change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

Hello Martin, or anyone else affected,

Accepted apport into precise-proposed. The package will build now and be available at http://launchpad.net/ubuntu/+source/apport/2.0.1-0ubuntu16 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please change the bug tag from verification-needed to verification-done. If it does not, change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

Hello Martin, or anyone else affected,

Accepted apport into precise-proposed. The package will build now and be available at http://launchpad.net/ubuntu/+source/apport/2.0.1-0ubuntu17 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please change the bug tag from verification-needed to verification-done. If it does not, change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

Hello Martin, or anyone else affected,

Accepted apport into quantal-proposed. The package will build now and be available at http://launchpad.net/ubuntu/+source/apport/2.6.1-0ubuntu9 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please change the bug tag from verification-needed to verification-done. If it does not, change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

I tested this using apport version 2.6.1-0ubuntu9 from quantal proposed and was able to submit a crash regarding xeyes e.g. it had a StacktraceAddressSignature.

StacktraceAddressSignature: /usr/bin/xeyes:11:x86_64:/lib/x86_64-linux-gnu/libc-2.15.so+e82c8:/usr/lib/x86_64-linux-gnu/libXt.so.6.0.0+2d458:/usr/lib/x86_64-linux-gnu/libXt.so.6.0.0+2edf3:/usr/lib/x86_64-linux-gnu/libXt.so.6.0.0+234bd:/usr/bin/xeyes+18e7:/lib/x86_64-linux-gnu/libc-2.15.so+2176d:/usr/bin/xeyes+195d:[stack]+1f718:[stack]+2032e

This bug was fixed in the package apport - 2.6.1-0ubuntu9

---------------
apport (2.6.1-0ubuntu9) quantal-proposed; urgency=low

  * Fix OSError crash in mark_report_upload(); regression from
    2.6.1-0ubuntu8.

apport (2.6.1-0ubuntu8) quantal-proposed; urgency=low

  * Ignore implausibly low addresses when computing
    StacktraceAddressSignature. These are usually artifacts from gdb when not
    having debug symbols, and having too many of them prevents proper
    client-side duplicate detection and proper bucketing in daisy.
    Backported from trunk r2541. (LP: #1084996)
  * mark_report_upload(): Refresh the .upload stamps if a previous version of
    the report was already uploaded, but another instance of the problem
    happened since then. Thanks Brian Murray. Backported from trunk r2540.
    (LP: #1084296)

apport (2.6.1-0ubuntu7) quantal-proposed; urgency=low

  * data/general-hooks/ubuntu.py: Deal with dpkg_log file being a string
    instead of bytes (LP: #1080915)
 -- Martin Pitt <email address hidden> Wed, 05 Dec 2012 10:16:00 +0000

Since precise verification is not done yet, I am going to add the fix for bug #1045986 and upload a new version for precise (this patch will be released in -security later today).

Uploaded 2.0.1-0ubuntu17.1 with the hardening fix. Please test it instead.

Note that the reuploaded precise package still needs to be reviewed and approved from the queue by the SRU team.

Hello Martin, or anyone else affected,

Accepted apport into precise-proposed. The package will build now and be available at http://launchpad.net/ubuntu/+source/apport/2.0.1-0ubuntu17.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

I tested apport version 2.0.1-0ubuntu17.1 from precise-proposed and verified that by xeyes crash does in fact have a StacktraceAddressSignature in it. I was also able to recreate the issue, no SAS in the crash report, using the apport version 2.0.1-0ubuntu15.1.

The verification of this Stable Release Update has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regresssions.

This bug was fixed in the package apport - 2.0.1-0ubuntu17.1

---------------
apport (2.0.1-0ubuntu17.1) precise-proposed; urgency=low

  * bin/apport-bug: Explicitly set the PATH to that of ENV_SUPATH in
    /etc/login.defs and unset ENV and CDPATH. We need do this so that confined
    applications using ubuntu-browsers.d/ubuntu-integration cannot abuse the
    environment to escape AppArmor confinement via this script (LP: #1045986).

apport (2.0.1-0ubuntu17) precise-proposed; urgency=low

  * Fix OSError crash in mark_report_upload(); regression from
    2.0.1-0ubuntu16.

apport (2.0.1-0ubuntu16) precise-proposed; urgency=low

  * Ignore implausibly low addresses when computing
    StacktraceAddressSignature. These are usually artifacts from gdb when not
    having debug symbols, and having too many of them prevents proper
    client-side duplicate detection and proper bucketing in daisy.
    Backported from trunk r2541. (LP: #1084996)
  * mark_report_upload(): Refresh the .upload stamps if a previous version of
    the report was already uploaded, but another instance of the problem
    happened since then. Thanks Brian Murray. Backported from trunk r2540.
    (LP: #1084296)
 -- Jamie Strandboge <email address hidden> Mon, 17 Dec 2012 16:20:20 -0600