1. 10 Aug, 2017 1 commit
  2. 14 Jul, 2017 1 commit
  3. 12 Jul, 2017 1 commit
    • Dmitry Vyukov's avatar
      fault-inject: support systematic fault injection · e41d5818
      Dmitry Vyukov authored
      Add /proc/self/task/<current-tid>/fail-nth file that allows failing
      0-th, 1-st, 2-nd and so on calls systematically.
      Excerpt from the added documentation:
      
       "Write to this file of integer N makes N-th call in the current task
        fail (N is 0-based). Read from this file returns a single char 'Y' or
        'N' that says if the fault setup with a previous write to this file
        was injected or not, and disables the fault if it wasn't yet injected.
        Note that this file enables all types of faults (slab, futex, etc).
        This setting takes precedence over all other generic settings like
        probability, interval, times, etc. But per-capability settings (e.g.
        fail_futex/ignore-private) take precedence over it. This feature is
        intended for systematic testing of faults in a single system call. See
        an example below"
      
      Why add a new setting:
      1. Existing settings are global rather than per-task.
         So parallel testing is not possible.
      2. attr->interval is close but it depends on attr->count
         which is non reset to 0, so interval does not work as expected.
      3. Trying to model this with existing settings requires manipulations
         of all of probability, interval, times, space, task-filter and
         unexposed count and per-task make-it-fail files.
      4. Existing settings are per-failure-type, and the set of failure
         types is potentially expanding.
      5. make-it-fail can't be changed by unprivileged user and aggressive
         stress testing better be done from an unprivileged user.
         Similarly, this would require opening the debugfs files to the
         unprivileged user, as he would need to reopen at least times file
         (not possible to pre-open before dropping privs).
      
      The proposed interface solves all of the above (see the example).
      
      We want to integrate this into syzkaller fuzzer.  A prototype has found
      10 bugs in kernel in first day of usage:
      
        https://groups.google.com/forum/#!searchin/syzkaller/%22FAULT_INJECTION%22%7Csort:relevance
      
      I've made the current interface work with all types of our sandboxes.
      For setuid the secret sauce was prctl(PR_SET_DUMPABLE, 1, 0, 0, 0) to
      make /proc entries non-root owned.  So I am fine with the current
      version of the code.
      
      [akpm@linux-foundation.org: fix build]
      Link: http://lkml.kernel.org/r/20170328130128.101773-1-dvyukov@google.comSigned-off-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Cc: Akinobu Mita <akinobu.mita@gmail.com>
      Cc: Michal Hocko <mhocko@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e41d5818
  4. 09 May, 2017 1 commit
  5. 23 Oct, 2015 1 commit
  6. 13 Dec, 2014 1 commit
  7. 03 Jun, 2013 1 commit
  8. 30 Apr, 2013 1 commit
  9. 20 Jun, 2012 1 commit
  10. 07 Mar, 2012 1 commit
  11. 04 Jan, 2012 1 commit
  12. 26 Oct, 2011 2 commits
  13. 04 Aug, 2011 1 commit
    • Akinobu Mita's avatar
      fault-injection: add ability to export fault_attr in arbitrary directory · dd48c085
      Akinobu Mita authored
      init_fault_attr_dentries() is used to export fault_attr via debugfs.
      But it can only export it in debugfs root directory.
      
      Per Forlin is working on mmc_fail_request which adds support to inject
      data errors after a completed host transfer in MMC subsystem.
      
      The fault_attr for mmc_fail_request should be defined per mmc host and
      export it in debugfs directory per mmc host like
      /sys/kernel/debug/mmc0/mmc_fail_request.
      
      init_fault_attr_dentries() doesn't help for mmc_fail_request.  So this
      introduces fault_create_debugfs_attr() which is able to create a
      directory in the arbitrary directory and replace
      init_fault_attr_dentries().
      
      [akpm@linux-foundation.org: extraneous semicolon, per Randy]
      Signed-off-by: default avatarAkinobu Mita <akinobu.mita@gmail.com>
      Tested-by: default avatarPer Forlin <per.forlin@linaro.org>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Cc: Pekka Enberg <penberg@kernel.org>
      Cc: Matt Mackall <mpm@selenic.com>
      Cc: Randy Dunlap <rdunlap@xenotime.net>
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      dd48c085
  14. 26 Jul, 2011 3 commits
  15. 11 Oct, 2009 1 commit
  16. 06 Jan, 2009 1 commit
  17. 08 Feb, 2008 1 commit
  18. 24 Jul, 2007 1 commit
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  20. 21 Feb, 2007 1 commit
  21. 15 Dec, 2006 1 commit
    • Linus Torvalds's avatar
      Remove stack unwinder for now · d1526e2c
      Linus Torvalds authored
      It has caused more problems than it ever really solved, and is
      apparently not getting cleaned up and fixed.  We can put it back when
      it's stable and isn't likely to make warning or bug events worse.
      
      In the meantime, enable frame pointers for more readable stack traces.
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      d1526e2c
  22. 08 Dec, 2006 6 commits