1. 09 Oct, 2014 1 commit
  2. 30 Mar, 2010 2 commits
    • Randy Dunlap's avatar
      kmemcheck: Fix build errors due to missing slab.h · ea5a9f0c
      Randy Dunlap authored
      mm/kmemcheck.c:69: error: dereferencing pointer to incomplete type
      mm/kmemcheck.c:69: error: 'SLAB_NOTRACK' undeclared (first use in this function)
      mm/kmemcheck.c:82: error: dereferencing pointer to incomplete type
      mm/kmemcheck.c:94: error: dereferencing pointer to incomplete type
      mm/kmemcheck.c:94: error: dereferencing pointer to incomplete type
      mm/kmemcheck.c:94: error: 'SLAB_DESTROY_BY_RCU' undeclared (first use in this function)
      Signed-off-by: default avatarRandy Dunlap <randy.dunlap@oracle.com>
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
    • Tejun Heo's avatar
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo authored
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      The script does the followings.
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
      The conversion was done in the following steps.
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
      6. percpu.h was updated not to include slab.h.
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Guess-its-ok-by: default avatarChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
  3. 15 Jun, 2009 2 commits
    • Vegard Nossum's avatar
      kmemcheck: add hooks for the page allocator · b1eeab67
      Vegard Nossum authored
      This adds support for tracking the initializedness of memory that
      was allocated with the page allocator. Highmem requests are not
      Cc: Dave Hansen <dave@linux.vnet.ibm.com>
      Acked-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
      [build fix for !CONFIG_KMEMCHECK]
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      [rebased for mainline inclusion]
      Signed-off-by: default avatarVegard Nossum <vegard.nossum@gmail.com>
    • Vegard Nossum's avatar
      kmemcheck: add mm functions · 2dff4405
      Vegard Nossum authored
      With kmemcheck enabled, the slab allocator needs to do this:
      1. Tell kmemcheck to allocate the shadow memory which stores the status of
         each byte in the allocation proper, e.g. whether it is initialized or
      2. Tell kmemcheck which parts of memory that should be marked uninitialized.
         There are actually a few more states, such as "not yet allocated" and
         "recently freed".
      If a slab cache is set up using the SLAB_NOTRACK flag, it will never return
      memory that can take page faults because of kmemcheck.
      If a slab cache is NOT set up using the SLAB_NOTRACK flag, callers can still
      request memory with the __GFP_NOTRACK flag. This does not prevent the page
      faults from occuring, however, but marks the object in question as being
      initialized so that no warnings will ever be produced for this object.
      In addition to (and in contrast to) __GFP_NOTRACK, the
      __GFP_NOTRACK_FALSE_POSITIVE flag indicates that the allocation should
      not be tracked _because_ it would produce a false positive. Their values
      are identical, but need not be so in the future (for example, we could now
      enable/disable false positives with a config option).
      Parts of this patch were contributed by Pekka Enberg but merged for
      Signed-off-by: default avatarVegard Nossum <vegard.nossum@gmail.com>
      Signed-off-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      [rebased for mainline inclusion]
      Signed-off-by: default avatarVegard Nossum <vegard.nossum@gmail.com>