1. 02 9月, 2009 1 次提交
    • D
      CRED: Add some configurable debugging [try #6] · e0e81739
      David Howells 提交于
      Add a config option (CONFIG_DEBUG_CREDENTIALS) to turn on some debug checking
      for credential management.  The additional code keeps track of the number of
      pointers from task_structs to any given cred struct, and checks to see that
      this number never exceeds the usage count of the cred struct (which includes
      all references, not just those from task_structs).
      
      Furthermore, if SELinux is enabled, the code also checks that the security
      pointer in the cred struct is never seen to be invalid.
      
      This attempts to catch the bug whereby inode_has_perm() faults in an nfsd
      kernel thread on seeing cred->security be a NULL pointer (it appears that the
      credential struct has been previously released):
      
      	http://www.kerneloops.org/oops.php?number=252883Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Signed-off-by: NJames Morris <jmorris@namei.org>
      e0e81739
  2. 25 6月, 2009 1 次提交
  3. 23 6月, 2009 1 次提交
  4. 21 6月, 2009 1 次提交
  5. 15 6月, 2009 2 次提交
  6. 12 6月, 2009 2 次提交
  7. 09 5月, 2009 1 次提交
  8. 23 4月, 2009 1 次提交
  9. 07 4月, 2009 1 次提交
  10. 01 4月, 2009 1 次提交
  11. 25 3月, 2009 2 次提交
  12. 05 3月, 2009 2 次提交
  13. 21 2月, 2009 1 次提交
  14. 19 2月, 2009 1 次提交
  15. 22 1月, 2009 1 次提交
  16. 19 1月, 2009 1 次提交
  17. 16 1月, 2009 1 次提交
  18. 08 1月, 2009 1 次提交
    • D
      NOMMU: Make VMAs per MM as for MMU-mode linux · 8feae131
      David Howells 提交于
      Make VMAs per mm_struct as for MMU-mode linux.  This solves two problems:
      
       (1) In SYSV SHM where nattch for a segment does not reflect the number of
           shmat's (and forks) done.
      
       (2) In mmap() where the VMA's vm_mm is set to point to the parent mm by an
           exec'ing process when VM_EXECUTABLE is specified, regardless of the fact
           that a VMA might be shared and already have its vm_mm assigned to another
           process or a dead process.
      
      A new struct (vm_region) is introduced to track a mapped region and to remember
      the circumstances under which it may be shared and the vm_list_struct structure
      is discarded as it's no longer required.
      
      This patch makes the following additional changes:
      
       (1) Regions are now allocated with alloc_pages() rather than kmalloc() and
           with no recourse to __GFP_COMP, so the pages are not composite.  Instead,
           each page has a reference on it held by the region.  Anything else that is
           interested in such a page will have to get a reference on it to retain it.
           When the pages are released due to unmapping, each page is passed to
           put_page() and will be freed when the page usage count reaches zero.
      
       (2) Excess pages are trimmed after an allocation as the allocation must be
           made as a power-of-2 quantity of pages.
      
       (3) VMAs are added to the parent MM's R/B tree and mmap lists.  As an MM may
           end up with overlapping VMAs within the tree, the VMA struct address is
           appended to the sort key.
      
       (4) Non-anonymous VMAs are now added to the backing inode's prio list.
      
       (5) Holes may be punched in anonymous VMAs with munmap(), releasing parts of
           the backing region.  The VMA and region structs will be split if
           necessary.
      
       (6) sys_shmdt() only releases one attachment to a SYSV IPC shared memory
           segment instead of all the attachments at that addresss.  Multiple
           shmat()'s return the same address under NOMMU-mode instead of different
           virtual addresses as under MMU-mode.
      
       (7) Core dumping for ELF-FDPIC requires fewer exceptions for NOMMU-mode.
      
       (8) /proc/maps is now the global list of mapped regions, and may list bits
           that aren't actually mapped anywhere.
      
       (9) /proc/meminfo gains a line (tagged "MmapCopy") that indicates the amount
           of RAM currently allocated by mmap to hold mappable regions that can't be
           mapped directly.  These are copies of the backing device or file if not
           anonymous.
      
      These changes make NOMMU mode more similar to MMU mode.  The downside is that
      NOMMU mode requires some extra memory to track things over NOMMU without this
      patch (VMAs are no longer shared, and there are now region structs).
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Tested-by: NMike Frysinger <vapier.adi@gmail.com>
      Acked-by: NPaul Mundt <lethal@linux-sh.org>
      8feae131
  19. 07 1月, 2009 1 次提交
  20. 30 12月, 2008 1 次提交
    • F
      tracing/kmemtrace: normalize the raw tracer event to the unified tracing API · 36994e58
      Frederic Weisbecker 提交于
      Impact: new tracer plugin
      
      This patch adapts kmemtrace raw events tracing to the unified tracing API.
      
      To enable and use this tracer, just do the following:
      
       echo kmemtrace > /debugfs/tracing/current_tracer
       cat /debugfs/tracing/trace
      
      You will have the following output:
      
       # tracer: kmemtrace
       #
       #
       # ALLOC  TYPE  REQ   GIVEN  FLAGS           POINTER         NODE    CALLER
       # FREE   |      |     |       |              |   |            |        |
       # |
      
      type_id 1 call_site 18446744071565527833 ptr 18446612134395152256
      type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
      type_id 1 call_site 18446744071565585534 ptr 18446612134405955584
      type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
      type_id 0 call_site 18446744071565636711 ptr 18446612134345164672 bytes_req 240 bytes_alloc 240 gfp_flags 208 node -1
      type_id 1 call_site 18446744071565585534 ptr 18446612134405955584
      type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
      type_id 0 call_site 18446744071565636711 ptr 18446612134345164912 bytes_req 240 bytes_alloc 240 gfp_flags 208 node -1
      type_id 1 call_site 18446744071565585534 ptr 18446612134405955584
      type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
      type_id 0 call_site 18446744071565636711 ptr 18446612134345165152 bytes_req 240 bytes_alloc 240 gfp_flags 208 node -1
      type_id 0 call_site 18446744071566144042 ptr 18446612134346191680 bytes_req 1304 bytes_alloc 1312 gfp_flags 208 node -1
      type_id 1 call_site 18446744071565585534 ptr 18446612134405955584
      type_id 0 call_site 18446744071565585597 ptr 18446612134405955584 bytes_req 4096 bytes_alloc 4096 gfp_flags 208 node -1
      type_id 1 call_site 18446744071565585534 ptr 18446612134405955584
      
      That was to stay backward compatible with the format output produced in
      inux/tracepoint.h.
      
      This is the default ouput, but note that I tried something else.
      
      If you change an option:
      
      echo kmem_minimalistic > /debugfs/trace_options
      
      and then cat /debugfs/trace, you will have the following output:
      
       # tracer: kmemtrace
       #
       #
       # ALLOC  TYPE  REQ   GIVEN  FLAGS           POINTER         NODE    CALLER
       # FREE   |      |     |       |              |   |            |        |
       # |
      
         -      C                            0xffff88007c088780          file_free_rcu
         +      K   4096   4096   000000d0   0xffff88007cad6000     -1   getname
         -      C                            0xffff88007cad6000          putname
         +      K   4096   4096   000000d0   0xffff88007cad6000     -1   getname
         +      K    240    240   000000d0   0xffff8800790dc780     -1   d_alloc
         -      C                            0xffff88007cad6000          putname
         +      K   4096   4096   000000d0   0xffff88007cad6000     -1   getname
         +      K    240    240   000000d0   0xffff8800790dc870     -1   d_alloc
         -      C                            0xffff88007cad6000          putname
         +      K   4096   4096   000000d0   0xffff88007cad6000     -1   getname
         +      K    240    240   000000d0   0xffff8800790dc960     -1   d_alloc
         +      K   1304   1312   000000d0   0xffff8800791d7340     -1   reiserfs_alloc_inode
         -      C                            0xffff88007cad6000          putname
         +      K   4096   4096   000000d0   0xffff88007cad6000     -1   getname
         -      C                            0xffff88007cad6000          putname
         +      K    992   1000   000000d0   0xffff880079045b58     -1   alloc_inode
         +      K    768   1024   000080d0   0xffff88007c096400     -1   alloc_pipe_info
         +      K    240    240   000000d0   0xffff8800790dca50     -1   d_alloc
         +      K    272    320   000080d0   0xffff88007c088780     -1   get_empty_filp
         +      K    272    320   000080d0   0xffff88007c088000     -1   get_empty_filp
      
      Yeah I shall confess kmem_minimalistic should be: kmem_alternative.
      
      Whatever, I find it more readable but this a personal opinion of course.
      We can drop it if you want.
      
      On the ALLOC/FREE column, + means an allocation and - a free.
      
      On the type column, you have K = kmalloc, C = cache, P = page
      
      I would like the flags to be GFP_* strings but that would not be easy to not
      break the column with strings....
      
      About the node...it seems to always be -1. I don't know why but that shouldn't
      be difficult to find.
      
      I moved linux/tracepoint.h to trace/tracepoint.h as well. I think that would
      be more easy to find the tracer headers if they are all in their common
      directory.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      36994e58
  21. 29 12月, 2008 3 次提交
  22. 19 12月, 2008 1 次提交
    • P
      "Tree RCU": scalable classic RCU implementation · 64db4cff
      Paul E. McKenney 提交于
      This patch fixes a long-standing performance bug in classic RCU that
      results in massive internal-to-RCU lock contention on systems with
      more than a few hundred CPUs.  Although this patch creates a separate
      flavor of RCU for ease of review and patch maintenance, it is intended
      to replace classic RCU.
      
      This patch still handles stress better than does mainline, so I am still
      calling it ready for inclusion.  This patch is against the -tip tree.
      Nevertheless, experience on an actual 1000+ CPU machine would still be
      most welcome.
      
      Most of the changes noted below were found while creating an rcutiny
      (which should permit ejecting the current rcuclassic) and while doing
      detailed line-by-line documentation.
      
      Updates from v9 (http://lkml.org/lkml/2008/12/2/334):
      
      o	Fixes from remainder of line-by-line code walkthrough,
      	including comment spelling, initialization, undesirable
      	narrowing due to type conversion, removing redundant memory
      	barriers, removing redundant local-variable initialization,
      	and removing redundant local variables.
      
      	I do not believe that any of these fixes address the CPU-hotplug
      	issues that Andi Kleen was seeing, but please do give it a whirl
      	in case the machine is smarter than I am.
      
      	A writeup from the walkthrough may be found at the following
      	URL, in case you are suffering from terminal insomnia or
      	masochism:
      
      	http://www.kernel.org/pub/linux/kernel/people/paulmck/tmp/rcutree-walkthrough.2008.12.16a.pdf
      
      o	Made rcutree tracing use seq_file, as suggested some time
      	ago by Lai Jiangshan.
      
      o	Added a .csv variant of the rcudata debugfs trace file, to allow
      	people having thousands of CPUs to drop the data into
      	a spreadsheet.	Tested with oocalc and gnumeric.  Updated
      	documentation to suit.
      
      Updates from v8 (http://lkml.org/lkml/2008/11/15/139):
      
      o	Fix a theoretical race between grace-period initialization and
      	force_quiescent_state() that could occur if more than three
      	jiffies were required to carry out the grace-period
      	initialization.  Which it might, if you had enough CPUs.
      
      o	Apply Ingo's printk-standardization patch.
      
      o	Substitute local variables for repeated accesses to global
      	variables.
      
      o	Fix comment misspellings and redundant (but harmless) increments
      	of ->n_rcu_pending (this latter after having explicitly added it).
      
      o	Apply checkpatch fixes.
      
      Updates from v7 (http://lkml.org/lkml/2008/10/10/291):
      
      o	Fixed a number of problems noted by Gautham Shenoy, including
      	the cpu-stall-detection bug that he was having difficulty
      	convincing me was real.  ;-)
      
      o	Changed cpu-stall detection to wait for ten seconds rather than
      	three in order to reduce false positive, as suggested by Ingo
      	Molnar.
      
      o	Produced a design document (http://lwn.net/Articles/305782/).
      	The act of writing this document uncovered a number of both
      	theoretical and "here and now" bugs as noted below.
      
      o	Fix dynticks_nesting accounting confusion, simplify WARN_ON()
      	condition, fix kerneldoc comments, and add memory barriers
      	in dynticks interface functions.
      
      o	Add more data to tracing.
      
      o	Remove unused "rcu_barrier" field from rcu_data structure.
      
      o	Count calls to rcu_pending() from scheduling-clock interrupt
      	to use as a surrogate timebase should jiffies stop counting.
      
      o	Fix a theoretical race between force_quiescent_state() and
      	grace-period initialization.  Yes, initialization does have to
      	go on for some jiffies for this race to occur, but given enough
      	CPUs...
      
      Updates from v6 (http://lkml.org/lkml/2008/9/23/448):
      
      o	Fix a number of checkpatch.pl complaints.
      
      o	Apply review comments from Ingo Molnar and Lai Jiangshan
      	on the stall-detection code.
      
      o	Fix several bugs in !CONFIG_SMP builds.
      
      o	Fix a misspelled config-parameter name so that RCU now announces
      	at boot time if stall detection is configured.
      
      o	Run tests on numerous combinations of configurations parameters,
      	which after the fixes above, now build and run correctly.
      
      Updates from v5 (http://lkml.org/lkml/2008/9/15/92, bad subject line):
      
      o	Fix a compiler error in the !CONFIG_FANOUT_EXACT case (blew a
      	changeset some time ago, and finally got around to retesting
      	this option).
      
      o	Fix some tracing bugs in rcupreempt that caused incorrect
      	totals to be printed.
      
      o	I now test with a more brutal random-selection online/offline
      	script (attached).  Probably more brutal than it needs to be
      	on the people reading it as well, but so it goes.
      
      o	A number of optimizations and usability improvements:
      
      	o	Make rcu_pending() ignore the grace-period timeout when
      		there is no grace period in progress.
      
      	o	Make force_quiescent_state() avoid going for a global
      		lock in the case where there is no grace period in
      		progress.
      
      	o	Rearrange struct fields to improve struct layout.
      
      	o	Make call_rcu() initiate a grace period if RCU was
      		idle, rather than waiting for the next scheduling
      		clock interrupt.
      
      	o	Invoke rcu_irq_enter() and rcu_irq_exit() only when
      		idle, as suggested by Andi Kleen.  I still don't
      		completely trust this change, and might back it out.
      
      	o	Make CONFIG_RCU_TRACE be the single config variable
      		manipulated for all forms of RCU, instead of the prior
      		confusion.
      
      	o	Document tracing files and formats for both rcupreempt
      		and rcutree.
      
      Updates from v4 for those missing v5 given its bad subject line:
      
      o	Separated dynticks interface so that NMIs and irqs call separate
      	functions, greatly simplifying it.  In particular, this code
      	no longer requires a proof of correctness.  ;-)
      
      o	Separated dynticks state out into its own per-CPU structure,
      	avoiding the duplicated accounting.
      
      o	The case where a dynticks-idle CPU runs an irq handler that
      	invokes call_rcu() is now correctly handled, forcing that CPU
      	out of dynticks-idle mode.
      
      o	Review comments have been applied (thank you all!!!).
      	For but one example, fixed the dynticks-ordering issue that
      	Manfred pointed out, saving me much debugging.  ;-)
      
      o	Adjusted rcuclassic and rcupreempt to handle dynticks changes.
      
      Attached is an updated patch to Classic RCU that applies a hierarchy,
      greatly reducing the contention on the top-level lock for large machines.
      This passes 10-hour concurrent rcutorture and online-offline testing on
      128-CPU ppc64 without dynticks enabled, and exposes some timekeeping
      bugs in presence of dynticks (exciting working on a system where
      "sleep 1" hangs until interrupted...), which were fixed in the
      2.6.27 kernel.  It is getting more reliable than mainline by some
      measures, so the next version will be against -tip for inclusion.
      See also Manfred Spraul's recent patches (or his earlier work from
      2004 at http://marc.info/?l=linux-kernel&m=108546384711797&w=2).
      We will converge onto a common patch in the fullness of time, but are
      currently exploring different regions of the design space.  That said,
      I have already gratefully stolen quite a few of Manfred's ideas.
      
      This patch provides CONFIG_RCU_FANOUT, which controls the bushiness
      of the RCU hierarchy.  Defaults to 32 on 32-bit machines and 64 on
      64-bit machines.  If CONFIG_NR_CPUS is less than CONFIG_RCU_FANOUT,
      there is no hierarchy.  By default, the RCU initialization code will
      adjust CONFIG_RCU_FANOUT to balance the hierarchy, so strongly NUMA
      architectures may choose to set CONFIG_RCU_FANOUT_EXACT to disable
      this balancing, allowing the hierarchy to be exactly aligned to the
      underlying hardware.  Up to two levels of hierarchy are permitted
      (in addition to the root node), allowing up to 16,384 CPUs on 32-bit
      systems and up to 262,144 CPUs on 64-bit systems.  I just know that I
      am going to regret saying this, but this seems more than sufficient
      for the foreseeable future.  (Some architectures might wish to set
      CONFIG_RCU_FANOUT=4, which would limit such architectures to 64 CPUs.
      If this becomes a real problem, additional levels can be added, but I
      doubt that it will make a significant difference on real hardware.)
      
      In the common case, a given CPU will manipulate its private rcu_data
      structure and the rcu_node structure that it shares with its immediate
      neighbors.  This can reduce both lock and memory contention by multiple
      orders of magnitude, which should eliminate the need for the strange
      manipulations that are reported to be required when running Linux on
      very large systems.
      
      Some shortcomings:
      
      o	More bugs will probably surface as a result of an ongoing
      	line-by-line code inspection.
      
      	Patches will be provided as required.
      
      o	There are probably hangs, rcutorture failures, &c.  Seems
      	quite stable on a 128-CPU machine, but that is kind of small
      	compared to 4096 CPUs.  However, seems to do better than
      	mainline.
      
      	Patches will be provided as required.
      
      o	The memory footprint of this version is several KB larger
      	than rcuclassic.
      
      	A separate UP-only rcutiny patch will be provided, which will
      	reduce the memory footprint significantly, even compared
      	to the old rcuclassic.  One such patch passes light testing,
      	and has a memory footprint smaller even than rcuclassic.
      	Initial reaction from various embedded guys was "it is not
      	worth it", so am putting it aside.
      
      Credits:
      
      o	Manfred Spraul for ideas, review comments, and bugs spotted,
      	as well as some good friendly competition.  ;-)
      
      o	Josh Triplett, Ingo Molnar, Peter Zijlstra, Mathieu Desnoyers,
      	Lai Jiangshan, Andi Kleen, Andy Whitcroft, and Andrew Morton
      	for reviews and comments.
      
      o	Thomas Gleixner for much-needed help with some timer issues
      	(see patches below).
      
      o	Jon M. Tollefson, Tim Pepper, Andrew Theurer, Jose R. Santos,
      	Andy Whitcroft, Darrick Wong, Nishanth Aravamudan, Anton
      	Blanchard, Dave Kleikamp, and Nathan Lynch for keeping machines
      	alive despite my heavy abuse^Wtesting.
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      64db4cff
  23. 26 11月, 2008 1 次提交
    • I
      debugobjects: add boot parameter default value · 3ae70205
      Ingo Molnar 提交于
      Impact: add .config driven boot parameter default value
      
      Right now debugobjects can only be activated if the debug_objects
      boot parameter is passed in via the boot command line.
      
      Make this more convenient (and randomizable) by also providing
      a .config method. Enable it by default. (DEBUG_OBJECTS itself
      is default-off)
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      3ae70205
  24. 17 10月, 2008 2 次提交
    • T
      block: add BIG FAT WARNING to CONFIG_DEBUG_BLOCK_EXT_DEVT · 0e11e342
      Tejun Heo 提交于
      CONFIG_DEBUG_BLOCK_EXT_DEVT can break booting even on some modern
      distros.  Add BIG FAT WARNING to keep people at a safe distance.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
      0e11e342
    • J
      driver core: basic infrastructure for per-module dynamic debug messages · 346e15be
      Jason Baron 提交于
      Base infrastructure to enable per-module debug messages.
      
      I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes
      control of debugging statements on a per-module basis in one /proc file,
      currently, <debugfs>/dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG,
      is not set, debugging statements can still be enabled as before, often by
      defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no
      affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set.
      
      The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That
      is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls
      can be dynamically enabled/disabled on a per-module basis.
      
      Future plans include extending this functionality to subsystems, that define 
      their own debug levels and flags.
      
      Usage:
      
      Dynamic debugging is controlled by the debugfs file, 
      <debugfs>/dynamic_printk/modules. This file contains a list of the modules that
      can be enabled. The format of the file is as follows:
      
      	<module_name> <enabled=0/1>
      		.
      		.
      		.
      
      	<module_name> : Name of the module in which the debug call resides
      	<enabled=0/1> : whether the messages are enabled or not
      
      For example:
      
      	snd_hda_intel enabled=0
      	fixup enabled=1
      	driver enabled=0
      
      Enable a module:
      
      	$echo "set enabled=1 <module_name>" > dynamic_printk/modules
      
      Disable a module:
      
      	$echo "set enabled=0 <module_name>" > dynamic_printk/modules
      
      Enable all modules:
      
      	$echo "set enabled=1 all" > dynamic_printk/modules
      
      Disable all modules:
      
      	$echo "set enabled=0 all" > dynamic_printk/modules
      
      Finally, passing "dynamic_printk" at the command line enables
      debugging for all modules. This mode can be turned off via the above
      disable command.
      
      [gkh: minor cleanups and tweaks to make the build work quietly]
      Signed-off-by: NJason Baron <jbaron@redhat.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      
      346e15be
  25. 09 10月, 2008 4 次提交
  26. 03 10月, 2008 1 次提交
    • P
      rcu: RCU-based detection of stalled CPUs for Classic RCU · 2133b5d7
      Paul E. McKenney 提交于
      This patch adds stalled-CPU detection to Classic RCU.  This capability
      is enabled by a new config variable CONFIG_RCU_CPU_STALL_DETECTOR, which
      defaults disabled.
      
      This is a debugging feature to detect infinite loops in kernel code, not
      something that non-kernel-hackers would be expected to care about.
      
      This feature can detect looping CPUs in !PREEMPT builds and looping CPUs
      with preemption disabled in PREEMPT builds.  This is essentially a port of
      this functionality from the treercu patch, replacing the stall debug patch
      that is already in tip/core/rcu (commit 67182ae1).
      
      The changes from the patch in tip/core/rcu include making the config
      variable name match that in treercu, changing from seconds to jiffies to
      avoid spurious warnings, and printing a boot message when this feature
      is enabled.
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      2133b5d7
  27. 10 9月, 2008 1 次提交
    • A
      debug: add notifier chain debugging · 1b2439db
      Arjan van de Ven 提交于
      during some development we suspected a case where we left something
      in a notifier chain that was from a module that was unloaded already...
      and that sort of thing is rather hard to track down.
      
      This patch adds a very simple sanity check (which isn't all that
      expensive) to make sure the notifier we're about to call is
      actually from either the kernel itself of from a still-loaded
      module, avoiding a hard-to-chase-down crash.
      Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      1b2439db
  28. 03 9月, 2008 1 次提交
    • T
      powerpc: Work around gcc's -fno-omit-frame-pointer bug · 7563dc64
      Tony Breeds 提交于
      This bug is causing random crashes
      (http://bugzilla.kernel.org/show_bug.cgi?id=11414).
      
      -fno-omit-frame-pointer is only needed on powerpc when -pg is also
      supplied, and there is a gcc bug that causes incorrect code generation
      on 32-bit powerpc when -fno-omit-frame-pointer is used---it uses stack
      locations below the stack pointer, which is not allowed by the ABI
      because those locations can and sometimes do get corrupted by an
      interrupt.
      
      This ensures that CONFIG_FRAME_POINTER is only selected by ftrace.
      When CONFIG_FTRACE is enabled we also pass -mno-sched-epilog to work
      around the gcc codegen bug.
      
      Patch based on work by:
      	Andreas Schwab <schwab@suse.de>
      	Segher Boessenkool <segher@kernel.crashing.org>
      Signed-off-by: NTony Breeds <tony@bakeyournoodle.com>
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      7563dc64
  29. 17 8月, 2008 1 次提交
  30. 13 8月, 2008 1 次提交
    • R
      docsrc: build Documentation/ sources · 3794f3e8
      Randy Dunlap 提交于
      Currently source files in the Documentation/ sub-dir can easily bit-rot
      since they are not generally buildable, either because they are hidden in
      text files or because there are no Makefile rules for them.  This needs to
      be fixed so that the source files remain usable and good examples of code
      instead of bad examples.
      
      Add the ability to build source files that are in the Documentation/ dir.
      Add to Kconfig as "BUILD_DOCSRC" config symbol.
      
      Use "CONFIG_BUILD_DOCSRC=1 make ..." to build objects from the
      Documentation/ sources.  Or enable BUILD_DOCSRC in the *config system.
      However, this symbol depends on HEADERS_CHECK since the header files need
      to be installed (for userspace builds).
      
      Built (using cross-tools) for x86-64, i386, alpha, ia64, sparc32,
      sparc64, powerpc, sh, m68k, & mips.
      Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
      Reviewed-by: NSam Ravnborg <sam@ravnborg.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      3794f3e8