1. 10 Dec, 2006 1 commit
  2. 08 Dec, 2006 1 commit
    • David Howells's avatar
      [PATCH] LOG2: Implement a general integer log2 facility in the kernel · f0d1b0b3
      David Howells authored
      This facility provides three entry points:
      
      	ilog2()		Log base 2 of unsigned long
      	ilog2_u32()	Log base 2 of u32
      	ilog2_u64()	Log base 2 of u64
      
      These facilities can either be used inside functions on dynamic data:
      
      	int do_something(long q)
      	{
      		...;
      		y = ilog2(x)
      		...;
      	}
      
      Or can be used to statically initialise global variables with constant values:
      
      	unsigned n = ilog2(27);
      
      When performing static initialisation, the compiler will report "error:
      initializer element is not constant" if asked to take a log of zero or of
      something not reducible to a constant.  They treat negative numbers as
      unsigned.
      
      When not dealing with a constant, they fall back to using fls() which permits
      them to use arch-specific log calculation instructions - such as BSR on
      x86/x86_64 or SCAN on FRV - if available.
      
      [akpm@osdl.org: MMC fix]
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Herbert Xu <herbert@gondor.apana.org.au>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Wojtek Kaniewski <wojtekka@toxygen.net>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      f0d1b0b3
  3. 27 Oct, 2006 1 commit
  4. 03 Oct, 2006 3 commits
  5. 02 Oct, 2006 3 commits
    • Arnd Bergmann's avatar
      [PATCH] provide kernel_execve on all architectures · fe74290d
      Arnd Bergmann authored
      This adds the new kernel_execve function on all architectures that were using
      _syscall3() to implement execve.
      
      The implementation uses code from the _syscall3 macros provided in the
      unistd.h header file.  I don't have cross-compilers for any of these
      architectures, so the patch is untested with the exception of i386.
      
      Most architectures can probably implement this in a nicer way in assembly or
      by combining it with the sys_execve implementation itself, but this should do
      it for now.
      
      [bunk@stusta.de: m68knommu build fix]
      [markh@osdl.org: build fix]
      [bero@arklinux.org: build fix]
      [ralf@linux-mips.org: mips fix]
      [schwidefsky@de.ibm.com: s390 fix]
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Cc: Andi Kleen <ak@muc.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Cc: Ian Molton <spyro@f2s.com>
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Hirokazu Takata <takata.hirokazu@renesas.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Kyle McMartin <kyle@mcmartin.ca>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
      Cc: Richard Curnow <rc@rc0.org.uk>
      Cc: William Lee Irwin III <wli@holomorphy.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
      Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: "Luck, Tony" <tony.luck@intel.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Roman Zippel <zippel@linux-m68k.org>
      Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      Signed-off-by: Bernhard Rosenkraenzer's avatarBernhard Rosenkraenzer <bero@arklinux.org>
      Signed-off-by: default avatarMark Haverkamp <markh@osdl.org>
      Signed-off-by: Adrian Bunk's avatarAdrian Bunk <bunk@stusta.de>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      fe74290d
    • Serge E. Hallyn's avatar
      [PATCH] namespaces: utsname: switch to using uts namespaces · e9ff3990
      Serge E. Hallyn authored
      Replace references to system_utsname to the per-process uts namespace
      where appropriate.  This includes things like uname.
      
      Changes: Per Eric Biederman's comments, use the per-process uts namespace
      	for ELF_PLATFORM, sunrpc, and parts of net/ipv4/ipconfig.c
      
      [jdike@addtoit.com: UML fix]
      [clg@fr.ibm.com: cleanup]
      [akpm@osdl.org: build fix]
      Signed-off-by: default avatarSerge E. Hallyn <serue@us.ibm.com>
      Cc: Kirill Korotaev <dev@openvz.org>
      Cc: "Eric W. Biederman" <ebiederm@xmission.com>
      Cc: Herbert Poetzl <herbert@13thfloor.at>
      Cc: Andrey Savochkin <saw@sw.ru>
      Signed-off-by: default avatarCedric Le Goater <clg@fr.ibm.com>
      Cc: Jeff Dike <jdike@addtoit.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      e9ff3990
    • Jeff Dike's avatar
      [PATCH] const struct tty_operations · b68e31d0
      Jeff Dike authored
      As part of an SMP cleanliness pass over UML, I consted a bunch of
      structures in order to not have to document their locking.  One of these
      structures was a struct tty_operations.  In order to const it in UML
      without introducing compiler complaints, the declaration of
      tty_set_operations needs to be changed, and then all of its callers need to
      be fixed.
      
      This patch declares all struct tty_operations in the tree as const.  In all
      cases, they are static and used only as input to tty_set_operations.  As an
      extra check, I ran an i386 allyesconfig build which produced no extra
      warnings.
      
      53 drivers are affected.  I checked the history of a bunch of them, and in
      most cases, there have been only a handful of maintenance changes in the
      last six months.  serial_core.c was the busiest one that I looked at.
      Signed-off-by: default avatarJeff Dike <jdike@addtoit.com>
      Acked-by: default avatarAlan Cox <alan@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      b68e31d0
  6. 01 Oct, 2006 1 commit
    • Atsushi Nemoto's avatar
      [PATCH] kill wall_jiffies · 8ef38609
      Atsushi Nemoto authored
      With 2.6.18-rc4-mm2, now wall_jiffies will always be the same as jiffies.
      So we can kill wall_jiffies completely.
      
      This is just a cleanup and logically should not change any real behavior
      except for one thing: RTC updating code in (old) ppc and xtensa use a
      condition "jiffies - wall_jiffies == 1".  This condition is never met so I
      suppose it is just a bug.  I just remove that condition only instead of
      kill the whole "if" block.
      
      [heiko.carstens@de.ibm.com: s390 build fix and cleanup]
      Signed-off-by: default avatarAtsushi Nemoto <anemo@mba.ocn.ne.jp>
      Cc: Andi Kleen <ak@muc.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Cc: Ian Molton <spyro@f2s.com>
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Hirokazu Takata <takata.hirokazu@renesas.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Kyle McMartin <kyle@mcmartin.ca>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
      Cc: Richard Curnow <rc@rc0.org.uk>
      Cc: William Lee Irwin III <wli@holomorphy.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
      Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: "Luck, Tony" <tony.luck@intel.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Roman Zippel <zippel@linux-m68k.org>
      Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      8ef38609
  7. 29 Sep, 2006 3 commits
    • Atsushi Nemoto's avatar
      [PATCH] simplify update_times (avoid jiffies/jiffies_64 aliasing problem) · 3171a030
      Atsushi Nemoto authored
      Pass ticks to do_timer() and update_times(), and adjust x86_64 and s390
      timer interrupt handler with this change.
      
      Currently update_times() calculates ticks by "jiffies - wall_jiffies", but
      callers of do_timer() should know how many ticks to update.  Passing ticks
      get rid of this redundant calculation.  Also there are another redundancy
      pointed out by Martin Schwidefsky.
      
      This cleanup make a barrier added by
      5aee405c needless.  So this patch removes
      it.
      
      As a bonus, this cleanup make wall_jiffies can be removed easily, since now
      wall_jiffies is always synced with jiffies.  (This patch does not really
      remove wall_jiffies.  It would be another cleanup patch)
      Signed-off-by: default avatarAtsushi Nemoto <anemo@mba.ocn.ne.jp>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: "Eric W. Biederman" <ebiederm@xmission.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: john stultz <johnstul@us.ibm.com>
      Cc: Andi Kleen <ak@muc.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Acked-by: default avatarRussell King <rmk@arm.linux.org.uk>
      Cc: Ian Molton <spyro@f2s.com>
      Cc: Mikael Starvik <starvik@axis.com>
      Acked-by: default avatarDavid Howells <dhowells@redhat.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Hirokazu Takata <takata.hirokazu@renesas.com>
      Acked-by: default avatarRalf Baechle <ralf@linux-mips.org>
      Cc: Kyle McMartin <kyle@mcmartin.ca>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
      Cc: Richard Curnow <rc@rc0.org.uk>
      Cc: William Lee Irwin III <wli@holomorphy.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
      Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
      Cc: Chris Zankel <chris@zankel.net>
      Acked-by: default avatar"Luck, Tony" <tony.luck@intel.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Roman Zippel <zippel@linux-m68k.org>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      3171a030
    • Sukadev Bhattiprolu's avatar
      [PATCH] pidspace: is_init() · f400e198
      Sukadev Bhattiprolu authored
      This is an updated version of Eric Biederman's is_init() patch.
      (http://lkml.org/lkml/2006/2/6/280).  It applies cleanly to 2.6.18-rc3 and
      replaces a few more instances of ->pid == 1 with is_init().
      
      Further, is_init() checks pid and thus removes dependency on Eric's other
      patches for now.
      
      Eric's original description:
      
      	There are a lot of places in the kernel where we test for init
      	because we give it special properties.  Most  significantly init
      	must not die.  This results in code all over the kernel test
      	->pid == 1.
      
      	Introduce is_init to capture this case.
      
      	With multiple pid spaces for all of the cases affected we are
      	looking for only the first process on the system, not some other
      	process that has pid == 1.
      Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
      Signed-off-by: default avatarSukadev Bhattiprolu <sukadev@us.ibm.com>
      Cc: Dave Hansen <haveblue@us.ibm.com>
      Cc: Serge Hallyn <serue@us.ibm.com>
      Cc: Cedric Le Goater <clg@fr.ibm.com>
      Cc: <lxc-devel@lists.sourceforge.net>
      Acked-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      f400e198
    • Al Viro's avatar
      [IPV4]: annotate struct in_ifaddr · a144ea4b
      Al Viro authored
      ifa_local, ifa_address, ifa_mask, ifa_broadcast and ifa_anycast are
      net-endian.  Annotated them and variables that are inferred to be
      net-endian.
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      a144ea4b
  8. 01 Sep, 2006 1 commit
  9. 14 Aug, 2006 1 commit
    • Horms's avatar
      [PATCH] Change panic_on_oops message to "Fatal exception" · 012c437d
      Horms authored
      Previously the message was "Fatal exception: panic_on_oops", as introduced
      in a recent patch whith removed a somewhat dangerous call to ssleep() in
      the panic_on_oops path.  However, Paul Mackerras suggested that this was
      somewhat confusing, leadind people to believe that it was panic_on_oops
      that was the root cause of the fatal exception.  On his suggestion, this
      patch changes the message to simply "Fatal exception".  A suitable oops
      message should already have been displayed.
      Signed-off-by: default avatarSimon Horman <horms@verge.net.au>
      Cc: Paul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      012c437d
  10. 31 Jul, 2006 1 commit
    • Horms's avatar
      [PATCH] panic_on_oops: remove ssleep() · cea6a4ba
      Horms authored
      This patch is part of an effort to unify the panic_on_oops behaviour across
      all architectures that implement it.
      
      It was pointed out to me by Andi Kleen that if an oops has occured in
      interrupt context, then calling sleep() in the oops path will only cause a
      panic, and that it would be really better for it not to be in the path at
      all.
      
      This patch removes the ssleep() call and reworks the console message
      accordinly.  I have a slght concern that the resulting console message is
      too long, feedback welcome.
      
      For powerpc it also unifies the 32bit and 64bit behaviour.
      
      Fror x86_64, this patch only updates the console message, as ssleep() is
      already not present.
      Signed-off-by: default avatarHorms <horms@verge.net.au>
      Acked-by: default avatarPaul Mackerras <paulus@samba.org>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Cc: "Luck, Tony" <tony.luck@intel.com>
      Cc: Andi Kleen <ak@muc.de>
      Cc: Chris Zankel <chris@zankel.net>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      cea6a4ba
  11. 10 Jul, 2006 1 commit
  12. 02 Jul, 2006 1 commit
  13. 30 Jun, 2006 1 commit
  14. 29 Jun, 2006 1 commit
    • Ingo Molnar's avatar
      [PATCH] genirq: rename desc->handler to desc->chip · d1bef4ed
      Ingo Molnar authored
      This patch-queue improves the generic IRQ layer to be truly generic, by adding
      various abstractions and features to it, without impacting existing
      functionality.
      
      While the queue can be best described as "fix and improve everything in the
      generic IRQ layer that we could think of", and thus it consists of many
      smaller features and lots of cleanups, the one feature that stands out most is
      the new 'irq chip' abstraction.
      
      The irq-chip abstraction is about describing and coding and IRQ controller
      driver by mapping its raw hardware capabilities [and quirks, if needed] in a
      straightforward way, without having to think about "IRQ flow"
      (level/edge/etc.) type of details.
      
      This stands in contrast with the current 'irq-type' model of genirq
      architectures, which 'mixes' raw hardware capabilities with 'flow' details.
      The patchset supports both types of irq controller designs at once, and
      converts i386 and x86_64 to the new irq-chip design.
      
      As a bonus side-effect of the irq-chip approach, chained interrupt controllers
      (master/slave PIC constructs, etc.) are now supported by design as well.
      
      The end result of this patchset intends to be simpler architecture-level code
      and more consolidation between architectures.
      
      We reused many bits of code and many concepts from Russell King's ARM IRQ
      layer, the merging of which was one of the motivations for this patchset.
      
      This patch:
      
      rename desc->handler to desc->chip.
      
      Originally i did not want to do this, because it's a big patch.  But having
      both "desc->handler", "desc->handle_irq" and "action->handler" caused a
      large degree of confusion and made the code appear alot less clean than it
      truly is.
      
      I have also attempted a dual approach as well by introducing a
      desc->chip alias - but that just wasnt robust enough and broke
      frequently.
      
      So lets get over with this quickly.  The conversion was done automatically
      via scripts and converts all the code in the kernel.
      
      This renaming patch is the first one amongst the patches, so that the
      remaining patches can stay flexible and can be merged and split up
      without having some big monolithic patch act as a merge barrier.
      
      [akpm@osdl.org: build fix]
      [akpm@osdl.org: another build fix]
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      d1bef4ed
  15. 28 Jun, 2006 1 commit
  16. 27 Jun, 2006 1 commit
  17. 25 Jun, 2006 1 commit
  18. 23 Jun, 2006 2 commits
    • Laurent MEYER's avatar
      [PATCH] fix incorrect SA_ONSTACK behaviour for 64-bit processes · d09042da
      Laurent MEYER authored
      - When setting a sighandler using sigaction() call, if the flag
        SA_ONSTACK is set and no alternate stack is provided via sigaltstack(),
        the kernel still try to install the alternate stack.  This behavior is
        the opposite of the one which is documented in Single Unix Specifications
        V3.
      
      - Also when setting an alternate stack using sigaltstack() with the flag
        SS_DISABLE, the kernel try to install the alternate stack on signal
        delivery.
      
      These two use cases makes the process crash at signal delivery.
      Signed-off-by: default avatarLaurent Meyer <meyerlau@fr.ibm.com>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Roman Zippel <zippel@linux-m68k.org>
      Cc: Kyle McMartin <kyle@mcmartin.ca>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
      Cc: Chris Zankel <chris@zankel.net>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      d09042da
    • Jesper Juhl's avatar
      [PATCH] xtensa: remove verify_area macros · b9e122c8
      Jesper Juhl authored
      verify_area() is still alive on xtensa in 2.6.17-rc3-git13 It would be nice
      to finally be rid of that function across the board.
      Signed-off-by: default avatarChris Zankel <chris@zankel.net>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      b9e122c8
  19. 22 Jun, 2006 1 commit
    • Richard Purdie's avatar
      [PATCH] zlib_inflate: Upgrade library code to a recent version · 4f3865fb
      Richard Purdie authored
      Upgrade the zlib_inflate implementation in the kernel from a patched
      version 1.1.3/4 to a patched 1.2.3.
      
      The code in the kernel is about seven years old and I noticed that the
      external zlib library's inflate performance was significantly faster (~50%)
      than the code in the kernel on ARM (and faster again on x86_32).
      
      For comparison the newer deflate code is 20% slower on ARM and 50% slower
      on x86_32 but gives an approx 1% compression ratio improvement.  I don't
      consider this to be an improvement for kernel use so have no plans to
      change the zlib_deflate code.
      
      Various changes have been made to the zlib code in the kernel, the most
      significant being the extra functions/flush option used by ppp_deflate.
      This update reimplements the features PPP needs to ensure it continues to
      work.
      
      This code has been tested on ARM under both JFFS2 (with zlib compression
      enabled) and ppp_deflate and on x86_32.  JFFS2 sees an approx.  10% real
      world file read speed improvement.
      
      This patch also removes ZLIB_VERSION as it no longer has a correct value.
      We don't need version checks anyway as the kernel's module handling will
      take care of that for us.  This removal is also more in keeping with the
      zlib author's wishes (http://www.zlib.net/zlib_faq.html#faq24) and I've
      added something to the zlib.h header to note its a modified version.
      Signed-off-by: default avatarRichard Purdie <rpurdie@rpsys.net>
      Acked-by: default avatarJoern Engel <joern@wh.fh-wedel.de>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      4f3865fb
  20. 09 Jun, 2006 1 commit
  21. 11 Apr, 2006 1 commit
  22. 31 Mar, 2006 1 commit
  23. 27 Mar, 2006 1 commit
    • Alan Stern's avatar
      [PATCH] Notifier chain update: API changes · e041c683
      Alan Stern authored
      The kernel's implementation of notifier chains is unsafe.  There is no
      protection against entries being added to or removed from a chain while the
      chain is in use.  The issues were discussed in this thread:
      
          http://marc.theaimsgroup.com/?l=linux-kernel&m=113018709002036&w=2
      
      We noticed that notifier chains in the kernel fall into two basic usage
      classes:
      
      	"Blocking" chains are always called from a process context
      	and the callout routines are allowed to sleep;
      
      	"Atomic" chains can be called from an atomic context and
      	the callout routines are not allowed to sleep.
      
      We decided to codify this distinction and make it part of the API.  Therefore
      this set of patches introduces three new, parallel APIs: one for blocking
      notifiers, one for atomic notifiers, and one for "raw" notifiers (which is
      really just the old API under a new name).  New kinds of data structures are
      used for the heads of the chains, and new routines are defined for
      registration, unregistration, and calling a chain.  The three APIs are
      explained in include/linux/notifier.h and their implementation is in
      kernel/sys.c.
      
      With atomic and blocking chains, the implementation guarantees that the chain
      links will not be corrupted and that chain callers will not get messed up by
      entries being added or removed.  For raw chains the implementation provides no
      guarantees at all; users of this API must provide their own protections.  (The
      idea was that situations may come up where the assumptions of the atomic and
      blocking APIs are not appropriate, so it should be possible for users to
      handle these things in their own way.)
      
      There are some limitations, which should not be too hard to live with.  For
      atomic/blocking chains, registration and unregistration must always be done in
      a process context since the chain is protected by a mutex/rwsem.  Also, a
      callout routine for a non-raw chain must not try to register or unregister
      entries on its own chain.  (This did happen in a couple of places and the code
      had to be changed to avoid it.)
      
      Since atomic chains may be called from within an NMI handler, they cannot use
      spinlocks for synchronization.  Instead we use RCU.  The overhead falls almost
      entirely in the unregister routine, which is okay since unregistration is much
      less frequent that calling a chain.
      
      Here is the list of chains that we adjusted and their classifications.  None
      of them use the raw API, so for the moment it is only a placeholder.
      
        ATOMIC CHAINS
        -------------
      arch/i386/kernel/traps.c:		i386die_chain
      arch/ia64/kernel/traps.c:		ia64die_chain
      arch/powerpc/kernel/traps.c:		powerpc_die_chain
      arch/sparc64/kernel/traps.c:		sparc64die_chain
      arch/x86_64/kernel/traps.c:		die_chain
      drivers/char/ipmi/ipmi_si_intf.c:	xaction_notifier_list
      kernel/panic.c:				panic_notifier_list
      kernel/profile.c:			task_free_notifier
      net/bluetooth/hci_core.c:		hci_notifier
      net/ipv4/netfilter/ip_conntrack_core.c:	ip_conntrack_chain
      net/ipv4/netfilter/ip_conntrack_core.c:	ip_conntrack_expect_chain
      net/ipv6/addrconf.c:			inet6addr_chain
      net/netfilter/nf_conntrack_core.c:	nf_conntrack_chain
      net/netfilter/nf_conntrack_core.c:	nf_conntrack_expect_chain
      net/netlink/af_netlink.c:		netlink_chain
      
        BLOCKING CHAINS
        ---------------
      arch/powerpc/platforms/pseries/reconfig.c:	pSeries_reconfig_chain
      arch/s390/kernel/process.c:		idle_chain
      arch/x86_64/kernel/process.c		idle_notifier
      drivers/base/memory.c:			memory_chain
      drivers/cpufreq/cpufreq.c		cpufreq_policy_notifier_list
      drivers/cpufreq/cpufreq.c		cpufreq_transition_notifier_list
      drivers/macintosh/adb.c:		adb_client_list
      drivers/macintosh/via-pmu.c		sleep_notifier_list
      drivers/macintosh/via-pmu68k.c		sleep_notifier_list
      drivers/macintosh/windfarm_core.c	wf_client_list
      drivers/usb/core/notify.c		usb_notifier_list
      drivers/video/fbmem.c			fb_notifier_list
      kernel/cpu.c				cpu_chain
      kernel/module.c				module_notify_list
      kernel/profile.c			munmap_notifier
      kernel/profile.c			task_exit_notifier
      kernel/sys.c				reboot_notifier_list
      net/core/dev.c				netdev_chain
      net/decnet/dn_dev.c:			dnaddr_chain
      net/ipv4/devinet.c:			inetaddr_chain
      
      It's possible that some of these classifications are wrong.  If they are,
      please let us know or submit a patch to fix them.  Note that any chain that
      gets called very frequently should be atomic, because the rwsem read-locking
      used for blocking chains is very likely to incur cache misses on SMP systems.
      (However, if the chain's callout routines may sleep then the chain cannot be
      atomic.)
      
      The patch set was written by Alan Stern and Chandra Seetharaman, incorporating
      material written by Keith Owens and suggestions from Paul McKenney and Andrew
      Morton.
      
      [jes@sgi.com: restructure the notifier chain initialization macros]
      Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
      Signed-off-by: default avatarChandra Seetharaman <sekharan@us.ibm.com>
      Signed-off-by: default avatarJes Sorensen <jes@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      e041c683
  24. 26 Mar, 2006 1 commit
  25. 23 Mar, 2006 2 commits
    • Andrew Morton's avatar
      [PATCH] more for_each_cpu() conversions · 394e3902
      Andrew Morton authored
      When we stop allocating percpu memory for not-possible CPUs we must not touch
      the percpu data for not-possible CPUs at all.  The correct way of doing this
      is to test cpu_possible() or to use for_each_cpu().
      
      This patch is a kernel-wide sweep of all instances of NR_CPUS.  I found very
      few instances of this bug, if any.  But the patch converts lots of open-coded
      test to use the preferred helper macros.
      
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: David Howells <dhowells@redhat.com>
      Acked-by: default avatarKyle McMartin <kyle@parisc-linux.org>
      Cc: Anton Blanchard <anton@samba.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: William Lee Irwin III <wli@holomorphy.com>
      Cc: Andi Kleen <ak@muc.de>
      Cc: Christian Zankel <chris@zankel.net>
      Cc: Philippe Elie <phil.el@wanadoo.fr>
      Cc: Nathan Scott <nathans@sgi.com>
      Cc: Jens Axboe <axboe@suse.de>
      Cc: Eric Dumazet <dada1@cosmosbay.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      394e3902
    • Adrian Bunk's avatar
      [PATCH] kill _INLINE_ · 41c28ff1
      Adrian Bunk authored
      This patch removes all occurances of _INLINE_ in the kernel.
      
      With the exception of tty_flip.h, I've simply removed the inline's since
      gcc should know best which functions to be inlined.
      Signed-off-by: Adrian Bunk's avatarAdrian Bunk <bunk@stusta.de>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      41c28ff1
  26. 22 Mar, 2006 3 commits
  27. 10 Mar, 2006 1 commit
  28. 07 Mar, 2006 1 commit
  29. 03 Feb, 2006 1 commit
  30. 12 Jan, 2006 1 commit