1. 17 4月, 2013 1 次提交
  2. 08 4月, 2013 1 次提交
  3. 13 3月, 2013 1 次提交
  4. 04 3月, 2013 1 次提交
  5. 03 3月, 2013 1 次提交
    • J
      Add HAVE_64BIT_ALIGNED_ACCESS · c19fa94a
      James Hogan 提交于
      On 64 bit architectures with no efficient unaligned access, padding and
      explicit alignment must be added in various places to prevent unaligned
      64bit accesses (such as taskstats and trace ring buffer).
      
      However this also needs to apply to 32 bit architectures with 64 bit
      accesses requiring alignment such as metag.
      
      This is solved by adding a new Kconfig symbol HAVE_64BIT_ALIGNED_ACCESS
      which defaults to 64BIT && !HAVE_EFFICIENT_UNALIGNED_ACCESS, and can be
      explicitly selected by METAG and any other relevant architectures. This
      can be used in various places to determine whether 64bit alignment is
      required.
      Signed-off-by: NJames Hogan <james.hogan@imgtec.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Eric Paris <eparis@redhat.com>
      Cc: Will Drewry <wad@chromium.org>
      c19fa94a
  6. 28 2月, 2013 1 次提交
  7. 14 2月, 2013 1 次提交
    • A
      burying unused conditionals · d64008a8
      Al Viro 提交于
      __ARCH_WANT_SYS_RT_SIGACTION,
      __ARCH_WANT_SYS_RT_SIGSUSPEND,
      __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND,
      __ARCH_WANT_COMPAT_SYS_SCHED_RR_GET_INTERVAL - not used anymore
      CONFIG_GENERIC_{SIGALTSTACK,COMPAT_RT_SIG{ACTION,QUEUEINFO,PENDING,PROCMASK}} -
      can be assumed always set.
      d64008a8
  8. 04 2月, 2013 7 次提交
  9. 22 1月, 2013 1 次提交
  10. 20 12月, 2012 2 次提交
  11. 18 12月, 2012 1 次提交
  12. 06 12月, 2012 1 次提交
    • D
      byteorder: allow arch to opt to use GCC intrinsics for byteswapping · cf66bb93
      David Woodhouse 提交于
      Since GCC 4.4, there have been __builtin_bswap32() and __builtin_bswap16()
      intrinsics. A __builtin_bswap16() came a little later (4.6 for PowerPC,
      48 for other platforms).
      
      By using these instead of the inline assembler that most architectures
      have in their __arch_swabXX() macros, we let the compiler see what's
      actually happening. The resulting code should be at least as good, and
      much *better* in the cases where it can be combined with a nearby load
      or store, using a load-and-byteswap or store-and-byteswap instruction
      (e.g. lwbrx/stwbrx on PowerPC, movbe on Atom).
      
      When GCC is sufficiently recent *and* the architecture opts in to using
      the intrinsics by setting CONFIG_ARCH_USE_BUILTIN_BSWAP, they will be
      used in preference to the __arch_swabXX() macros. An architecture which
      does not set ARCH_USE_BUILTIN_BSWAP will continue to use its own
      hand-crafted macros.
      Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
      Acked-by: NH. Peter Anvin <hpa@linux.intel.com>
      cf66bb93
  13. 01 12月, 2012 1 次提交
    • F
      context_tracking: New context tracking susbsystem · 91d1aa43
      Frederic Weisbecker 提交于
      Create a new subsystem that probes on kernel boundaries
      to keep track of the transitions between level contexts
      with two basic initial contexts: user or kernel.
      
      This is an abstraction of some RCU code that use such tracking
      to implement its userspace extended quiescent state.
      
      We need to pull this up from RCU into this new level of indirection
      because this tracking is also going to be used to implement an "on
      demand" generic virtual cputime accounting. A necessary step to
      shutdown the tick while still accounting the cputime.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Li Zhong <zhong@linux.vnet.ibm.com>
      Cc: Gilad Ben-Yossef <gilad@benyossef.com>
      Reviewed-by: NSteven Rostedt <rostedt@goodmis.org>
      [ paulmck: fix whitespace error and email address. ]
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      91d1aa43
  14. 29 11月, 2012 1 次提交
    • A
      generic sys_fork / sys_vfork / sys_clone · d2125043
      Al Viro 提交于
      ... and get rid of idiotic struct pt_regs * in asm-generic/syscalls.h
      prototypes of the same, while we are at it.  Eventually we want those
      in linux/syscalls.h, of course, but that'll have to wait a bit.
      
      Note that there are *three* variants of sys_clone() order of arguments.
      Braindamage galore...
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      d2125043
  15. 13 10月, 2012 1 次提交
    • A
      infrastructure for saner ret_from_kernel_thread semantics · a74fb73c
      Al Viro 提交于
      * allow kernel_execve() leave the actual return to userland to
      caller (selected by CONFIG_GENERIC_KERNEL_EXECVE).  Callers
      updated accordingly.
      * architecture that does select GENERIC_KERNEL_EXECVE in its
      Kconfig should have its ret_from_kernel_thread() do this:
      	call schedule_tail
      	call the callback left for it by copy_thread(); if it ever
      returns, that's because it has just done successful kernel_execve()
      	jump to return from syscall
      IOW, its only difference from ret_from_fork() is that it does call the
      callback.
      * such an architecture should also get rid of ret_from_kernel_execve()
      and __ARCH_WANT_KERNEL_EXECVE
      
      This is the last part of infrastructure patches in that area - from
      that point on work on different architectures can live independently.
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      a74fb73c
  16. 09 10月, 2012 1 次提交
    • G
      thp, x86: introduce HAVE_ARCH_TRANSPARENT_HUGEPAGE · 15626062
      Gerald Schaefer 提交于
      Cleanup patch in preparation for transparent hugepage support on s390.
      Adding new architectures to the TRANSPARENT_HUGEPAGE config option can
      make the "depends" line rather ugly, like "depends on (X86 || (S390 &&
      64BIT)) && MMU".
      
      This patch adds a HAVE_ARCH_TRANSPARENT_HUGEPAGE instead.  x86 already has
      MMU "def_bool y", so the MMU check is superfluous there and
      HAVE_ARCH_TRANSPARENT_HUGEPAGE can be selected in arch/x86/Kconfig.
      Signed-off-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Hillf Danton <dhillf@gmail.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      15626062
  17. 01 10月, 2012 1 次提交
    • A
      preparation for generic kernel_thread() · 2aa3a7f8
      Al Viro 提交于
      Let architectures select GENERIC_KERNEL_THREAD and have their copy_thread()
      treat NULL regs as "it came from kernel_thread(), sp argument contains
      the function new thread will be calling and stack_size - the argument for
      that function".  Switching the architectures begins shortly...
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      2aa3a7f8
  18. 28 9月, 2012 1 次提交
    • D
      Make most arch asm/module.h files use asm-generic/module.h · 786d35d4
      David Howells 提交于
      Use the mapping of Elf_[SPE]hdr, Elf_Addr, Elf_Sym, Elf_Dyn, Elf_Rel/Rela,
      ELF_R_TYPE() and ELF_R_SYM() to either the 32-bit version or the 64-bit version
      into asm-generic/module.h for all arches bar MIPS.
      
      Also, use the generic definition mod_arch_specific where possible.
      
      To this end, I've defined three new config bools:
      
       (*) HAVE_MOD_ARCH_SPECIFIC
      
           Arches define this if they don't want to use the empty generic
           mod_arch_specific struct.
      
       (*) MODULES_USE_ELF_RELA
      
           Arches define this if their modules can contain RELA records.  This causes
           the Elf_Rela mapping to be emitted and allows apply_relocate_add() to be
           defined by the arch rather than have the core emit an error message.
      
       (*) MODULES_USE_ELF_REL
      
           Arches define this if their modules can contain REL records.  This causes
           the Elf_Rel mapping to be emitted and allows apply_relocate() to be
           defined by the arch rather than have the core emit an error message.
      
      Note that it is possible to allow both REL and RELA records: m68k and mips are
      two arches that do this.
      
      With this, some arch asm/module.h files can be deleted entirely and replaced
      with a generic-y marker in the arch Kbuild file.
      
      Additionally, I have removed the bits from m32r and score that handle the
      unsupported type of relocation record as that's now handled centrally.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Acked-by: NSam Ravnborg <sam@ravnborg.org>
      Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
      786d35d4
  19. 26 9月, 2012 1 次提交
    • F
      rcu: Settle config for userspace extended quiescent state · 2b1d5024
      Frederic Weisbecker 提交于
      Create a new config option under the RCU menu that put
      CPUs under RCU extended quiescent state (as in dynticks
      idle mode) when they run in userspace. This require
      some contribution from architectures to hook into kernel
      and userspace boundaries.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Alessio Igor Bogani <abogani@kernel.org>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Avi Kivity <avi@redhat.com>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Geoff Levand <geoff@infradead.org>
      Cc: Gilad Ben Yossef <gilad@benyossef.com>
      Cc: Hakan Akkan <hakanakkan@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Josh Triplett <josh@joshtriplett.org>
      Cc: Kevin Hilman <khilman@ti.com>
      Cc: Max Krasnyansky <maxk@qualcomm.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephen Hemminger <shemminger@vyatta.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
      2b1d5024
  20. 25 9月, 2012 1 次提交
    • F
      cputime: Make finegrained irqtime accounting generally available · fdf9c356
      Frederic Weisbecker 提交于
      There is no known reason for this option to be unavailable on other
      archs than x86. They just need to call enable_sched_clock_irqtime()
      if they have a sufficiently finegrained clock to make it working.
      
      Move it to the general option and let the user choose between
      it and pure tick based or virtual cputime accounting.
      
      Note that virtual cputime accounting already performs a finegrained
      irqtime accounting. CONFIG_IRQ_TIME_ACCOUNTING is a kind of middle ground
      between tick and virtual based accounting. So CONFIG_IRQ_TIME_ACCOUNTING
      and CONFIG_VIRT_CPU_ACCOUNTING are mutually exclusive choices.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      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: Ingo Molnar <mingo@kernel.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      fdf9c356
  21. 17 8月, 2012 1 次提交
    • F
      cputime: Generalize CONFIG_VIRT_CPU_ACCOUNTING · b952741c
      Frederic Weisbecker 提交于
      S390, ia64 and powerpc all define their own version
      of CONFIG_VIRT_CPU_ACCOUNTING. Generalize the config
      and its description to a single place to avoid
      duplication.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      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: Ingo Molnar <mingo@kernel.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      b952741c
  22. 10 8月, 2012 2 次提交
    • J
      perf: Add ability to attach user stack dump to sample · c5ebcedb
      Jiri Olsa 提交于
      Introducing PERF_SAMPLE_STACK_USER sample type bit to trigger the dump
      of the user level stack on sample. The size of the dump is specified by
      sample_stack_user value.
      
      Being able to dump parts of the user stack, starting from the stack
      pointer, will be useful to make a post mortem dwarf CFI based stack
      unwinding.
      
      Added HAVE_PERF_USER_STACK_DUMP config option to determine if the
      architecture provides user stack dump on perf event samples.  This needs
      access to the user stack pointer which is not unified across
      architectures. Enabling this for x86 architecture.
      Signed-off-by: NJiri Olsa <jolsa@redhat.com>
      Original-patch-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: "Frank Ch. Eigler" <fche@redhat.com>
      Cc: Arun Sharma <asharma@fb.com>
      Cc: Benjamin Redelings <benjamin.redelings@nescent.org>
      Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
      Cc: Cyrill Gorcunov <gorcunov@openvz.org>
      Cc: Frank Ch. Eigler <fche@redhat.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Robert Richter <robert.richter@amd.com>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Tom Zanussi <tzanussi@gmail.com>
      Cc: Ulrich Drepper <drepper@gmail.com>
      Link: http://lkml.kernel.org/r/1344345647-11536-6-git-send-email-jolsa@redhat.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      c5ebcedb
    • J
      perf: Unified API to record selective sets of arch registers · c5e63197
      Jiri Olsa 提交于
      This brings a new API to help the selective dump of registers on event
      sampling, and its implementation for x86 arch.
      
      Added HAVE_PERF_REGS config option to determine if the architecture
      provides perf registers ABI.
      
      The information about desired registers will be passed in u64 mask.
      It's up to the architecture to map the registers into the mask bits.
      
      For the x86 arch implementation, both 32 and 64 bit registers bits are
      defined within single enum to ensure 64 bit system can provide register
      dump for compat task if needed in the future.
      Original-patch-by: NFrederic Weisbecker <fweisbec@gmail.com>
      [ Added missing linux/errno.h include ]
      Signed-off-by: NJiri Olsa <jolsa@redhat.com>
      Cc: "Frank Ch. Eigler" <fche@redhat.com>
      Cc: Arun Sharma <asharma@fb.com>
      Cc: Benjamin Redelings <benjamin.redelings@nescent.org>
      Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
      Cc: Cyrill Gorcunov <gorcunov@openvz.org>
      Cc: Frank Ch. Eigler <fche@redhat.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Robert Richter <robert.richter@amd.com>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Tom Zanussi <tzanussi@gmail.com>
      Cc: Ulrich Drepper <drepper@gmail.com>
      Link: http://lkml.kernel.org/r/1344345647-11536-2-git-send-email-jolsa@redhat.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      c5e63197
  23. 31 7月, 2012 1 次提交
  24. 21 5月, 2012 1 次提交
  25. 08 5月, 2012 2 次提交
  26. 07 5月, 2012 1 次提交
    • S
      tracing: Provide trace events interface for uprobes · f3f096cf
      Srikar Dronamraju 提交于
      Implements trace_event support for uprobes. In its current form
      it can be used to put probes at a specified offset in a file and
      dump the required registers when the code flow reaches the
      probed address.
      
      The following example shows how to dump the instruction pointer
      and %ax a register at the probed text address.  Here we are
      trying to probe zfree in /bin/zsh:
      
       # cd /sys/kernel/debug/tracing/
       # cat /proc/`pgrep  zsh`/maps | grep /bin/zsh | grep r-xp
       00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh
       # objdump -T /bin/zsh | grep -w zfree
       0000000000446420 g    DF .text  0000000000000012  Base
       zfree # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events
       # cat uprobe_events
       p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420
       # echo 1 > events/uprobes/enable
       # sleep 20
       # echo 0 > events/uprobes/enable
       # cat trace
       # tracer: nop
       #
       #           TASK-PID    CPU#    TIMESTAMP  FUNCTION
       #              | |       |          |         |
                    zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79
                    zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79
                    zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79
                    zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79
      Signed-off-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>
      Acked-by: NSteven Rostedt <rostedt@goodmis.org>
      Acked-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
      Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com>
      Cc: Linux-mm <linux-mm@kvack.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: Christoph Hellwig <hch@infradead.org>
      Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
      Cc: Anton Arapov <anton@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/20120411103043.GB29437@linux.vnet.ibm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      f3f096cf
  27. 05 5月, 2012 2 次提交
    • T
      init_task: Replace CONFIG_HAVE_GENERIC_INIT_TASK · a6359d1e
      Thomas Gleixner 提交于
      Now that all archs except ia64 are converted, replace the config and
      let the ia64 select CONFIG_ARCH_INIT_TASK
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/20120503085035.867948914@linutronix.de
      a6359d1e
    • T
      init_task: Create generic init_task instance · a4a2eb49
      Thomas Gleixner 提交于
      All archs define init_task in the same way (except ia64, but there is
      no particular reason why ia64 cannot use the common version). Create a
      generic instance so all archs can be converted over.
      
      The config switch is temporary and will be removed when all archs are
      converted over.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Chen Liqin <liqin.chen@sunplusct.com>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: David Howells <dhowells@redhat.com>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
      Cc: Hirokazu Takata <takata@linux-m32r.org>
      Cc: James E.J. Bottomley <jejb@parisc-linux.org>
      Cc: Jesper Nilsson <jesper.nilsson@axis.com>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Mark Salter <msalter@redhat.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Matt Turner <mattst88@gmail.com>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Mike Frysinger <vapier@gentoo.org>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Richard Kuo <rkuo@codeaurora.org>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Link: http://lkml.kernel.org/r/20120503085034.092585287@linutronix.de
      a4a2eb49
  28. 26 4月, 2012 1 次提交
    • T
      smp: Provide generic idle thread allocation · 29d5e047
      Thomas Gleixner 提交于
      All SMP architectures have magic to fork the idle task and to store it
      for reusage when cpu hotplug is enabled. Provide a generic
      infrastructure for it.
      
      Create/reinit the idle thread for the cpu which is brought up in the
      generic code and hand the thread pointer to the architecture code via
      __cpu_up().
      
      Note, that fork_idle() is called via a workqueue, because this
      guarantees that the idle thread does not get a reference to a user
      space VM. This can happen when the boot process did not bring up all
      possible cpus and a later cpu_up() is initiated via the sysfs
      interface. In that case fork_idle() would be called in the context of
      the user space task and take a reference on the user space VM.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
      Cc: Matt Turner <mattst88@gmail.com>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Mike Frysinger <vapier@gentoo.org>
      Cc: Jesper Nilsson <jesper.nilsson@axis.com>
      Cc: Richard Kuo <rkuo@codeaurora.org>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Hirokazu Takata <takata@linux-m32r.org>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: David Howells <dhowells@redhat.com>
      Cc: James E.J. Bottomley <jejb@parisc-linux.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: x86@kernel.org
      Acked-by: NVenkatesh Pallipadi <venki@google.com>
      Link: http://lkml.kernel.org/r/20120420124557.102478630@linutronix.de
      29d5e047
  29. 14 4月, 2012 2 次提交
    • W
      ptrace,seccomp: Add PTRACE_SECCOMP support · fb0fadf9
      Will Drewry 提交于
      This change adds support for a new ptrace option, PTRACE_O_TRACESECCOMP,
      and a new return value for seccomp BPF programs, SECCOMP_RET_TRACE.
      
      When a tracer specifies the PTRACE_O_TRACESECCOMP ptrace option, the
      tracer will be notified, via PTRACE_EVENT_SECCOMP, for any syscall that
      results in a BPF program returning SECCOMP_RET_TRACE.  The 16-bit
      SECCOMP_RET_DATA mask of the BPF program return value will be passed as
      the ptrace_message and may be retrieved using PTRACE_GETEVENTMSG.
      
      If the subordinate process is not using seccomp filter, then no
      system call notifications will occur even if the option is specified.
      
      If there is no tracer with PTRACE_O_TRACESECCOMP when SECCOMP_RET_TRACE
      is returned, the system call will not be executed and an -ENOSYS errno
      will be returned to userspace.
      
      This change adds a dependency on the system call slow path.  Any future
      efforts to use the system call fast path for seccomp filter will need to
      address this restriction.
      Signed-off-by: NWill Drewry <wad@chromium.org>
      Acked-by: NEric Paris <eparis@redhat.com>
      
      v18: - rebase
           - comment fatal_signal check
           - acked-by
           - drop secure_computing_int comment
      v17: - ...
      v16: - update PT_TRACE_MASK to 0xbf4 so that STOP isn't clear on SETOPTIONS call (indan@nul.nu)
             [note PT_TRACE_MASK disappears in linux-next]
      v15: - add audit support for non-zero return codes
           - clean up style (indan@nul.nu)
      v14: - rebase/nochanges
      v13: - rebase on to 88ebdda6
             (Brings back a change to ptrace.c and the masks.)
      v12: - rebase to linux-next
           - use ptrace_event and update arch/Kconfig to mention slow-path dependency
           - drop all tracehook changes and inclusion (oleg@redhat.com)
      v11: - invert the logic to just make it a PTRACE_SYSCALL accelerator
             (indan@nul.nu)
      v10: - moved to PTRACE_O_SECCOMP / PT_TRACE_SECCOMP
      v9:  - n/a
      v8:  - guarded PTRACE_SECCOMP use with an ifdef
      v7:  - introduced
      Signed-off-by: NJames Morris <james.l.morris@oracle.com>
      fb0fadf9
    • W
      seccomp: Add SECCOMP_RET_TRAP · bb6ea430
      Will Drewry 提交于
      Adds a new return value to seccomp filters that triggers a SIGSYS to be
      delivered with the new SYS_SECCOMP si_code.
      
      This allows in-process system call emulation, including just specifying
      an errno or cleanly dumping core, rather than just dying.
      Suggested-by: NMarkus Gutschke <markus@chromium.org>
      Suggested-by: NJulien Tinnes <jln@chromium.org>
      Signed-off-by: NWill Drewry <wad@chromium.org>
      Acked-by: NEric Paris <eparis@redhat.com>
      
      v18: - acked-by, rebase
           - don't mention secure_computing_int() anymore
      v15: - use audit_seccomp/skip
           - pad out error spacing; clean up switch (indan@nul.nu)
      v14: - n/a
      v13: - rebase on to 88ebdda6
      v12: - rebase on to linux-next
      v11: - clarify the comment (indan@nul.nu)
           - s/sigtrap/sigsys
      v10: - use SIGSYS, syscall_get_arch, updates arch/Kconfig
             note suggested-by (though original suggestion had other behaviors)
      v9:  - changes to SIGILL
      v8:  - clean up based on changes to dependent patches
      v7:  - introduction
      Signed-off-by: NJames Morris <james.l.morris@oracle.com>
      bb6ea430