1. 07 Apr, 2014 40 commits
    • Mark Salter's avatar
      arm64: add early_ioremap support · bf4b558e
      Mark Salter authored
      
      
      Add support for early IO or memory mappings which are needed before the
      normal ioremap() is usable.  This also adds fixmap support for permanent
      fixed mappings such as that used by the earlyprintk device register
      region.
      Signed-off-by: default avatarMark Salter <msalter@redhat.com>
      Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      Cc: Borislav Petkov <borislav.petkov@amd.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      bf4b558e
    • Mark Salter's avatar
      arm64: initialize pgprot info earlier in boot · 0bf757c7
      Mark Salter authored
      
      
      Presently, paging_init() calls init_mem_pgprot() to initialize pgprot
      values used by macros such as PAGE_KERNEL, PAGE_KERNEL_EXEC, etc.
      
      The new fixmap and early_ioremap support also needs to use these macros
      before paging_init() is called.  This patch moves the init_mem_pgprot()
      call out of paging_init() and into setup_arch() so that pgprot_default
      gets initialized in time for fixmap and early_ioremap.
      Signed-off-by: default avatarMark Salter <msalter@redhat.com>
      Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Borislav Petkov <borislav.petkov@amd.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      0bf757c7
    • Mark Salter's avatar
      x86: use generic early_ioremap · 5b7c73e0
      Mark Salter authored
      
      
      Move x86 over to the generic early ioremap implementation.
      Signed-off-by: default avatarMark Salter <msalter@redhat.com>
      Acked-by: default avatarH. Peter Anvin <hpa@zytor.com>
      Cc: Borislav Petkov <borislav.petkov@amd.com>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5b7c73e0
    • Mark Salter's avatar
      mm: create generic early_ioremap() support · 9e5c33d7
      Mark Salter authored
      
      
      This patch creates a generic implementation of early_ioremap() support
      based on the existing x86 implementation.  early_ioremp() is useful for
      early boot code which needs to temporarily map I/O or memory regions
      before normal mapping functions such as ioremap() are available.
      
      Some architectures have optional MMU.  In the no-MMU case, the remap
      functions simply return the passed in physical address and the unmap
      functions do nothing.
      Signed-off-by: default avatarMark Salter <msalter@redhat.com>
      Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      Acked-by: default avatarH. Peter Anvin <hpa@zytor.com>
      Cc: Borislav Petkov <borislav.petkov@amd.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9e5c33d7
    • Dave Young's avatar
      x86/mm: sparse warning fix for early_memremap · 6b550f6f
      Dave Young authored
      
      
      This patch series takes the common bits from the x86 early ioremap
      implementation and creates a generic implementation which may be used by
      other architectures.  The early ioremap interfaces are intended for
      situations where boot code needs to make temporary virtual mappings
      before the normal ioremap interfaces are available.  Typically, this
      means before paging_init() has run.
      
      This patch (of 6):
      
      There's a lot of sparse warnings for code like below: void *a =
      early_memremap(phys_addr, size);
      
      early_memremap intend to map kernel memory with ioremap facility, the
      return pointer should be a kernel ram pointer instead of iomem one.
      
      For making the function clearer and supressing sparse warnings this patch
      do below two things:
      1. cast to (__force void *) for the return value of early_memremap
      2. add early_memunmap function and pass (__force void __iomem *) to iounmap
      
      From Boris:
        "Ingo told me yesterday, it makes sense too.  I'd guess we can try it.
         FWIW, all callers of early_memremap use the memory they get remapped
         as normal memory so we should be safe"
      Signed-off-by: default avatarDave Young <dyoung@redhat.com>
      Signed-off-by: default avatarMark Salter <msalter@redhat.com>
      Acked-by: default avatarH. Peter Anvin <hpa@zytor.com>
      Cc: Borislav Petkov <borislav.petkov@amd.com>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      6b550f6f
    • Josh Triplett's avatar
      lglock: map to spinlock when !CONFIG_SMP · 64b47e8f
      Josh Triplett authored
      
      
      When the system has only one CPU, lglock is effectively a spinlock; map
      it directly to spinlock to eliminate the indirection and duplicate code.
      
      In addition to removing overhead, this drops 1.6k of code with a
      defconfig modified to have !CONFIG_SMP, and 1.1k with a minimal config.
      Signed-off-by: default avatarJosh Triplett <josh@joshtriplett.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Michal Marek <mmarek@suse.cz>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: David Howells <dhowells@redhat.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Nick Piggin <npiggin@kernel.dk>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      64b47e8f
    • Christoph Lameter's avatar
      percpu: add preemption checks to __this_cpu ops · 188a8140
      Christoph Lameter authored
      
      
      We define a check function in order to avoid trouble with the include
      files.  Then the higher level __this_cpu macros are modified to invoke
      the preemption check.
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: default avatarChristoph Lameter <cl@linux.com>
      Acked-by: default avatarIngo Molnar <mingo@kernel.org>
      Cc: Tejun Heo <tj@kernel.org>
      Tested-by: default avatarGrygorii Strashko <grygorii.strashko@ti.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      188a8140
    • Christoph Lameter's avatar
      vmstat: use raw_cpu_ops to avoid false positives on preemption checks · 293b6a4c
      Christoph Lameter authored
      
      
      vm counters are allowed to be racy.  Use raw_cpu_ops to avoid the
      local_irq_disable overhead and to avoid preemption checks which will be
      added to the __this_cpu operations.
      
      [akpm@linux-foundation.org: Add comment.  Again.]
      Signed-off-by: default avatarChristoph Lameter <cl@linux.com>
      Reported-by: default avatarSergey Senozhatsky <sergey.senozhatsky@gmail.com>
      Cc: Dave Chinner <dchinner@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      293b6a4c
    • Christoph Lameter's avatar
      slub: use raw_cpu_inc for incrementing statistics · 88da03a6
      Christoph Lameter authored
      
      
      Statistics are not critical to the operation of the allocation but
      should also not cause too much overhead.
      
      When __this_cpu_inc is altered to check if preemption is disabled this
      triggers.  Use raw_cpu_inc to avoid the checks.  Using this_cpu_ops may
      cause interrupt disable/enable sequences on various arches which may
      significantly impact allocator performance.
      
      [akpm@linux-foundation.org: add comment]
      Signed-off-by: default avatarChristoph Lameter <cl@linux.com>
      Cc: Fengguang Wu <fengguang.wu@intel.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      88da03a6
    • Christoph Lameter's avatar
      net: replace __this_cpu_inc in route.c with raw_cpu_inc · 3ed66e91
      Christoph Lameter authored
      The RT_CACHE_STAT_INC macro triggers the new preemption checks
      for __this_cpu ops.
      
      I do not see any other synchronization that would allow the use of a
      __this_cpu operation here however in commit dbd2915c ("[IPV4]:
      RT_CACHE_STAT_INC() warning fix") Andrew justifies the use of
      raw_smp_processor_id() here because "we do not care" about races.  In
      the past we agreed that the price of disabling interrupts here to get
      consistent counters would be too high.  These counters may be inaccurate
      due to race conditions.
      
      The use of __this_cpu op improves the situation already from what commit
      dbd2915c
      
       did since the single instruction emitted on x86 does not
      allow the race to occur anymore.  However, non x86 platforms could still
      experience a race here.
      
      Trace:
      
        __this_cpu_add operation in preemptible [00000000] code: avahi-daemon/1193
        caller is __this_cpu_preempt_check+0x38/0x60
        CPU: 1 PID: 1193 Comm: avahi-daemon Tainted: GF            3.12.0-rc4+ #187
        Call Trace:
          check_preemption_disabled+0xec/0x110
          __this_cpu_preempt_check+0x38/0x60
          __ip_route_output_key+0x575/0x8c0
          ip_route_output_flow+0x27/0x70
          udp_sendmsg+0x825/0xa20
          inet_sendmsg+0x85/0xc0
          sock_sendmsg+0x9c/0xd0
          ___sys_sendmsg+0x37c/0x390
          __sys_sendmsg+0x49/0x90
          SyS_sendmsg+0x12/0x20
          tracesys+0xe1/0xe6
      Signed-off-by: default avatarChristoph Lameter <cl@linux.com>
      Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
      Acked-by: default avatarIngo Molnar <mingo@kernel.org>
      Cc: Eric Dumazet <edumazet@google.com>
      Cc: Tejun Heo <tj@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      3ed66e91
    • Christoph Lameter's avatar
      modules: use raw_cpu_write for initialization of per cpu refcount. · 08f141d3
      Christoph Lameter authored
      
      
      The initialization of a structure is not subject to synchronization.
      The use of __this_cpu would trigger a false positive with the additional
      preemption checks for __this_cpu ops.
      
      So simply disable the check through the use of raw_cpu ops.
      
      Trace:
      
        __this_cpu_write operation in preemptible [00000000] code: modprobe/286
        caller is __this_cpu_preempt_check+0x38/0x60
        CPU: 3 PID: 286 Comm: modprobe Tainted: GF            3.12.0-rc4+ #187
        Call Trace:
          dump_stack+0x4e/0x82
          check_preemption_disabled+0xec/0x110
          __this_cpu_preempt_check+0x38/0x60
          load_module+0xcfd/0x2650
          SyS_init_module+0xa6/0xd0
          tracesys+0xe1/0xe6
      Signed-off-by: default avatarChristoph Lameter <cl@linux.com>
      Acked-by: default avatarIngo Molnar <mingo@kernel.org>
      Acked-by: default avatarRusty Russell <rusty@rustcorp.com.au>
      Cc: Tejun Heo <tj@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      08f141d3
    • Christoph Lameter's avatar
      mm: use raw_cpu ops for determining current NUMA node · dc322a99
      Christoph Lameter authored
      With the preempt checking logic for __this_cpu_ops we will get false
      positives from locations in the code that use numa_node_id.
      
      Before the __this_cpu ops where introduced there were no checks for
      preemption present either.  smp_raw_processor_id() was used.  See
      
        http://www.spinics.net/lists/linux-numa/msg00641.html
      
      Therefore we need to use raw_cpu_read here to avoid false postives.
      
      Note that this issue has been discussed in prior years.  If the process
      changes nodes after retrieving the current numa node then that is
      acceptable since most uses of numa_node etc are for optimization and not
      for correctness.
      
      There were suggestions to implement a raw_numa_node_id in order to do
      preempt checks for numa_node_id as well.  But I think we better defer
      that to another patch since that would mean investigating how
      numa_node_id() is used throughout the kernel which would increase the
      scope of this patchset significantly.  After all preemption was never
      checked before when numa_node_id() was used.
      
      Some sample traces:
      
      __this_cpu_read operation in preemptible [00000000] code: login/1456
      caller is __this_cpu_preempt_check+0x2b/0x2d
      CPU: 0 PID: 1456 Comm: login Not tainted 3.12.0-rc4-cl-00062-g2fe80d3b-dirty #185
      Call Trace:
        dump_stack+0x4e/0x82
        check_preemption_disabled+0xc5/0xe0
        __this_cpu_preempt_check+0x2b/0x2d
        get_task_policy+0x1d/0x49
        get_vma_policy+0x14/0x76
        alloc_pages_vma+0x35/0xff
        handle_mm_fault+0x290/0x73b
        __do_page_fault+0x3fe/0x44d
        do_page_fault+0x9/0xc
        page_fault+0x22/0x30
        generic_file_aio_read+0x38e/0x624
        do_sync_read+0x54/0x73
        vfs_read+0x9d/0x12a
        SyS_read+0x47/0x7e
        cstar_dispatch+0x7/0x23
      
      caller is __this_cpu_preempt_check+0x2b/0x2d
      CPU: 0 PID: 1456 Comm: login Not tainted 3.12.0-rc4-cl-00062-g2fe80d3b
      
      -dirty #185
      Call Trace:
        dump_stack+0x4e/0x82
        check_preemption_disabled+0xc5/0xe0
        __this_cpu_preempt_check+0x2b/0x2d
        alloc_pages_current+0x8f/0xbc
        __page_cache_alloc+0xb/0xd
        __do_page_cache_readahead+0xf4/0x219
        ra_submit+0x1c/0x20
        ondemand_readahead+0x28c/0x2b4
        page_cache_sync_readahead+0x38/0x3a
        generic_file_aio_read+0x261/0x624
        do_sync_read+0x54/0x73
        vfs_read+0x9d/0x12a
        SyS_read+0x47/0x7e
        cstar_dispatch+0x7/0x23
      Signed-off-by: default avatarChristoph Lameter <cl@linux.com>
      Acked-by: default avatarIngo Molnar <mingo@kernel.org>
      Cc: Alex Shi <alex.shi@intel.com>
      Cc: Tejun Heo <tj@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      dc322a99
    • Christoph Lameter's avatar
      percpu: add raw_cpu_ops · b3ca1c10
      Christoph Lameter authored
      
      
      The kernel has never been audited to ensure that this_cpu operations are
      consistently used throughout the kernel.  The code generated in many
      places can be improved through the use of this_cpu operations (which
      uses a segment register for relocation of per cpu offsets instead of
      performing address calculations).
      
      The patch set also addresses various consistency issues in general with
      the per cpu macros.
      
      A. The semantics of __this_cpu_ptr() differs from this_cpu_ptr only
         because checks are skipped. This is typically shown through a raw_
         prefix. So this patch set changes the places where __this_cpu_ptr()
         is used to raw_cpu_ptr().
      
      B. There has been the long term wish by some that __this_cpu operations
         would check for preemption. However, there are cases where preemption
         checks need to be skipped. This patch set adds raw_cpu operations that
         do not check for preemption and then adds preemption checks to the
         __this_cpu operations.
      
      C. The use of __get_cpu_var is always a reference to a percpu variable
         that can also be handled via a this_cpu operation. This patch set
         replaces all uses of __get_cpu_var with this_cpu operations.
      
      D. We can then use this_cpu RMW operations in various places replacing
         sequences of instructions by a single one.
      
      E. The use of this_cpu operations throughout will allow other arches than
         x86 to implement optimized references and RMV operations to work with
         per cpu local data.
      
      F. The use of this_cpu operations opens up the possibility to
         further optimize code that relies on synchronization through
         per cpu data.
      
      The patch set works in a couple of stages:
      
      I. Patch 1 adds the additional raw_cpu operations and raw_cpu_ptr().
          Also converts the existing __this_cpu_xx_# primitive in the x86
          code to raw_cpu_xx_#.
      
      II. Patch 2-4 use the raw_cpu operations in places that would give
           us false positives once they are enabled.
      
      III. Patch 5 adds preemption checks to __this_cpu operations to allow
          checking if preemption is properly disabled when these functions
          are used.
      
      IV. Patches 6-20 are patches that simply replace uses of __get_cpu_var
         with this_cpu_ptr. They do not depend on any changes to the percpu
         code. No preemption tests are skipped if they are applied.
      
      V. Patches 21-46 are conversion patches that use this_cpu operations
         in various kernel subsystems/drivers or arch code.
      
      VI.  Patches 47/48 (not included in this series) remove no longer used
          functions (__this_cpu_ptr and __get_cpu_var).  These should only be
          applied after all the conversion patches have made it and after we
          have done additional passes through the kernel to ensure that none of
          the uses of these functions remain.
      
      This patch (of 46):
      
      The patches following this one will add preemption checks to __this_cpu
      ops so we need to have an alternative way to use this_cpu operations
      without preemption checks.
      
      raw_cpu_ops will be the basis for all other ops since these will be the
      operations that do not implement any checks.
      
      Primitive operations are renamed by this patch from __this_cpu_xxx to
      raw_cpu_xxxx.
      
      Also change the uses of the x86 percpu primitives in preempt.h.
      These depend directly on asm/percpu.h (header #include nesting issue).
      Signed-off-by: default avatarPeter Zijlstra <peterz@infradead.org>
      Signed-off-by: default avatarChristoph Lameter <cl@linux.com>
      Acked-by: default avatarIngo Molnar <mingo@kernel.org>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
      Cc: Alex Shi <alex.shi@intel.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Bryan Wu <cooloney@gmail.com>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
      Cc: David Daney <david.daney@cavium.com>
      Cc: David Miller <davem@davemloft.net>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Dimitri Sivanich <sivanich@sgi.com>
      Cc: Dipankar Sarma <dipankar@in.ibm.com>
      Cc: Eric Dumazet <edumazet@google.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: H. Peter Anvin <hpa@linux.intel.com>
      Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
      Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
      Cc: Hedi Berriche <hedi@sgi.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Helge Deller <deller@gmx.de>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: James Hogan <james.hogan@imgtec.com>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: John Stultz <john.stultz@linaro.org>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Matt Turner <mattst88@gmail.com>
      Cc: Mike Frysinger <vapier@gentoo.org>
      Cc: Mike Travis <travis@sgi.com>
      Cc: Neil Brown <neilb@suse.de>
      Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Rafael J. Wysocki <rjw@sisk.pl>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Robert Richter <rric@kernel.org>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Russell King <rmk+kernel@arm.linux.org.uk>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Wim Van Sebroeck <wim@iguana.be>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b3ca1c10
    • Dave Jones's avatar
      slub: fix leak of 'name' in sysfs_slab_add · 54b6a731
      Dave Jones authored
      
      
      The failure paths of sysfs_slab_add don't release the allocation of
      'name' made by create_unique_id() a few lines above the context of the
      diff below.  Create a common exit path to make it more obvious what
      needs freeing.
      
      [vdavydov@parallels.com: free the name only if !unmergeable]
      Signed-off-by: default avatarDave Jones <davej@fedoraproject.org>
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      54b6a731
    • Vladimir Davydov's avatar
      slub: rework sysfs layout for memcg caches · 9a41707b
      Vladimir Davydov authored
      
      
      Currently, we try to arrange sysfs entries for memcg caches in the same
      manner as for global caches.  Apart from turning /sys/kernel/slab into a
      mess when there are a lot of kmem-active memcgs created, it actually
      does not work properly - we won't create more than one link to a memcg
      cache in case its parent is merged with another cache.  For instance, if
      A is a root cache merged with another root cache B, we will have the
      following sysfs setup:
      
        X
        A -> X
        B -> X
      
      where X is some unique id (see create_unique_id()).  Now if memcgs M and
      N start to allocate from cache A (or B, which is the same), we will get:
      
        X
        X:M
        X:N
        A -> X
        B -> X
        A:M -> X:M
        A:N -> X:N
      
      Since B is an alias for A, we won't get entries B:M and B:N, which is
      confusing.
      
      It is more logical to have entries for memcg caches under the
      corresponding root cache's sysfs directory.  This would allow us to keep
      sysfs layout clean, and avoid such inconsistencies like one described
      above.
      
      This patch does the trick.  It creates a "cgroup" kset in each root
      cache kobject to keep its children caches there.
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Cc: Glauber Costa <glommer@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9a41707b
    • Vladimir Davydov's avatar
      slub: adjust memcg caches when creating cache alias · 84d0ddd6
      Vladimir Davydov authored
      
      
      Otherwise, kzalloc() called from a memcg won't clear the whole object.
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Cc: Glauber Costa <glommer@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      84d0ddd6
    • Vladimir Davydov's avatar
      memcg, slab: do not destroy children caches if parent has aliases · b8529907
      Vladimir Davydov authored
      
      
      Currently we destroy children caches at the very beginning of
      kmem_cache_destroy().  This is wrong, because the root cache will not
      necessarily be destroyed in the end - if it has aliases (refcount > 0),
      kmem_cache_destroy() will simply decrement its refcount and return.  In
      this case, at best we will get a bunch of warnings in dmesg, like this
      one:
      
        kmem_cache_destroy kmalloc-32:0: Slab cache still has objects
        CPU: 1 PID: 7139 Comm: modprobe Tainted: G    B   W    3.13.0+ #117
        Call Trace:
          dump_stack+0x49/0x5b
          kmem_cache_destroy+0xdf/0xf0
          kmem_cache_destroy_memcg_children+0x97/0xc0
          kmem_cache_destroy+0xf/0xf0
          xfs_mru_cache_uninit+0x21/0x30 [xfs]
          exit_xfs_fs+0x2e/0xc44 [xfs]
          SyS_delete_module+0x198/0x1f0
          system_call_fastpath+0x16/0x1b
      
      At worst - if kmem_cache_destroy() will race with an allocation from a
      memcg cache - the kernel will panic.
      
      This patch fixes this by moving children caches destruction after the
      check if the cache has aliases.  Plus, it forbids destroying a root
      cache if it still has children caches, because each children cache keeps
      a reference to its parent.
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Cc: Glauber Costa <glommer@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b8529907
    • Vladimir Davydov's avatar
      memcg, slab: unregister cache from memcg before starting to destroy it · 051dd460
      Vladimir Davydov authored
      
      
      Currently, memcg_unregister_cache(), which deletes the cache being
      destroyed from the memcg_slab_caches list, is called after
      __kmem_cache_shutdown() (see kmem_cache_destroy()), which starts to
      destroy the cache.
      
      As a result, one can access a partially destroyed cache while traversing
      a memcg_slab_caches list, which can have deadly consequences (for
      instance, cache_show() called for each cache on a memcg_slab_caches list
      from mem_cgroup_slabinfo_read() will dereference pointers to already
      freed data).
      
      To fix this, let's move memcg_unregister_cache() before the cache
      destruction process beginning, issuing memcg_register_cache() on failure.
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Cc: Glauber Costa <glommer@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      051dd460
    • Vladimir Davydov's avatar
      memcg, slab: separate memcg vs root cache creation paths · 794b1248
      Vladimir Davydov authored
      
      
      Memcg-awareness turned kmem_cache_create() into a dirty interweaving of
      memcg-only and except-for-memcg calls.  To clean this up, let's move the
      code responsible for memcg cache creation to a separate function.
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Cc: Glauber Costa <glommer@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      794b1248
    • Vladimir Davydov's avatar
      memcg, slab: cleanup memcg cache creation · 5722d094
      Vladimir Davydov authored
      
      
      This patch cleans up the memcg cache creation path as follows:
      
      - Move memcg cache name creation to a separate function to be called
        from kmem_cache_create_memcg().  This allows us to get rid of the mutex
        protecting the temporary buffer used for the name formatting, because
        the whole cache creation path is protected by the slab_mutex.
      
      - Get rid of memcg_create_kmem_cache().  This function serves as a proxy
        to kmem_cache_create_memcg().  After separating the cache name creation
        path, it would be reduced to a function call, so let's inline it.
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Cc: Glauber Costa <glommer@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5722d094
    • Vladimir Davydov's avatar
      memcg, slab: never try to merge memcg caches · a44cb944
      Vladimir Davydov authored
      
      
      When a kmem cache is created (kmem_cache_create_memcg()), we first try to
      find a compatible cache that already exists and can handle requests from
      the new cache, i.e.  has the same object size, alignment, ctor, etc.  If
      there is such a cache, we do not create any new caches, instead we simply
      increment the refcount of the cache found and return it.
      
      Currently we do this procedure not only when creating root caches, but
      also for memcg caches.  However, there is no point in that, because, as
      every memcg cache has exactly the same parameters as its parent and cache
      merging cannot be turned off in runtime (only on boot by passing
      "slub_nomerge"), the root caches of any two potentially mergeable memcg
      caches should be merged already, i.e.  it must be the same root cache, and
      therefore we couldn't even get to the memcg cache creation, because it
      already exists.
      
      The only exception is boot caches - they are explicitly forbidden to be
      merged by setting their refcount to -1.  There are currently only two of
      them - kmem_cache and kmem_cache_node, which are used in slab internals (I
      do not count kmalloc caches as their refcount is set to 1 immediately
      after creation).  Since they are prevented from merging preliminary I
      guess we should avoid to merge their children too.
      
      So let's remove the useless code responsible for merging memcg caches.
      Signed-off-by: default avatarVladimir Davydov <vdavydov@parallels.com>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Pekka Enberg <penberg@kernel.org>
      Cc: Glauber Costa <glommer@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a44cb944
    • David Howells's avatar
      asm/system.h: um: arch_align_stack() moved to asm/exec.h · cf7bc58f
      David Howells authored
      
      
      arch_align_stack() moved to asm/exec.h, so change the comment referring to
      asm/system.h which no longer exists.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      cf7bc58f
    • David Howells's avatar
      asm/system.h: clean asm/system.h from docs · 95663285
      David Howells authored
      
      
      Clean asm/system.h from docs as nothing should refer to that header anymore.
      Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      95663285
    • Gideon Israel Dsouza's avatar
      kernel: use macros from compiler.h instead of __attribute__((...)) · 52f5684c
      Gideon Israel Dsouza authored
      
      
      To increase compiler portability there is <linux/compiler.h> which
      provides convenience macros for various gcc constructs.  Eg: __weak for
      __attribute__((weak)).  I've replaced all instances of gcc attributes
      with the right macro in the kernel subsystem.
      Signed-off-by: default avatarGideon Israel Dsouza <gidisrael@gmail.com>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Ingo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      52f5684c
    • Uwe Kleine-König's avatar
      Kconfig: rename HAS_IOPORT to HAS_IOPORT_MAP · ce816fa8
      Uwe Kleine-König authored
      
      
      If the renamed symbol is defined lib/iomap.c implements ioport_map and
      ioport_unmap and currently (nearly) all platforms define the port
      accessor functions outb/inb and friend unconditionally.  So
      HAS_IOPORT_MAP is the better name for this.
      
      Consequently NO_IOPORT is renamed to NO_IOPORT_MAP.
      
      The motivation for this change is to reintroduce a symbol HAS_IOPORT
      that signals if outb/int et al are available.  I will address that at
      least one merge window later though to keep surprises to a minimum and
      catch new introductions of (HAS|NO)_IOPORT.
      
      The changes in this commit were done using:
      
      	$ git grep -l -E '(NO|HAS)_IOPORT' | xargs perl -p -i -e 's/\b((?:CONFIG_)?(?:NO|HAS)_IOPORT)\b/$1_MAP/'
      Signed-off-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
      Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ce816fa8
    • Davidlohr Bueso's avatar
      ipc: use device_initcall · 6d08a256
      Davidlohr Bueso authored
      
      
      ... since __initcall is now deprecated.
      Signed-off-by: default avatarDavidlohr Bueso <davidlohr@hp.com>
      Cc: Manfred Spraul <manfred@colorfullife.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      6d08a256
    • Davidlohr Bueso's avatar
      ipc/compat.c: remove sc_semopm macro · 187841a8
      Davidlohr Bueso authored
      This macro appears to have been introduced back in the 2.5 era for
      semtimedop32 backward compatibility on ia32:
      
        https://lkml.org/lkml/2003/4/28/78
      
      
      
      Nowadays, this syscall in compat just defaults back to the code found in
      sem.c, so it is no longer used and can thus be removed:
      
      long compat_sys_semtimedop(int semid, struct sembuf __user *tsems,
      		unsigned nsops, const struct compat_timespec __user *timeout)
      {
      	struct timespec __user *ts64;
      	if (compat_convert_timespec(&ts64, timeout))
      		return -EFAULT;
      	return sys_semtimedop(semid, tsems, nsops, ts64);
      }
      
      Furthermore, there are no users in compat.c.  After this change, kernel
      builds just fine with both CONFIG_SYSVIPC_COMPAT and CONFIG_SYSVIPC.
      Signed-off-by: default avatarDavidlohr Bueso <davidlohr@hp.com>
      Cc: Manfred Spraul <manfred@colorfullife.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      187841a8
    • Daniel M. Weeks's avatar
      initramfs: debug detected compression method · 6aa7a29a
      Daniel M. Weeks authored
      
      
      This can greatly aid in narrowing down the real source of initramfs
      problems such as failures related to the compression of the in-kernel
      initramfs when an external initramfs is in use as well.  Existing errors
      are ambiguous as to which initramfs is a problem and why.
      
      [akpm@linux-foundation.org: use pr_debug()]
      Signed-off-by: default avatarDaniel M. Weeks <dan@danweeks.net>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      6aa7a29a
    • Dave Jones's avatar
      fault-injection: set bounds on what /proc/self/make-it-fail accepts. · 16caed31
      Dave Jones authored
      
      
      /proc/self/make-it-fail is a boolean, but accepts any number, including
      negative ones.  Change variable to unsigned, and cap upper bound at 1.
      
      [akpm@linux-foundation.org: don't make make_it_fail unsigned]
      Signed-off-by: default avatarDave Jones <davej@fedoraproject.org>
      Reviewed-by: default avatarAkinobu Mita <akinobu.mita@gmail.com>
      Cc: David Rientjes <rientjes@google.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      16caed31
    • Josh Triplett's avatar
      x86: always define BUG() and HAVE_ARCH_BUG, even with !CONFIG_BUG · b06dd879
      Josh Triplett authored
      
      
      This ensures that BUG() always has a definition that causes a trap (via
      an undefined instruction), and that the compiler still recognizes the
      code following BUG() as unreachable, avoiding warnings that would
      otherwise appear (such as on non-void functions that don't return a
      value after BUG()).
      
      In addition to saving a few bytes over the generic infinite-loop
      implementation, this implementation traps rather than looping, which
      potentially allows for better error-recovery behavior (such as by
      rebooting).
      Signed-off-by: default avatarJosh Triplett <josh@joshtriplett.org>
      Reported-by: default avatarArnd Bergmann <arnd@arndb.de>
      Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b06dd879
    • Josh Triplett's avatar
      bug: Make BUG() always stop the machine · a4b5d580
      Josh Triplett authored
      
      
      When !CONFIG_BUG and !HAVE_ARCH_BUG, define the generic BUG() as an
      infinite loop rather than a no-op.  This avoids undefined behavior if
      execution ever actually reaches BUG(), and avoids warnings about code
      after BUG() (such as on non-void functions calling BUG() and then not
      returning).
      
      bloat-o-meter results:
      
        add/remove: 0/0 grow/shrink: 43/10 up/down: 235/-98 (137)
        function                             old     new   delta
        umount_collect                       119     138     +19
        notify_change                        306     324     +18
        xstate_enable_boot_cpu               252     269     +17
        kunmap                                54      70     +16
        balloon_page_dequeue                 112     126     +14
        mm_take_all_locks                    223     233     +10
        list_lru_walk_node                   143     152      +9
        vma_adjust                          1059    1067      +8
        pcpu_setup_first_chunk              1130    1138      +8
        mm_drop_all_locks                    143     151      +8
        ns_capable                            55      62      +7
        anon_transport_class_unregister        8      15      +7
        srcu_init_notifier_head               35      41      +6
        shrink_dcache_for_umount             174     180      +6
        kunmap_high                           99     105      +6
        end_page_writeback                    43      49      +6
        do_exit                             1339    1345      +6
        __kfifo_dma_out_prepare_r             86      92      +6
        __kfifo_dma_in_prepare_r              90      96      +6
        fixup_user_fault                     120     125      +5
        repair_env_string                     73      77      +4
        read_cache_pages_invalidate_page      56      60      +4
        isolate_lru_pages.isra               142     146      +4
        do_notify_parent_cldstop             255     259      +4
        cpu_init                             370     374      +4
        utimes_common                        270     272      +2
        tasklet_hi_action                     91      93      +2
        tasklet_action                        91      93      +2
        set_pte_vaddr                         46      48      +2
        find_get_pages_tag                   202     204      +2
        early_iounmap                        185     187      +2
        __native_set_fixmap                   36      38      +2
        __get_user_pages                     822     824      +2
        __early_ioremap                      299     301      +2
        yield_task_stop                        1       2      +1
        tick_resume                           37      38      +1
        switched_to_stop                       1       2      +1
        switched_to_idle                       1       2      +1
        prio_changed_stop                      1       2      +1
        prio_changed_idle                      1       2      +1
        pm_qos_power_read                    111     112      +1
        arch_cpu_idle_dead                     1       2      +1
        __insert_vmap_area                   140     141      +1
        sys_renameat                         614     612      -2
        mm_fault_error                       297     295      -2
        SyS_renameat                         614     612      -2
        sys_linkat                           416     413      -3
        SyS_linkat                           416     413      -3
        chmod_common                         129     122      -7
        proc_cap_handler                     240     225     -15
        __schedule                           849     831     -18
        sys_madvise                         1077    1054     -23
        SyS_madvise                         1077    1054     -23
      Signed-off-by: default avatarJosh Triplett <josh@joshtriplett.org>
      Reported-by: default avatarArnd Bergmann <arnd@arndb.de>
      Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a4b5d580
    • Josh Triplett's avatar
      bug: when !CONFIG_BUG, make WARN call no_printk to check format and args · 4e50ebde
      Josh Triplett authored
      
      
      The stub version of WARN for !CONFIG_BUG completely ignored its format
      string and subsequent arguments; make it check them instead, using
      no_printk.
      Signed-off-by: default avatarJosh Triplett <josh@joshtriplett.org>
      Reported-by: default avatarArnd Bergmann <arnd@arndb.de>
      Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      4e50ebde
    • Josh Triplett's avatar
    • Josh Triplett's avatar
      bug: when !CONFIG_BUG, simplify WARN_ON_ONCE and family · b607e70e
      Josh Triplett authored
      
      
      When !CONFIG_BUG, WARN_ON and family become simple passthroughs of their
      condition argument; however, WARN_ON_ONCE and family still have conditions
      and a boolean to detect one-time invocation, even though the warning
      they'd emit doesn't exist.  Make the existing definitions conditional on
      CONFIG_BUG, and add definitions for !CONFIG_BUG that map to the
      passthrough versions of WARN and WARN_ON.
      
      This saves 4.4k on a minimized configuration (smaller than allnoconfig),
      and 20.6k with defconfig plus CONFIG_BUG=n.
      Signed-off-by: default avatarJosh Triplett <josh@joshtriplett.org>
      Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b607e70e
    • Josh Triplett's avatar
      kconfig: make allnoconfig disable options behind EMBEDDED and EXPERT · 5d2acfc7
      Josh Triplett authored
      
      
      "make allnoconfig" exists to ease testing of minimal configurations.
      Documentation/SubmitChecklist includes a note to test with allnoconfig.
      This helps catch missing dependencies on common-but-not-required
      functionality, which might otherwise go unnoticed.
      
      However, allnoconfig still leaves many symbols enabled, because they're
      hidden behind CONFIG_EMBEDDED or CONFIG_EXPERT.  For instance, allnoconfig
      still has CONFIG_PRINTK and CONFIG_BLOCK enabled, so drivers don't
      typically get build-tested with those disabled.
      
      To address this, introduce a new Kconfig option "allnoconfig_y", used on
      symbols which only exist to hide other symbols.  Set it on CONFIG_EMBEDDED
      (which then selects CONFIG_EXPERT).  allnoconfig will then disable all the
      symbols hidden behind those.
      Signed-off-by: default avatarJosh Triplett <josh@joshtriplett.org>
      Tested-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Michal Marek <mmarek@suse.cz>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5d2acfc7
    • Josh Triplett's avatar
      ppc: make PPC_BOOK3S_64 select IRQ_WORK · 527518f1
      Josh Triplett authored
      
      
      Fix breakage which will be exposed by the patch "kconfig: make allnoconfig
      disable options behind EMBEDDED and EXPERT".
      
      arch/powerpc/kernel/mce.c, compiled in for PPC_BOOK3S_64, calls
      functions only built when IRQ_WORK, so select it.  Fixes the following
      build error:
      
        arch/powerpc/kernel/built-in.o: In function `.machine_check_queue_event':
        (.text+0x11260): undefined reference to `.irq_work_queue'
      Signed-off-by: default avatarJosh Triplett <josh@joshtriplett.org>
      Reported-by: default avatarStephen Rothwell <sfr@canb.auug.org.au>
      Acked-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      527518f1
    • Josh Triplett's avatar
      ia64: select CONFIG_TTY for use of tty_write_message in unaligned · 6035d9db
      Josh Triplett authored
      
      
      Fix breakage which will be exposed by the patch "kconfig: make allnoconfig
      disable options behind EMBEDDED and EXPERT".
      
      arch/ia64/kernel/unaligned.c uses tty_write_message to print an
      unaligned access exception to the TTY of the current user process.
      Enable TTY to prevent a build error.
      
      Minimal fix, on the basis that few people on ia64 will care deeply about
      kernel size enough to turn off TTY.  Ideally, I'd instead suggest
      dropping the tty_write_message entirely, and just leaving the printk.
      Bonus: no need to sprintf first.
      Signed-off-by: default avatarJosh Triplett <josh@joshtriplett.org>
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Cc: "Luck, Tony" <tony.luck@intel.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      6035d9db
    • Geert Uytterhoeven's avatar
      cris: cpuinfo_op should depend on CONFIG_PROC_FS · c638b107
      Geert Uytterhoeven authored
      
      
      Fix breakage which will be exposed by the patch "kconfig: make allnoconfig
      disable options behind EMBEDDED and EXPERT".
      
      Now allnoconfig started disabling CONFIG_PROC_FS:
      
          arch/cris/kernel/built-in.o:(.rodata+0xc): undefined reference to `show_cpuinfo'
          make: *** [vmlinux] Error 1
      Signed-off-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: Jesper Nilsson <jesper.nilsson@axis.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c638b107
    • Josh Triplett's avatar
      cris: make ETRAX_ARCH_V10 select TTY for use in debugport · ae797bdf
      Josh Triplett authored
      
      
      Fix breakage which will be exposed by the patch "kconfig: make allnoconfig
      disable options behind EMBEDDED and EXPERT".
      
      arch/cris/arch-v10/kernel/debugport.c, compiled in unconditionally with
      ETRAX_ARCH_V10, requires TTY, so select TTY to avoid a build failure.
      Signed-off-by: default avatarJosh Triplett <josh@joshtriplett.org>
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: Jesper Nilsson <jesper.nilsson@axis.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ae797bdf
    • Dan Carpenter's avatar
      drivers/misc/sgi-gru/grukdump.c: cleanup gru_dump_context() a little · b6a83d92
      Dan Carpenter authored
      
      
      "ret" is zero here so we can remove the "!ret" part of the condition.
      "uhdr" is alread a __user pointer so we can remove the cast.
      Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
      Acked-by: default avatarDimitri Sivanich <sivanich@sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b6a83d92