lkml.org 
[lkml]   [2014]   [Jan]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    Subject[PATCH 0/3] kernel/mm -- audit/fix core code using module_init
    Date
    This series had an interesting genesis in chain on effects, typical 
    of how things can creep and spill over.

    I wanted to clobber pointless instances of #include <linux/init.h>
    mostly left behind from __cpuinit and __devinit removal. But to
    fully complete that, I had to plan to move module_init into module.h;
    which meant to get rid of the non-modular callers of module_init().

    But I couldn't replace them with the 1:1 mapping to __initcall(),
    because we aren't supposed to use that anymore. And finally, I
    couldn't just use the 1:1 mapping of __initcall to device_initcall(),
    because it looks like crap to be using device_initcall in what is
    clearly not device/driver code. And hence we end up being faced with
    checking and/or changing initcall ordering.

    Here we fix up kernel/ and mm/ -- the one point of interest was
    uncovering an oops when trying to make ksm_init a subsys_initcall,
    which in turn led to the 1st patch in the series, which reprioritized
    creation of the mm_kobj.

    There are other __initcall in mm/ that we probably want to look at
    and reprioritize in the future. But for now I just fixed the one that
    was obviously problematic and blocking the other required priority
    changes in ksm.c and huge_memory.c

    Boot tested on today's master, with x86-32 and powerpc (sbc8548).

    For completeness, here is what happens when one tries to make ksm_init
    as subsys_initcall, if the mm_kobj is created too late in device_initcall.

    Paul.

    ------------[ cut here ]------------
    kernel BUG at fs/sysfs/group.c:94!
    invalid opcode: 0000 [#1] SMP
    Modules linked in:
    CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.13.0-rc8+ #12
    Hardware name: Dell Computer Corporation OptiPlex GX270 /0Y1057, BIOS A07 06/26/2006
    task: f5860000 ti: f5846000 task.ti: f5846000
    EIP: 0060:[<c11884d4>] EFLAGS: 00010246 CPU: 0
    EIP is at internal_create_group+0x244/0x270
    EAX: 00000000 EBX: c199e5c9 ECX: c1929f60 EDX: 00000000
    ESI: f59947c0 EDI: 00000000 EBP: f5847ed8 ESP: f5847ea4
    DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
    CR0: 8005003b CR2: ffe14000 CR3: 01a2b000 CR4: 000007d0
    Stack:
    f59947c0 f5847ed4 c106fdfb 00000000 34561000 00000000 00000000 00000000
    c1929f60 f59947c0 c199e5c9 f59947c0 00000000 f5847ee0 c118852c f5847f00
    c199e68c c111cde0 00000000 ffffffff c1856da4 c199e5c9 00000004 f5847f70
    Call Trace:
    [<c106fdfb>] ? try_to_wake_up+0x18b/0x230
    [<c199e5c9>] ? procswaps_init+0x27/0x27
    [<c118852c>] sysfs_create_group+0xc/0x10
    [<c199e68c>] ksm_init+0xc3/0x15b
    [<c111cde0>] ? run_store+0x2b0/0x2b0
    [<c199e5c9>] ? procswaps_init+0x27/0x27
    [<c10004b2>] do_one_initcall+0xe2/0x140
    [<c1061463>] ? parameq+0x13/0x70
    [<c197e4cc>] ? do_early_param+0x7a/0x7a
    [<c1061699>] ? parse_args+0x1d9/0x340
    [<c107c6a0>] ? __wake_up+0x40/0x50
    [<c197eb73>] kernel_init_freeable+0x129/0x1cd
    [<c197e4cc>] ? do_early_param+0x7a/0x7a
    [<c16bd19b>] kernel_init+0xb/0x100
    [<c16d44b7>] ret_from_kernel_thread+0x1b/0x28
    [<c16bd190>] ? rest_init+0x60/0x60

    ---

    Paul Gortmaker (3):
    mm: make creation of the mm_kobj happen earlier than device_initcall
    kernel: audit/fix non-modular users of module_init in core code
    mm: audit/fix non-modular users of module_init in core code

    kernel/hung_task.c | 3 +--
    kernel/kexec.c | 4 ++--
    kernel/profile.c | 2 +-
    kernel/sched/stats.c | 2 +-
    kernel/user.c | 3 +--
    kernel/user_namespace.c | 2 +-
    mm/huge_memory.c | 2 +-
    mm/ksm.c | 2 +-
    mm/mm_init.c | 3 +--
    mm/mmap.c | 6 +++---
    mm/mmu_notifier.c | 3 +--
    11 files changed, 14 insertions(+), 18 deletions(-)

    --
    1.8.5.2



    \
     
     \ /
      Last update: 2014-01-15 04:01    [W:0.027 / U:1.240 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site