30 Jul, 2009

1 commit

  • Once a structure goes over PAGE_SIZE*2, we see occasional allocation
    failures. Some people have chosen to switch over to things like vmalloc()
    that will let them keep array-like access to such a large structures.
    But, vmalloc() has plenty of downsides.

    Here's an alternative. I think it's what Andrew was suggesting here:

    http://lkml.org/lkml/2009/7/2/518

    I call it a flexible array. It does all of its work in PAGE_SIZE bits, so
    never does an order>0 allocation. The base level has
    PAGE_SIZE-2*sizeof(int) bytes of storage for pointers to the second level.
    So, with a 32-bit arch, you get about 4MB (4183112 bytes) of total
    storage when the objects pack nicely into a page. It is half that on
    64-bit because the pointers are twice the size. There's a table detailing
    this in the code.

    There are kerneldocs for the functions, but here's an
    overview:

    flex_array_alloc() - dynamically allocate a base structure
    flex_array_free() - free the array and all of the
    second-level pages
    flex_array_free_parts() - free the second-level pages, but
    not the base (for static bases)
    flex_array_put() - copy into the array at the given index
    flex_array_get() - copy out of the array at the given index
    flex_array_prealloc() - preallocate the second-level pages
    between the given indexes to
    guarantee no allocs will occur at
    put() time.

    We could also potentially just pass the "element_size" into each of the
    API functions instead of storing it internally. That would get us one
    more base pointer on 32-bit.

    I've been testing this by running it in userspace. The header and patch
    that I've been using are here, as well as the little script I'm using to
    generate the size table which goes in the kerneldocs.

    http://sr71.net/~dave/linux/flexarray/

    [akpm@linux-foundation.org: coding-style fixes]
    Signed-off-by: Dave Hansen
    Reviewed-by: KAMEZAWA Hiroyuki
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Dave Hansen
     

19 Jun, 2009

1 commit

  • This patch adds lib/gcd.c which contains a greatest common divider
    implementation taken from sound/core/pcm_timer.c

    Several usages of this new library function will be sent to subsystem
    maintainers.

    [akpm@linux-foundation.org: use swap() (pointed out by Joe)]
    [akpm@linux-foundation.org: just add gcd.o to obj-y, remove Kconfig changes]
    Signed-off-by: Florian Fainelli
    Cc: Sergei Shtylyov
    Cc: Takashi Iwai
    Cc: Simon Horman
    Cc: Julius Volz
    Cc: David S. Miller
    Cc: Patrick McHardy
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Florian Fainelli
     

15 Jun, 2009

1 commit

  • Many processor architectures have no 64-bit atomic instructions, but
    we need atomic64_t in order to support the perf_counter subsystem.

    This adds an implementation of 64-bit atomic operations using hashed
    spinlocks to provide atomicity. For each atomic operation, the address
    of the atomic64_t variable is hashed to an index into an array of 16
    spinlocks. That spinlock is taken (with interrupts disabled) around the
    operation, which can then be coded non-atomically within the lock.

    On UP, all the spinlock manipulation goes away and we simply disable
    interrupts around each operation. In fact gcc eliminates the whole
    atomic64_lock variable as well.

    Signed-off-by: Paul Mackerras
    Signed-off-by: Benjamin Herrenschmidt

    Paul Mackerras
     

12 Jun, 2009

2 commits


11 Jun, 2009

1 commit


25 Apr, 2009

1 commit

  • Currently, although find_last_bit is EXPORTed, it is statically linked
    with the kernel and is referenced only under CONFIG_SMP.

    When CONFIG_SMP is undefined and find_last_bit is referenced only by
    modules, linking fails with:

    ERROR: "find_last_bit" [fs/nfs/nfs.ko] undefined!

    Cc: Rusty Russell
    Cc: Trond Myklebust
    Signed-off-by: Fred Isaman
    Signed-off-by: Benny Halevy
    Signed-off-by: Linus Torvalds

    Fred Isaman
     

29 Mar, 2009

1 commit


28 Mar, 2009

1 commit


27 Mar, 2009

2 commits

  • * 'sched-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (46 commits)
    sched: Add comments to find_busiest_group() function
    sched: Refactor the power savings balance code
    sched: Optimize the !power_savings_balance during fbg()
    sched: Create a helper function to calculate imbalance
    sched: Create helper to calculate small_imbalance in fbg()
    sched: Create a helper function to calculate sched_domain stats for fbg()
    sched: Define structure to store the sched_domain statistics for fbg()
    sched: Create a helper function to calculate sched_group stats for fbg()
    sched: Define structure to store the sched_group statistics for fbg()
    sched: Fix indentations in find_busiest_group() using gotos
    sched: Simple helper functions for find_busiest_group()
    sched: remove unused fields from struct rq
    sched: jiffies not printed per CPU
    sched: small optimisation of can_migrate_task()
    sched: fix typos in documentation
    sched: add avg_overlap decay
    x86, sched_clock(): mark variables read-mostly
    sched: optimize ttwu vs group scheduling
    sched: TIF_NEED_RESCHED -> need_reshed() cleanup
    sched: don't rebalance if attached on NULL domain
    ...

    Linus Torvalds
     
  • * git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (61 commits)
    Dynamic debug: fix pr_fmt() build error
    Dynamic debug: allow simple quoting of words
    dynamic debug: update docs
    dynamic debug: combine dprintk and dynamic printk
    sysfs: fix some bin_vm_ops errors
    kobject: don't block for each kobject_uevent
    sysfs: only allow one scheduled removal callback per kobj
    Driver core: Fix device_move() vs. dpm list ordering, v2
    Driver core: some cleanup on drivers/base/sys.c
    Driver core: implement uevent suppress in kobject
    vcs: hook sysfs devices into object lifetime instead of "binding"
    driver core: fix passing platform_data
    driver core: move platform_data into platform_device
    sysfs: don't block indefinitely for unmapped files.
    driver core: move knode_bus into private structure
    driver core: move knode_driver into private structure
    driver core: move klist_children into private structure
    driver core: create a private portion of struct device
    driver core: remove polling for driver_probe_done(v5)
    sysfs: reference sysfs_dirent from sysfs inodes
    ...

    Fixed conflicts in drivers/sh/maple/maple.c manually

    Linus Torvalds
     

25 Mar, 2009

1 commit

  • This patch combines Greg Bank's dprintk() work with the existing dynamic
    printk patchset, we are now calling it 'dynamic debug'.

    The new feature of this patchset is a richer /debugfs control file interface,
    (an example output from my system is at the bottom), which allows fined grained
    control over the the debug output. The output can be controlled by function,
    file, module, format string, and line number.

    for example, enabled all debug messages in module 'nf_conntrack':

    echo -n 'module nf_conntrack +p' > /mnt/debugfs/dynamic_debug/control

    to disable them:

    echo -n 'module nf_conntrack -p' > /mnt/debugfs/dynamic_debug/control

    A further explanation can be found in the documentation patch.

    Signed-off-by: Greg Banks
    Signed-off-by: Jason Baron
    Signed-off-by: Greg Kroah-Hartman

    Jason Baron
     

05 Mar, 2009

1 commit


04 Mar, 2009

1 commit


16 Jan, 2009

1 commit

  • Ingo Molnar wrote:

    > here's a new build failure with tip/sched/rt:
    >
    > LD .tmp_vmlinux1
    > kernel/built-in.o: In function `set_curr_task_rt':
    > sched.c:(.text+0x3675): undefined reference to `plist_del'
    > kernel/built-in.o: In function `pick_next_task_rt':
    > sched.c:(.text+0x37ce): undefined reference to `plist_del'
    > kernel/built-in.o: In function `enqueue_pushable_task':
    > sched.c:(.text+0x381c): undefined reference to `plist_del'

    Eliminate the plist library kconfig and make it available
    unconditionally.

    Signed-off-by: Peter Zijlstra
    Signed-off-by: Ingo Molnar

    Peter Zijlstra
     

09 Jan, 2009

1 commit


06 Jan, 2009

1 commit


05 Jan, 2009

1 commit

  • Impact: New code for initramfs decompression, new features

    This is the second part of the bzip2/lzma patch

    The bzip patch is based on an idea by Christian Ludwig, includes support for
    compressing the kernel with bzip2 or lzma rather than gzip. Both
    compressors give smaller sizes than gzip. Lzma's decompresses faster
    than bzip2.

    It also supports ramdisks and initramfs' compressed using these two
    compressors.

    The functionality has been successfully used for a couple of years by
    the udpcast project

    This version applies to "tip" kernel 2.6.28

    This part contains:
    - support for new compressions (bzip2 and lzma) in initramfs and
    old-style ramdisk
    - config dialog for kernel compression (but new kernel compressions
    not yet supported)

    Signed-off-by: Alain Knaff
    Signed-off-by: H. Peter Anvin

    Alain Knaff
     

01 Jan, 2009

1 commit


14 Nov, 2008

1 commit

  • Inaugurate copy-on-write credentials management. This uses RCU to manage the
    credentials pointer in the task_struct with respect to accesses by other tasks.
    A process may only modify its own credentials, and so does not need locking to
    access or modify its own credentials.

    A mutex (cred_replace_mutex) is added to the task_struct to control the effect
    of PTRACE_ATTACHED on credential calculations, particularly with respect to
    execve().

    With this patch, the contents of an active credentials struct may not be
    changed directly; rather a new set of credentials must be prepared, modified
    and committed using something like the following sequence of events:

    struct cred *new = prepare_creds();
    int ret = blah(new);
    if (ret < 0) {
    abort_creds(new);
    return ret;
    }
    return commit_creds(new);

    There are some exceptions to this rule: the keyrings pointed to by the active
    credentials may be instantiated - keyrings violate the COW rule as managing
    COW keyrings is tricky, given that it is possible for a task to directly alter
    the keys in a keyring in use by another task.

    To help enforce this, various pointers to sets of credentials, such as those in
    the task_struct, are declared const. The purpose of this is compile-time
    discouragement of altering credentials through those pointers. Once a set of
    credentials has been made public through one of these pointers, it may not be
    modified, except under special circumstances:

    (1) Its reference count may incremented and decremented.

    (2) The keyrings to which it points may be modified, but not replaced.

    The only safe way to modify anything else is to create a replacement and commit
    using the functions described in Documentation/credentials.txt (which will be
    added by a later patch).

    This patch and the preceding patches have been tested with the LTP SELinux
    testsuite.

    This patch makes several logical sets of alteration:

    (1) execve().

    This now prepares and commits credentials in various places in the
    security code rather than altering the current creds directly.

    (2) Temporary credential overrides.

    do_coredump() and sys_faccessat() now prepare their own credentials and
    temporarily override the ones currently on the acting thread, whilst
    preventing interference from other threads by holding cred_replace_mutex
    on the thread being dumped.

    This will be replaced in a future patch by something that hands down the
    credentials directly to the functions being called, rather than altering
    the task's objective credentials.

    (3) LSM interface.

    A number of functions have been changed, added or removed:

    (*) security_capset_check(), ->capset_check()
    (*) security_capset_set(), ->capset_set()

    Removed in favour of security_capset().

    (*) security_capset(), ->capset()

    New. This is passed a pointer to the new creds, a pointer to the old
    creds and the proposed capability sets. It should fill in the new
    creds or return an error. All pointers, barring the pointer to the
    new creds, are now const.

    (*) security_bprm_apply_creds(), ->bprm_apply_creds()

    Changed; now returns a value, which will cause the process to be
    killed if it's an error.

    (*) security_task_alloc(), ->task_alloc_security()

    Removed in favour of security_prepare_creds().

    (*) security_cred_free(), ->cred_free()

    New. Free security data attached to cred->security.

    (*) security_prepare_creds(), ->cred_prepare()

    New. Duplicate any security data attached to cred->security.

    (*) security_commit_creds(), ->cred_commit()

    New. Apply any security effects for the upcoming installation of new
    security by commit_creds().

    (*) security_task_post_setuid(), ->task_post_setuid()

    Removed in favour of security_task_fix_setuid().

    (*) security_task_fix_setuid(), ->task_fix_setuid()

    Fix up the proposed new credentials for setuid(). This is used by
    cap_set_fix_setuid() to implicitly adjust capabilities in line with
    setuid() changes. Changes are made to the new credentials, rather
    than the task itself as in security_task_post_setuid().

    (*) security_task_reparent_to_init(), ->task_reparent_to_init()

    Removed. Instead the task being reparented to init is referred
    directly to init's credentials.

    NOTE! This results in the loss of some state: SELinux's osid no
    longer records the sid of the thread that forked it.

    (*) security_key_alloc(), ->key_alloc()
    (*) security_key_permission(), ->key_permission()

    Changed. These now take cred pointers rather than task pointers to
    refer to the security context.

    (4) sys_capset().

    This has been simplified and uses less locking. The LSM functions it
    calls have been merged.

    (5) reparent_to_kthreadd().

    This gives the current thread the same credentials as init by simply using
    commit_thread() to point that way.

    (6) __sigqueue_alloc() and switch_uid()

    __sigqueue_alloc() can't stop the target task from changing its creds
    beneath it, so this function gets a reference to the currently applicable
    user_struct which it then passes into the sigqueue struct it returns if
    successful.

    switch_uid() is now called from commit_creds(), and possibly should be
    folded into that. commit_creds() should take care of protecting
    __sigqueue_alloc().

    (7) [sg]et[ug]id() and co and [sg]et_current_groups.

    The set functions now all use prepare_creds(), commit_creds() and
    abort_creds() to build and check a new set of credentials before applying
    it.

    security_task_set[ug]id() is called inside the prepared section. This
    guarantees that nothing else will affect the creds until we've finished.

    The calling of set_dumpable() has been moved into commit_creds().

    Much of the functionality of set_user() has been moved into
    commit_creds().

    The get functions all simply access the data directly.

    (8) security_task_prctl() and cap_task_prctl().

    security_task_prctl() has been modified to return -ENOSYS if it doesn't
    want to handle a function, or otherwise return the return value directly
    rather than through an argument.

    Additionally, cap_task_prctl() now prepares a new set of credentials, even
    if it doesn't end up using it.

    (9) Keyrings.

    A number of changes have been made to the keyrings code:

    (a) switch_uid_keyring(), copy_keys(), exit_keys() and suid_keys() have
    all been dropped and built in to the credentials functions directly.
    They may want separating out again later.

    (b) key_alloc() and search_process_keyrings() now take a cred pointer
    rather than a task pointer to specify the security context.

    (c) copy_creds() gives a new thread within the same thread group a new
    thread keyring if its parent had one, otherwise it discards the thread
    keyring.

    (d) The authorisation key now points directly to the credentials to extend
    the search into rather pointing to the task that carries them.

    (e) Installing thread, process or session keyrings causes a new set of
    credentials to be created, even though it's not strictly necessary for
    process or session keyrings (they're shared).

    (10) Usermode helper.

    The usermode helper code now carries a cred struct pointer in its
    subprocess_info struct instead of a new session keyring pointer. This set
    of credentials is derived from init_cred and installed on the new process
    after it has been cloned.

    call_usermodehelper_setup() allocates the new credentials and
    call_usermodehelper_freeinfo() discards them if they haven't been used. A
    special cred function (prepare_usermodeinfo_creds()) is provided
    specifically for call_usermodehelper_setup() to call.

    call_usermodehelper_setkeys() adjusts the credentials to sport the
    supplied keyring as the new session keyring.

    (11) SELinux.

    SELinux has a number of changes, in addition to those to support the LSM
    interface changes mentioned above:

    (a) selinux_setprocattr() no longer does its check for whether the
    current ptracer can access processes with the new SID inside the lock
    that covers getting the ptracer's SID. Whilst this lock ensures that
    the check is done with the ptracer pinned, the result is only valid
    until the lock is released, so there's no point doing it inside the
    lock.

    (12) is_single_threaded().

    This function has been extracted from selinux_setprocattr() and put into
    a file of its own in the lib/ directory as join_session_keyring() now
    wants to use it too.

    The code in SELinux just checked to see whether a task shared mm_structs
    with other tasks (CLONE_VM), but that isn't good enough. We really want
    to know if they're part of the same thread group (CLONE_THREAD).

    (13) nfsd.

    The NFS server daemon now has to use the COW credentials to set the
    credentials it is going to use. It really needs to pass the credentials
    down to the functions it calls, but it can't do that until other patches
    in this series have been applied.

    Signed-off-by: David Howells
    Acked-by: James Morris
    Signed-off-by: James Morris

    David Howells
     

21 Oct, 2008

1 commit

  • Due to confusion between the ftrace infrastructure and the gcc profiling
    tracer "ftrace", this patch renames the config options from FTRACE to
    FUNCTION_TRACER. The other two names that are offspring from FTRACE
    DYNAMIC_FTRACE and FTRACE_MCOUNT_RECORD will stay the same.

    This patch was generated mostly by script, and partially by hand.

    Signed-off-by: Steven Rostedt
    Signed-off-by: Ingo Molnar

    Steven Rostedt
     

17 Oct, 2008

1 commit

  • Base infrastructure to enable per-module debug messages.

    I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes
    control of debugging statements on a per-module basis in one /proc file,
    currently, /dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG,
    is not set, debugging statements can still be enabled as before, often by
    defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no
    affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set.

    The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That
    is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls
    can be dynamically enabled/disabled on a per-module basis.

    Future plans include extending this functionality to subsystems, that define
    their own debug levels and flags.

    Usage:

    Dynamic debugging is controlled by the debugfs file,
    /dynamic_printk/modules. This file contains a list of the modules that
    can be enabled. The format of the file is as follows:


    .
    .
    .

    : Name of the module in which the debug call resides
    : whether the messages are enabled or not

    For example:

    snd_hda_intel enabled=0
    fixup enabled=1
    driver enabled=0

    Enable a module:

    $echo "set enabled=1 " > dynamic_printk/modules

    Disable a module:

    $echo "set enabled=0 " > dynamic_printk/modules

    Enable all modules:

    $echo "set enabled=1 all" > dynamic_printk/modules

    Disable all modules:

    $echo "set enabled=0 all" > dynamic_printk/modules

    Finally, passing "dynamic_printk" at the command line enables
    debugging for all modules. This mode can be turned off via the above
    disable command.

    [gkh: minor cleanups and tweaks to make the build work quietly]

    Signed-off-by: Jason Baron
    Signed-off-by: Greg Kroah-Hartman

    Jason Baron
     

04 Oct, 2008

1 commit

  • This patch adds the ability to print sizes in either units of 10^3 (SI)
    or 2^10 (Binary) units. It rounds up to three significant figures and
    can be used for either memory or storage capacities.

    Oh, and I'm fully aware that 64 bits is only 16EiB ... the Zetta and
    Yotta units are added for future proofing against the day we have 128
    bit computers ...

    [fujita.tomonori@lab.ntt.co.jp: fix missed unsigned long long cast]
    Signed-off-by: James Bottomley

    James Bottomley
     

27 Jul, 2008

2 commits

  • This implements a platform-independent version of show_mem().

    Signed-off-by: Johannes Weiner
    Cc: Richard Henderson
    Cc: Ivan Kokshaysky
    Cc: Haavard Skinnemoen
    Cc: Bryan Wu
    Cc: Chris Zankel
    Cc: Ingo Molnar
    Cc: Jeff Dike
    Cc: David S. Miller
    Cc: Paul Mundt
    Cc: Heiko Carstens
    Cc: Martin Schwidefsky
    Cc: David Howells
    Cc: Benjamin Herrenschmidt
    Cc: Paul Mackerras
    Cc: Yoshinori Sato
    Cc: Ralf Baechle
    Cc: Greg Ungerer
    Cc: Geert Uytterhoeven
    Cc: Roman Zippel
    Cc: Hirokazu Takata
    Cc: Mikael Starvik
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Johannes Weiner
     
  • This adds the new function task_current_syscall() on machines where the
    asm/syscall.h interface is supported (CONFIG_HAVE_ARCH_TRACEHOOK). It's
    exported for modules to use in the future. This function safely samples
    the state of a blocked thread to collect what system call it is blocked
    in, and the six system call argument registers.

    Signed-off-by: Roland McGrath
    Cc: Oleg Nesterov
    Reviewed-by: Ingo Molnar
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Roland McGrath
     

25 Jul, 2008

1 commit

  • This updates to define the key routines as constant
    functions, which the macros will then call. Newer code can now call
    bcd2bin() instead of SCREAMING BCD2BIN() TO THE FOUR WINDS.

    This lets each driver shrink their codespace by using N function calls to
    a single (global) copy of those routines, instead of N inlined copies of
    these functions per driver.

    These routines aren't used in speed-critical code. Almost all callers are
    in the RTC framework. Typical per-driver savings is near 300 bytes.

    Signed-off-by: David Brownell
    Acked-by: Adrian Bunk
    Cc: Alessandro Zummo
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    David Brownell
     

17 Jul, 2008

2 commits

  • make function tracing more robust: do not trace library functions.

    We've already got a sizable list of exceptions:

    ifdef CONFIG_FTRACE
    # Do not profile string.o, since it may be used in early boot or vdso
    CFLAGS_REMOVE_string.o = -pg
    # Also do not profile any debug utilities
    CFLAGS_REMOVE_spinlock_debug.o = -pg
    CFLAGS_REMOVE_list_debug.o = -pg
    CFLAGS_REMOVE_debugobjects.o = -pg
    CFLAGS_REMOVE_find_next_bit.o = -pg
    CFLAGS_REMOVE_cpumask.o = -pg
    CFLAGS_REMOVE_bitmap.o = -pg
    endif

    ... and the pattern has been that random library functionality showed
    up in ftrace's critical path (outside of its recursion check), causing
    hard to debug lockups.

    So be a bit defensive about it and exclude all lib/*.o functions by
    default. It's not that they are overly interesting for tracing purposes
    anyway. Specific ones can still be traced, in an opt-in manner.

    Signed-off-by: Ingo Molnar

    Ingo Molnar
     
  • MAXSMP brings in lots of use of various bitops in smp_processor_id()
    and friends - causing ftrace to lock up during bootup:

    calling anon_inode_init+0x0/0x130
    initcall anon_inode_init+0x0/0x130 returned 0 after 0 msecs
    calling acpi_event_init+0x0/0x57
    [ hard hang ]

    So exclude the bitops facilities from tracing.

    Signed-off-by: Ingo Molnar

    Ingo Molnar
     

16 Jul, 2008

1 commit

  • * git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (102 commits)
    [SCSI] scsi_dh: fix kconfig related build errors
    [SCSI] sym53c8xx: Fix bogus sym_que_entry re-implementation of container_of
    [SCSI] scsi_cmnd.h: remove double inclusion of linux/blkdev.h
    [SCSI] make struct scsi_{host,target}_type static
    [SCSI] fix locking in host use of blk_plug_device()
    [SCSI] zfcp: Cleanup external header file
    [SCSI] zfcp: Cleanup code in zfcp_erp.c
    [SCSI] zfcp: zfcp_fsf cleanup.
    [SCSI] zfcp: consolidate sysfs things into one file.
    [SCSI] zfcp: Cleanup of code in zfcp_aux.c
    [SCSI] zfcp: Cleanup of code in zfcp_scsi.c
    [SCSI] zfcp: Move status accessors from zfcp to SCSI include file.
    [SCSI] zfcp: Small QDIO cleanups
    [SCSI] zfcp: Adapter reopen for large number of unsolicited status
    [SCSI] zfcp: Fix error checking for ELS ADISC requests
    [SCSI] zfcp: wait until adapter is finished with ERP during auto-port
    [SCSI] ibmvfc: IBM Power Virtual Fibre Channel Adapter Client Driver
    [SCSI] sg: Add target reset support
    [SCSI] lib: Add support for the T10 (SCSI) Data Integrity Field CRC
    [SCSI] sd: Move scsi_disk() accessor function to sd.h
    ...

    Linus Torvalds
     

12 Jul, 2008

1 commit


24 May, 2008

3 commits

  • This patch removes the Makefile turd and uses the nice CFLAGS_REMOVE macro
    in the lib directory.

    Signed-off-by: Steven Rostedt
    Signed-off-by: Ingo Molnar
    Signed-off-by: Thomas Gleixner

    Steven Rostedt
     
  • The debug functions in spin_lock debugging pollute the output of the
    function tracer. This patch adds the debug files in the lib director
    to those that should not be compiled with mcount tracing.

    Signed-off-by: Steven Rostedt
    Signed-off-by: Ingo Molnar
    Signed-off-by: Thomas Gleixner

    Steven Rostedt
     
  • Most archs define the string and memory compare functions in assembly.
    Some do not. But these functions may be used in some archs at early
    boot up.

    Since most archs define this code in assembly and they are not usually
    traced, there's no need to trace them when they are not defined in
    assembly.

    This patch removes the -pg from the CFLAGS for lib/string.o.
    This prevents the string functions use in either vdso or early bootup
    from crashing the system.

    Signed-off-by: Steven Rostedt
    Signed-off-by: Ingo Molnar
    Signed-off-by: Thomas Gleixner

    Steven Rostedt
     

30 Apr, 2008

1 commit

  • We can see an ever repeating problem pattern with objects of any kind in the
    kernel:

    1) freeing of active objects
    2) reinitialization of active objects

    Both problems can be hard to debug because the crash happens at a point where
    we have no chance to decode the root cause anymore. One problem spot are
    kernel timers, where the detection of the problem often happens in interrupt
    context and usually causes the machine to panic.

    While working on a timer related bug report I had to hack specialized code
    into the timer subsystem to get a reasonable hint for the root cause. This
    debug hack was fine for temporary use, but far from a mergeable solution due
    to the intrusiveness into the timer code.

    The code further lacked the ability to detect and report the root cause
    instantly and keep the system operational.

    Keeping the system operational is important to get hold of the debug
    information without special debugging aids like serial consoles and special
    knowledge of the bug reporter.

    The problems described above are not restricted to timers, but timers tend to
    expose it usually in a full system crash. Other objects are less explosive,
    but the symptoms caused by such mistakes can be even harder to debug.

    Instead of creating specialized debugging code for the timer subsystem a
    generic infrastructure is created which allows developers to verify their code
    and provides an easy to enable debug facility for users in case of trouble.

    The debugobjects core code keeps track of operations on static and dynamic
    objects by inserting them into a hashed list and sanity checking them on
    object operations and provides additional checks whenever kernel memory is
    freed.

    The tracked object operations are:
    - initializing an object
    - adding an object to a subsystem list
    - deleting an object from a subsystem list

    Each operation is sanity checked before the operation is executed and the
    subsystem specific code can provide a fixup function which allows to prevent
    the damage of the operation. When the sanity check triggers a warning message
    and a stack trace is printed.

    The list of operations can be extended if the need arises. For now it's
    limited to the requirements of the first user (timers).

    The core code enqueues the objects into hash buckets. The hash index is
    generated from the address of the object to simplify the lookup for the check
    on kfree/vfree. Each bucket has it's own spinlock to avoid contention on a
    global lock.

    The debug code can be compiled in without being active. The runtime overhead
    is minimal and could be optimized by asm alternatives. A kernel command line
    option enables the debugging code.

    Thanks to Ingo Molnar for review, suggestions and cleanup patches.

    Signed-off-by: Thomas Gleixner
    Signed-off-by: Ingo Molnar
    Cc: Greg KH
    Cc: Randy Dunlap
    Cc: Kay Sievers
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Thomas Gleixner
     

29 Apr, 2008

1 commit

  • Due to the rcupreempt.h WARN_ON trigged, I got 2G syslog file. For some
    serious complaining of kernel, we need repeat the warnings, so here I isolate
    the ratelimit part of printk.c to a standalone file.

    Signed-off-by: Dave Young
    Acked-by: Paul E. McKenney
    Tested-by: Paul E. McKenney
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Dave Young
     

27 Apr, 2008

1 commit

  • Generic versions of __find_first_bit and __find_first_zero_bit
    are introduced as simplified versions of __find_next_bit and
    __find_next_zero_bit. Their compilation and use are guarded by
    a new config variable GENERIC_FIND_FIRST_BIT.

    The generic versions of find_first_bit and find_first_zero_bit
    are implemented in terms of the newly introduced __find_first_bit
    and __find_first_zero_bit.

    This patch does not remove the i386-specific implementation,
    but it does switch i386 to use the generic functions by setting
    GENERIC_FIND_FIRST_BIT=y for X86_32.

    Signed-off-by: Alexander van Heukelum
    Signed-off-by: Ingo Molnar

    Alexander van Heukelum
     

22 Apr, 2008

1 commit

  • * 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc: (202 commits)
    [POWERPC] Fix compile breakage for 64-bit UP configs
    [POWERPC] Define copy_siginfo_from_user32
    [POWERPC] Add compat handler for PTRACE_GETSIGINFO
    [POWERPC] i2c: Fix build breakage introduced by OF helpers
    [POWERPC] Optimize fls64() on 64-bit processors
    [POWERPC] irqtrace support for 64-bit powerpc
    [POWERPC] Stacktrace support for lockdep
    [POWERPC] Move stackframe definitions to common header
    [POWERPC] Fix device-tree locking vs. interrupts
    [POWERPC] Make pci_bus_to_host()'s struct pci_bus * argument const
    [POWERPC] Remove unused __max_memory variable
    [POWERPC] Simplify xics direct/lpar irq_host setup
    [POWERPC] Use pseries_setup_i8259_cascade() in pseries_mpic_init_IRQ()
    [POWERPC] Turn xics_setup_8259_cascade() into a generic pseries_setup_i8259_cascade()
    [POWERPC] Move xics_setup_8259_cascade() into platforms/pseries/setup.c
    [POWERPC] Use asm-generic/bitops/find.h in bitops.h
    [POWERPC] 83xx: mpc8315 - fix USB UTMI Host setup
    [POWERPC] 85xx: Fix the size of qe muram for MPC8568E
    [POWERPC] 86xx: mpc86xx_hpcn - Temporarily accept old dts node identifier.
    [POWERPC] 86xx: mark functions static, other minor cleanups
    ...

    Linus Torvalds
     

19 Apr, 2008

1 commit

  • * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6.26: (1090 commits)
    [NET]: Fix and allocate less memory for ->priv'less netdevices
    [IPV6]: Fix dangling references on error in fib6_add().
    [NETLABEL]: Fix NULL deref in netlbl_unlabel_staticlist_gen() if ifindex not found
    [PKT_SCHED]: Fix datalen check in tcf_simp_init().
    [INET]: Uninline the __inet_inherit_port call.
    [INET]: Drop the inet_inherit_port() call.
    SCTP: Initialize partial_bytes_acked to 0, when all of the data is acked.
    [netdrvr] forcedeth: internal simplifications; changelog removal
    phylib: factor out get_phy_id from within get_phy_device
    PHY: add BCM5464 support to broadcom PHY driver
    cxgb3: Fix __must_check warning with dev_dbg.
    tc35815: Statistics cleanup
    natsemi: fix MMIO for PPC 44x platforms
    [TIPC]: Cleanup of TIPC reference table code
    [TIPC]: Optimized initialization of TIPC reference table
    [TIPC]: Remove inlining of reference table locking routines
    e1000: convert uint16_t style integers to u16
    ixgb: convert uint16_t style integers to u16
    sb1000.c: make const arrays static
    sb1000.c: stop inlining largish static functions
    ...

    Linus Torvalds
     

17 Apr, 2008

1 commit

  • Semaphores are no longer performance-critical, so a generic C
    implementation is better for maintainability, debuggability and
    extensibility. Thanks to Peter Zijlstra for fixing the lockdep
    warning. Thanks to Harvey Harrison for pointing out that the
    unlikely() was unnecessary.

    Signed-off-by: Matthew Wilcox
    Acked-by: Ingo Molnar

    Matthew Wilcox
     

29 Mar, 2008

1 commit

  • The knock-out. The pcounter abstraction is not used any longer in the
    kernel.

    Not sure whether this should go via netdev tree, but as far as I
    remember it was added via this one, and besides Eric thinks that
    Andrew shouldn't mind this.

    Signed-off-by: Pavel Emelyanov
    Signed-off-by: David S. Miller

    Pavel Emelyanov