20 Feb, 2013

1 commit

  • Pull perf changes from Ingo Molnar:
    "There are lots of improvements, the biggest changes are:

    Main kernel side changes:

    - Improve uprobes performance by adding 'pre-filtering' support, by
    Oleg Nesterov.

    - Make some POWER7 events available in sysfs, equivalent to what was
    done on x86, from Sukadev Bhattiprolu.

    - tracing updates by Steve Rostedt - mostly misc fixes and smaller
    improvements.

    - Use perf/event tracing to report PCI Express advanced errors, by
    Tony Luck.

    - Enable northbridge performance counters on AMD family 15h, by Jacob
    Shin.

    - This tracing commit:

    tracing: Remove the extra 4 bytes of padding in events

    changes the ABI. All involved parties (PowerTop in particular)
    seem to agree that it's safe to do now with the introduction of
    libtraceevent, but the devil is in the details ...

    Main tooling side changes:

    - Add 'event group view', from Namyung Kim:

    To use it, 'perf record' should group events when recording. And
    then perf report parses the saved group relation from file header
    and prints them together if --group option is provided. You can
    use the 'perf evlist' command to see event group information:

    $ perf record -e '{ref-cycles,cycles}' noploop 1
    [ perf record: Woken up 2 times to write data ]
    [ perf record: Captured and wrote 0.385 MB perf.data (~16807 samples) ]

    $ perf evlist --group
    {ref-cycles,cycles}

    With this example, default perf report will show you each event
    separately.

    You can use --group option to enable event group view:

    $ perf report --group
    ...
    # group: {ref-cycles,cycles}
    # ========
    # Samples: 7K of event 'anon group { ref-cycles, cycles }'
    # Event count (approx.): 6876107743
    #
    # Overhead Command Shared Object Symbol
    # ................ ....... ................. ..........................
    99.84% 99.76% noploop noploop [.] main
    0.07% 0.00% noploop ld-2.15.so [.] strcmp
    0.03% 0.00% noploop [kernel.kallsyms] [k] timerqueue_del
    0.03% 0.03% noploop [kernel.kallsyms] [k] sched_clock_cpu
    0.02% 0.00% noploop [kernel.kallsyms] [k] account_user_time
    0.01% 0.00% noploop [kernel.kallsyms] [k] __alloc_pages_nodemask
    0.00% 0.00% noploop [kernel.kallsyms] [k] native_write_msr_safe
    0.00% 0.11% noploop [kernel.kallsyms] [k] _raw_spin_lock
    0.00% 0.06% noploop [kernel.kallsyms] [k] find_get_page
    0.00% 0.02% noploop [kernel.kallsyms] [k] rcu_check_callbacks
    0.00% 0.02% noploop [kernel.kallsyms] [k] __current_kernel_time

    As you can see the Overhead column now contains both of ref-cycles
    and cycles and header line shows group information also - 'anon
    group { ref-cycles, cycles }'. The output is sorted by period of
    group leader first.

    - Initial GTK+ annotate browser, from Namhyung Kim.

    - Add option for runtime switching perf data file in perf report,
    just press 's' and a menu with the valid files found in the current
    directory will be presented, from Feng Tang.

    - Add support to display whole group data for raw columns, from Jiri
    Olsa.

    - Add per processor socket count aggregation in perf stat, from
    Stephane Eranian.

    - Add interval printing in 'perf stat', from Stephane Eranian.

    - 'perf test' improvements

    - Add support for wildcards in tracepoint system name, from Jiri
    Olsa.

    - Add anonymous huge page recognition, from Joshua Zhu.

    - perf build-id cache now can show DSOs present in a perf.data file
    that are not in the cache, to integrate with build-id servers being
    put in place by organizations such as Fedora.

    - perf top now shares more of the evsel config/creation routines with
    'record', paving the way for further integration like 'top'
    snapshots, etc.

    - perf top now supports DWARF callchains.

    - Fix mmap limitations on 32-bit, fix from David Miller.

    - 'perf bench numa mem' NUMA performance measurement suite

    - ... and lots of fixes, performance improvements, cleanups and other
    improvements I failed to list - see the shortlog and git log for
    details."

    * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (270 commits)
    perf/x86/amd: Enable northbridge performance counters on AMD family 15h
    perf/hwbp: Fix cleanup in case of kzalloc failure
    perf tools: Fix build with bison 2.3 and older.
    perf tools: Limit unwind support to x86 archs
    perf annotate: Make it to be able to skip unannotatable symbols
    perf gtk/annotate: Fail early if it can't annotate
    perf gtk/annotate: Show source lines with gray color
    perf gtk/annotate: Support multiple event annotation
    perf ui/gtk: Implement basic GTK2 annotation browser
    perf annotate: Fix warning message on a missing vmlinux
    perf buildid-cache: Add --update option
    uprobes/perf: Avoid uprobe_apply() whenever possible
    uprobes/perf: Teach trace_uprobe/perf code to use UPROBE_HANDLER_REMOVE
    uprobes/perf: Teach trace_uprobe/perf code to pre-filter
    uprobes/perf: Teach trace_uprobe/perf code to track the active perf_event's
    uprobes: Introduce uprobe_apply()
    perf: Introduce hw_perf_event->tp_target and ->tp_list
    uprobes/perf: Always increment trace_uprobe->nhit
    uprobes/tracing: Kill uprobe_trace_consumer, embed uprobe_consumer into trace_uprobe
    uprobes/tracing: Introduce is_trace_uprobe_enabled()
    ...

    Linus Torvalds
     

05 Feb, 2013

1 commit

  • The seccomp filters are currently built for the build host, not for the
    machine that they are going to run on, but they are also built for with
    the -m32 flag if the kernel is built for a 32 bit machine, both of which
    seems rather odd.

    It broke allyesconfig on my machine, which is x86-64, but building for
    32 bit ARM, with this error message:

    In file included from /usr/include/stdio.h:28:0,
    from samples/seccomp/bpf-fancy.c:15:
    /usr/include/features.h:324:26: fatal error: bits/predefs.h: No such file or directory

    because there are no 32 bit libc headers installed on this machine. We
    should really be building all the samples for the target machine rather
    than the build host, but since the infrastructure for that appears to be
    missing right now, let's be a little bit smarter and not pass the '-m32'
    flag to the HOSTCC when cross- compiling.

    Signed-off-by: Arnd Bergmann
    Acked-by: Kees Cook
    Cc: Heiko Carstens
    Cc: James Morris
    Acked-by: Will Drewry
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Arnd Bergmann
     

26 Jan, 2013

1 commit

  • The tracepoint sample code was used to teach developers how to
    create their own tracepoints. But now the trace_events have been
    added as a higher level that is used directly by developers today.

    Only the trace_event code should use the tracepoint interface
    directly and no new tracepoints should be added.

    Besides, the example had a race condition with the use of the
    ->d_name.name dentry field, as pointed out by Al Viro.

    Best just to remove the code so it wont be used by other developers.

    Link: http://lkml.kernel.org/r/20130123225523.GY4939@ZenIV.linux.org.uk

    Cc: Al Viro
    Acked-by: Mathieu Desnoyers
    Signed-off-by: Steven Rostedt

    Steven Rostedt
     

04 Jan, 2013

1 commit

  • CONFIG_HOTPLUG is going away as an option. As a result, the __dev*
    markings need to be removed.

    This change removes the last of the __dev* markings from the kernel from
    a variety of different, tiny, places.

    Based on patches originally written by Bill Pemberton, but redone by me
    in order to handle some of the coding style issues better, by hand.

    Cc: Bill Pemberton
    Signed-off-by: Greg Kroah-Hartman

    Greg Kroah-Hartman
     

12 Sep, 2012

1 commit

  • On s390 the flag to force 31 builds is -m31 instead of -m32 unlike
    on all (?) other architectures.

    Fixes this compile error:

    HOSTCC samples/seccomp/bpf-direct.o
    cc1: error: unrecognized command line option "-m32"
    make[2]: *** [samples/seccomp/bpf-direct.o] Error 1

    Signed-off-by: Heiko Carstens
    Acked-by: Kees Cook
    Signed-off-by: James Morris

    Heiko Carstens
     

17 Aug, 2012

1 commit


03 Aug, 2012

1 commit

  • The LO_ARG define needs to consider endianness also for 32 bit builds.

    The "bpf_fancy" test case didn't work on s390 in 32 bit and compat mode
    because the LO_ARG define resulted in a BPF program which read the upper
    halve of the 64 bit system call arguments instead of the lower halves.

    Signed-off-by: Heiko Carstens
    Acked-by: Kees Cook
    Signed-off-by: James Morris

    Heiko Carstens
     

25 Jul, 2012

1 commit

  • Pull HID updates from Jiri Kosina:
    "The list of changes worth pointing out explicitly:

    - We are getting 'UHID', which is a new framework for implementing HID
    transport drivers in userspace (this is different from HIDRAW, which
    is transport-independent and provides report parsing facilities;
    uhid is for the other (transport) part of the pipeline).

    It's needed for (and currently being used by) Bluetooth-LowEnergy,
    as its specification mandates things we don't want in the kernel.

    Written by David Herrmann.

    - there have been quite a few bugs in runtime suspend/resume paths
    (probably never reported to actually happen in the wild, but still).
    Alan Stern fixed those.

    - a few other driver updates and fixes and random new device support."

    * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid: (45 commits)
    HID: add ASUS AIO keyboard model AK1D
    HID: add support for Cypress barcode scanner 04B4:ED81
    HID: Allow drivers to be their own listener
    HID: usbhid: fix error paths in suspend
    HID: usbhid: check for suspend or reset before restarting
    HID: usbhid: replace HID_REPORTED_IDLE with HID_SUSPENDED
    HID: usbhid: inline some simple routines
    HID: usbhid: fix autosuspend calls
    HID: usbhid: fix use-after-free bug
    HID: hid-core: optimize in case of hidraw
    HID: hidraw: fix list->buffer memleak
    HID: uhid: Fix sending events with invalid data
    HID: roccat: added sensor sysfs attribute for Savu
    HID: Add driver for Holtek based keyboards with broken HID
    HID: Add suport for the brightness control keys on HP keyboards
    HID: magicmouse: Implement Multi-touch Protocol B (MT-B)
    HID: magicmouse: Removing report_touches switch
    HID: roccat: rename roccat_common functions to roccat_common2
    HID: roccat: fix wrong hid_err usage on struct usb_device
    HID: roccat: move functionality to roccat-common
    ...

    Linus Torvalds
     

28 Jun, 2012

1 commit


18 Jun, 2012

1 commit

  • This adds an example user-space program that emulates a 3 button mouse
    with wheel. It detects keyboard presses and moves the mouse accordingly.

    It register a fake HID device to feed the raw HID reports into the kernel.
    In this example, you could use uinput to get the same result, but this
    shows how to get the same behavior with uhid so you don't need HID parsers
    in user-space.

    Signed-off-by: David Herrmann
    Signed-off-by: Jiri Kosina

    David Herrmann
     

19 Apr, 2012

1 commit

  • This change fixes the compilation error triggered here for
    i386 allmodconfig in linux-next:
    http://kisskb.ellerman.id.au/kisskb/buildresult/6123842/

    Logic attempting to predict the host architecture has been
    removed from the Makefile. Instead, the bpf-direct sample
    should now compile on any architecture, but if the architecture
    is not supported, it will compile a minimal main() function.

    This change also ensures the samples are not compiled when
    there is no seccomp filter support.

    (Note, I wasn't able to reproduce the error locally, but
    the existing approach was clearly flawed. This tweak
    should resolve your issue and avoid other future weirdness.)

    Reported-by: Paul Gortmaker
    Suggested-by: Kees Cook
    Signed-off-by: Will Drewry
    Signed-off-by: James Morris

    Will Drewry
     

14 Apr, 2012

1 commit

  • Documents how system call filtering using Berkeley Packet
    Filter programs works and how it may be used.
    Includes an example for x86 and a semi-generic
    example using a macro-based code generator.

    Acked-by: Eric Paris
    Signed-off-by: Will Drewry
    Acked-by: Kees Cook

    v18: - added acked by
    - update no new privs numbers
    v17: - remove @compat note and add Pitfalls section for arch checking
    (keescook@chromium.org)
    v16: -
    v15: -
    v14: - rebase/nochanges
    v13: - rebase on to 88ebdda6159ffc15699f204c33feb3e431bf9bdc
    v12: - comment on the ptrace_event use
    - update arch support comment
    - note the behavior of SECCOMP_RET_DATA when there are multiple filters
    (keescook@chromium.org)
    - lots of samples/ clean up incl 64-bit bpf-direct support
    (markus@chromium.org)
    - rebase to linux-next
    v11: - overhaul return value language, updates (keescook@chromium.org)
    - comment on do_exit(SIGSYS)
    v10: - update for SIGSYS
    - update for new seccomp_data layout
    - update for ptrace option use
    v9: - updated bpf-direct.c for SIGILL
    v8: - add PR_SET_NO_NEW_PRIVS to the samples.
    v7: - updated for all the new stuff in v7: TRAP, TRACE
    - only talk about PR_SET_SECCOMP now
    - fixed bad JLE32 check (coreyb@linux.vnet.ibm.com)
    - adds dropper.c: a simple system call disabler
    v6: - tweak the language to note the requirement of
    PR_SET_NO_NEW_PRIVS being called prior to use. (luto@mit.edu)
    v5: - update sample to use system call arguments
    - adds a "fancy" example using a macro-based generator
    - cleaned up bpf in the sample
    - update docs to mention arguments
    - fix prctl value (eparis@redhat.com)
    - language cleanup (rdunlap@xenotime.net)
    v4: - update for no_new_privs use
    - minor tweaks
    v3: - call out BPF Berkeley Packet Filter (rdunlap@xenotime.net)
    - document use of tentative always-unprivileged
    - guard sample compilation for i386 and x86_64
    v2: - move code to samples (corbet@lwn.net)
    Signed-off-by: James Morris

    Will Drewry
     

09 Feb, 2012

1 commit

  • Add an rpmsg driver sample, which demonstrates how to communicate with
    an AMP-configured remote processor over the rpmsg bus.

    Note how once probed, the driver can immediately start sending messages
    using the rpmsg_send() API, without having to worry about creating endpoints
    or allocating rpmsg addresses: all that work is done by the rpmsg bus,
    and the required information is already embedded in the rpmsg channel
    that the driver is probed with.

    In this sample, the driver simply sends a "Hello World!" message to the remote
    processor repeatedly.

    Designed with Brian Swetland .

    Signed-off-by: Ohad Ben-Cohen
    Cc: Brian Swetland
    Cc: Arnd Bergmann
    Cc: Grant Likely
    Cc: Tony Lindgren
    Cc: Russell King
    Cc: Rusty Russell
    Cc: Andrew Morton
    Cc: Greg KH
    Cc: Stephen Boyd

    Ohad Ben-Cohen
     

01 Nov, 2011

1 commit


01 Jul, 2011

2 commits

  • The perf_event overflow handler does not receive any caller-derived
    argument, so many callers need to resort to looking up the perf_event
    in their local data structure. This is ugly and doesn't scale if a
    single callback services many perf_events.

    Fix by adding a context parameter to perf_event_create_kernel_counter()
    (and derived hardware breakpoints APIs) and storing it in the perf_event.
    The field can be accessed from the callback as event->overflow_handler_context.
    All callers are updated.

    Signed-off-by: Avi Kivity
    Signed-off-by: Peter Zijlstra
    Link: http://lkml.kernel.org/r/1309362157-6596-2-git-send-email-avi@redhat.com
    Signed-off-by: Ingo Molnar

    Avi Kivity
     
  • The nmi parameter indicated if we could do wakeups from the current
    context, if not, we would set some state and self-IPI and let the
    resulting interrupt do the wakeup.

    For the various event classes:

    - hardware: nmi=0; PMI is in fact an NMI or we run irq_work_run from
    the PMI-tail (ARM etc.)
    - tracepoint: nmi=0; since tracepoint could be from NMI context.
    - software: nmi=[0,1]; some, like the schedule thing cannot
    perform wakeups, and hence need 0.

    As one can see, there is very little nmi=1 usage, and the down-side of
    not using it is that on some platforms some software events can have a
    jiffy delay in wakeup (when arch_irq_work_raise isn't implemented).

    The up-side however is that we can remove the nmi parameter and save a
    bunch of conditionals in fast paths.

    Signed-off-by: Peter Zijlstra
    Cc: Michael Cree
    Cc: Will Deacon
    Cc: Deng-Cheng Zhu
    Cc: Anton Blanchard
    Cc: Eric B Munson
    Cc: Heiko Carstens
    Cc: Paul Mundt
    Cc: David S. Miller
    Cc: Frederic Weisbecker
    Cc: Jason Wessel
    Cc: Don Zickus
    Link: http://lkml.kernel.org/n/tip-agjev8eu666tvknpb3iaj0fg@git.kernel.org
    Signed-off-by: Ingo Molnar

    Peter Zijlstra
     

23 May, 2011

1 commit


21 Apr, 2011

1 commit

  • samples/hid-example.o needs some Kconfig and Makefile additions in order
    to build. It should use headers from the build tree, so use
    HEADERS_CHECK to require that those header files be present.

    Change the kconfig symbol from tristate to bool since userspace cannot be
    built as loadable modules.

    However, I don't understand why the userspace header files are not present
    as reported in Andrew's build log, since it builds OK on x86_64 without
    any of these changes.

    Signed-off-by: Randy Dunlap
    Cc: Alan Ott
    Cc: Jiri Kosina
    Signed-off-by: Andrew Morton
    Signed-off-by: Jiri Kosina

    Randy Dunlap
     

09 Apr, 2011

1 commit

  • On systems where userspace doesn't have new hidraw.h populated to
    /usr/include, the hidraw sample won't compile as it's missing the new
    ioctl defitions.

    Introduce temporary ugly workaround to define the ioctls "manually"
    in such cases, just to avoid miscompilation in allmodconfig cases.

    Reported-by: Stephen Rothwell
    Signed-off-by: Jiri Kosina

    Jiri Kosina
     

31 Mar, 2011

1 commit


22 Mar, 2011

1 commit


30 Oct, 2010

1 commit


23 Oct, 2010

1 commit

  • * 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
    vfs: make no_llseek the default
    vfs: don't use BKL in default_llseek
    llseek: automatically add .llseek fop
    libfs: use generic_file_llseek for simple_attr
    mac80211: disallow seeks in minstrel debug code
    lirc: make chardev nonseekable
    viotape: use noop_llseek
    raw: use explicit llseek file operations
    ibmasmfs: use generic_file_llseek
    spufs: use llseek in all file operations
    arm/omap: use generic_file_llseek in iommu_debug
    lkdtm: use generic_file_llseek in debugfs
    net/wireless: use generic_file_llseek in debugfs
    drm: use noop_llseek

    Linus Torvalds
     

15 Oct, 2010

1 commit

  • All file_operations should get a .llseek operation so we can make
    nonseekable_open the default for future file operations without a
    .llseek pointer.

    The three cases that we can automatically detect are no_llseek, seq_lseek
    and default_llseek. For cases where we can we can automatically prove that
    the file offset is always ignored, we use noop_llseek, which maintains
    the current behavior of not returning an error from a seek.

    New drivers should normally not use noop_llseek but instead use no_llseek
    and call nonseekable_open at open time. Existing drivers can be converted
    to do the same when the maintainer knows for certain that no user code
    relies on calling seek on the device file.

    The generated code is often incorrectly indented and right now contains
    comments that clarify for each added line why a specific variant was
    chosen. In the version that gets submitted upstream, the comments will
    be gone and I will manually fix the indentation, because there does not
    seem to be a way to do that using coccinelle.

    Some amount of new code is currently sitting in linux-next that should get
    the same modifications, which I will do at the end of the merge window.

    Many thanks to Julia Lawall for helping me learn to write a semantic
    patch that does all this.

    ===== begin semantic patch =====
    // This adds an llseek= method to all file operations,
    // as a preparation for making no_llseek the default.
    //
    // The rules are
    // - use no_llseek explicitly if we do nonseekable_open
    // - use seq_lseek for sequential files
    // - use default_llseek if we know we access f_pos
    // - use noop_llseek if we know we don't access f_pos,
    // but we still want to allow users to call lseek
    //
    @ open1 exists @
    identifier nested_open;
    @@
    nested_open(...)
    {

    }

    @ open exists@
    identifier open_f;
    identifier i, f;
    identifier open1.nested_open;
    @@
    int open_f(struct inode *i, struct file *f)
    {

    }

    @ read disable optional_qualifier exists @
    identifier read_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    expression E;
    identifier func;
    @@
    ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
    {

    }

    @ read_no_fpos disable optional_qualifier exists @
    identifier read_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    @@
    ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
    {
    ... when != off
    }

    @ write @
    identifier write_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    expression E;
    identifier func;
    @@
    ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
    {

    }

    @ write_no_fpos @
    identifier write_f;
    identifier f, p, s, off;
    type ssize_t, size_t, loff_t;
    @@
    ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
    {
    ... when != off
    }

    @ fops0 @
    identifier fops;
    @@
    struct file_operations fops = {
    ...
    };

    @ has_llseek depends on fops0 @
    identifier fops0.fops;
    identifier llseek_f;
    @@
    struct file_operations fops = {
    ...
    .llseek = llseek_f,
    ...
    };

    @ has_read depends on fops0 @
    identifier fops0.fops;
    identifier read_f;
    @@
    struct file_operations fops = {
    ...
    .read = read_f,
    ...
    };

    @ has_write depends on fops0 @
    identifier fops0.fops;
    identifier write_f;
    @@
    struct file_operations fops = {
    ...
    .write = write_f,
    ...
    };

    @ has_open depends on fops0 @
    identifier fops0.fops;
    identifier open_f;
    @@
    struct file_operations fops = {
    ...
    .open = open_f,
    ...
    };

    // use no_llseek if we call nonseekable_open
    ////////////////////////////////////////////
    @ nonseekable1 depends on !has_llseek && has_open @
    identifier fops0.fops;
    identifier nso ~= "nonseekable_open";
    @@
    struct file_operations fops = {
    ... .open = nso, ...
    +.llseek = no_llseek, /* nonseekable */
    };

    @ nonseekable2 depends on !has_llseek @
    identifier fops0.fops;
    identifier open.open_f;
    @@
    struct file_operations fops = {
    ... .open = open_f, ...
    +.llseek = no_llseek, /* open uses nonseekable */
    };

    // use seq_lseek for sequential files
    /////////////////////////////////////
    @ seq depends on !has_llseek @
    identifier fops0.fops;
    identifier sr ~= "seq_read";
    @@
    struct file_operations fops = {
    ... .read = sr, ...
    +.llseek = seq_lseek, /* we have seq_read */
    };

    // use default_llseek if there is a readdir
    ///////////////////////////////////////////
    @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier readdir_e;
    @@
    // any other fop is used that changes pos
    struct file_operations fops = {
    ... .readdir = readdir_e, ...
    +.llseek = default_llseek, /* readdir is present */
    };

    // use default_llseek if at least one of read/write touches f_pos
    /////////////////////////////////////////////////////////////////
    @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier read.read_f;
    @@
    // read fops use offset
    struct file_operations fops = {
    ... .read = read_f, ...
    +.llseek = default_llseek, /* read accesses f_pos */
    };

    @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier write.write_f;
    @@
    // write fops use offset
    struct file_operations fops = {
    ... .write = write_f, ...
    + .llseek = default_llseek, /* write accesses f_pos */
    };

    // Use noop_llseek if neither read nor write accesses f_pos
    ///////////////////////////////////////////////////////////

    @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier read_no_fpos.read_f;
    identifier write_no_fpos.write_f;
    @@
    // write fops use offset
    struct file_operations fops = {
    ...
    .write = write_f,
    .read = read_f,
    ...
    +.llseek = noop_llseek, /* read and write both use no f_pos */
    };

    @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier write_no_fpos.write_f;
    @@
    struct file_operations fops = {
    ... .write = write_f, ...
    +.llseek = noop_llseek, /* write uses no f_pos */
    };

    @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    identifier read_no_fpos.read_f;
    @@
    struct file_operations fops = {
    ... .read = read_f, ...
    +.llseek = noop_llseek, /* read uses no f_pos */
    };

    @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
    identifier fops0.fops;
    @@
    struct file_operations fops = {
    ...
    +.llseek = noop_llseek, /* no read or write fn */
    };
    ===== End semantic patch =====

    Signed-off-by: Arnd Bergmann
    Cc: Julia Lawall
    Cc: Christoph Hellwig

    Arnd Bergmann
     

02 Oct, 2010

1 commit

  • The kfifo_dma family of functions use sg_mark_end() on the last element in
    their scatterlist. This forces use of a fresh scatterlist for each DMA
    operation, which makes recycling a single scatterlist impossible.

    Change the behavior of the kfifo_dma functions to match the usage of the
    dma_map_sg function. This means that users must respect the returned
    nents value. The sample code is updated to reflect the change.

    This bug is trivial to cause: call kfifo_dma_in_prepare() such that it
    prepares a scatterlist with a single entry comprising the whole fifo.
    This is the case when you map the entirety of a newly created empty fifo.
    This causes the setup_sgl() function to mark the first scatterlist entry
    as the end of the chain, no matter what comes after it.

    Afterwards, add and remove some data from the fifo such that another call
    to kfifo_dma_in_prepare() will create two scatterlist entries. It returns
    nents=2. However, due to the previous sg_mark_end() call, sg_is_last()
    will now return true for the first scatterlist element. This causes the
    sample code to print a single scatterlist element when it should print
    two.

    By removing the call to sg_mark_end(), we make the API as similar as
    possible to the DMA mapping API. All users are required to respect the
    returned nents.

    Signed-off-by: Ira W. Snyder
    Cc: Stefani Seibold
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Ira W. Snyder
     

21 Aug, 2010

5 commits

  • Provide a check in all the kfifo examples to validate the correct
    execution of each testcase.

    Signed-off-by: Andrea Righi
    Acked-by: Stefani Seibold
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Andrea Righi
     
  • We use a dynamically allocated kfifo in the dma example, so we need to
    free it when unloading the module.

    Signed-off-by: Andrea Righi
    Acked-by: Stefani Seibold
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Andrea Righi
     
  • The scatterlist is used uninitialized in kfifo_dma_in_prepare(). This
    triggers the following bug if CONFIG_DEBUG_SG=y:

    ------------[ cut here ]------------
    kernel BUG at include/linux/scatterlist.h:65!
    invalid opcode: 0000 [#1] PREEMPT SMP
    ...
    Call Trace:
    [] setup_sgl+0x6b/0xe0
    [] ? example_init+0x0/0x265 [dma_example]
    [] __kfifo_dma_in_prepare+0x21/0x30
    [] example_init+0x124/0x265 [dma_example]
    [] ? trace_module_notify+0x25/0x370
    [] ? free_pages_prepare+0x11e/0x1e0
    [] ? get_parent_ip+0x11/0x50
    [] ? trace_module_notify+0x25/0x370
    [] ? trace_hardirqs_on+0xd/0x10
    [] ? mutex_unlock+0xe/0x10
    [] ? trace_module_notify+0x41/0x370
    [] ? __blocking_notifier_call_chain+0x45/0x80
    [] ? vfree+0x2a/0x30
    [] ? up_read+0x23/0x40
    [] ? __blocking_notifier_call_chain+0x65/0x80
    [] do_one_initcall+0x43/0x180
    [] sys_init_module+0xba/0x200
    [] system_call_fastpath+0x16/0x1b
    RIP [] setup_sgl_buf+0x1a1/0x1b0
    RSP
    ---[ end trace a72b979fd3c1d3a5 ]---

    Add the proper initialization to avoid the bug.

    Signed-off-by: Andrea Righi
    Acked-by: Stefani Seibold
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Andrea Righi
     
  • Provide a static array of expected items that kfifo should contain at the
    end of the test to validate it.

    Signed-off-by: Andrea Righi
    Cc: Stefani Seibold
    Cc: Greg KH
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Andrea Righi
     
  • Add a testcase for kfifo_skip() to the byte stream fifo example.

    Signed-off-by: Andrea Righi
    Cc: Greg KH
    Acked-by: Stefani Seibold
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Andrea Righi
     

11 Aug, 2010

1 commit

  • Add four examples to the kernel sample directory.

    It shows how to handle:
    - a byte stream fifo
    - a integer type fifo
    - a dynamic record sized fifo
    - the fifo DMA functions

    [akpm@linux-foundation.org: coding-style fixes]
    Signed-off-by: Stefani Seibold
    Cc: Greg KH
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Stefani Seibold
     

05 Aug, 2010

1 commit

  • This KProbes example is a little useless if it doesn't print anything.
    For MIPS print similar messages to those produced on x86 and PPC.

    Signed-off-by: David Daney
    To: linux-mips@linux-mips.org
    To: ananth@in.ibm.com
    To: anil.s.keshavamurthy@intel.com
    To: davem@davemloft.net
    To: masami.hiramatsu.pt@hitachi.com
    Cc: linux-kernel@vger.kernel.org
    Cc: hschauhan@nulltrace.org
    Patchwork: https://patchwork.linux-mips.org/patch/1528/
    Signed-off-by: Ralf Baechle

    David Daney
     

14 May, 2010

1 commit

  • This patch adds data to be passed to tracepoint callbacks.

    The created functions from DECLARE_TRACE() now need a mandatory data
    parameter. For example:

    DECLARE_TRACE(mytracepoint, int value, value)

    Will create the register function:

    int register_trace_mytracepoint((void(*)(void *data, int value))probe,
    void *data);

    As the first argument, all callbacks (probes) must take a (void *data)
    parameter. So a callback for the above tracepoint will look like:

    void myprobe(void *data, int value)
    {
    }

    The callback may choose to ignore the data parameter.

    This change allows callbacks to register a private data pointer along
    with the function probe.

    void mycallback(void *data, int value);

    register_trace_mytracepoint(mycallback, mydata);

    Then the mycallback() will receive the "mydata" as the first parameter
    before the args.

    A more detailed example:

    DECLARE_TRACE(mytracepoint, TP_PROTO(int status), TP_ARGS(status));

    /* In the C file */

    DEFINE_TRACE(mytracepoint, TP_PROTO(int status), TP_ARGS(status));

    [...]

    trace_mytracepoint(status);

    /* In a file registering this tracepoint */

    int my_callback(void *data, int status)
    {
    struct my_struct my_data = data;
    [...]
    }

    [...]
    my_data = kmalloc(sizeof(*my_data), GFP_KERNEL);
    init_my_data(my_data);
    register_trace_mytracepoint(my_callback, my_data);

    The same callback can also be registered to the same tracepoint as long
    as the data registered is different. Note, the data must also be used
    to unregister the callback:

    unregister_trace_mytracepoint(my_callback, my_data);

    Because of the data parameter, tracepoints declared this way can not have
    no args. That is:

    DECLARE_TRACE(mytracepoint, TP_PROTO(void), TP_ARGS());

    will cause an error.

    If no arguments are needed, a new macro can be used instead:

    DECLARE_TRACE_NOARGS(mytracepoint);

    Since there are no arguments, the proto and args fields are left out.

    This is part of a series to make the tracepoint footprint smaller:

    text data bss dec hex filename
    4913961 1088356 861512 6863829 68bbd5 vmlinux.orig
    4914025 1088868 861512 6864405 68be15 vmlinux.class
    4918492 1084612 861512 6864616 68bee8 vmlinux.tracepoint

    Again, this patch also increases the size of the kernel, but
    lays the ground work for decreasing it.

    v5: Fixed net/core/drop_monitor.c to handle these updates.

    v4: Moved the DECLARE_TRACE() DECLARE_TRACE_NOARGS out of the
    #ifdef CONFIG_TRACE_POINTS, since the two are the same in both
    cases. The __DECLARE_TRACE() is what changes.
    Thanks to Frederic Weisbecker for pointing this out.

    v3: Made all register_* functions require data to be passed and
    all callbacks to take a void * parameter as its first argument.
    This makes the calling functions comply with C standards.

    Also added more comments to the modifications of DECLARE_TRACE().

    v2: Made the DECLARE_TRACE() have the ability to pass arguments
    and added a new DECLARE_TRACE_NOARGS() for tracepoints that
    do not need any arguments.

    Acked-by: Mathieu Desnoyers
    Acked-by: Masami Hiramatsu
    Acked-by: Frederic Weisbecker
    Cc: Neil Horman
    Cc: David S. Miller
    Signed-off-by: Steven Rostedt

    Steven Rostedt
     

30 Mar, 2010

1 commit

  • …it slab.h inclusion from percpu.h

    percpu.h is included by sched.h and module.h and thus ends up being
    included when building most .c files. percpu.h includes slab.h which
    in turn includes gfp.h making everything defined by the two files
    universally available and complicating inclusion dependencies.

    percpu.h -> slab.h dependency is about to be removed. Prepare for
    this change by updating users of gfp and slab facilities include those
    headers directly instead of assuming availability. As this conversion
    needs to touch large number of source files, the following script is
    used as the basis of conversion.

    http://userweb.kernel.org/~tj/misc/slabh-sweep.py

    The script does the followings.

    * Scan files for gfp and slab usages and update includes such that
    only the necessary includes are there. ie. if only gfp is used,
    gfp.h, if slab is used, slab.h.

    * When the script inserts a new include, it looks at the include
    blocks and try to put the new include such that its order conforms
    to its surrounding. It's put in the include block which contains
    core kernel includes, in the same order that the rest are ordered -
    alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
    doesn't seem to be any matching order.

    * If the script can't find a place to put a new include (mostly
    because the file doesn't have fitting include block), it prints out
    an error message indicating which .h file needs to be added to the
    file.

    The conversion was done in the following steps.

    1. The initial automatic conversion of all .c files updated slightly
    over 4000 files, deleting around 700 includes and adding ~480 gfp.h
    and ~3000 slab.h inclusions. The script emitted errors for ~400
    files.

    2. Each error was manually checked. Some didn't need the inclusion,
    some needed manual addition while adding it to implementation .h or
    embedding .c file was more appropriate for others. This step added
    inclusions to around 150 files.

    3. The script was run again and the output was compared to the edits
    from #2 to make sure no file was left behind.

    4. Several build tests were done and a couple of problems were fixed.
    e.g. lib/decompress_*.c used malloc/free() wrappers around slab
    APIs requiring slab.h to be added manually.

    5. The script was run on all .h files but without automatically
    editing them as sprinkling gfp.h and slab.h inclusions around .h
    files could easily lead to inclusion dependency hell. Most gfp.h
    inclusion directives were ignored as stuff from gfp.h was usually
    wildly available and often used in preprocessor macros. Each
    slab.h inclusion directive was examined and added manually as
    necessary.

    6. percpu.h was updated not to include slab.h.

    7. Build test were done on the following configurations and failures
    were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
    distributed build env didn't work with gcov compiles) and a few
    more options had to be turned off depending on archs to make things
    build (like ipr on powerpc/64 which failed due to missing writeq).

    * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
    * powerpc and powerpc64 SMP allmodconfig
    * sparc and sparc64 SMP allmodconfig
    * ia64 SMP allmodconfig
    * s390 SMP allmodconfig
    * alpha SMP allmodconfig
    * um on x86_64 SMP allmodconfig

    8. percpu.h modifications were reverted so that it could be applied as
    a separate patch and serve as bisection point.

    Given the fact that I had only a couple of failures from tests on step
    6, I'm fairly confident about the coverage of this conversion patch.
    If there is a breakage, it's likely to be something in one of the arch
    headers which should be easily discoverable easily on most builds of
    the specific arch.

    Signed-off-by: Tejun Heo <tj@kernel.org>
    Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

    Tejun Heo
     

10 Mar, 2010

1 commit


08 Mar, 2010

3 commits

  • Constify struct sysfs_ops.

    This is part of the ops structure constification
    effort started by Arjan van de Ven et al.

    Benefits of this constification:

    * prevents modification of data that is shared
    (referenced) by many other structure instances
    at runtime

    * detects/prevents accidental (but not intentional)
    modification attempts on archs that enforce
    read-only kernel data at runtime

    * potentially better optimized code as the compiler
    can assume that the const data cannot be changed

    * the compiler/linker move const data into .rodata
    and therefore exclude them from false sharing

    Signed-off-by: Emese Revfy
    Acked-by: David Teigland
    Acked-by: Matt Domsch
    Acked-by: Maciej Sosnowski
    Acked-by: Hans J. Koch
    Acked-by: Pekka Enberg
    Acked-by: Jens Axboe
    Acked-by: Stephen Hemminger
    Signed-off-by: Greg Kroah-Hartman

    Emese Revfy
     
  • No change in functionality.

    Signed-off-by: Radu Voicilas
    Signed-off-by: Greg Kroah-Hartman

    Radu Voicilas
     
  • No change in functionality.

    Signed-off-by: Radu Voicilas
    Signed-off-by: Greg Kroah-Hartman

    Radu Voicilas
     

27 Feb, 2010

1 commit

  • Add __percpu sparse annotations to hw_breakpoint.

    These annotations are to make sparse consider percpu variables to be
    in a different address space and warn if accessed without going
    through percpu accessors. This patch doesn't affect normal builds.

    In kernel/hw_breakpoint.c, per_cpu(nr_task_bp_pinned, cpu)'s will
    trigger spurious noderef related warnings from sparse. Changing it to
    &per_cpu(nr_task_bp_pinned[0], cpu) will work around the problem but
    deemed to ugly by the maintainer. Leave it alone until better
    solution can be found.

    Signed-off-by: Tejun Heo
    Cc: Stephen Rothwell
    Cc: K.Prasad
    LKML-Reference:
    Signed-off-by: Frederic Weisbecker

    Tejun Heo
     

12 Dec, 2009

1 commit

  • …/git/tip/linux-2.6-tip

    * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (57 commits)
    x86, perf events: Check if we have APIC enabled
    perf_event: Fix variable initialization in other codepaths
    perf kmem: Fix unused argument build warning
    perf symbols: perf_header__read_build_ids() offset'n'size should be u64
    perf symbols: dsos__read_build_ids() should read both user and kernel buildids
    perf tools: Align long options which have no short forms
    perf kmem: Show usage if no option is specified
    sched: Mark sched_clock() as notrace
    perf sched: Add max delay time snapshot
    perf tools: Correct size given to memset
    perf_event: Fix perf_swevent_hrtimer() variable initialization
    perf sched: Fix for getting task's execution time
    tracing/kprobes: Fix field creation's bad error handling
    perf_event: Cleanup for cpu_clock_perf_event_update()
    perf_event: Allocate children's perf_event_ctxp at the right time
    perf_event: Clean up __perf_event_init_context()
    hw-breakpoints: Modify breakpoints without unregistering them
    perf probe: Update perf-probe document
    perf probe: Support --del option
    trace-kprobe: Support delete probe syntax
    ...

    Linus Torvalds