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    Subject[PATCH V7 00/15] perf/x86: Add perf text poke events
    Date
    Hi

    Here are patches to add a text poke event to record changes to kernel text
    (i.e. self-modifying code) in order to support tracers like Intel PT
    decoding through jump labels, kprobes and ftrace trampolines.

    The first 8 patches make the kernel changes and the subsequent patches are
    tools changes.

    The next 4 patches add support for updating perf tools' data cache
    with the changed bytes.

    The next patch is an Intel PT specific tools change.

    The final 2 patches add perf script --show-text-poke-events option

    Patches also here:

    git://git.infradead.org/users/ahunter/linux-perf.git text_poke

    Changes in V7

    perf: Add perf text poke event
    perf/x86: Add support for perf text poke event for text_poke_bp_batch() callers
    kprobes: Add symbols for kprobe insn pages
    kprobes: Add perf ksymbol events for kprobe insn pages
    perf/x86: Add perf text poke events for kprobes
    ftrace: Add symbols for ftrace trampolines
    ftrace: Add perf ksymbol events for ftrace trampolines
    ftrace: Add perf text poke events for ftrace trampolines

    Added Peter's Ack
    Improved commit message for text_poke events for ftrace trampolines

    perf kcore_copy: Fix module map when there are no modules loaded
    perf evlist: Disable 'immediate' events last
    perf tools: Add support for PERF_RECORD_TEXT_POKE
    perf tools: Add support for PERF_RECORD_KSYMBOL_TYPE_OOL
    perf intel-pt: Add support for text poke events
    perf script: Add option --show-text-poke-events
    perf script: Show text poke address symbol

    Re-based on Arnaldo's perf/core branch

    Changes in V6

    perf: Add perf text poke event

    Adjustments due to re-base on top of cgroup event patches

    perf/x86: Add perf text poke events for kprobes

    Expand commit message
    Add Masami's Ack

    perf tools: Add support for PERF_RECORD_TEXT_POKE

    Adjustments due to re-base on top of cgroup event patches
    Improvements to perf_event__fprintf_text_poke()

    perf script: Add option --show-text-poke-events
    perf script: Show text poke address symbol

    New patches

    Changes in V5

    perf/x86: Add perf text poke events for kprobes

    Simplify optimized kprobes events (Peter)

    Changes in V4

    kprobes: Add symbols for kprobe insn pages

    Change "module name" from kprobe to __builtin__kprobes
    Added comment about "module name" use

    ftrace: Add symbols for ftrace trampolines

    Change "module name" from ftrace to __builtin__ftrace
    Move calls of ftrace_add_trampoline_to_kallsyms() and
    ftrace_remove_trampoline_from_kallsyms() into
    kernel/trace/ftrace.c
    Added comment about "module name" use

    ftrace: Add perf ksymbol events for ftrace trampolines

    Move changes into kernel/trace/ftrace.c

    ftrace: Add perf text poke events for ftrace trampolines

    Move changes into kernel/trace/ftrace.c

    Changes in V3:

    perf: Add perf text poke event

    To prevent warning, cast pointer to (unsigned long) not (u64)

    kprobes: Add symbols for kprobe insn pages

    Expand commit message
    Remove un-needed declarations of kprobe_cache_get_kallsym() and arch_kprobe_get_kallsym() when !CONFIG_KPROBES

    ftrace: Add symbols for ftrace trampolines

    Expand commit message
    Make ftrace_get_trampoline_kallsym() static

    Changes in V2:

    perf: Add perf text poke event

    Separate out x86 changes
    The text poke event now has old len and new len
    Revised commit message

    perf/x86: Add support for perf text poke event for text_poke_bp_batch() callers

    New patch containing x86 changes from original first patch

    kprobes: Add symbols for kprobe insn pages
    kprobes: Add perf ksymbol events for kprobe insn pages
    perf/x86: Add perf text poke events for kprobes
    ftrace: Add symbols for ftrace trampolines
    ftrace: Add perf ksymbol events for ftrace trampolines
    ftrace: Add perf text poke events for ftrace trampolines
    perf kcore_copy: Fix module map when there are no modules loaded
    perf evlist: Disable 'immediate' events last

    New patches

    perf tools: Add support for PERF_RECORD_TEXT_POKE

    The text poke event now has old len and new len
    Also select ksymbol events with text poke events

    perf tools: Add support for PERF_RECORD_KSYMBOL_TYPE_OOL

    New patch

    perf intel-pt: Add support for text poke events

    The text poke event now has old len and new len
    Allow for the address not having a map yet


    Changes since RFC:

    Dropped 'flags' from the new event. The consensus seemed to be that text
    pokes should employ a scheme similar to x86's INT3 method instead.

    dropped tools patches already applied.


    Example:

    For jump labels, the kernel needs
    CONFIG_JUMP_LABEL=y
    and also an easy to flip jump label is in sysctl_schedstats() which needs
    CONFIG_SCHEDSTATS=y
    CONFIG_PROC_SYSCTL=y
    CONFIG_SCHED_DEBUG=y

    Also note the 'sudo perf record' is put into the background which, as
    written, needs sudo credential caching (otherwise the background task
    will stop awaiting the sudo password), hence the 'sudo echo' to start.

    Before:

    $ sudo echo
    $ sudo perf record -o perf.data.before --kcore -a -e intel_pt//k -m,64M &
    [1] 1640
    $ cat /proc/sys/kernel/sched_schedstats
    0
    $ sudo bash -c 'echo 1 > /proc/sys/kernel/sched_schedstats'
    $ cat /proc/sys/kernel/sched_schedstats
    1
    $ sudo bash -c 'echo 0 > /proc/sys/kernel/sched_schedstats'
    $ cat /proc/sys/kernel/sched_schedstats
    0
    $ sudo kill 1640
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 16.635 MB perf.data.before ]
    $ perf script -i perf.data.before --itrace=e >/dev/null
    Warning:
    1946 instruction trace errors

    After:

    $ sudo echo
    $ sudo perf record -o perf.data.after --kcore -a -e intel_pt//k -m,64M &
    [1] 1882
    $ cat /proc/sys/kernel/sched_schedstats
    0
    $ sudo bash -c 'echo 1 > /proc/sys/kernel/sched_schedstats'
    $ cat /proc/sys/kernel/sched_schedstats
    1
    $ sudo bash -c 'echo 0 > /proc/sys/kernel/sched_schedstats'
    $ cat /proc/sys/kernel/sched_schedstats
    0
    $ sudo kill 1882
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 10.893 MB perf.data.after ]
    $ perf script -i perf.data.after --itrace=e
    $


    Adrian Hunter (15):
    perf: Add perf text poke event
    perf/x86: Add support for perf text poke event for text_poke_bp_batch() callers
    kprobes: Add symbols for kprobe insn pages
    kprobes: Add perf ksymbol events for kprobe insn pages
    perf/x86: Add perf text poke events for kprobes
    ftrace: Add symbols for ftrace trampolines
    ftrace: Add perf ksymbol events for ftrace trampolines
    ftrace: Add perf text poke events for ftrace trampolines
    perf kcore_copy: Fix module map when there are no modules loaded
    perf evlist: Disable 'immediate' events last
    perf tools: Add support for PERF_RECORD_TEXT_POKE
    perf tools: Add support for PERF_RECORD_KSYMBOL_TYPE_OOL
    perf intel-pt: Add support for text poke events
    perf script: Add option --show-text-poke-events
    perf script: Show text poke address symbol

    arch/x86/include/asm/kprobes.h | 2 +
    arch/x86/kernel/alternative.c | 37 ++++++++++-
    arch/x86/kernel/kprobes/core.c | 15 ++++-
    arch/x86/kernel/kprobes/opt.c | 38 +++++++++--
    include/linux/ftrace.h | 12 ++--
    include/linux/kprobes.h | 15 +++++
    include/linux/perf_event.h | 8 +++
    include/uapi/linux/perf_event.h | 26 +++++++-
    kernel/events/core.c | 90 +++++++++++++++++++++++++-
    kernel/kallsyms.c | 42 +++++++++++--
    kernel/kprobes.c | 57 +++++++++++++++++
    kernel/trace/ftrace.c | 101 +++++++++++++++++++++++++++++-
    tools/include/uapi/linux/perf_event.h | 26 +++++++-
    tools/lib/perf/include/perf/event.h | 9 +++
    tools/perf/Documentation/perf-script.txt | 4 ++
    tools/perf/arch/x86/util/intel-pt.c | 4 ++
    tools/perf/builtin-record.c | 45 +++++++++++++
    tools/perf/builtin-script.c | 23 ++++++-
    tools/perf/tests/perf-record.c | 4 +-
    tools/perf/util/dso.c | 3 +
    tools/perf/util/dso.h | 1 +
    tools/perf/util/event.c | 62 +++++++++++++++++-
    tools/perf/util/event.h | 9 ++-
    tools/perf/util/evlist.c | 31 ++++++---
    tools/perf/util/evsel.c | 7 ++-
    tools/perf/util/intel-pt.c | 77 ++++++++++++++++++++++-
    tools/perf/util/machine.c | 49 +++++++++++++++
    tools/perf/util/machine.h | 3 +
    tools/perf/util/map.c | 5 ++
    tools/perf/util/map.h | 3 +-
    tools/perf/util/perf_api_probe.c | 10 +++
    tools/perf/util/perf_api_probe.h | 1 +
    tools/perf/util/perf_event_attr_fprintf.c | 1 +
    tools/perf/util/record.h | 1 +
    tools/perf/util/session.c | 23 +++++++
    tools/perf/util/symbol-elf.c | 7 +++
    tools/perf/util/symbol.c | 1 +
    tools/perf/util/tool.h | 3 +-
    38 files changed, 815 insertions(+), 40 deletions(-)


    Regards
    Adrian

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