Re: [PATCH v5 0/6] enable creating [k,u]probe with perf_event_open
On 4/9/18 9:45 PM, Ravi Bangoria wrote: Hi Song, On 12/07/2017 04:15 AM, Song Liu wrote: With current kernel, user space tools can only create/destroy [k,u]probes with a text-based API (kprobe_events and uprobe_events in tracefs). This approach relies on user space to clean up the [k,u]probe after using them. However, this is not easy for user space to clean up properly. To solve this problem, we introduce a file descriptor based API. Specifically, we extended perf_event_open to create [k,u]probe, and attach this [k,u]probe to the file descriptor created by perf_event_open. These [k,u]probe are associated with this file descriptor, so they are not available in tracefs. Sorry for being late. One simple question.. Will it be good to support k/uprobe arguments with perf_event_open()? Do you have any plans about that? no plans for that. People that use text based interfaces should probably be using text interfaces consistently. imo mixing FD-based kprobe api with text is not worth the complexity.
Re: [PATCH v5 0/6] enable creating [k,u]probe with perf_event_open
Hi Song, On 12/07/2017 04:15 AM, Song Liu wrote: > With current kernel, user space tools can only create/destroy [k,u]probes > with a text-based API (kprobe_events and uprobe_events in tracefs). This > approach relies on user space to clean up the [k,u]probe after using them. > However, this is not easy for user space to clean up properly. > > To solve this problem, we introduce a file descriptor based API. > Specifically, we extended perf_event_open to create [k,u]probe, and attach > this [k,u]probe to the file descriptor created by perf_event_open. These > [k,u]probe are associated with this file descriptor, so they are not > available in tracefs. Sorry for being late. One simple question.. Will it be good to support k/uprobe arguments with perf_event_open()? Do you have any plans about that? Thanks, Ravi
Re: [PATCH v5 0/6] enable creating [k,u]probe with perf_event_open
Took 1-4, Thanks!
Re: [PATCH v5 0/6] enable creating [k,u]probe with perf_event_open
> On Dec 8, 2017, at 11:57 AM, Daniel Borkmannwrote: > > On 12/06/2017 11:45 PM, Song Liu wrote: >> Changes PATCH v4 to PATCH v5: >> Remove PERF_PROBE_CONFIG_IS_RETPROBE from uapi, use PMU_FORMAT_ATTR >> instead. >> >> Changes PATCH v3 to PATCH v4: >> Remove uapi define MAX_PROBE_FUNC_NAME_LEN, use KSYM_NAME_LEN instead. >> Add flag PERF_PROBE_CONFIG_IS_RETPROBE for config field of [k,u]probe. >> Optimize ifdef's of CONFIG_KPROBE_EVENTS and CONFIG_UPROBE_EVENTS. >> Optimize checks in perf_event_is_tracing(). >> Optimize perf_tp_register(). >> >> Changes PATCH v2 to PATCH v3: >> Remove fixed type PERF_TYPE_KPROBE and PERF_TYPE_UPROBE, use dynamic >> type instead. >> Update userspace (samples/bpf, bcc) to look up type from sysfs. >> Change License info in test_many_kprobe_user.c as Philippe Ombredanne >> suggested. >> >> Changes PATCH v1 to PATCH v2: >> Split PERF_TYPE_PROBE into PERF_TYPE_KPROBE and PERF_TYPE_UPROBE. >> Split perf_probe into perf_kprobe and perf_uprobe. >> Remove struct probe_desc, use config1 and config2 instead. >> >> Changes RFC v2 to PATCH v1: >> Check type PERF_TYPE_PROBE in perf_event_set_filter(). >> Rebase on to tip perf/core. >> >> Changes RFC v1 to RFC v2: >> Fix build issue reported by kbuild test bot by adding ifdef of >> CONFIG_KPROBE_EVENTS, and CONFIG_UPROBE_EVENTS. >> >> RFC v1 cover letter: >> >> This is to follow up the discussion over "new kprobe api" at Linux >> Plumbers 2017: >> >> https://urldefense.proofpoint.com/v2/url?u=https-3A__www.linuxplumbersconf.org_2017_ocw_proposals_4808=DwICaQ=5VD0RTtNlTh3ycd41b3MUw=dR8692q0_uaizy0jkrBJQM5k2hfm4CiFxYT8KaysFrg=iAtBi3jXPYfFgvhHTsv8oWyUKiyEwnGZ34-4jniREz4=87sxRxoRkJJenQjCtFLJFXkMLvd_rHkY8ZGON9em1Jc= >> >> With current kernel, user space tools can only create/destroy [k,u]probes >> with a text-based API (kprobe_events and uprobe_events in tracefs). This >> approach relies on user space to clean up the [k,u]probe after using them. >> However, this is not easy for user space to clean up properly. >> >> To solve this problem, we introduce a file descriptor based API. >> Specifically, we extended perf_event_open to create [k,u]probe, and attach >> this [k,u]probe to the file descriptor created by perf_event_open. These >> [k,u]probe are associated with this file descriptor, so they are not >> available in tracefs. >> >> We reuse large portion of existing trace_kprobe and trace_uprobe code. >> Currently, the file descriptor API does not support arguments as the >> text-based API does. This should not be a problem, as user of the file >> decriptor based API read data through other methods (bpf, etc.). >> >> I also include a patch to to bcc, and a patch to man-page perf_even_open. >> Please see the list below. A fork of bcc with this patch is also available >> on github: >> >> https://github.com/liu-song-6/bcc/tree/perf_event_open > > Peter / Stephen, I presume this will be routed through one of you, if > not please yell. > > Thanks, > Daniel > Dear Peter, Do you have further feedbacks/comments on these patches? If not, could you please confirm they are ready for merge? Thanks and Best Regards, Song
Re: [PATCH v5 0/6] enable creating [k,u]probe with perf_event_open
On 12/06/2017 11:45 PM, Song Liu wrote: > Changes PATCH v4 to PATCH v5: > Remove PERF_PROBE_CONFIG_IS_RETPROBE from uapi, use PMU_FORMAT_ATTR > instead. > > Changes PATCH v3 to PATCH v4: > Remove uapi define MAX_PROBE_FUNC_NAME_LEN, use KSYM_NAME_LEN instead. > Add flag PERF_PROBE_CONFIG_IS_RETPROBE for config field of [k,u]probe. > Optimize ifdef's of CONFIG_KPROBE_EVENTS and CONFIG_UPROBE_EVENTS. > Optimize checks in perf_event_is_tracing(). > Optimize perf_tp_register(). > > Changes PATCH v2 to PATCH v3: > Remove fixed type PERF_TYPE_KPROBE and PERF_TYPE_UPROBE, use dynamic > type instead. > Update userspace (samples/bpf, bcc) to look up type from sysfs. > Change License info in test_many_kprobe_user.c as Philippe Ombredanne > suggested. > > Changes PATCH v1 to PATCH v2: > Split PERF_TYPE_PROBE into PERF_TYPE_KPROBE and PERF_TYPE_UPROBE. > Split perf_probe into perf_kprobe and perf_uprobe. > Remove struct probe_desc, use config1 and config2 instead. > > Changes RFC v2 to PATCH v1: > Check type PERF_TYPE_PROBE in perf_event_set_filter(). > Rebase on to tip perf/core. > > Changes RFC v1 to RFC v2: > Fix build issue reported by kbuild test bot by adding ifdef of > CONFIG_KPROBE_EVENTS, and CONFIG_UPROBE_EVENTS. > > RFC v1 cover letter: > > This is to follow up the discussion over "new kprobe api" at Linux > Plumbers 2017: > > https://www.linuxplumbersconf.org/2017/ocw/proposals/4808 > > With current kernel, user space tools can only create/destroy [k,u]probes > with a text-based API (kprobe_events and uprobe_events in tracefs). This > approach relies on user space to clean up the [k,u]probe after using them. > However, this is not easy for user space to clean up properly. > > To solve this problem, we introduce a file descriptor based API. > Specifically, we extended perf_event_open to create [k,u]probe, and attach > this [k,u]probe to the file descriptor created by perf_event_open. These > [k,u]probe are associated with this file descriptor, so they are not > available in tracefs. > > We reuse large portion of existing trace_kprobe and trace_uprobe code. > Currently, the file descriptor API does not support arguments as the > text-based API does. This should not be a problem, as user of the file > decriptor based API read data through other methods (bpf, etc.). > > I also include a patch to to bcc, and a patch to man-page perf_even_open. > Please see the list below. A fork of bcc with this patch is also available > on github: > > https://github.com/liu-song-6/bcc/tree/perf_event_open Peter / Stephen, I presume this will be routed through one of you, if not please yell. Thanks, Daniel > man-pages patch: > perf_event_open.2: add type kprobe and uprobe > > bcc patch: > bcc: Try use new API to create [k,u]probe with perf_event_open > > kernel patches: > > Song Liu (6): > perf: prepare perf_event.h for new types perf_kprobe and perf_uprobe > perf: copy new perf_event.h to tools/include/uapi > perf: implement pmu perf_kprobe > perf: implement pmu perf_uprobe > bpf: add option for bpf_load.c to use perf_kprobe > bpf: add new test test_many_kprobe > > include/linux/trace_events.h | 8 ++ > include/uapi/linux/perf_event.h | 4 + > kernel/events/core.c | 131 +++- > kernel/trace/trace_event_perf.c | 102 +++ > kernel/trace/trace_kprobe.c | 91 +++-- > kernel/trace/trace_probe.h| 11 ++ > kernel/trace/trace_uprobe.c | 86 ++-- > samples/bpf/Makefile | 3 + > samples/bpf/bpf_load.c| 66 ++-- > samples/bpf/bpf_load.h| 14 +++ > samples/bpf/test_many_kprobe_user.c | 186 > ++ > tools/include/uapi/linux/perf_event.h | 4 + > 12 files changed, 677 insertions(+), 29 deletions(-) > create mode 100644 samples/bpf/test_many_kprobe_user.c > > -- > 2.9.5 >
Re: [PATCH v5 0/6] enable creating [k,u]probe with perf_event_open
Song, On Wed, Dec 6, 2017 at 11:45 PM, Song Liuwrote: > Changes PATCH v4 to PATCH v5: > Remove PERF_PROBE_CONFIG_IS_RETPROBE from uapi, use PMU_FORMAT_ATTR > instead. > > Changes PATCH v3 to PATCH v4: > Remove uapi define MAX_PROBE_FUNC_NAME_LEN, use KSYM_NAME_LEN instead. > Add flag PERF_PROBE_CONFIG_IS_RETPROBE for config field of [k,u]probe. > Optimize ifdef's of CONFIG_KPROBE_EVENTS and CONFIG_UPROBE_EVENTS. > Optimize checks in perf_event_is_tracing(). > Optimize perf_tp_register(). > > Changes PATCH v2 to PATCH v3: > Remove fixed type PERF_TYPE_KPROBE and PERF_TYPE_UPROBE, use dynamic > type instead. > Update userspace (samples/bpf, bcc) to look up type from sysfs. > Change License info in test_many_kprobe_user.c as Philippe Ombredanne > suggested. > > Changes PATCH v1 to PATCH v2: > Split PERF_TYPE_PROBE into PERF_TYPE_KPROBE and PERF_TYPE_UPROBE. > Split perf_probe into perf_kprobe and perf_uprobe. > Remove struct probe_desc, use config1 and config2 instead. > > Changes RFC v2 to PATCH v1: > Check type PERF_TYPE_PROBE in perf_event_set_filter(). > Rebase on to tip perf/core. > > Changes RFC v1 to RFC v2: > Fix build issue reported by kbuild test bot by adding ifdef of > CONFIG_KPROBE_EVENTS, and CONFIG_UPROBE_EVENTS. > > RFC v1 cover letter: > > This is to follow up the discussion over "new kprobe api" at Linux > Plumbers 2017: > > https://www.linuxplumbersconf.org/2017/ocw/proposals/4808 > > With current kernel, user space tools can only create/destroy [k,u]probes > with a text-based API (kprobe_events and uprobe_events in tracefs). This > approach relies on user space to clean up the [k,u]probe after using them. > However, this is not easy for user space to clean up properly. > > To solve this problem, we introduce a file descriptor based API. > Specifically, we extended perf_event_open to create [k,u]probe, and attach > this [k,u]probe to the file descriptor created by perf_event_open. These > [k,u]probe are associated with this file descriptor, so they are not > available in tracefs. > > We reuse large portion of existing trace_kprobe and trace_uprobe code. > Currently, the file descriptor API does not support arguments as the > text-based API does. This should not be a problem, as user of the file > decriptor based API read data through other methods (bpf, etc.). > > I also include a patch to to bcc, and a patch to man-page perf_even_open. > Please see the list below. A fork of bcc with this patch is also available > on github: > > https://github.com/liu-song-6/bcc/tree/perf_event_open > > Thanks, > Song > > man-pages patch: > perf_event_open.2: add type kprobe and uprobe > > bcc patch: > bcc: Try use new API to create [k,u]probe with perf_event_open > > kernel patches: > > Song Liu (6): > perf: prepare perf_event.h for new types perf_kprobe and perf_uprobe > perf: copy new perf_event.h to tools/include/uapi > perf: implement pmu perf_kprobe > perf: implement pmu perf_uprobe > bpf: add option for bpf_load.c to use perf_kprobe > bpf: add new test test_many_kprobe > > include/linux/trace_events.h | 8 ++ > include/uapi/linux/perf_event.h | 4 + > kernel/events/core.c | 131 +++- > kernel/trace/trace_event_perf.c | 102 +++ > kernel/trace/trace_kprobe.c | 91 +++-- > kernel/trace/trace_probe.h| 11 ++ > kernel/trace/trace_uprobe.c | 86 ++-- > samples/bpf/Makefile | 3 + > samples/bpf/bpf_load.c| 66 ++-- > samples/bpf/bpf_load.h| 14 +++ > samples/bpf/test_many_kprobe_user.c | 186 > ++ > tools/include/uapi/linux/perf_event.h | 4 + > 12 files changed, 677 insertions(+), 29 deletions(-) > create mode 100644 samples/bpf/test_many_kprobe_user.c > > -- > 2.9.5 Thank you for using the SPDX ids! For this: Acked-by: Philippe Ombredanne
[PATCH v5 0/6] enable creating [k,u]probe with perf_event_open
Changes PATCH v4 to PATCH v5: Remove PERF_PROBE_CONFIG_IS_RETPROBE from uapi, use PMU_FORMAT_ATTR instead. Changes PATCH v3 to PATCH v4: Remove uapi define MAX_PROBE_FUNC_NAME_LEN, use KSYM_NAME_LEN instead. Add flag PERF_PROBE_CONFIG_IS_RETPROBE for config field of [k,u]probe. Optimize ifdef's of CONFIG_KPROBE_EVENTS and CONFIG_UPROBE_EVENTS. Optimize checks in perf_event_is_tracing(). Optimize perf_tp_register(). Changes PATCH v2 to PATCH v3: Remove fixed type PERF_TYPE_KPROBE and PERF_TYPE_UPROBE, use dynamic type instead. Update userspace (samples/bpf, bcc) to look up type from sysfs. Change License info in test_many_kprobe_user.c as Philippe Ombredanne suggested. Changes PATCH v1 to PATCH v2: Split PERF_TYPE_PROBE into PERF_TYPE_KPROBE and PERF_TYPE_UPROBE. Split perf_probe into perf_kprobe and perf_uprobe. Remove struct probe_desc, use config1 and config2 instead. Changes RFC v2 to PATCH v1: Check type PERF_TYPE_PROBE in perf_event_set_filter(). Rebase on to tip perf/core. Changes RFC v1 to RFC v2: Fix build issue reported by kbuild test bot by adding ifdef of CONFIG_KPROBE_EVENTS, and CONFIG_UPROBE_EVENTS. RFC v1 cover letter: This is to follow up the discussion over "new kprobe api" at Linux Plumbers 2017: https://www.linuxplumbersconf.org/2017/ocw/proposals/4808 With current kernel, user space tools can only create/destroy [k,u]probes with a text-based API (kprobe_events and uprobe_events in tracefs). This approach relies on user space to clean up the [k,u]probe after using them. However, this is not easy for user space to clean up properly. To solve this problem, we introduce a file descriptor based API. Specifically, we extended perf_event_open to create [k,u]probe, and attach this [k,u]probe to the file descriptor created by perf_event_open. These [k,u]probe are associated with this file descriptor, so they are not available in tracefs. We reuse large portion of existing trace_kprobe and trace_uprobe code. Currently, the file descriptor API does not support arguments as the text-based API does. This should not be a problem, as user of the file decriptor based API read data through other methods (bpf, etc.). I also include a patch to to bcc, and a patch to man-page perf_even_open. Please see the list below. A fork of bcc with this patch is also available on github: https://github.com/liu-song-6/bcc/tree/perf_event_open Thanks, Song man-pages patch: perf_event_open.2: add type kprobe and uprobe bcc patch: bcc: Try use new API to create [k,u]probe with perf_event_open kernel patches: Song Liu (6): perf: prepare perf_event.h for new types perf_kprobe and perf_uprobe perf: copy new perf_event.h to tools/include/uapi perf: implement pmu perf_kprobe perf: implement pmu perf_uprobe bpf: add option for bpf_load.c to use perf_kprobe bpf: add new test test_many_kprobe include/linux/trace_events.h | 8 ++ include/uapi/linux/perf_event.h | 4 + kernel/events/core.c | 131 +++- kernel/trace/trace_event_perf.c | 102 +++ kernel/trace/trace_kprobe.c | 91 +++-- kernel/trace/trace_probe.h| 11 ++ kernel/trace/trace_uprobe.c | 86 ++-- samples/bpf/Makefile | 3 + samples/bpf/bpf_load.c| 66 ++-- samples/bpf/bpf_load.h| 14 +++ samples/bpf/test_many_kprobe_user.c | 186 ++ tools/include/uapi/linux/perf_event.h | 4 + 12 files changed, 677 insertions(+), 29 deletions(-) create mode 100644 samples/bpf/test_many_kprobe_user.c -- 2.9.5