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tracing/user_events: Remove eBPF interfaces

PATCH In review Beau Belgrave 3 participants 3 messages Mar 29, 2022

Subsystems (6)
Networking Network drivers Documentation BPF +2 more subsystems
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Beau Belgrave

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#0 lore raw

PATCH 1/1 tracing/user_events: Remove eBPF interfaces

Remove eBPF interfaces within user_events to ensure they are fully reviewed.

Link https://lore.kernel.org/all/20220329165718.GA10381@kbox/ open here
Signed-off-by Beau Belgrave <[email protected]>
---
 Documentation/trace/user_events.rst | 14 ++----
 include/uapi/linux/user_events.h    | 53 ---------------------
 kernel/trace/trace_events_user.c    | 73 +----------------------------
 3 files changed, 4 insertions(+), 136 deletions(-)
Documentation/trace/user_events.rst +3 -11
index bddedabaca80..c180936f49fc 100644
@@ -7,7 +7,7 @@ user_events: User-based Event Tracing
 Overview
 --------
 User based trace events allow user processes to create events and trace data
-that can be viewed via existing tools, such as ftrace, perf and eBPF.
+that can be viewed via existing tools, such as ftrace and perf.
 To enable this feature, build your kernel with CONFIG_USER_EVENTS=y.
 
 Programs can view status of the events via

@@ -67,8 +67,7 @@ The command string format is as follows::
 
 Supported Flags
 ^^^^^^^^^^^^^^^
-**BPF_ITER** - EBPF programs attached to this event will get the raw iovec
-struct instead of any data copies for max performance.
+None yet
 
 Field Format
 ^^^^^^^^^^^^

@@ -160,7 +159,7 @@ The following values are defined to aid in checking what has been attached:
 
 **EVENT_STATUS_FTRACE** - Bit set if ftrace has been attached (Bit 0).
 
-**EVENT_STATUS_PERF** - Bit set if perf/eBPF has been attached (Bit 1).
+**EVENT_STATUS_PERF** - Bit set if perf has been attached (Bit 1).
 
 Writing Data
 ------------

@@ -204,13 +203,6 @@ It's advised for user programs to do the following::
 
 **NOTE:** *The write_index is not emitted out into the trace being recorded.*
 
-EBPF
-----
-EBPF programs that attach to a user-based event tracepoint are given a pointer
-to a struct user_bpf_context. The bpf context contains the data type (which can
-be a user or kernel buffer, or can be a pointer to the iovec) and the data
-length that was emitted (minus the write_index).
-
 Example Code
 ------------
 See sample code in samples/user_events.
include/uapi/linux/user_events.h +0 -53

63 lines not on this page · raw message

kernel/trace/trace_events_user.c +1 -72

110 lines not on this page · raw message

base-commit: 5efabdadcf4a5b9a37847ecc85ba71cf2eff0fcf

Signature · 1 line
2.25.1
maintainer
#2 lore raw
Quoted 8 lines · On Tue, 29 Mar 2022 11:19:05 -0700 Alexei Starovoitov…
Quoted 6 lines · Beau Belgrave

Remove eBPF interfaces within user_events to ensure they are fully reviewed.

Link https://lore.kernel.org/all/20220329165718.GA10381@kbox/ open here
Quoted 9 lines
Quoted 1 line
Signed-off-by Beau Belgrave <[email protected]>

Thanks for the quick revert.

Steven,

since you've applied the initial set please take this one and send pull req to Linus asap.

Relax Alexei,

I'll send it to Linus after it goes through my testing process with all my other patches in queue. An ABI is only defined by the main release "5.18" and not the rc releases (like 5.18-rc1). But it will definitely be gone before rc2.

-- Steve