Bug 2232542

Summary:	[bcc] Type: 'unsigned char[256]' not recognized. Please define the data with ctypes manually.
Product:	Red Hat Enterprise Linux 9	Reporter:	Adrián Moreno <amorenoz>
Component:	bcc	Assignee:	Jerome Marchand <jmarchan>
Status:	CLOSED MIGRATED	QA Contact:	Ziqian SUN (Zamir) <zsun>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	9.0	CC:	ctrautma, echaudro, jmarchan, ldoskova, ralongi, rdossant, tredaelli
Target Milestone:	rc	Keywords:	MigratedToJIRA, Triaged
Target Release:	---	Flags:	pm-rhel: mirror+
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2023-09-25 17:10:41 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Adrián Moreno 2023-08-17 10:11:38 UTC

Description of problem:

When you build a program using bcc's automatic C types binding that contains a simple type such as "unsigned char[256]" a runtime error is triggered:

"""
Type: 'unsigned char[256]' not recognized. Please define the data with ctypes manually.

Exception ignored on calling ctypes callback function: <function RingBuf.open_ring_buffer.<locals>.ringbuf_cb_ at 0x7ff64df49940>
"""

I tracked the error to be a regression introduced in 0.24 by:

ca1d3fd0 bcc: Fix array type handling due to llvm changes

I also fixed the issue upstream with:

8f8e9a2c bcc: Fix multi-word array type handling (#4412)

However, we (OVS team) ship some BCC scripts for rhel-9 as part of openvswitch3.1-test package which are affected by this.
So this is a request to z-stream the fix to the relevant rhel-9 versions.

Version-Release number of selected component (if applicable):

From 0.24 up to 0.26 both included.

How reproducible:

100%

Steps to Reproduce:
1. Run a BCC program with "unsigned char []" as a Ctype that is shared between ebpf and userspace, e.g: https://github.com/openvswitch/ovs/blob/master/utilities/usdt-scripts/upcall_cost.py


Actual results:

An exception is thrown:
"""
Type: 'unsigned char[256]' not recognized. Please define the data with ctypes manually.

Exception ignored on calling ctypes callback function: <function RingBuf.open_ring_buffer.<locals>.ringbuf_cb_ at 0x7ff64df49940>
"""

Expected results:

No exception should be thrown.

Additional info:

Comment 1 Adrián Moreno 2023-08-17 12:30:19 UTC

I think we also need this in rhel8. Just checked and it ships with bcc 0.25 which is also affected.

Comment 2 RHEL Program Management 2023-09-25 16:52:34 UTC

Issue migration from Bugzilla to Jira is in process at this time. This will be the last message in Jira copied from the Bugzilla bug.

Comment 3 RHEL Program Management 2023-09-25 17:10:41 UTC

This BZ has been automatically migrated to the issues.redhat.com Red Hat Issue Tracker. All future work related to this report will be managed there.

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