Bug 2203082

Summary: [aarch64] Kernel stacktraces from perf don't show function names unless kernel-debuginfo is installed
Product: Red Hat Enterprise Linux 9 Reporter: Ondrej Mosnacek <omosnace>
Component: kernelAssignee: Michael Petlan <mpetlan>
kernel sub component: Perf QA Contact: Qiao Zhao <qzhao>
Status: CLOSED MIGRATED Docs Contact:
Severity: medium    
Priority: unspecified CC: acme, zsun
Version: 9.2Keywords: MigratedToJIRA, Triaged
Target Milestone: rcFlags: pm-rhel: mirror+
Target Release: ---   
Hardware: aarch64   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: If docs needed, set a value
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Story Points: ---
Clone Of: Environment:
Last Closed: 2023-09-25 16:46:02 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 Ondrej Mosnacek 2023-05-11 07:57:28 UTC
Description of problem:
Somewhere between RHEL-9.1 and RHEL-9.2 perf became unable to print function names in kernel stack traces from events on aarch64 unless kernel-debuginfo is installed. On RHEL-9.1 and also on all other arches on RHEL-9.2/9.3 it is able to infer the function names without it (presumably using /proc/kallsyms).

The issue also appears when I boot a RHEL-9.2 kernel on RHEL-9.1 userspace, so it seems to be a regression in the kernel rather than the userspace tools/libraries.

Version-Release number of selected component (if applicable):
Last known good: kernel-5.14.0-162.23.1.el9_1.aarch64
First known bad: kernel-5.14.0-284.14.1.el9_2.aarch64

How reproducible:
Always.

Steps to Reproduce:
1. perf record -g sleep 1
2. perf script

Actual results:
perf-exec 21437   257.001297:          1 cycles: 
        ffffa2362e8ce7d0 [unknown] ([unknown])
        ffffa2362e9f90e0 [unknown] ([unknown])
        ffffa2362ea6a728 [unknown] ([unknown])
        ffffa2362e9f6714 [unknown] ([unknown])
        ffffa2362e9f785c [unknown] ([unknown])
        ffffa2362e9f7fc4 [unknown] ([unknown])
        ffffa2362e9f80b0 [unknown] ([unknown])
        ffffa2362e9f84e8 [unknown] ([unknown])
        ffffa2362e9f85bc [unknown] ([unknown])
        ffffa2362e67636c [unknown] ([unknown])
        ffffa2362e676514 [unknown] ([unknown])
        ffffa2362e67654c [unknown] ([unknown])
        ffffa2362f279348 [unknown] ([unknown])
        ffffa2362f279cb4 [unknown] ([unknown])
        ffffa2362e6615c0 [unknown] ([unknown])
            ffff8147c9cc [unknown] ([unknown])
[...]

Expected results:
perf-exec 21046   143.835852:          1 cycles: 
        ffffb7d2558f43a0 perf_event_remove_on_exec+0x0 ([kernel.kallsyms])
        ffffb7d255a02614 begin_new_exec+0x2e4 ([kernel.kallsyms])
        ffffb7d255a73ae0 load_elf_binary+0x65c ([kernel.kallsyms])
        ffffb7d2559ffb34 search_binary_handler+0xd4 ([kernel.kallsyms])
        ffffb7d255a0191c exec_binprm+0x5c ([kernel.kallsyms])
        ffffb7d255a01c24 bprm_execve.part.0+0x184 ([kernel.kallsyms])
        ffffb7d255a01d10 bprm_execve+0x60 ([kernel.kallsyms])
        ffffb7d255a01ec4 do_execveat_common+0x184 ([kernel.kallsyms])
        ffffb7d255a01f90 __arm64_sys_execve+0x3c ([kernel.kallsyms])
        ffffb7d2556a65cc invoke_syscall.constprop.0+0x7c ([kernel.kallsyms])
        ffffb7d2556a6774 el0_svc_common.constprop.0+0x154 ([kernel.kallsyms])
        ffffb7d2556a67ac do_el0_svc+0x2c ([kernel.kallsyms])
        ffffb7d25625c648 el0_svc+0x38 ([kernel.kallsyms])
        ffffb7d25625cf9c el0t_64_sync_handler+0x9c ([kernel.kallsyms])
        ffffb7d2556915c0 el0t_64_sync+0x174 ([kernel.kallsyms])
            ffffaf9cc9cc [unknown] ([unknown])
[...]

Comment 1 Michael Petlan 2023-07-19 14:33:12 UTC
5.14.0-284.11.1.el9_2.aarch64 is also bad

Comment 2 Michael Petlan 2023-07-20 07:22:39 UTC
perf-5.14.0-340.el9.aarch64 works OK, so RHEL-9.3 solves this problem

Comment 3 RHEL Program Management 2023-09-25 16:44:59 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 4 RHEL Program Management 2023-09-25 16:46:02 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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