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: | kernel | Assignee: | Michael Petlan <mpetlan> |
| kernel sub component: | Perf | QA Contact: | Qiao Zhao <qzhao> |
| Status: | NEW --- | Docs Contact: | |
| Severity: | medium | ||
| Priority: | unspecified | CC: | acme, zsun |
| Version: | 9.2 | Keywords: | Triaged |
| Target Milestone: | rc | ||
| Target Release: | --- | ||
| Hardware: | aarch64 | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | If docs needed, set a value | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 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: | |||
5.14.0-284.11.1.el9_2.aarch64 is also bad perf-5.14.0-340.el9.aarch64 works OK, so RHEL-9.3 solves this problem |
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]) [...]