Re: [**EXTERNAL**] Re: [PPC][Tracing] Missing syscalls:* ftrace/perf events on PowerPC vs x86

Hi Hari,

I could find and resolve the syscall tracing issue.

The root cause was that within my toolchain and the PPC64_ELF_ABI_v1, the symbol resolver can provide data symbols without a leading dot (e.g., sys_read instead of .sys_read). In our system running kernel v5.10.x, this was causing a mismatch that prevented ftrace from correctly mapping metadata to syscall numbers.

https://elixir.bootlin.com/linux/v5.10.174/source/arch/powerpc/include/asm/ftrace.h#L78

I could fix this by modifying the matching function to be dot-agnostic.

Also found the fix in the upstream:
https://lore.kernel.org/all/20221201161442.2127231-1-mjeanson@efficios.com/ (local)

We might need to backport this to earlier 5.x stable version.

-- Mohammad

________________________________
From: Hari Bathini <hbathini@linux.ibm.com>
Sent: February 20, 2026 2:54 AM
To: Nassiri, Mohammad <redacted>; linuxppc-dev@lists.ozlabs.org <redacted>
Cc: linux-trace-users@vger.kernel.org <redacted>; michael@ellerman.id.au <redacted>; masami.hiramatsu@linaro.org <redacted>; Christophe Leroy <redacted>; Nicholas Piggin <npiggin@gmail.com>; rostedt@goodmis.org <rostedt@goodmis.org>
Subject: Re: [**EXTERNAL**] Re: [PPC][Tracing] Missing syscalls:* ftrace/perf events on PowerPC vs x86



On 18/02/26 7:26 pm, Nassiri, Mohammad wrote:

quoted

You should see syscall enter/exit tracepoints on v5.10.x without syscall
wrapper patchset referred above. Are you using v5.10.250 ?
Also, would help, if you can share the .config you used.

Hi Hari,

Hi Mohammad,

No, I'm not using the latest v5.10.250. I tested on two versions --- v5.10.174 and v5.10.239 --- and I still see the issue on both.
For your reference, here is a grep from my .config showing most of the tracing options I enabled while troubleshooting this issue.

OK. Tried v5.10.250 as well as v5.10.174 with the similar config
options. Could see syscall enter/exit tracepoints..

- Hari