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

[Nassiri, Mohammad]

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/

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

-- Mohammad

________________________________
From: Hari Bathini <hbathini at linux.ibm.com>
Sent: February 20, 2026 2:54 AM
To: Nassiri, Mohammad <mnassiri at ciena.com>; linuxppc-dev at lists.ozlabs.org <linuxppc-dev at lists.ozlabs.org>
Cc: linux-trace-users at vger.kernel.org <linux-trace-users at vger.kernel.org>; michael at ellerman.id.au <michael at ellerman.id.au>; masami.hiramatsu at linaro.org <masami.hiramatsu at linaro.org>; Christophe Leroy <christophe.leroy at csgroup.eu>; Nicholas Piggin <npiggin at gmail.com>; rostedt at goodmis.org <rostedt at 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:
>> 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
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