Re: [GIT PULL] ftrace: Updates for 6.15

[Christian Loehle <christian.loehle@arm.com>]

On 3/31/25 17:57, Christian Loehle wrote:
> 
> 
> ________________________________________
> From: pr-tracker-bot@kernel.org <pr-tracker-bot@kernel.org>
> Sent: 28 March 2025 00:09
> To: Steven Rostedt <rostedt@goodmis.org>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>; LKML <linux-kernel@vger.kernel.org>; Masami Hiramatsu <mhiramat@kernel.org>; Mark Rutland <Mark.Rutland@arm.com>; Mathieu Desnoyers <mathieu.desnoyers@efficios.com>; Andrew Morton <akpm@linux-foundation.org>; Haiyue Wang <haiyuewa@163.com>; Jiapeng Chong <jiapeng.chong@linux.alibaba.com>; Sasha Levin <sashal@kernel.org>; Sven Schnelle <svens@linux.ibm.com>; Tengda Wu <wutengda@huaweicloud.com>
> Subject: Re: [GIT PULL] ftrace: Updates for 6.15
> 
> 
>> The pull request you sent on Tue, 25 Mar 2025 19:39:35 -0400:
>>
>>> git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git ftrace-v6.15
>>
>> has been merged into torvalds/linux.git:
>> https://git.kernel.org/torvalds/c/31eb415bf6f06c90fdd9b635caf3a6c5110a38b6
>>
>> Thank you!
>>
>> --
>> Deet-doot-dot, I am a bot.
>> https://korg.docs.kernel.org/prtracker.html
> 
> Hi Steven,
> I'm pretty sure this causes the build to fail on linus' tree and next:
> 4e82c87058f4 (HEAD -> master, origin/master, origin/HEAD) Merge tag 'rust-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux
> 
> aarch64-linux-gnu-ld: Unexpected GOT/PLT entries detected!
> aarch64-linux-gnu-ld: Unexpected run-time procedure linkages detected!
> aarch64-linux-gnu-ld: kernel/trace/trace_output.o: in function `print_function_args':
> /home/chrloe01/development/linux-mainline/kernel/trace/trace_output.c:712: undefined reference to `btf_find_func_proto'
> aarch64-linux-gnu-ld: /home/chrloe01/development/linux-mainline/kernel/trace/trace_output.c:716: undefined reference to `btf_get_func_param'
> make[2]: *** [scripts/Makefile.vmlinux:77: vmlinux] Error 1
> make[1]: *** [/data_nvme1n1/chrloe01/development/linux-mainline/Makefile:1234: vmlinux] Error 2
> make: *** [Makefile:251: __sub-make] Error 2
> 
> Sound familiar?
> grep BTF .config
> CONFIG_DEBUG_INFO_BTF=y
> CONFIG_PAHOLE_HAS_SPLIT_BTF=y
> CONFIG_DEBUG_INFO_BTF_MODULES=y
> # CONFIG_MODULE_ALLOW_BTF_MISMATCH is not set
> 
> Enabling CONFIG_PROBE_EVENTS_BTF_ARGS passes the build.
> 

In linus' tree we have:
76fe0337c219 ftrace: Add arguments to function tracer
c7a60a733c37 ftrace: Have funcgraph-args take affect during tracing
ff5c9c576e75 ftrace: Add support for function argument to graph tracer
533c20b062d7 ftrace: Add print_function_args()
3d44e1d1575a md: switch personalities to use md_submodule_head

3d44e1d1575a md: switch personalities to use md_submodule_head
builds fine.

533c20b062d7 ftrace: Add print_function_args()
is the first one to fail but with:
kernel/trace/trace_output.c: In function ‘print_function_args’:
kernel/trace/trace_output.c:724:26: error: ‘FTRACE_REGS_MAX_ARGS’ undeclared (first use in this function)
  724 |                 if (a == FTRACE_REGS_MAX_ARGS) {
      |                          ^~~~~~~~~~~~~~~~~~~~
kernel/trace/trace_output.c:724:26: note: each undeclared identifier is reported only once for each function it appears in

then 
ff5c9c576e75 ftrace: Add support for function argument to graph tracer
shows

aarch64-linux-gnu-ld: Unexpected GOT/PLT entries detected!
aarch64-linux-gnu-ld: Unexpected run-time procedure linkages detected!
aarch64-linux-gnu-ld: kernel/trace/trace_output.o: in function `print_function_args':
/home/chrloe01/development/linux-mainline/kernel/trace/trace_output.c:711: undefined reference to `btf_find_func_proto'
aarch64-linux-gnu-ld: /home/chrloe01/development/linux-mainline/kernel/trace/trace_output.c:715: undefined reference to `btf_get_func_param'
make[2]: *** [scripts/Makefile.vmlinux:77: vmlinux] Error 1
make[1]: *** [/data_nvme1n1/chrloe01/development/linux-mainline/Makefile:1226: vmlinux] Error 2
make: *** [Makefile:251: __sub-make] Error 2
make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- -j16 -s Image  5747.92s user 554.69s system 830% cpu 12:38.50 total

fails just like reported linus' tree.