From: Song Shuai <suagrfillet@gmail.com>
To: guoren@kernel.org, paul.walmsley@sifive.com, palmer@dabbelt.com,
aou@eecs.berkeley.edu, rostedt@goodmis.org, mhiramat@kernel.org,
mark.rutland@arm.com, peterz@infradead.org, jolsa@redhat.com,
bp@suse.de, jpoimboe@kernel.org
Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
Song Shuai <suagrfillet@gmail.com>
Subject: [PATCH 0/2] riscv/ftrace: add WITH_DIRECT_CALLS support
Date: Wed, 23 Nov 2022 22:20:23 +0800 [thread overview]
Message-ID: <20221123142025.1504030-1-suagrfillet@gmail.com> (raw)
This series adds DYNAMIC_FTRACE_WITH_DIRECT_CALLS support for RISC-V.
SAMPLE_FTRACE_DIRECT and SAMPLE_FTRACE_DIRECT_MULTI are also included
here as the samples for testing DIRECT_CALLS related interface.
First, select the DYNAMIC_FTRACE_WITH_DIRECT_CALLS to provide
register_ftrace_direct[_multi] interfaces allowing user to register
the customed trampoline (direct_caller) as the mcount for one or
more target functions. And modify_ftrace_direct[_multi] are also
provided for modify direct_caller.
At the same time, the samples in ./samples/ftrace/ can be built
as kerenl module for testing these interfaces with SAMPLE_FTRACE_DIRECT
and SAMPLE_FTRACE_DIRECT_MULTI selected.
Second, to make the direct_caller and the other ftrace hooks
(eg. function/fgraph tracer, k[ret]probes) co-exist, a temporary register
are nominated to store the address of direct_caller in ftrace_regs_caller.
After the setting of the address direct_caller by direct_ops->func and
the RESTORE_REGS in ftrace_regs_caller, direct_caller will be jumped to
by the `jr` inst.
The following tests have been passed in my local qemu-riscv64 virt machine.
1. tests with CONFIG_FTRACE_STARTUP_TEST
2. tests of samples/ftrace/ftrace*.ko
3. manual tests with any combination of the following hooks
- function/function_graph tracer
- ftrace*.ko
- kprobe/kretprobe
For your reference, here is the log when function tracer, kretprobe and
ftrace-direct-too.ko co-hooks the handle_mm_fault function.
```
[root@stage4 tracing]# echo handle_mm_fault > set_ftrace_filter
[root@stage4 tracing]# echo 'r:myr handle_mm_fault' > kprobe_events
[root@stage4 tracing]# echo function > current_tracer
[root@stage4 tracing]# echo 1 > events/kprobes/myr/enable
[root@stage4 tracing]# insmod /root/ftrace-direct-too.ko
[root@stage4 tracing]#
[root@stage4 tracing]# cat trace | tail
cat-388 [000] ...1. 583.051438: myr: (do_page_fault+0x16c/0x5f2 <- handle_mm_fault)
cat-388 [000] ...2. 583.057930: handle_mm_fault <-do_page_fault
cat-388 [000] ..... 583.057990: my_direct_func: handle mm fault vma=000000002d9fe19c address=ffffffae9b7000 flags=215
cat-388 [000] ...1. 583.058284: myr: (do_page_fault+0x16c/0x5f2 <- handle_mm_fault)
tail-389 [001] ...2. 583.059062: handle_mm_fault <-do_page_fault
tail-389 [001] ..... 583.059104: my_direct_func: handle mm fault vma=0000000017f3c48e address=aaaaaabebf3000 flags=215
tail-389 [001] ...1. 583.059325: myr: (do_page_fault+0x16c/0x5f2 <- handle_mm_fault)
tail-389 [001] ...2. 583.060371: handle_mm_fault <-do_page_fault
tail-389 [001] ..... 583.060410: my_direct_func: handle mm fault vma=0000000017f3c48e address=aaaaaabebf1000 flags=255
tail-389 [001] ...1. 583.060996: myr: (do_page_fault+0x16c/0x5f2 <- handle_mm_fault)
```
Note1:
This series is based on (riscv/ftrace: make ftrace_caller call ftrace_graph_func)
in this repo -> https://github.com/guoren83/linux/commits/ftrace_fixup_v3 .
Note2:
The checkpatch.pl will output some warnings on this series, like this
```
WARNING: Prefer using '"%s...", __func__' to using 'my_direct_func2', this function's name, in a string
111: FILE: samples/ftrace/ftrace-direct-multi-modify.c:48:
+" call my_direct_func2\n"
```
The reason is that checkpatch depends on patch context providing the
function name. In the above warning, my_direct_func2 has some codeline
distance with the changed trunk, so its declaration doesn't come into
the patch, and then the warning jumps out.
You may notice the location of `my_ip` variable changes in the 2nd patch.
I did that for reducing the warnings to some extent. But killing all the
warnings will makes the patch less readable, so I stopped here.
--
Song
Song Shuai (2):
riscv/ftrace: add DYNAMIC_FTRACE_WITH_DIRECT_CALLS support
samples/ftrace: add riscv support for SAMPLE_FTRACE_DIRECT[_MULTI]
arch/riscv/Kconfig | 3 ++
arch/riscv/include/asm/ftrace.h | 6 ++++
arch/riscv/kernel/mcount-dyn.S | 4 +++
samples/ftrace/ftrace-direct-modify.c | 35 ++++++++++++++++++-
samples/ftrace/ftrace-direct-multi-modify.c | 37 +++++++++++++++++++++
samples/ftrace/ftrace-direct-multi.c | 22 ++++++++++++
samples/ftrace/ftrace-direct-too.c | 26 +++++++++++++++
samples/ftrace/ftrace-direct.c | 22 ++++++++++++
8 files changed, 154 insertions(+), 1 deletion(-)
--
2.20.1
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
next reply other threads:[~2022-11-23 14:20 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-23 14:20 Song Shuai [this message]
2022-11-23 14:20 ` [PATCH 1/2] riscv/ftrace: add DYNAMIC_FTRACE_WITH_DIRECT_CALLS support Song Shuai
2022-11-23 15:15 ` Guo Ren
[not found] ` <CAJF2gTTwvApRaGhZJxOrdcjWUC9DN-WF_7EKcHXx5HZ9Jkd5EA@mail.gmail.com>
2022-11-23 17:27 ` Song Shuai
2022-11-24 2:08 ` Guo Ren
2022-11-24 2:52 ` Song Shuai
2022-11-24 3:09 ` Song Shuai
2022-11-24 3:40 ` Guo Ren
2022-11-24 11:48 ` Song Shuai
2022-11-24 15:11 ` Guo Ren
2022-11-24 15:31 ` Guo Ren
2022-11-25 1:53 ` Song Shuai
2022-11-25 3:10 ` Guo Ren
2022-11-25 6:33 ` Song Shuai
2022-11-28 10:12 ` [PATCH 1/2] riscv: ftrace: Add " guoren
2022-11-28 10:12 ` [PATCH 2/2] samples: ftrace: Add riscv support for SAMPLE_FTRACE_DIRECT[_MULTI] guoren
2022-11-28 10:21 ` Guo Ren
2022-11-28 12:55 ` Guo Ren
2022-11-28 12:54 ` [PATCH 1/2] riscv: ftrace: Add DYNAMIC_FTRACE_WITH_DIRECT_CALLS support Guo Ren
2022-11-28 10:17 ` [PATCH 1/2] riscv/ftrace: add " Guo Ren
2022-11-28 12:54 ` Guo Ren
2022-11-28 13:16 ` Guo Ren
2022-11-28 13:29 ` Song Shuai
2022-11-23 14:20 ` [PATCH 2/2] samples/ftrace: add riscv support for SAMPLE_FTRACE_DIRECT[_MULTI] Song Shuai
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20221123142025.1504030-1-suagrfillet@gmail.com \
--to=suagrfillet@gmail.com \
--cc=aou@eecs.berkeley.edu \
--cc=bp@suse.de \
--cc=guoren@kernel.org \
--cc=jolsa@redhat.com \
--cc=jpoimboe@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-riscv@lists.infradead.org \
--cc=mark.rutland@arm.com \
--cc=mhiramat@kernel.org \
--cc=palmer@dabbelt.com \
--cc=paul.walmsley@sifive.com \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).