From: Florent Revest <revest@chromium.org>
To: linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
bpf@vger.kernel.org
Cc: catalin.marinas@arm.com, will@kernel.org, rostedt@goodmis.org,
mhiramat@kernel.org, mark.rutland@arm.com, ast@kernel.org,
daniel@iogearbox.net, andrii@kernel.org, kpsingh@kernel.org,
jolsa@kernel.org, xukuohai@huaweicloud.com, lihuafei1@huawei.com,
Florent Revest <revest@chromium.org>
Subject: [PATCH v6 0/5] Add ftrace direct call for arm64
Date: Wed, 5 Apr 2023 20:02:45 +0200 [thread overview]
Message-ID: <20230405180250.2046566-1-revest@chromium.org> (raw)
This series adds ftrace direct call support to arm64.
This makes BPF tracing programs (fentry/fexit/fmod_ret/lsm) work on arm64.
It is meant to be taken by the arm64 tree but it depends on the
trace-direct-v6.3-rc3 tag of the linux-trace tree:
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git
That tag was created by Steven Rostedt so the arm64 tree can pull the prior work
this depends on. [1]
Thanks to the ftrace refactoring under that tag, an ftrace_ops backing a ftrace
direct call will only ever point to *one* direct call. This means we can look up
the direct called trampoline address stored in the ops from the ftrace_caller
trampoline in the case when the destination would be out of reach of a BL
instruction at the ftrace callsite. This fixes limitations of previous attempts
such as [2].
This series has been tested on arm64 with:
1- CONFIG_FTRACE_SELFTEST
2- samples/ftrace/*.ko (cf: patch 4)
3- tools/testing/selftests/bpf/test_progs (cf: patch 5)
Changes since v5 [3]:
- Fixed saving the fourth argument of handle_mm_fault in both the x86 (patch 3)
and arm64 (as part of patch 4) "ftrace-direct-too" sample trampolines
- Fixed the address of the traced function logged by some direct call samples
(ftrace-direct-multi and ftrace-direct-multi-modify) by moving lr into x0
1: https://lore.kernel.org/all/ZB2Nl7fzpHoq5V20@FVFF77S0Q05N/
2: https://lore.kernel.org/all/20220913162732.163631-1-xukuohai@huaweicloud.com/
3: https://lore.kernel.org/bpf/20230403113552.2857693-1-revest@chromium.org/
Florent Revest (5):
arm64: ftrace: Add direct call support
arm64: ftrace: Simplify get_ftrace_plt
samples: ftrace: Save required argument registers in sample
trampolines
arm64: ftrace: Add direct call trampoline samples support
selftests/bpf: Update the tests deny list on aarch64
arch/arm64/Kconfig | 6 ++
arch/arm64/include/asm/ftrace.h | 22 +++++
arch/arm64/kernel/asm-offsets.c | 6 ++
arch/arm64/kernel/entry-ftrace.S | 90 ++++++++++++++++----
arch/arm64/kernel/ftrace.c | 46 +++++++---
samples/ftrace/ftrace-direct-modify.c | 34 ++++++++
samples/ftrace/ftrace-direct-multi-modify.c | 40 +++++++++
samples/ftrace/ftrace-direct-multi.c | 24 ++++++
samples/ftrace/ftrace-direct-too.c | 40 +++++++--
samples/ftrace/ftrace-direct.c | 24 ++++++
tools/testing/selftests/bpf/DENYLIST.aarch64 | 82 ++----------------
11 files changed, 306 insertions(+), 108 deletions(-)
--
2.40.0.577.gac1e443424-goog
next reply other threads:[~2023-04-05 18:03 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-05 18:02 Florent Revest [this message]
2023-04-05 18:02 ` [PATCH v6 1/5] arm64: ftrace: Add direct call support Florent Revest
2023-04-05 18:02 ` [PATCH v6 2/5] arm64: ftrace: Simplify get_ftrace_plt Florent Revest
2023-04-05 18:02 ` [PATCH v6 3/5] samples: ftrace: Save required argument registers in sample trampolines Florent Revest
2023-04-05 20:40 ` Steven Rostedt
2023-04-06 10:22 ` Mark Rutland
2023-04-05 18:02 ` [PATCH v6 4/5] arm64: ftrace: Add direct call trampoline samples support Florent Revest
2023-04-06 10:50 ` Mark Rutland
2023-04-05 18:02 ` [PATCH v6 5/5] selftests/bpf: Update the tests deny list on aarch64 Florent Revest
2023-04-11 15:56 ` [PATCH v6 0/5] Add ftrace direct call for arm64 Mark Rutland
2023-04-11 16:47 ` Steven Rostedt
2023-04-11 17:08 ` Will Deacon
2023-04-11 17:44 ` Steven Rostedt
2023-04-11 17:54 ` Will Deacon
2023-04-12 9:50 ` Mark Rutland
2023-04-24 20:09 ` Steven Rostedt
2023-04-11 18:37 ` Will Deacon
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=20230405180250.2046566-1-revest@chromium.org \
--to=revest@chromium.org \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=catalin.marinas@arm.com \
--cc=daniel@iogearbox.net \
--cc=jolsa@kernel.org \
--cc=kpsingh@kernel.org \
--cc=lihuafei1@huawei.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-trace-kernel@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=mhiramat@kernel.org \
--cc=rostedt@goodmis.org \
--cc=will@kernel.org \
--cc=xukuohai@huaweicloud.com \
/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).