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To: Guo Ren <guoren@kernel.org>, Steven Rostedt <rostedt@goodmis.org>,
 Ingo Molnar <mingo@redhat.com>,
 "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>,
 Helge Deller <deller@gmx.de>, Michael Ellerman <mpe@ellerman.id.au>,
 Benjamin Herrenschmidt <benh@kernel.crashing.org>,
 Paul Mackerras <paulus@samba.org>, Paul Walmsley <paul.walmsley@sifive.com>,
 Palmer Dabbelt <palmer@dabbelt.com>, Albert Ou <aou@eecs.berkeley.edu>,
 Thomas Gleixner <tglx@linutronix.de>, Borislav Petkov <bp@alien8.de>,
 x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
 Josh Poimboeuf <jpoimboe@redhat.com>, Jiri Kosina <jikos@kernel.org>,
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 Joe Lawrence <joe.lawrence@redhat.com>,
 Colin Ian King <colin.king@canonical.com>,
 Masami Hiramatsu <mhiramat@kernel.org>,
 "Peter Zijlstra (Intel)" <peterz@infradead.org>,
 Nicholas Piggin <npiggin@gmail.com>, Jisheng Zhang <jszhang@kernel.org>,
 linux-csky@vger.kernel.org, linux-kernel@vger.kernel.org,
 linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
 linux-riscv@lists.infradead.org, live-patching@vger.kernel.org
Subject: [PATCH 0/2] ftrace: make sure preemption disabled on recursion testing
Message-ID: <8c7de46d-9869-aa5e-2bb9-5dbc2eda395e@linux.alibaba.com>
Date: Tue, 12 Oct 2021 13:39:16 +0800
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 <linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org>

The testing show that perf_ftrace_function_call() are using
smp_processor_id() with preemption enabled, all the checking
on CPU could be wrong after preemption, PATCH 1/2 will fix
that.

Besides, as Peter point out, the testing of recursion within
the section between ftrace_test_recursion_trylock()/_unlock()
pair also need the preemption disabled as the documentation
explained, PATCH 2/2 will make sure on that.

Michael Wang (2):
  ftrace: disable preemption on the testing of recursion
  ftrace: prevent preemption in perf_ftrace_function_call()

 arch/csky/kernel/probes/ftrace.c     |  2 --
 arch/parisc/kernel/ftrace.c          |  2 --
 arch/powerpc/kernel/kprobes-ftrace.c |  2 --
 arch/riscv/kernel/probes/ftrace.c    |  2 --
 arch/x86/kernel/kprobes/ftrace.c     |  2 --
 include/linux/trace_recursion.h      | 10 +++++++++-
 kernel/livepatch/patch.c             |  6 ------
 kernel/trace/trace_event_perf.c      | 17 +++++++++++++----
 kernel/trace/trace_functions.c       |  5 -----
 9 files changed, 22 insertions(+), 26 deletions(-)

-- 
1.8.3.1