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| author | Steven Rostedt (Google) <rostedt@goodmis.org> | 2023-12-13 17:54:03 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-01-20 11:50:07 +0100 |
| commit | b0407f68d917ea2df347decd02465cd9e1f4541d (patch) | |
| tree | 0ab0a7f24993339808a71b71d25896aa189a8594 | |
| parent | 07787918c6cf54f1c7b78771b90fa62dee1c7403 (diff) | |
| download | linux-stable-b0407f68d917ea2df347decd02465cd9e1f4541d.tar.gz linux-stable-b0407f68d917ea2df347decd02465cd9e1f4541d.tar.bz2 linux-stable-b0407f68d917ea2df347decd02465cd9e1f4541d.zip | |
ring-buffer: Do not record in NMI if the arch does not support cmpxchg in NMI
[ Upstream commit 712292308af2265cd9b126aedfa987f10f452a33 ]
As the ring buffer recording requires cmpxchg() to work, if the
architecture does not support cmpxchg in NMI, then do not do any recording
within an NMI.
Link: https://lore.kernel.org/linux-trace-kernel/20231213175403.6fc18540@gandalf.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | kernel/trace/ring_buffer.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 71cad4f1323c..1285e7fb597e 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -3644,6 +3644,12 @@ rb_reserve_next_event(struct trace_buffer *buffer, int nr_loops = 0; int add_ts_default; + /* ring buffer does cmpxchg, make sure it is safe in NMI context */ + if (!IS_ENABLED(CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG) && + (unlikely(in_nmi()))) { + return NULL; + } + rb_start_commit(cpu_buffer); /* The commit page can not change after this */ |