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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> | 2024-01-25 14:33:30 -0800 |
| commit | 70887567dd96c2f5b46d853b603de30ea22741a2 (patch) | |
| tree | 0da593ecd9606fc3f1b67c6e954e9848085102c6 /kernel | |
| parent | 9a9d6a726688a0ed9fb16458d6918e51aadce9b5 (diff) | |
| download | linux-stable-70887567dd96c2f5b46d853b603de30ea22741a2.tar.gz linux-stable-70887567dd96c2f5b46d853b603de30ea22741a2.tar.bz2 linux-stable-70887567dd96c2f5b46d853b603de30ea22741a2.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>
Diffstat (limited to 'kernel')
| -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 b627bc820540..d2903d8834fe 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2891,6 +2891,12 @@ rb_reserve_next_event(struct ring_buffer *buffer, int nr_loops = 0; u64 diff; + /* 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); #ifdef CONFIG_RING_BUFFER_ALLOW_SWAP |