ftrace: Protect ftrace_graph_hash with ftrace_sync

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[ Upstream commit 54a16ff6f2 ]

As function_graph tracer can run when RCU is not "watching", it can not be
protected by synchronize_rcu() it requires running a task on each CPU before
it can be freed. Calling schedule_on_each_cpu(ftrace_sync) needs to be used.

Link: https://lore.kernel.org/r/20200205131110.GT2935@paulmck-ThinkPad-P72

Cc: stable@vger.kernel.org
Fixes: b9b0c831be ("ftrace: Convert graph filter to use hash tables")
Reported-by: "Paul E. McKenney" <paulmck@kernel.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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This commit is contained in:

Steven Rostedt (VMware) 2020-02-05 09:20:32 -05:00 • committed by Greg Kroah-Hartman

parent 1cd057a400

commit 3fdc8ff881

2 changed files with 11 additions and 2 deletions

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11

kernel/trace/ftrace.c

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2

kernel/trace/trace.h

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