diff options
| author | Masami Hiramatsu <mhiramat@kernel.org> | 2017-10-20 08:43:39 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-12-10 13:40:40 +0100 |
| commit | 5715de464ac8ef97fdc0daacd41ac35dcd412e2f (patch) | |
| tree | 84df8d90153917f7065297d053b192c4f944689d /arch/Kconfig | |
| parent | c36100e295ffc4d957b0884a82bd32ac5a135c51 (diff) | |
kprobes: Use synchronize_rcu_tasks() for optprobe with CONFIG_PREEMPT=y
[ Upstream commit a30b85df7d599f626973e9cd3056fe755bd778e0 ]
We want to wait for all potentially preempted kprobes trampoline
execution to have completed. This guarantees that any freed
trampoline memory is not in use by any task in the system anymore.
synchronize_rcu_tasks() gives such a guarantee, so use it.
Also, this guarantees to wait for all potentially preempted tasks
on the instructions which will be replaced with a jump.
Since this becomes a problem only when CONFIG_PREEMPT=y, enable
CONFIG_TASKS_RCU=y for synchronize_rcu_tasks() in that case.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Naveen N . Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/150845661962.5443.17724352636247312231.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/Kconfig')
| -rw-r--r-- | arch/Kconfig | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index 057370a0ac4e..400b9e1b2f27 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -91,7 +91,7 @@ config STATIC_KEYS_SELFTEST config OPTPROBES def_bool y depends on KPROBES && HAVE_OPTPROBES - depends on !PREEMPT + select TASKS_RCU if PREEMPT config KPROBES_ON_FTRACE def_bool y |