diff options
author | Paul E. McKenney <paulmck@kernel.org> | 2020-08-07 13:44:10 -0700 |
---|---|---|
committer | Paul E. McKenney <paulmck@kernel.org> | 2020-08-24 18:40:27 -0700 |
commit | 3d29aaf1ef992b5b4612fe32b9e6f517f7bba904 (patch) | |
tree | 5ea92127640c2899da6805a887d25c9e249c5154 /Documentation/admin-guide/kernel-parameters.txt | |
parent | 4e025f52a1e0e8ff4e303fa0a80e2061ccfa27d6 (diff) |
rcu: Provide optional RCU-reader exit delay for strict GPs
The goal of this series is to increase the probability of tools like
KASAN detecting that an RCU-protected pointer was used outside of its
RCU read-side critical section. Thus far, the approach has been to make
grace periods and callback processing happen faster. Another approach
is to delay the pointer leaker. This commit therefore allows a delay
to be applied to exit from RCU read-side critical sections.
This slowdown is specified by a new rcutree.rcu_unlock_delay kernel boot
parameter that specifies this delay in microseconds, defaulting to zero.
Reported-by Jann Horn <jannh@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
-rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index bdc1f33fd3d1..cb9062440dda 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -4152,6 +4152,15 @@ This wake_up() will be accompanied by a WARN_ONCE() splat and an ftrace_dump(). + rcutree.rcu_unlock_delay= [KNL] + In CONFIG_RCU_STRICT_GRACE_PERIOD=y kernels, + this specifies an rcu_read_unlock()-time delay + in microseconds. This defaults to zero. + Larger delays increase the probability of + catching RCU pointer leaks, that is, buggy use + of RCU-protected pointers after the relevant + rcu_read_unlock() has completed. + rcutree.sysrq_rcu= [KNL] Commandeer a sysrq key to dump out Tree RCU's rcu_node tree with an eye towards determining |