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| author | Aaron Tomlin <atomlin@redhat.com> | 2022-07-11 20:17:19 +0300 |
|---|---|---|
| committer | Luis Chamberlain <mcgrof@kernel.org> | 2022-07-11 20:19:09 +0300 |
| commit | e69a66147d49506062cd837f3b230ee3e98102ab (patch) | |
| tree | 1d2690c89d6befa274bb80a8bb908baac1d2f2cd /Documentation | |
| parent | 2cc39179acbbe524127f0427cee92b629db4d64b (diff) | |
| download | linux-e69a66147d49506062cd837f3b230ee3e98102ab.tar.xz | |
module: kallsyms: Ensure preemption in add_kallsyms() with PREEMPT_RT
The commit 08126db5ff73 ("module: kallsyms: Fix suspicious rcu usage")
under PREEMPT_RT=y, disabling preemption introduced an unbounded
latency since the loop is not fixed. This change caused a regression
since previously preemption was not disabled and we would dereference
RCU-protected pointers explicitly. That being said, these pointers
cannot change.
Before kallsyms-specific data is prepared/or set-up, we ensure that
the unformed module is known to be unique i.e. does not already exist
(see load_module()). Therefore, we can fix this by using the common and
more appropriate RCU flavour as this section of code can be safely
preempted.
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Fixes: 08126db5ff73 ("module: kallsyms: Fix suspicious rcu usage")
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Diffstat (limited to 'Documentation')
0 files changed, 0 insertions, 0 deletions