On 6/21/26 11:19 AM, Runyu Xiao wrote: > read_file_mod_stats() dumps dup_failed_modules while holding > module_mutex, but the loop uses list_for_each_entry_rcu() without > telling lockdep about that non-RCU protection. > > The same list is already traversed in try_add_failed_module() with > lockdep_is_held(&module_mutex) as the RCU-list lockdep condition. Use > the same condition for the debugfs stats dump so CONFIG_PROVE_RCU_LIST > can see the documented protection. > > This was found by our static analysis tool and then manually reviewed > against the current tree. The dynamic triage evidence is a > target-matched CONFIG_PROVE_RCU_LIST warning; the change is limited > to documenting the existing protection contract. > > This is a lockdep annotation cleanup. It does not change the list > lifetime or serialization rules. > > Signed-off-by: Runyu Xiao <[email protected]> > --- > kernel/module/stats.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/kernel/module/stats.c b/kernel/module/stats.c > index 3ba0e98b3c91..79c227a72a21 100644 > --- a/kernel/module/stats.c > +++ b/kernel/module/stats.c > @@ -382,7 +382,8 @@ static ssize_t read_file_mod_stats(struct file *file, > char __user *user_buf, > mutex_lock(&module_mutex); > > > - list_for_each_entry_rcu(mod_fail, &dup_failed_modules, list) { > + list_for_each_entry_rcu(mod_fail, &dup_failed_modules, list, > + lockdep_is_held(&module_mutex)) { > if (WARN_ON_ONCE(++count_failed >= MAX_FAILED_MOD_PRINT)) > goto out_unlock; > len += scnprintf(buf + len, size - len, "%25s\t%15lu\t%25s\n", > mod_fail->name,
The same fix was posted previously in: https://lore.kernel.org/linux-modules/e4za26n3jj3366oqt47hdwfze2rvsyjcujjhjj4jvbtihkleg6@kxasstqoia22/ -- Cheers, Petr
