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module: Use RCU in find_symbol().

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module_assert_mutex_or_preempt() is not needed in find_symbol(). The
function checks for RCU-sched or the module_mutex to be acquired. The
list_for_each_entry_rcu() below does the same check.

Remove module_assert_mutex_or_preempt() from try_add_tainted_module().
Use RCU protection to invoke find_symbol() and update callers.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250108090457.512198-11-bigeasy@linutronix.de
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
This commit is contained in:
Sebastian Andrzej Siewior
2025-01-08 10:04:39 +01:00
committed by Petr Pavlu
parent 435bbcc3be
commit 2ff49f8931
2 changed files with 19 additions and 25 deletions
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kernel/module/version.c
+7 -7
View File
@@ -79,17 +79,17 @@ int check_modstruct_version(const struct load_info *info,
.name = "module_layout",
.gplok = true,
};
bool have_symbol;
/*
* Since this should be found in kernel (which can't be removed), no
* locking is necessary -- use preempt_disable() to placate lockdep.
* locking is necessary. Regardless use a RCU read section to keep
* lockdep happy.
*/
preempt_disable();
if (!find_symbol(&fsa)) {
preempt_enable();
BUG();
}
preempt_enable();
scoped_guard(rcu)
have_symbol = find_symbol(&fsa);
BUG_ON(!have_symbol);
return check_version(info, "module_layout", mod, fsa.crc);
}