__module_address() can be invoked within a RCU section, there is no
requirement to have preemption disabled.
I'm not sure if using rcu_read_lock() will introduce the regression that
has been fixed in commit 14c4c8e41511a ("cfi: Use
rcu_read_{un}lock_sched_notrace").
Cc: Elliot Berman <quic_eberman@xxxxxxxxxxx>
Cc: Kees Cook <kees@xxxxxxxxxx>
Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
Cc: Sami Tolvanen <samitolvanen@xxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: llvm@xxxxxxxxxxxxxxx
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
kernel/cfi.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/kernel/cfi.c b/kernel/cfi.c
index 08caad7767176..c8f2b5a51b2e6 100644
--- a/kernel/cfi.c
+++ b/kernel/cfi.c
@@ -71,6 +71,10 @@ static bool is_module_cfi_trap(unsigned long addr)
struct module *mod;
bool found = false;
+ /*
+ * XXX this could be RCU protected but would it introcude the regression
+ * fixed in 14c4c8e41511a ("cfi: Use rcu_read_{un}lock_sched_notrace")
+ */
rcu_read_lock_sched_notrace();
mod = __module_address(addr);
--
2.45.2
