From: Vladimir Riabchun Date: Fri, 12 Sep 2025 11:28:55 +0000 (+0200) Subject: ftrace: Fix softlockup in ftrace_module_enable X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=4099b98203d6b33d990586542fa5beee408032a3;p=thirdparty%2Fkernel%2Fstable.git ftrace: Fix softlockup in ftrace_module_enable A soft lockup was observed when loading amdgpu module. If a module has a lot of tracable functions, multiple calls to kallsyms_lookup can spend too much time in RCU critical section and with disabled preemption, causing kernel panic. This is the same issue that was fixed in commit d0b24b4e91fc ("ftrace: Prevent RCU stall on PREEMPT_VOLUNTARY kernels") and commit 42ea22e754ba ("ftrace: Add cond_resched() to ftrace_graph_set_hash()"). Fix it the same way by adding cond_resched() in ftrace_module_enable. Link: https://lore.kernel.org/aMQD9_lxYmphT-up@vova-pc Signed-off-by: Vladimir Riabchun Signed-off-by: Steven Rostedt (Google) --- diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index a69067367c296..42bd2ba68a821 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -7535,6 +7535,8 @@ void ftrace_module_enable(struct module *mod) if (!within_module(rec->ip, mod)) break; + cond_resched(); + /* Weak functions should still be ignored */ if (!test_for_valid_rec(rec)) { /* Clear all other flags. Should not be enabled anyway */