On Fri, 26 Feb 2021 10:02:53 +0800 Jacob Wen <jian.w.wen@xxxxxxxxxx> wrote: > Freeing a slab name generally means removing a kernel module. > See the callers of kmem_cache_destroy. > > We need to fix some of the trace events that call TP_printk with %pS > to get a symbol of a kernel module that maybe removed later. No. If the symbol is not found in the kallsyms lookup at the time of reading the trace, it will act just like a %p and print the address. Yes, it can change the reading of the trace file form one read to the next, but it's harmless, and it's been like this since ftrace was introduced back in 2009. -- Steve