Messages in this thread | | | From | Chuck Lever III <> | Subject | Re: possible trace_printk() bug in v5.19-rc1 | Date | Thu, 16 Jun 2022 15:36:43 +0000 |
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> On Jun 16, 2022, at 11:34 AM, Steven Rostedt <rostedt@goodmis.org> wrote: > > On Thu, 16 Jun 2022 15:22:26 +0000 > Chuck Lever III <chuck.lever@oracle.com> wrote: > >> Hi Steve- >> >> Since v5.19-rc1, trace_printk() no longer displays a function >> name, but rather a kernel address. I don't have time at the >> moment to track this down to a specific commit, just parking >> it here in case someone can get to it sooner than me. >> >> <idle>-0 [003] 269.397568: bprint: 0xffffffffc0cccab7: nf=0xffff888172dbfba0 still on the LRU or a dispose list >> <idle>-0 [003] 269.397576: bprint: 0xffffffffc0cccafa: nf=0xffff888172dbfba0 >> <idle>-0 [003] 269.397583: bprint: 0xffffffffc0cccab7: nf=0xffff8881726cd4d8 still on the LRU or a dispose list >> <idle>-0 [003] 269.397584: bprint: 0xffffffffc0cccafa: nf=0xffff8881726cd4d8 >> > > It uses the normal vsprintf() in the kernel (that is, it prints the > function address just like printk() does with %pS). So if trace_printk() is > broken, then so is printk(). > > But one reason for this is if you have a trace_printk() in a module, do the > record, and then remove the module. The function name will also be removed > from kallsyms, leaving you with only the function address. > > Did you remove any modules before displaying the trace?
I haven't explicitly removed nfsd.ko, and lsmod says it's still there. And, trace_printk was working as expected on v5.18.
-- Chuck Lever
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