Hi Steven, Gentle ping on this v3.
While rechecking the selftest, I found that the unload checks can miss a failure: if the first test string remains in printk_formats but the second is gone, the test still passes. The first negated grep returns nonzero, but set -e does not terminate the script for a negated command. I reproduced this with a fixture containing only the first string. I would add explicit failure handling (|| exit_fail) to both checks. Would you prefer a v4 with this correction? I can also make the final rmmod failure fatal and add a comment explaining that trace_bprintk_fmt_cnt counts permanently retained, unique formats and therefore is not decremented on module unload. The current test checks the exported mappings, but does not exercise the new membership lookup through a TRACE_EVENT and the tp_printk path. I can extend coverage there as well if you would like it included in v4. Thanks, Cao Ruichuang
