Hi! A few days ago I've installed the linux-4.9.0-16-amd64 update on my Stretch machine, a Lenovo X220 laptop. _After_ that (not yet sure whether _because_ of that) the system started misbehaving, including:
- hanging with backtraces on shutdown, once with enough of a working kernel for Alt-SysRq-EISUB to work, and once a complete hang - files on / suddenly turning out to be damaged (e.g. Firefox starts up well in the morning, then, without any updates, crashes in the afternoon and keeps crashing on startup; debsums -c shows 2 damaged *.so) - scary-looking error messages in dmesg, including "general protection fault", "swap_free: Bad swap file entry", "BUG: Bad page map in process", "BUG: Bad rss-counter state", "Bad pagetable". (Logs available if needed.) I was going to blame this on the RAM or the SSD (the latter had been bought in 2016), but I cannot get a conclusive proof of either being at fault. Last night I ran 10 hours of memtest, then booted linux-4.9.0-15-amd64 with "memtest" parameter added (no errors found either way), ran everything I could think of (badblocks -n of the SSD swap partition, `stress` with -c/-i/-m, some computations I usually work on), but was unable to reproduce any problems. I also tried hibernating and resuming the laptop, which gave me "Uhhuh. NMI received for unknown reason 3c on CPU 0". Not sure if it's related to the current bunch of problems, because I've always been getting it from time to time, usually after resuming. Does anyone have any hints on how to diagnose this further? -- Best regards, Ivan