On 2/5/20 10:55 PM, Christian Borntraeger wrote: > I only got your cover letter, but not the patch itself. Can you resend? Patch itself had another subject: "[PATCH 1/1] cio_ignore_proc_seq_next should increase position index" https://www.spinics.net/lists/linux-s390/msg30430.html It was reviewed by Cornelia Huck https://www.spinics.net/lists/linux-s390/msg30433.html > On 24.01.20 06:48, Vasily Averin wrote: >> In Aug 2018 NeilBrown noticed >> commit 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code and interface") >> "Some ->next functions do not increment *pos when they return NULL... >> Note that such ->next functions are buggy and should be fixed. >> A simple demonstration is >> >> dd if=/proc/swaps bs=1000 skip=1 >> >> Choose any block size larger than the size of /proc/swaps. This will >> always show the whole last line of /proc/swaps" >> >> Described problem is still actual. If you make lseek into middle of last output line >> following read will output end of last line and whole last line once again. >> >> $ dd if=/proc/swaps bs=1 # usual output >> Filename Type Size Used Priority >> /dev/dm-0 partition 4194812 97536 -2 >> 104+0 records in >> 104+0 records out >> 104 bytes copied >> >> $ dd if=/proc/swaps bs=40 skip=1 # last line was generated twice >> dd: /proc/swaps: cannot skip to specified offset >> v/dm-0 partition 4194812 97536 -2 >> /dev/dm-0 partition 4194812 97536 -2 >> 3+1 records in >> 3+1 records out >> 131 bytes copied >> >> There are lot of other affected files, I've found 30+ including >> /proc/net/ip_tables_matches and /proc/sysvipc/* >> >> Following patch fixes s390-related file >> >> https://bugzilla.kernel.org/show_bug.cgi?id=206283 >> >> Vasily Averin (1): >> cio_ignore_proc_seq_next should increase position index >> >> drivers/s390/cio/blacklist.c | 5 +++-- >> 1 file changed, 3 insertions(+), 2 deletions(-) >> >
