On Mon, Mar 7, 2022 at 12:23 PM Philipp Rudo <prudo@xxxxxxxxxx> wrote: > > Hi, > > dumping the dmesg can cause an endless loop for the old prink mechanism (> > v3.5.0 and < v5.10.0) when the log_buf got corrupted. This series fixes those > cases by adding a cycle detection. The cycle detection is implemented in a > generic way so that it can be reused in other parts of makedumpfile. > > Thanks > Philipp > > Philipp Rudo (3): > makedumpfile: add generic cycle detection > makedumpfile: use pointer arithmetics for dump_dmesg > makedumpfile: use cycle detection when parsing the prink log_buf > > Makefile | 2 +- > detect_cycle.c | 99 ++++++++++++++++++++++++++++++++++++++++++++++++++ > detect_cycle.h | 40 ++++++++++++++++++++ > makedumpfile.c | 65 +++++++++++++++++++++++++-------- > 4 files changed, 190 insertions(+), 16 deletions(-) > create mode 100644 detect_cycle.c > create mode 100644 detect_cycle.h > > -- > 2.35.1 > You can add Tested-by: Dave Wysochanski <dwysocha@xxxxxxxxxx> As I mentioned in the Red Hat bug, for my testing, I ran over 1,000 vmcores as a test set comparing "makedumpfile --dump-dmesg" output and saw no difference. Then I ran the one vmcore we found the loop on, and with these patches the loop was correctly detected and makedumpfile terminated rather than running forever. I'm still reviewing code a bit and may have a few minor bits of feedback in a few days. However, I don't offhand see anything that sticks out as wrong so far the code looks good. Thanks for doing this patchset. _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
