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 v2: * Rename 'idx' to 'ptr' * Also print the non-loop part when a cycle was detected. Such a situation can happen when log_buf wrapped around in the kernel (log_first_idx != 0) and the corruption occurred on an idx < log_first_idx. * Add patch 4 fixing a bug independent from the memory corruption but found while investigating it. Philipp Rudo (4): makedumpfile: add generic cycle detection makedumpfile: use pointer arithmetics for dump_dmesg makedumpfile: use cycle detection when parsing the prink log_buf makedumpfile: print error when reading with unsupported compression Makefile | 2 +- detect_cycle.c | 99 +++++++++++++++++++++++++++++++++++++ detect_cycle.h | 40 +++++++++++++++ makedumpfile.c | 131 ++++++++++++++++++++++++++++++++++++++++--------- 4 files changed, 247 insertions(+), 25 deletions(-) create mode 100644 detect_cycle.c create mode 100644 detect_cycle.h -- 2.35.1 _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
