diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 2c92b3d9ea3077df8cd5d272cc48335e66a64681..1c80521fd43602041d797032a26cac79f665314c 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -8910,12 +8910,8 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) cnt++; - /* reset all but tr, trace, and overruns */ - memset(&iter.seq, 0, - sizeof(struct trace_iterator) - - offsetof(struct trace_iterator, seq)); + trace_iterator_reset(&iter); iter.iter_flags |= TRACE_FILE_LAT_FMT; - iter.pos = -1; if (trace_find_next_entry_inc(&iter) != NULL) { int ret; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 82c70b63d37510261c011b1ce3f683719f8f22c3..005f08629b8bed8d9d6ec0bcc5a10255cc0d7094 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1966,4 +1966,22 @@ static inline void tracer_hardirqs_off(unsigned long a0, unsigned long a1) { } extern struct trace_iterator *tracepoint_print_iter; +/* + * Reset the state of the trace_iterator so that it can read consumed data. + * Normally, the trace_iterator is used for reading the data when it is not + * consumed, and must retain state. + */ +static __always_inline void trace_iterator_reset(struct trace_iterator *iter) +{ + const size_t offset = offsetof(struct trace_iterator, seq); + + /* + * Keep gcc from complaining about overwriting more than just one + * member in the structure. + */ + memset((char *)iter + offset, 0, sizeof(struct trace_iterator) - offset); + + iter->pos = -1; +} + #endif /* _LINUX_KERNEL_TRACE_H */ diff --git a/kernel/trace/trace_kdb.c b/kernel/trace/trace_kdb.c index 6c1ae6b752d1997310dbc487808be4a01c749b40..cca65044c14c03b45b62ee44c0498cbc06f01458 100644 --- a/kernel/trace/trace_kdb.c +++ b/kernel/trace/trace_kdb.c @@ -37,12 +37,8 @@ static void ftrace_dump_buf(int skip_entries, long cpu_file) if (skip_entries) kdb_printf("(skipping %d entries)\n", skip_entries); - /* reset all but tr, trace, and overruns */ - memset(&iter.seq, 0, - sizeof(struct trace_iterator) - - offsetof(struct trace_iterator, seq)); + trace_iterator_reset(&iter); iter.iter_flags |= TRACE_FILE_LAT_FMT; - iter.pos = -1; if (cpu_file == RING_BUFFER_ALL_CPUS) { for_each_tracing_cpu(cpu) {