diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace_kdb.c | 45 |
1 files changed, 31 insertions, 14 deletions
diff --git a/kernel/trace/trace_kdb.c b/kernel/trace/trace_kdb.c index 4b666643d69f..6c1ae6b752d1 100644 --- a/kernel/trace/trace_kdb.c +++ b/kernel/trace/trace_kdb.c @@ -17,29 +17,25 @@ #include "trace.h" #include "trace_output.h" +static struct trace_iterator iter; +static struct ring_buffer_iter *buffer_iter[CONFIG_NR_CPUS]; + static void ftrace_dump_buf(int skip_entries, long cpu_file) { - /* use static because iter can be a bit big for the stack */ - static struct trace_iterator iter; - static struct ring_buffer_iter *buffer_iter[CONFIG_NR_CPUS]; struct trace_array *tr; unsigned int old_userobj; int cnt = 0, cpu; - trace_init_global_iter(&iter); - iter.buffer_iter = buffer_iter; tr = iter.tr; - for_each_tracing_cpu(cpu) { - atomic_inc(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled); - } - old_userobj = tr->trace_flags; /* don't look at user memory in panic mode */ tr->trace_flags &= ~TRACE_ITER_SYM_USEROBJ; kdb_printf("Dumping ftrace buffer:\n"); + if (skip_entries) + kdb_printf("(skipping %d entries)\n", skip_entries); /* reset all but tr, trace, and overruns */ memset(&iter.seq, 0, @@ -90,10 +86,6 @@ out: tr->trace_flags = old_userobj; for_each_tracing_cpu(cpu) { - atomic_dec(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled); - } - - for_each_tracing_cpu(cpu) { if (iter.buffer_iter[cpu]) { ring_buffer_read_finish(iter.buffer_iter[cpu]); iter.buffer_iter[cpu] = NULL; @@ -109,6 +101,8 @@ static int kdb_ftdump(int argc, const char **argv) int skip_entries = 0; long cpu_file; char *cp; + int cnt; + int cpu; if (argc > 2) return KDB_ARGCOUNT; @@ -129,7 +123,29 @@ static int kdb_ftdump(int argc, const char **argv) } kdb_trap_printk++; + + trace_init_global_iter(&iter); + iter.buffer_iter = buffer_iter; + + for_each_tracing_cpu(cpu) { + atomic_inc(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled); + } + + /* A negative skip_entries means skip all but the last entries */ + if (skip_entries < 0) { + if (cpu_file == RING_BUFFER_ALL_CPUS) + cnt = trace_total_entries(NULL); + else + cnt = trace_total_entries_cpu(NULL, cpu_file); + skip_entries = max(cnt + skip_entries, 0); + } + ftrace_dump_buf(skip_entries, cpu_file); + + for_each_tracing_cpu(cpu) { + atomic_dec(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled); + } + kdb_trap_printk--; return 0; @@ -138,7 +154,8 @@ static int kdb_ftdump(int argc, const char **argv) static __init int kdb_ftrace_register(void) { kdb_register_flags("ftdump", kdb_ftdump, "[skip_#entries] [cpu]", - "Dump ftrace log", 0, KDB_ENABLE_ALWAYS_SAFE); + "Dump ftrace log; -skip dumps last #entries", 0, + KDB_ENABLE_ALWAYS_SAFE); return 0; } |