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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155// SPDX-License-Identifier: GPL-2.0/* * kdb helper for dumping the ftrace buffer * * Copyright (C) 2010 Jason Wessel <jason.wessel@windriver.com> * * ftrace_dump_buf based on ftrace_dump: * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com> * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com> * */#include <linux/init.h>#include <linux/kgdb.h>#include <linux/kdb.h>#include <linux/ftrace.h>
#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){ struct trace_array *tr; unsigned int old_userobj; int cnt = 0, cpu;
tr = iter.tr;
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);
trace_iterator_reset(&iter); iter.iter_flags |= TRACE_FILE_LAT_FMT;
if (cpu_file == RING_BUFFER_ALL_CPUS) { for_each_tracing_cpu(cpu) { iter.buffer_iter[cpu] = ring_buffer_read_start(iter.array_buffer->buffer, cpu, GFP_ATOMIC); tracing_iter_reset(&iter, cpu); } } else { iter.cpu_file = cpu_file; iter.buffer_iter[cpu_file] = ring_buffer_read_start(iter.array_buffer->buffer, cpu_file, GFP_ATOMIC); tracing_iter_reset(&iter, cpu_file); }
while (trace_find_next_entry_inc(&iter)) { if (!cnt) kdb_printf("---------------------------------\n"); cnt++;
if (!skip_entries) { print_trace_line(&iter); trace_printk_seq(&iter.seq); } else { skip_entries--; }
if (KDB_FLAG(CMD_INTERRUPT)) goto out; }
if (!cnt) kdb_printf(" (ftrace buffer empty)\n"); else kdb_printf("---------------------------------\n");
out: tr->trace_flags = old_userobj;
for_each_tracing_cpu(cpu) { if (iter.buffer_iter[cpu]) { ring_buffer_read_finish(iter.buffer_iter[cpu]); iter.buffer_iter[cpu] = NULL; } }}
/* * kdb_ftdump - Dump the ftrace log buffer */static int kdb_ftdump(int argc, const char **argv){ int skip_entries = 0; long cpu_file; int err; int cnt;
if (argc > 2) return KDB_ARGCOUNT;
if (argc && kstrtoint(argv[1], 0, &skip_entries)) return KDB_BADINT;
if (argc == 2) { err = kstrtol(argv[2], 0, &cpu_file); if (err || cpu_file >= NR_CPUS || cpu_file < 0 || !cpu_online(cpu_file)) return KDB_BADINT; } else { cpu_file = RING_BUFFER_ALL_CPUS; }
kdb_trap_printk++;
trace_init_global_iter(&iter); iter.buffer_iter = buffer_iter;
tracer_tracing_disable(iter.tr);
/* 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);
tracer_tracing_enable(iter.tr);
kdb_trap_printk--;
return 0;}
static kdbtab_t ftdump_cmd = { .name = "ftdump", .func = kdb_ftdump, .usage = "[skip_#entries] [cpu]", .help = "Dump ftrace log; -skip dumps last #entries", .flags = KDB_ENABLE_ALWAYS_SAFE,};
static __init int kdb_ftrace_register(void){ kdb_register(&ftdump_cmd); return 0;}
late_initcall(kdb_ftrace_register);