diff options
| -rw-r--r-- | Documentation/trace/ftrace.txt | 83 | ||||
| -rw-r--r-- | include/linux/ftrace_event.h | 3 | ||||
| -rw-r--r-- | include/linux/ring_buffer.h | 1 | ||||
| -rw-r--r-- | kernel/trace/Kconfig | 10 | ||||
| -rw-r--r-- | kernel/trace/ring_buffer.c | 18 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 222 | ||||
| -rw-r--r-- | kernel/trace/trace.h | 1 | ||||
| -rw-r--r-- | kernel/trace/trace_clock.c | 2 | ||||
| -rw-r--r-- | kernel/trace/trace_functions_graph.c | 8 | ||||
| -rw-r--r-- | samples/Kconfig | 6 | ||||
| -rw-r--r-- | samples/Makefile | 2 | ||||
| -rw-r--r-- | samples/tracepoints/Makefile | 6 | ||||
| -rw-r--r-- | samples/tracepoints/tp-samples-trace.h | 11 | ||||
| -rw-r--r-- | samples/tracepoints/tracepoint-probe-sample.c | 57 | ||||
| -rw-r--r-- | samples/tracepoints/tracepoint-probe-sample2.c | 44 | ||||
| -rw-r--r-- | samples/tracepoints/tracepoint-sample.c | 57 |
16 files changed, 288 insertions, 243 deletions
diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt index 6f51fed45f2..53d6a3c51d8 100644 --- a/Documentation/trace/ftrace.txt +++ b/Documentation/trace/ftrace.txt @@ -1842,6 +1842,89 @@ an error. # cat buffer_size_kb 85 +Snapshot +-------- +CONFIG_TRACER_SNAPSHOT makes a generic snapshot feature +available to all non latency tracers. (Latency tracers which +record max latency, such as "irqsoff" or "wakeup", can't use +this feature, since those are already using the snapshot +mechanism internally.) + +Snapshot preserves a current trace buffer at a particular point +in time without stopping tracing. Ftrace swaps the current +buffer with a spare buffer, and tracing continues in the new +current (=previous spare) buffer. + +The following debugfs files in "tracing" are related to this +feature: + + snapshot: + + This is used to take a snapshot and to read the output + of the snapshot. Echo 1 into this file to allocate a + spare buffer and to take a snapshot (swap), then read + the snapshot from this file in the same format as + "trace" (described above in the section "The File + System"). Both reads snapshot and tracing are executable + in parallel. When the spare buffer is allocated, echoing + 0 frees it, and echoing else (positive) values clear the + snapshot contents. + More details are shown in the table below. + + status\input | 0 | 1 | else | + --------------+------------+------------+------------+ + not allocated |(do nothing)| alloc+swap | EINVAL | + --------------+------------+------------+------------+ + allocated | free | swap | clear | + --------------+------------+------------+------------+ + +Here is an example of using the snapshot feature. + + # echo 1 > events/sched/enable + # echo 1 > snapshot + # cat snapshot +# tracer: nop +# +# entries-in-buffer/entries-written: 71/71 #P:8 +# +# _-----=> irqs-off +# / _----=> need-resched +# | / _---=> hardirq/softirq +# || / _--=> preempt-depth +# ||| / delay +# TASK-PID CPU# |||| TIMESTAMP FUNCTION +# | | | |||| | | + <idle>-0 [005] d... 2440.603828: sched_switch: prev_comm=swapper/5 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=snapshot-test-2 next_pid=2242 next_prio=120 + sleep-2242 [005] d... 2440.603846: sched_switch: prev_comm=snapshot-test-2 prev_pid=2242 prev_prio=120 prev_state=R ==> next_comm=kworker/5:1 next_pid=60 next_prio=120 +[...] + <idle>-0 [002] d... 2440.707230: sched_switch: prev_comm=swapper/2 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=snapshot-test-2 next_pid=2229 next_prio=120 + + # cat trace +# tracer: nop +# +# entries-in-buffer/entries-written: 77/77 #P:8 +# +# _-----=> irqs-off +# / _----=> need-resched +# | / _---=> hardirq/softirq +# || / _--=> preempt-depth +# ||| / delay +# TASK-PID CPU# |||| TIMESTAMP FUNCTION +# | | | |||| | | + <idle>-0 [007] d... 2440.707395: sched_switch: prev_comm=swapper/7 prev_pid=0 prev_prio=120 prev_state=R ==> next_comm=snapshot-test-2 next_pid=2243 next_prio=120 + snapshot-test-2-2229 [002] d... 2440.707438: sched_switch: prev_comm=snapshot-test-2 prev_pid=2229 prev_prio=120 prev_state=S ==> next_comm=swapper/2 next_pid=0 next_prio=120 +[...] + + +If you try to use this snapshot feature when current tracer is +one of the latency tracers, you will get the following results. + + # echo wakeup > current_tracer + # echo 1 > snapshot +bash: echo: write error: Device or resource busy + # cat snapshot +cat: snapshot: Device or resource busy + ----------- More details can be found in the source code, in the diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h index 6f8d0b77006..13a54d0bdfa 100644 --- a/include/linux/ftrace_event.h +++ b/include/linux/ftrace_event.h @@ -83,6 +83,9 @@ struct trace_iterator { long idx; cpumask_var_t started; + + /* it's true when current open file is snapshot */ + bool snapshot; }; enum trace_iter_flags { diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h index 519777e3fa0..1342e69542f 100644 --- a/include/linux/ring_buffer.h +++ b/include/linux/ring_buffer.h @@ -167,6 +167,7 @@ unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu); unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu); unsigned long ring_buffer_commit_overrun_cpu(struct ring_buffer *buffer, int cpu); unsigned long ring_buffer_dropped_events_cpu(struct ring_buffer *buffer, int cpu); +unsigned long ring_buffer_read_events_cpu(struct ring_buffer *buffer, int cpu); u64 ring_buffer_time_stamp(struct ring_buffer *buffer, int cpu); void ring_buffer_normalize_time_stamp(struct ring_buffer *buffer, diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index cdc9d284d24..36567564e22 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -253,6 +253,16 @@ config FTRACE_SYSCALLS help Basic tracer to catch the syscall entry and exit events. +config TRACER_SNAPSHOT + bool "Create a snapshot trace buffer" + select TRACER_MAX_TRACE + help + Allow tracing users to take snapshot of the current buffer using the + ftrace interface, e.g.: + + echo 1 > /sys/kernel/debug/tracing/snapshot + cat snapshot + config TRACE_BRANCH_PROFILING bool select GENERIC_TRACER diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 13950d9027c..7244acde77b 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -3103,6 +3103,24 @@ ring_buffer_dropped_events_cpu(struct ring_buffer *buffer, int cpu) EXPORT_SYMBOL_GPL(ring_buffer_dropped_events_cpu); /** + * ring_buffer_read_events_cpu - get the number of events successfully read + * @buffer: The ring buffer + * @cpu: The per CPU buffer to get the number of events read + */ +unsigned long +ring_buffer_read_events_cpu(struct ring_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + + if (!cpumask_test_cpu(cpu, buffer->cpumask)) + return 0; + + cpu_buffer = buffer->buffers[cpu]; + return cpu_buffer->read; +} +EXPORT_SYMBOL_GPL(ring_buffer_read_events_cpu); + +/** * ring_buffer_entries - get the number of entries in a buffer * @buffer: The ring buffer * diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index d2a658349ca..5d520b7bb4c 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -249,7 +249,7 @@ static unsigned long trace_buf_size = TRACE_BUF_SIZE_DEFAULT; static struct tracer *trace_types __read_mostly; /* current_trace points to the tracer that is currently active */ -static struct tracer *current_trace __read_mostly; +static struct tracer *current_trace __read_mostly = &nop_trace; /* * trace_types_lock is used to protect the trace_types list. @@ -710,12 +710,11 @@ update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) WARN_ON_ONCE(!irqs_disabled()); - /* If we disabled the tracer, stop now */ - if (current_trace == &nop_trace) - return; - - if (WARN_ON_ONCE(!current_trace->use_max_tr)) + if (!current_trace->allocated_snapshot) { + /* Only the nop tracer should hit this when disabling */ + WARN_ON_ONCE(current_trace != &nop_trace); return; + } arch_spin_lock(&ftrace_max_lock); @@ -743,10 +742,8 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) return; WARN_ON_ONCE(!irqs_disabled()); - if (!current_trace->use_max_tr) { - WARN_ON_ONCE(1); + if (WARN_ON_ONCE(!current_trace->allocated_snapshot)) return; - } arch_spin_lock(&ftrace_max_lock); @@ -866,10 +863,13 @@ int register_tracer(struct tracer *type) current_trace = type; - /* If we expanded the buffers, make sure the max is expanded too */ - if (ring_buffer_expanded && type->use_max_tr) - ring_buffer_resize(max_tr.buffer, trace_buf_size, - RING_BUFFER_ALL_CPUS); + if (type->use_max_tr) { + /* If we expanded the buffers, make sure the max is expanded too */ + if (ring_buffer_expanded) + ring_buffer_resize(max_tr.buffer, trace_buf_size, + RING_BUFFER_ALL_CPUS); + type->allocated_snapshot = true; + } /* the test is responsible for initializing and enabling */ pr_info("Testing tracer %s: ", type->name); @@ -885,10 +885,14 @@ int register_tracer(struct tracer *type) /* Only reset on passing, to avoid touching corrupted buffers */ tracing_reset_online_cpus(tr); - /* Shrink the max buffer again */ - if (ring_buffer_expanded && type->use_max_tr) - ring_buffer_resize(max_tr.buffer, 1, - RING_BUFFER_ALL_CPUS); + if (type->use_max_tr) { + type->allocated_snapshot = false; + + /* Shrink the max buffer again */ + if (ring_buffer_expanded) + ring_buffer_resize(max_tr.buffer, 1, + RING_BUFFER_ALL_CPUS); + } printk(KERN_CONT "PASSED\n"); } @@ -1344,7 +1348,7 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer, */ preempt_disable_notrace(); - use_stack = ++__get_cpu_var(ftrace_stack_reserve); + use_stack = __this_cpu_inc_return(ftrace_stack_reserve); /* * We don't need any atomic variables, just a barrier. * If an interrupt comes in, we don't care, because it would @@ -1398,7 +1402,7 @@ static void __ftrace_trace_stack(struct ring_buffer *buffer, out: /* Again, don't let gcc optimize things here */ barrier(); - __get_cpu_var(ftrace_stack_reserve)--; + __this_cpu_dec(ftrace_stack_reserve); preempt_enable_notrace(); } @@ -1948,21 +1952,27 @@ void tracing_iter_reset(struct trace_iterator *iter, int cpu) static void *s_start(struct seq_file *m, loff_t *pos) { struct trace_iterator *iter = m->private; - static struct tracer *old_tracer; int cpu_file = iter->cpu_file; void *p = NULL; loff_t l = 0; int cpu; - /* copy the tracer to avoid using a global lock all around */ + /* + * copy the tracer to avoid using a global lock all around. + * iter->trace is a copy of current_trace, the pointer to the + * name may be used instead of a strcmp(), as iter->trace->name + * will point to the same string as current_trace->name. + */ mutex_lock(&trace_types_lock); - if (unlikely(old_tracer != current_trace && current_trace)) { - old_tracer = current_trace; + if (unlikely(current_trace && iter->trace->name != current_trace->name)) *iter->trace = *current_trace; - } mutex_unlock(&trace_types_lock); - atomic_inc(&trace_record_cmdline_disabled); + if (iter->snapshot && iter->trace->use_max_tr) + return ERR_PTR(-EBUSY); + + if (!iter->snapshot) + atomic_inc(&trace_record_cmdline_disabled); if (*pos != iter->pos) { iter->ent = NULL; @@ -2001,7 +2011,11 @@ static void s_stop(struct seq_file *m, void *p) { struct trace_iterator *iter = m->private; - atomic_dec(&trace_record_cmdline_disabled); + if (iter->snapshot && iter->trace->use_max_tr) + return; + + if (!iter->snapshot) + atomic_dec(&trace_record_cmdline_disabled); trace_access_unlock(iter->cpu_file); trace_event_read_unlock(); } @@ -2086,8 +2100,7 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter) unsigned long total; const char *name = "preemption"; - if (type) - name = type->name; + name = type->name; get_total_entries(tr, &total, &entries); @@ -2436,7 +2449,7 @@ static const struct seq_operations tracer_seq_ops = { }; static struct trace_iterator * -__tracing_open(struct inode *inode, struct file *file) +__tracing_open(struct inode *inode, struct file *file, bool snapshot) { long cpu_file = (long) inode->i_private; struct trace_iterator *iter; @@ -2463,16 +2476,16 @@ __tracing_open(struct inode *inode, struct file *file) if (!iter->trace) goto fail; - if (current_trace) - *iter->trace = *current_trace; + *iter->trace = *current_trace; if (!zalloc_cpumask_var(&iter->started, GFP_KERNEL)) goto fail; - if (current_trace && current_trace->print_max) + if (current_trace->print_max || snapshot) iter->tr = &max_tr; else iter->tr = &global_trace; + iter->snapshot = snapshot; iter->pos = -1; mutex_init(&iter->mutex); iter->cpu_file = cpu_file; @@ -2489,8 +2502,9 @@ __tracing_open(struct inode *inode, struct file *file) if (trace_clocks[trace_clock_id].in_ns) iter->iter_flags |= TRACE_FILE_TIME_IN_NS; - /* stop the trace while dumping */ - tracing_stop(); + /* stop the trace while dumping if we are not opening "snapshot" */ + if (!iter->snapshot) + tracing_stop(); if (iter->cpu_file == TRACE_PIPE_ALL_CPU) { for_each_tracing_cpu(cpu) { @@ -2553,8 +2567,9 @@ static int tracing_release(struct inode *inode, struct file *file) if (iter->trace && iter->trace->close) iter->trace->close(iter); - /* reenable tracing if it was previously enabled */ - tracing_start(); + if (!iter->snapshot) + /* reenable tracing if it was previously enabled */ + tracing_start(); mutex_unlock(&trace_types_lock); mutex_destroy(&iter->mutex); @@ -2582,7 +2597,7 @@ static int tracing_open(struct inode *inode, struct file *file) } if (file->f_mode & FMODE_READ) { - iter = __tracing_open(inode, file); + iter = __tracing_open(inode, file, false); if (IS_ERR(iter)) ret = PTR_ERR(iter); else if (trace_flags & TRACE_ITER_LATENCY_FMT) @@ -3020,10 +3035,7 @@ tracing_set_trace_read(struct file *filp, char __user *ubuf, int r; mutex_lock(&trace_types_lock); - if (current_trace) - r = sprintf(buf, "%s\n", current_trace->name); - else - r = sprintf(buf, "\n"); + r = sprintf(buf, "%s\n", current_trace->name); mutex_unlock(&trace_types_lock); return simple_read_from_buffer(ubuf, cnt, ppos, buf, r); @@ -3214,10 +3226,10 @@ static int tracing_set_tracer(const char *buf) goto out; trace_branch_disable(); - if (current_trace && current_trace->reset) + if (current_trace->reset) current_trace->reset(tr); - had_max_tr = current_trace && current_trace->use_max_tr; + had_max_tr = current_trace->allocated_snapshot; current_trace = &nop_trace; if (had_max_tr && !t->use_max_tr) { @@ -3236,6 +3248,8 @@ static int tracing_set_tracer(const char *buf) */ ring_buffer_resize(max_tr.buffer, 1, RING_BUFFER_ALL_CPUS); set_buffer_entries(&max_tr, 1); + tracing_reset_online_cpus(&max_tr); + current_trace->allocated_snapshot = false; } destroy_trace_option_files(topts); @@ -3246,6 +3260,7 @@ static int tracing_set_tracer(const char *buf) RING_BUFFER_ALL_CPUS); if (ret < 0) goto out; + t->allocated_snapshot = true; } if (t->init) { @@ -3353,8 +3368,7 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp) ret = -ENOMEM; goto fail; } - if (current_trace) - *iter->trace = *current_trace; + *iter->trace = *current_trace; if (!alloc_cpumask_var(&iter->started, GFP_KERNEL)) { ret = -ENOMEM; @@ -3494,7 +3508,6 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { struct trace_iterator *iter = filp->private_data; - static struct tracer *old_tracer; ssize_t sret; /* return any leftover data */ @@ -3506,10 +3519,8 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, /* copy the tracer to avoid using a global lock all around */ mutex_lock(&trace_types_lock); - if (unlikely(old_tracer != current_trace && current_trace)) { - old_tracer = current_trace; + if (unlikely(iter->trace->name != current_trace->name)) *iter->trace = *current_trace; - } mutex_unlock(&trace_types_lock); /* @@ -3665,7 +3676,6 @@ static ssize_t tracing_splice_read_pipe(struct file *filp, .ops = &tracing_pipe_buf_ops, .spd_release = tracing_spd_release_pipe, }; - static struct tracer *old_tracer; ssize_t ret; size_t rem; unsigned int i; @@ -3675,10 +3685,8 @@ static ssize_t tracing_splice_read_pipe(struct file *filp, /* copy the tracer to avoid using a global lock all around */ mutex_lock(&trace_types_lock); - if (unlikely(old_tracer != current_trace && current_trace)) { - old_tracer = current_trace; + if (unlikely(iter->trace->name != current_trace->name)) *iter->trace = *current_trace; - } mutex_unlock(&trace_types_lock); mutex_lock(&iter->mutex); @@ -4070,6 +4078,87 @@ static int tracing_clock_open(struct inode *inode, struct file *file) return single_open(file, tracing_clock_show, NULL); } +#ifdef CONFIG_TRACER_SNAPSHOT +static int tracing_snapshot_open(struct inode *inode, struct file *file) +{ + struct trace_iterator *iter; + int ret = 0; + + if (file->f_mode & FMODE_READ) { + iter = __tracing_open(inode, file, true); + if (IS_ERR(iter)) + ret = PTR_ERR(iter); + } + return ret; +} + +static ssize_t +tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt, + loff_t *ppos) +{ + unsigned long val; + int ret; + + ret = tracing_update_buffers(); + if (ret < 0) + return ret; + + ret = kstrtoul_from_user(ubuf, cnt, 10, &val); + if (ret) + return ret; + + mutex_lock(&trace_types_lock); + + if (current_trace->use_max_tr) { + ret = -EBUSY; + goto out; + } + + switch (val) { + case 0: + if (current_trace->allocated_snapshot) { + /* free spare buffer */ + ring_buffer_resize(max_tr.buffer, 1, + RING_BUFFER_ALL_CPUS); + set_buffer_entries(&max_tr, 1); + tracing_reset_online_cpus(&max_tr); + current_trace->allocated_snapshot = false; + } + break; + case 1: + if (!current_trace->allocated_snapshot) { + /* allocate spare buffer */ + ret = resize_buffer_duplicate_size(&max_tr, + &global_trace, RING_BUFFER_ALL_CPUS); + if (ret < 0) + break; + current_trace->allocated_snapshot = true; + } + + local_irq_disable(); + /* Now, we're going to swap */ + update_max_tr(&global_trace, current, smp_processor_id()); + local_irq_enable(); + break; + default: + if (current_trace->allocated_snapshot) + tracing_reset_online_cpus(&max_tr); + else + ret = -EINVAL; + break; + } + + if (ret >= 0) { + *ppos += cnt; + ret = cnt; + } +out: + mutex_unlock(&trace_types_lock); + return ret; +} +#endif /* CONFIG_TRACER_SNAPSHOT */ + + static const struct file_operations tracing_max_lat_fops = { .open = tracing_open_generic, .read = tracing_max_lat_read, @@ -4126,6 +4215,16 @@ static const struct file_operations trace_clock_fops = { .write = tracing_clock_write, }; +#ifdef CONFIG_TRACER_SNAPSHOT +static const struct file_operations snapshot_fops = { + .open = tracing_snapshot_open, + .read = seq_read, + .write = tracing_snapshot_write, + .llseek = tracing_seek, + .release = tracing_release, +}; +#endif /* CONFIG_TRACER_SNAPSHOT */ + struct ftrace_buffer_info { struct trace_array *tr; void *spare; @@ -4430,6 +4529,9 @@ tracing_stats_read(struct file *filp, char __user *ubuf, cnt = ring_buffer_dropped_events_cpu(tr->buffer, cpu); trace_seq_printf(s, "dropped events: %ld\n", cnt); + cnt = ring_buffer_read_events_cpu(tr->buffer, cpu); + trace_seq_printf(s, "read events: %ld\n", cnt); + count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len); kfree(s); @@ -4506,7 +4608,7 @@ struct dentry *tracing_init_dentry(void) static struct dentry *d_percpu; -struct dentry *tracing_dentry_percpu(void) +static struct dentry *tracing_dentry_percpu(void) { static int once; struct dentry *d_tracer; @@ -4922,6 +5024,11 @@ static __init int tracer_init_debugfs(void) &ftrace_update_tot_cnt, &tracing_dyn_info_fops); #endif +#ifdef CONFIG_TRACER_SNAPSHOT + trace_create_file("snapshot", 0644, d_tracer, + (void *) TRACE_PIPE_ALL_CPU, &snapshot_fops); +#endif + create_trace_options_dir(); for_each_tracing_cpu(cpu) @@ -5030,6 +5137,7 @@ __ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode) if (disable_tracing) ftrace_kill(); + /* Simulate the iterator */ trace_init_global_iter(&iter); for_each_tracing_cpu(cpu) { @@ -5041,10 +5149,6 @@ __ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode) /* don't look at user memory in panic mode */ trace_flags &= ~TRACE_ITER_SYM_USEROBJ; - /* Simulate the iterator */ - iter.tr = &global_trace; - iter.trace = current_trace; - switch (oops_dump_mode) { case DUMP_ALL: iter.cpu_file = TRACE_PIPE_ALL_CPU; @@ -5189,7 +5293,7 @@ __init static int tracer_alloc_buffers(void) init_irq_work(&trace_work_wakeup, trace_wake_up); register_tracer(&nop_trace); - current_trace = &nop_trace; + /* All seems OK, enable tracing */ tracing_disabled = 0; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 04a2c7ab173..57d7e5397d5 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -287,6 +287,7 @@ struct tracer { struct tracer_flags *flags; bool print_max; bool use_max_tr; + bool allocated_snapshot; }; diff --git a/kernel/trace/trace_clock.c b/kernel/trace/trace_clock.c index 22b638b28e4..24bf48eabfc 100644 --- a/kernel/trace/trace_clock.c +++ b/kernel/trace/trace_clock.c @@ -84,7 +84,7 @@ u64 notrace trace_clock_global(void) local_irq_save(flags); this_cpu = raw_smp_processor_id(); - now = cpu_clock(this_cpu); + now = sched_clock_cpu(this_cpu); /* * If in an NMI context then dont risk lockups and return the * cpu_clock() time: diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 7008d2e13cf..39ada66389c 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -191,10 +191,16 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer) ftrace_pop_return_trace(&trace, &ret, frame_pointer); trace.rettime = trace_clock_local(); - ftrace_graph_return(&trace); barrier(); current->curr_ret_stack--; + /* + * The trace should run after decrementing the ret counter + * in case an interrupt were to come in. We don't want to + * lose the interrupt if max_depth is set. + */ + ftrace_graph_return(&trace); + if (unlikely(!ret)) { ftrace_graph_stop(); WARN_ON(1); diff --git a/samples/Kconfig b/samples/Kconfig index 7b6792a18c0..6181c2cc9ca 100644 --- a/samples/Kconfig +++ b/samples/Kconfig @@ -5,12 +5,6 @@ menuconfig SAMPLES if SAMPLES -config SAMPLE_TRACEPOINTS - tristate "Build tracepoints examples -- loadable modules only" - depends on TRACEPOINTS && m - help - This build tracepoints example modules. - config SAMPLE_TRACE_EVENTS tristate "Build trace_events examples -- loadable modules only" depends on EVENT_TRACING && m diff --git a/samples/Makefile b/samples/Makefile index 5ef08bba96c..1a60c62e204 100644 --- a/samples/Makefile +++ b/samples/Makefile @@ -1,4 +1,4 @@ # Makefile for Linux samples code -obj-$(CONFIG_SAMPLES) += kobject/ kprobes/ tracepoints/ trace_events/ \ +obj-$(CONFIG_SAMPLES) += kobject/ kprobes/ trace_events/ \ hw_breakpoint/ kfifo/ kdb/ hidraw/ rpmsg/ seccomp/ diff --git a/samples/tracepoints/Makefile b/samples/tracepoints/Makefile deleted file mode 100644 index 36479ad9ae1..00000000000 --- a/samples/tracepoints/Makefile +++ /dev/null @@ -1,6 +0,0 @@ -# builds the tracepoint example kernel modules; -# then to use one (as root): insmod <module_name.ko> - -obj-$(CONFIG_SAMPLE_TRACEPOINTS) += tracepoint-sample.o -obj-$(CONFIG_SAMPLE_TRACEPOINTS) += tracepoint-probe-sample.o -obj-$(CONFIG_SAMPLE_TRACEPOINTS) += tracepoint-probe-sample2.o diff --git a/samples/tracepoints/tp-samples-trace.h b/samples/tracepoints/tp-samples-trace.h deleted file mode 100644 index 4d46be96596..00000000000 --- a/samples/tracepoints/tp-samples-trace.h +++ /dev/null @@ -1,11 +0,0 @@ -#ifndef _TP_SAMPLES_TRACE_H -#define _TP_SAMPLES_TRACE_H - -#include <linux/proc_fs.h> /* for struct inode and struct file */ -#include <linux/tracepoint.h> - -DECLARE_TRACE(subsys_event, - TP_PROTO(struct inode *inode, struct file *file), - TP_ARGS(inode, file)); -DECLARE_TRACE_NOARGS(subsys_eventb); -#endif diff --git a/samples/tracepoints/tracepoint-probe-sample.c b/samples/tracepoints/tracepoint-probe-sample.c deleted file mode 100644 index 744c0b9652a..00000000000 --- a/samples/tracepoints/tracepoint-probe-sample.c +++ /dev/null @@ -1,57 +0,0 @@ -/* - * tracepoint-probe-sample.c - * - * sample tracepoint probes. - */ - -#include <linux/module.h> -#include <linux/file.h> -#include <linux/dcache.h> -#include "tp-samples-trace.h" - -/* - * Here the caller only guarantees locking for struct file and struct inode. - * Locking must therefore be done in the probe to use the dentry. - */ -static void probe_subsys_event(void *ignore, - struct inode *inode, struct file *file) -{ - path_get(&file->f_path); - dget(file->f_path.dentry); - printk(KERN_INFO "Event is encountered with filename %s\n", - file->f_path.dentry->d_name.name); - dput(file->f_path.dentry); - path_put(&file->f_path); -} - -static void probe_subsys_eventb(void *ignore) -{ - printk(KERN_INFO "Event B is encountered\n"); -} - -static int __init tp_sample_trace_init(void) -{ - int ret; - - ret = register_trace_subsys_event(probe_subsys_event, NULL); - WARN_ON(ret); - ret = register_trace_subsys_eventb(probe_subsys_eventb, NULL); - WARN_ON(ret); - - return 0; -} - -module_init(tp_sample_trace_init); - -static void __exit tp_sample_trace_exit(void) -{ - unregister_trace_subsys_eventb(probe_subsys_eventb, NULL); - unregister_trace_subsys_event(probe_subsys_event, NULL); - tracepoint_synchronize_unregister(); -} - -module_exit(tp_sample_trace_exit); - -MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Mathieu Desnoyers"); -MODULE_DESCRIPTION("Tracepoint Probes Samples"); diff --git a/samples/tracepoints/tracepoint-probe-sample2.c b/samples/tracepoints/tracepoint-probe-sample2.c deleted file mode 100644 index 9fcf990e5d4..00000000000 --- a/samples/tracepoints/tracepoint-probe-sample2.c +++ /dev/null @@ -1,44 +0,0 @@ -/* - * tracepoint-probe-sample2.c - * - * 2nd sample tracepoint probes. - */ - -#include <linux/module.h> -#include <linux/fs.h> -#include "tp-samples-trace.h" - -/* - * Here the caller only guarantees locking for struct file and struct inode. - * Locking must therefore be done in the probe to use the dentry. - */ -static void probe_subsys_event(void *ignore, - struct inode *inode, struct file *file) -{ - printk(KERN_INFO "Event is encountered with inode number %lu\n", - inode->i_ino); -} - -static int __init tp_sample_trace_init(void) -{ - int ret; - - ret = register_trace_subsys_event(probe_subsys_event, NULL); - WARN_ON(ret); - - return 0; -} - -module_init(tp_sample_trace_init); - -static void __exit tp_sample_trace_exit(void) -{ - unregister_trace_subsys_event(probe_subsys_event, NULL); - tracepoint_synchronize_unregister(); -} - -module_exit(tp_sample_trace_exit); - -MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Mathieu Desnoyers"); -MODULE_DESCRIPTION("Tracepoint Probes Samples"); diff --git a/samples/tracepoints/tracepoint-sample.c b/samples/tracepoints/tracepoint-sample.c deleted file mode 100644 index f4d89e008c3..00000000000 --- a/samples/tracepoints/tracepoint-sample.c +++ /dev/null @@ -1,57 +0,0 @@ -/* tracepoint-sample.c - * - * Executes a tracepoint when /proc/tracepoint-sample is opened. - * - * (C) Copyright 2007 Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> - * - * This file is released under the GPLv2. - * See the file COPYING for more details. - */ - -#include <linux/module.h> -#include <linux/sched.h> -#include <linux/proc_fs.h> -#include "tp-samples-trace.h" - -DEFINE_TRACE(subsys_event); -DEFINE_TRACE(subsys_eventb); - -struct proc_dir_entry *pentry_sample; - -static int my_open(struct inode *inode, struct file *file) -{ - int i; - - trace_subsys_event(inode, file); - for (i = 0; i < 10; i++) - trace_subsys_eventb(); - return -EPERM; -} - -static const struct file_operations mark_ops = { - .open = my_open, - .llseek = noop_llseek, -}; - -static int __init sample_init(void) -{ - printk(KERN_ALERT "sample init\n"); - pentry_sample = proc_create("tracepoint-sample", 0444, NULL, - &mark_ops); - if (!pentry_sample) - return -EPERM; - return 0; -} - -static void __exit sample_exit(void) -{ - printk(KERN_ALERT "sample exit\n"); - remove_proc_entry("tracepoint-sample", NULL); -} - -module_init(sample_init) -module_exit(sample_exit) - -MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Mathieu Desnoyers"); -MODULE_DESCRIPTION("Tracepoint sample"); |