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-rw-r--r--kernel/trace/Kconfig70
-rw-r--r--kernel/trace/Makefile5
-rw-r--r--kernel/trace/blktrace.c91
-rw-r--r--kernel/trace/ftrace.c79
-rw-r--r--kernel/trace/ring_buffer.c114
-rw-r--r--kernel/trace/trace.c26
-rw-r--r--kernel/trace/trace_events.c4
-rw-r--r--kernel/trace/trace_events_filter.c6
-rw-r--r--kernel/trace/trace_functions_graph.c6
-rw-r--r--kernel/trace/trace_output.c85
-rw-r--r--kernel/trace/trace_output.h4
-rw-r--r--kernel/trace/trace_stack.c2
-rw-r--r--kernel/trace/trace_sysprof.c3
13 files changed, 357 insertions, 138 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index d7f01e6e8ba..ae048a2dbbe 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -56,6 +56,13 @@ config CONTEXT_SWITCH_TRACER
select MARKERS
bool
+# All tracer options should select GENERIC_TRACER. For those options that are
+# enabled by all tracers (context switch and event tracer) they select TRACING.
+# This allows those options to appear when no other tracer is selected. But the
+# options do not appear when something else selects it. We need the two options
+# GENERIC_TRACER and TRACING to avoid circular dependencies to accomplish the
+# hidding of the automatic options options.
+
config TRACING
bool
select DEBUG_FS
@@ -66,6 +73,10 @@ config TRACING
select BINARY_PRINTF
select EVENT_TRACING
+config GENERIC_TRACER
+ bool
+ select TRACING
+
#
# Minimum requirements an architecture has to meet for us to
# be able to offer generic tracing facilities:
@@ -95,7 +106,7 @@ config FUNCTION_TRACER
depends on HAVE_FUNCTION_TRACER
select FRAME_POINTER
select KALLSYMS
- select TRACING
+ select GENERIC_TRACER
select CONTEXT_SWITCH_TRACER
help
Enable the kernel to trace every kernel function. This is done
@@ -126,7 +137,7 @@ config IRQSOFF_TRACER
depends on TRACE_IRQFLAGS_SUPPORT
depends on GENERIC_TIME
select TRACE_IRQFLAGS
- select TRACING
+ select GENERIC_TRACER
select TRACER_MAX_TRACE
help
This option measures the time spent in irqs-off critical
@@ -136,7 +147,7 @@ config IRQSOFF_TRACER
disabled by default and can be runtime (re-)started
via:
- echo 0 > /debugfs/tracing/tracing_max_latency
+ echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
(Note that kernel size and overhead increases with this option
enabled. This option and the preempt-off timing option can be
@@ -147,7 +158,7 @@ config PREEMPT_TRACER
default n
depends on GENERIC_TIME
depends on PREEMPT
- select TRACING
+ select GENERIC_TRACER
select TRACER_MAX_TRACE
help
This option measures the time spent in preemption off critical
@@ -157,7 +168,7 @@ config PREEMPT_TRACER
disabled by default and can be runtime (re-)started
via:
- echo 0 > /debugfs/tracing/tracing_max_latency
+ echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
(Note that kernel size and overhead increases with this option
enabled. This option and the irqs-off timing option can be
@@ -166,7 +177,7 @@ config PREEMPT_TRACER
config SYSPROF_TRACER
bool "Sysprof Tracer"
depends on X86
- select TRACING
+ select GENERIC_TRACER
select CONTEXT_SWITCH_TRACER
help
This tracer provides the trace needed by the 'Sysprof' userspace
@@ -174,44 +185,33 @@ config SYSPROF_TRACER
config SCHED_TRACER
bool "Scheduling Latency Tracer"
- select TRACING
+ select GENERIC_TRACER
select CONTEXT_SWITCH_TRACER
select TRACER_MAX_TRACE
help
This tracer tracks the latency of the highest priority task
to be scheduled in, starting from the point it has woken up.
-config ENABLE_CONTEXT_SWITCH_TRACER
- bool "Trace process context switches"
- select TRACING
- select CONTEXT_SWITCH_TRACER
- help
- This tracer gets called from the context switch and records
- all switching of tasks.
-
-config ENABLE_EVENT_TRACING
- bool "Trace various events in the kernel"
+config ENABLE_DEFAULT_TRACERS
+ bool "Trace process context switches and events"
+ depends on !GENERIC_TRACER
select TRACING
help
This tracer hooks to various trace points in the kernel
allowing the user to pick and choose which trace point they
- want to trace.
-
- Note, all tracers enable event tracing. This option is
- only a convenience to enable event tracing when no other
- tracers are selected.
+ want to trace. It also includes the sched_switch tracer plugin.
config FTRACE_SYSCALLS
bool "Trace syscalls"
depends on HAVE_FTRACE_SYSCALLS
- select TRACING
+ select GENERIC_TRACER
select KALLSYMS
help
Basic tracer to catch the syscall entry and exit events.
config BOOT_TRACER
bool "Trace boot initcalls"
- select TRACING
+ select GENERIC_TRACER
select CONTEXT_SWITCH_TRACER
help
This tracer helps developers to optimize boot times: it records
@@ -228,7 +228,7 @@ config BOOT_TRACER
config TRACE_BRANCH_PROFILING
bool
- select TRACING
+ select GENERIC_TRACER
choice
prompt "Branch Profiling"
@@ -261,7 +261,7 @@ config PROFILE_ANNOTATED_BRANCHES
This tracer profiles all the the likely and unlikely macros
in the kernel. It will display the results in:
- /debugfs/tracing/profile_annotated_branch
+ /sys/kernel/debug/tracing/profile_annotated_branch
Note: this will add a significant overhead, only turn this
on if you need to profile the system's use of these macros.
@@ -274,7 +274,7 @@ config PROFILE_ALL_BRANCHES
taken in the kernel is recorded whether it hit or miss.
The results will be displayed in:
- /debugfs/tracing/profile_branch
+ /sys/kernel/debug/tracing/profile_branch
This option also enables the likely/unlikely profiler.
@@ -308,7 +308,7 @@ config BRANCH_TRACER
config POWER_TRACER
bool "Trace power consumption behavior"
depends on X86
- select TRACING
+ select GENERIC_TRACER
help
This tracer helps developers to analyze and optimize the kernels
power management decisions, specifically the C-state and P-state
@@ -344,7 +344,7 @@ config STACK_TRACER
select KALLSYMS
help
This special tracer records the maximum stack footprint of the
- kernel and displays it in debugfs/tracing/stack_trace.
+ kernel and displays it in /sys/kernel/debug/tracing/stack_trace.
This tracer works by hooking into every function call that the
kernel executes, and keeping a maximum stack depth value and
@@ -363,14 +363,14 @@ config STACK_TRACER
config HW_BRANCH_TRACER
depends on HAVE_HW_BRANCH_TRACER
bool "Trace hw branches"
- select TRACING
+ select GENERIC_TRACER
help
This tracer records all branches on the system in a circular
buffer giving access to the last N branches for each cpu.
config KMEMTRACE
bool "Trace SLAB allocations"
- select TRACING
+ select GENERIC_TRACER
help
kmemtrace provides tracing for slab allocator functions, such as
kmalloc, kfree, kmem_cache_alloc, kmem_cache_free etc.. Collected
@@ -390,7 +390,7 @@ config KMEMTRACE
config WORKQUEUE_TRACER
bool "Trace workqueues"
- select TRACING
+ select GENERIC_TRACER
help
The workqueue tracer provides some statistical informations
about each cpu workqueue thread such as the number of the
@@ -406,7 +406,7 @@ config BLK_DEV_IO_TRACE
select RELAY
select DEBUG_FS
select TRACEPOINTS
- select TRACING
+ select GENERIC_TRACER
select STACKTRACE
help
Say Y here if you want to be able to trace the block layer actions
@@ -467,7 +467,7 @@ config FTRACE_SELFTEST
config FTRACE_STARTUP_TEST
bool "Perform a startup test on ftrace"
- depends on TRACING
+ depends on GENERIC_TRACER
select FTRACE_SELFTEST
help
This option performs a series of startup tests on ftrace. On bootup
@@ -478,7 +478,7 @@ config FTRACE_STARTUP_TEST
config MMIOTRACE
bool "Memory mapped IO tracing"
depends on HAVE_MMIOTRACE_SUPPORT && PCI
- select TRACING
+ select GENERIC_TRACER
help
Mmiotrace traces Memory Mapped I/O access and is meant for
debugging and reverse engineering. It is called from the ioremap
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index 658aace8c41..ce3b1cd0273 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -45,7 +45,10 @@ obj-$(CONFIG_HW_BRANCH_TRACER) += trace_hw_branches.o
obj-$(CONFIG_POWER_TRACER) += trace_power.o
obj-$(CONFIG_KMEMTRACE) += kmemtrace.o
obj-$(CONFIG_WORKQUEUE_TRACER) += trace_workqueue.o
-obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o
+obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o
+ifeq ($(CONFIG_BLOCK),y)
+obj-$(CONFIG_EVENT_TRACING) += blktrace.o
+endif
obj-$(CONFIG_EVENT_TRACING) += trace_events.o
obj-$(CONFIG_EVENT_TRACING) += trace_export.o
obj-$(CONFIG_FTRACE_SYSCALLS) += trace_syscalls.o
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index e3abf55bc8e..39af8af6fc3 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -23,10 +23,14 @@
#include <linux/mutex.h>
#include <linux/debugfs.h>
#include <linux/time.h>
-#include <trace/block.h>
#include <linux/uaccess.h>
+
+#include <trace/events/block.h>
+
#include "trace_output.h"
+#ifdef CONFIG_BLK_DEV_IO_TRACE
+
static unsigned int blktrace_seq __read_mostly = 1;
static struct trace_array *blk_tr;
@@ -665,12 +669,12 @@ static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
if (blk_pc_request(rq)) {
what |= BLK_TC_ACT(BLK_TC_PC);
- __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors,
- rq->cmd_len, rq->cmd);
+ __blk_add_trace(bt, 0, blk_rq_bytes(rq), rw,
+ what, rq->errors, rq->cmd_len, rq->cmd);
} else {
what |= BLK_TC_ACT(BLK_TC_FS);
- __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9,
- rw, what, rq->errors, 0, NULL);
+ __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq), rw,
+ what, rq->errors, 0, NULL);
}
}
@@ -877,11 +881,11 @@ void blk_add_driver_data(struct request_queue *q,
return;
if (blk_pc_request(rq))
- __blk_add_trace(bt, 0, rq->data_len, 0, BLK_TA_DRV_DATA,
- rq->errors, len, data);
+ __blk_add_trace(bt, 0, blk_rq_bytes(rq), 0,
+ BLK_TA_DRV_DATA, rq->errors, len, data);
else
- __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9,
- 0, BLK_TA_DRV_DATA, rq->errors, len, data);
+ __blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq), 0,
+ BLK_TA_DRV_DATA, rq->errors, len, data);
}
EXPORT_SYMBOL_GPL(blk_add_driver_data);
@@ -1658,3 +1662,72 @@ int blk_trace_init_sysfs(struct device *dev)
return sysfs_create_group(&dev->kobj, &blk_trace_attr_group);
}
+#endif /* CONFIG_BLK_DEV_IO_TRACE */
+
+#ifdef CONFIG_EVENT_TRACING
+
+void blk_dump_cmd(char *buf, struct request *rq)
+{
+ int i, end;
+ int len = rq->cmd_len;
+ unsigned char *cmd = rq->cmd;
+
+ if (!blk_pc_request(rq)) {
+ buf[0] = '\0';
+ return;
+ }
+
+ for (end = len - 1; end >= 0; end--)
+ if (cmd[end])
+ break;
+ end++;
+
+ for (i = 0; i < len; i++) {
+ buf += sprintf(buf, "%s%02x", i == 0 ? "" : " ", cmd[i]);
+ if (i == end && end != len - 1) {
+ sprintf(buf, " ..");
+ break;
+ }
+ }
+}
+
+void blk_fill_rwbs(char *rwbs, u32 rw, int bytes)
+{
+ int i = 0;
+
+ if (rw & WRITE)
+ rwbs[i++] = 'W';
+ else if (rw & 1 << BIO_RW_DISCARD)
+ rwbs[i++] = 'D';
+ else if (bytes)
+ rwbs[i++] = 'R';
+ else
+ rwbs[i++] = 'N';
+
+ if (rw & 1 << BIO_RW_AHEAD)
+ rwbs[i++] = 'A';
+ if (rw & 1 << BIO_RW_BARRIER)
+ rwbs[i++] = 'B';
+ if (rw & 1 << BIO_RW_SYNCIO)
+ rwbs[i++] = 'S';
+ if (rw & 1 << BIO_RW_META)
+ rwbs[i++] = 'M';
+
+ rwbs[i] = '\0';
+}
+
+void blk_fill_rwbs_rq(char *rwbs, struct request *rq)
+{
+ int rw = rq->cmd_flags & 0x03;
+ int bytes;
+
+ if (blk_discard_rq(rq))
+ rw |= (1 << BIO_RW_DISCARD);
+
+ bytes = blk_rq_bytes(rq);
+
+ blk_fill_rwbs(rwbs, rw, bytes);
+}
+
+#endif /* CONFIG_EVENT_TRACING */
+
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 140699a9a8a..bb60732ade0 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -32,6 +32,7 @@
#include <trace/events/sched.h>
#include <asm/ftrace.h>
+#include <asm/setup.h>
#include "trace_output.h"
#include "trace_stat.h"
@@ -598,7 +599,7 @@ function_profile_call(unsigned long ip, unsigned long parent_ip)
local_irq_save(flags);
stat = &__get_cpu_var(ftrace_profile_stats);
- if (!stat->hash)
+ if (!stat->hash || !ftrace_profile_enabled)
goto out;
rec = ftrace_find_profiled_func(stat, ip);
@@ -629,7 +630,7 @@ static void profile_graph_return(struct ftrace_graph_ret *trace)
local_irq_save(flags);
stat = &__get_cpu_var(ftrace_profile_stats);
- if (!stat->hash)
+ if (!stat->hash || !ftrace_profile_enabled)
goto out;
calltime = trace->rettime - trace->calltime;
@@ -723,6 +724,10 @@ ftrace_profile_write(struct file *filp, const char __user *ubuf,
ftrace_profile_enabled = 1;
} else {
ftrace_profile_enabled = 0;
+ /*
+ * unregister_ftrace_profiler calls stop_machine
+ * so this acts like an synchronize_sched.
+ */
unregister_ftrace_profiler();
}
}
@@ -2369,6 +2374,45 @@ void ftrace_set_notrace(unsigned char *buf, int len, int reset)
ftrace_set_regex(buf, len, reset, 0);
}
+/*
+ * command line interface to allow users to set filters on boot up.
+ */
+#define FTRACE_FILTER_SIZE COMMAND_LINE_SIZE
+static char ftrace_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
+static char ftrace_filter_buf[FTRACE_FILTER_SIZE] __initdata;
+
+static int __init set_ftrace_notrace(char *str)
+{
+ strncpy(ftrace_notrace_buf, str, FTRACE_FILTER_SIZE);
+ return 1;
+}
+__setup("ftrace_notrace=", set_ftrace_notrace);
+
+static int __init set_ftrace_filter(char *str)
+{
+ strncpy(ftrace_filter_buf, str, FTRACE_FILTER_SIZE);
+ return 1;
+}
+__setup("ftrace_filter=", set_ftrace_filter);
+
+static void __init set_ftrace_early_filter(char *buf, int enable)
+{
+ char *func;
+
+ while (buf) {
+ func = strsep(&buf, ",");
+ ftrace_set_regex(func, strlen(func), 0, enable);
+ }
+}
+
+static void __init set_ftrace_early_filters(void)
+{
+ if (ftrace_filter_buf[0])
+ set_ftrace_early_filter(ftrace_filter_buf, 1);
+ if (ftrace_notrace_buf[0])
+ set_ftrace_early_filter(ftrace_notrace_buf, 0);
+}
+
static int
ftrace_regex_release(struct inode *inode, struct file *file, int enable)
{
@@ -2829,6 +2873,8 @@ void __init ftrace_init(void)
if (ret)
pr_warning("Failed to register trace ftrace module notifier\n");
+ set_ftrace_early_filters();
+
return;
failed:
ftrace_disabled = 1;
@@ -3172,12 +3218,12 @@ static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
}
if (t->ret_stack == NULL) {
- t->curr_ret_stack = -1;
- /* Make sure IRQs see the -1 first: */
- barrier();
- t->ret_stack = ret_stack_list[start++];
atomic_set(&t->tracing_graph_pause, 0);
atomic_set(&t->trace_overrun, 0);
+ t->curr_ret_stack = -1;
+ /* Make sure the tasks see the -1 first: */
+ smp_wmb();
+ t->ret_stack = ret_stack_list[start++];
}
} while_each_thread(g, t);
@@ -3235,8 +3281,10 @@ static int start_graph_tracing(void)
return -ENOMEM;
/* The cpu_boot init_task->ret_stack will never be freed */
- for_each_online_cpu(cpu)
- ftrace_graph_init_task(idle_task(cpu));
+ for_each_online_cpu(cpu) {
+ if (!idle_task(cpu)->ret_stack)
+ ftrace_graph_init_task(idle_task(cpu));
+ }
do {
ret = alloc_retstack_tasklist(ret_stack_list);
@@ -3328,18 +3376,25 @@ void unregister_ftrace_graph(void)
/* Allocate a return stack for newly created task */
void ftrace_graph_init_task(struct task_struct *t)
{
+ /* Make sure we do not use the parent ret_stack */
+ t->ret_stack = NULL;
+
if (ftrace_graph_active) {
- t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
+ struct ftrace_ret_stack *ret_stack;
+
+ ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
* sizeof(struct ftrace_ret_stack),
GFP_KERNEL);
- if (!t->ret_stack)
+ if (!ret_stack)
return;
t->curr_ret_stack = -1;
atomic_set(&t->tracing_graph_pause, 0);
atomic_set(&t->trace_overrun, 0);
t->ftrace_timestamp = 0;
- } else
- t->ret_stack = NULL;
+ /* make curr_ret_stack visable before we add the ret_stack */
+ smp_wmb();
+ t->ret_stack = ret_stack;
+ }
}
void ftrace_graph_exit_task(struct task_struct *t)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 16b24d49604..dc4dc70171c 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -10,6 +10,7 @@
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/hardirq.h>
+#include <linux/kmemcheck.h>
#include <linux/module.h>
#include <linux/percpu.h>
#include <linux/mutex.h>
@@ -370,6 +371,9 @@ static inline int test_time_stamp(u64 delta)
/* Max payload is BUF_PAGE_SIZE - header (8bytes) */
#define BUF_MAX_DATA_SIZE (BUF_PAGE_SIZE - (sizeof(u32) * 2))
+/* Max number of timestamps that can fit on a page */
+#define RB_TIMESTAMPS_PER_PAGE (BUF_PAGE_SIZE / RB_LEN_TIME_STAMP)
+
int ring_buffer_print_page_header(struct trace_seq *s)
{
struct buffer_data_page field;
@@ -423,6 +427,8 @@ struct ring_buffer {
atomic_t record_disabled;
cpumask_var_t cpumask;
+ struct lock_class_key *reader_lock_key;
+
struct mutex mutex;
struct ring_buffer_per_cpu **buffers;
@@ -562,6 +568,7 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu)
cpu_buffer->cpu = cpu;
cpu_buffer->buffer = buffer;
spin_lock_init(&cpu_buffer->reader_lock);
+ lockdep_set_class(&cpu_buffer->reader_lock, buffer->reader_lock_key);
cpu_buffer->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
INIT_LIST_HEAD(&cpu_buffer->pages);
@@ -632,7 +639,8 @@ static int rb_cpu_notify(struct notifier_block *self,
* when the buffer wraps. If this flag is not set, the buffer will
* drop data when the tail hits the head.
*/
-struct ring_buffer *ring_buffer_alloc(unsigned long size, unsigned flags)
+struct ring_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags,
+ struct lock_class_key *key)
{
struct ring_buffer *buffer;
int bsize;
@@ -655,6 +663,7 @@ struct ring_buffer *ring_buffer_alloc(unsigned long size, unsigned flags)
buffer->pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE);
buffer->flags = flags;
buffer->clock = trace_clock_local;
+ buffer->reader_lock_key = key;
/* need at least two pages */
if (buffer->pages == 1)
@@ -712,7 +721,7 @@ struct ring_buffer *ring_buffer_alloc(unsigned long size, unsigned flags)
kfree(buffer);
return NULL;
}
-EXPORT_SYMBOL_GPL(ring_buffer_alloc);
+EXPORT_SYMBOL_GPL(__ring_buffer_alloc);
/**
* ring_buffer_free - free a ring buffer.
@@ -1262,6 +1271,7 @@ rb_move_tail(struct ring_buffer_per_cpu *cpu_buffer,
if (tail < BUF_PAGE_SIZE) {
/* Mark the rest of the page with padding */
event = __rb_page_index(tail_page, tail);
+ kmemcheck_annotate_bitfield(event, bitfield);
rb_event_set_padding(event);
}
@@ -1319,6 +1329,7 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
return NULL;
event = __rb_page_index(tail_page, tail);
+ kmemcheck_annotate_bitfield(event, bitfield);
rb_update_event(event, type, length);
/* The passed in type is zero for DATA */
@@ -1335,6 +1346,38 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
return event;
}
+static inline int
+rb_try_to_discard(struct ring_buffer_per_cpu *cpu_buffer,
+ struct ring_buffer_event *event)
+{
+ unsigned long new_index, old_index;
+ struct buffer_page *bpage;
+ unsigned long index;
+ unsigned long addr;
+
+ new_index = rb_event_index(event);
+ old_index = new_index + rb_event_length(event);
+ addr = (unsigned long)event;
+ addr &= PAGE_MASK;
+
+ bpage = cpu_buffer->tail_page;
+
+ if (bpage->page == (void *)addr && rb_page_write(bpage) == old_index) {
+ /*
+ * This is on the tail page. It is possible that
+ * a write could come in and move the tail page
+ * and write to the next page. That is fine
+ * because we just shorten what is on this page.
+ */
+ index = local_cmpxchg(&bpage->write, old_index, new_index);
+ if (index == old_index)
+ return 1;
+ }
+
+ /* could not discard */
+ return 0;
+}
+
static int
rb_add_time_stamp(struct ring_buffer_per_cpu *cpu_buffer,
u64 *ts, u64 *delta)
@@ -1377,16 +1420,23 @@ rb_add_time_stamp(struct ring_buffer_per_cpu *cpu_buffer,
event->array[0] = *delta >> TS_SHIFT;
} else {
cpu_buffer->commit_page->page->time_stamp = *ts;
- event->time_delta = 0;
- event->array[0] = 0;
+ /* try to discard, since we do not need this */
+ if (!rb_try_to_discard(cpu_buffer, event)) {
+ /* nope, just zero it */
+ event->time_delta = 0;
+ event->array[0] = 0;
+ }
}
cpu_buffer->write_stamp = *ts;
/* let the caller know this was the commit */
ret = 1;
} else {
- /* Darn, this is just wasted space */
- event->time_delta = 0;
- event->array[0] = 0;
+ /* Try to discard the event */
+ if (!rb_try_to_discard(cpu_buffer, event)) {
+ /* Darn, this is just wasted space */
+ event->time_delta = 0;
+ event->array[0] = 0;
+ }
ret = 0;
}
@@ -1682,10 +1732,6 @@ void ring_buffer_discard_commit(struct ring_buffer *buffer,
struct ring_buffer_event *event)
{
struct ring_buffer_per_cpu *cpu_buffer;
- unsigned long new_index, old_index;
- struct buffer_page *bpage;
- unsigned long index;
- unsigned long addr;
int cpu;
/* The event is discarded regardless */
@@ -1701,24 +1747,8 @@ void ring_buffer_discard_commit(struct ring_buffer *buffer,
cpu = smp_processor_id();
cpu_buffer = buffer->buffers[cpu];
- new_index = rb_event_index(event);
- old_index = new_index + rb_event_length(event);
- addr = (unsigned long)event;
- addr &= PAGE_MASK;
-
- bpage = cpu_buffer->tail_page;
-
- if (bpage == (void *)addr && rb_page_write(bpage) == old_index) {
- /*
- * This is on the tail page. It is possible that
- * a write could come in and move the tail page
- * and write to the next page. That is fine
- * because we just shorten what is on this page.
- */
- index = local_cmpxchg(&bpage->write, old_index, new_index);
- if (index == old_index)
- goto out;
- }
+ if (!rb_try_to_discard(cpu_buffer, event))
+ goto out;
/*
* The commit is still visible by the reader, so we
@@ -2253,8 +2283,8 @@ static void rb_advance_iter(struct ring_buffer_iter *iter)
* Check if we are at the end of the buffer.
*/
if (iter->head >= rb_page_size(iter->head_page)) {
- if (RB_WARN_ON(buffer,
- iter->head_page == cpu_buffer->commit_page))
+ /* discarded commits can make the page empty */
+ if (iter->head_page == cpu_buffer->commit_page)
return;
rb_inc_iter(iter);
return;
@@ -2297,12 +2327,10 @@ rb_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts)
/*
* We repeat when a timestamp is encountered. It is possible
* to get multiple timestamps from an interrupt entering just
- * as one timestamp is about to be written. The max times
- * that this can happen is the number of nested interrupts we
- * can have. Nesting 10 deep of interrupts is clearly
- * an anomaly.
+ * as one timestamp is about to be written, or from discarded
+ * commits. The most that we can have is the number on a single page.
*/
- if (RB_WARN_ON(cpu_buffer, ++nr_loops > 10))
+ if (RB_WARN_ON(cpu_buffer, ++nr_loops > RB_TIMESTAMPS_PER_PAGE))
return NULL;
reader = rb_get_reader_page(cpu_buffer);
@@ -2368,14 +2396,14 @@ rb_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
again:
/*
- * We repeat when a timestamp is encountered. It is possible
- * to get multiple timestamps from an interrupt entering just
- * as one timestamp is about to be written. The max times
- * that this can happen is the number of nested interrupts we
- * can have. Nesting 10 deep of interrupts is clearly
- * an anomaly.
+ * We repeat when a timestamp is encountered.
+ * We can get multiple timestamps by nested interrupts or also
+ * if filtering is on (discarding commits). Since discarding
+ * commits can be frequent we can get a lot of timestamps.
+ * But we limit them by not adding timestamps if they begin
+ * at the start of a page.
*/
- if (RB_WARN_ON(cpu_buffer, ++nr_loops > 10))
+ if (RB_WARN_ON(cpu_buffer, ++nr_loops > RB_TIMESTAMPS_PER_PAGE))
return NULL;
if (rb_per_cpu_empty(cpu_buffer))
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index a3a8a87d7e9..c1878bfb2e1 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -344,7 +344,7 @@ static raw_spinlock_t ftrace_max_lock =
/*
* Copy the new maximum trace into the separate maximum-trace
* structure. (this way the maximum trace is permanently saved,
- * for later retrieval via /debugfs/tracing/latency_trace)
+ * for later retrieval via /sys/kernel/debug/tracing/latency_trace)
*/
static void
__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
@@ -2414,21 +2414,20 @@ static const struct file_operations tracing_iter_fops = {
static const char readme_msg[] =
"tracing mini-HOWTO:\n\n"
- "# mkdir /debug\n"
- "# mount -t debugfs nodev /debug\n\n"
- "# cat /debug/tracing/available_tracers\n"
+ "# mount -t debugfs nodev /sys/kernel/debug\n\n"
+ "# cat /sys/kernel/debug/tracing/available_tracers\n"
"wakeup preemptirqsoff preemptoff irqsoff function sched_switch nop\n\n"
- "# cat /debug/tracing/current_tracer\n"
+ "# cat /sys/kernel/debug/tracing/current_tracer\n"
"nop\n"
- "# echo sched_switch > /debug/tracing/current_tracer\n"
- "# cat /debug/tracing/current_tracer\n"
+ "# echo sched_switch > /sys/kernel/debug/tracing/current_tracer\n"
+ "# cat /sys/kernel/debug/tracing/current_tracer\n"
"sched_switch\n"
- "# cat /debug/tracing/trace_options\n"
+ "# cat /sys/kernel/debug/tracing/trace_options\n"
"noprint-parent nosym-offset nosym-addr noverbose\n"
- "# echo print-parent > /debug/tracing/trace_options\n"
- "# echo 1 > /debug/tracing/tracing_enabled\n"
- "# cat /debug/tracing/trace > /tmp/trace.txt\n"
- "echo 0 > /debug/tracing/tracing_enabled\n"
+ "# echo print-parent > /sys/kernel/debug/tracing/trace_options\n"
+ "# echo 1 > /sys/kernel/debug/tracing/tracing_enabled\n"
+ "# cat /sys/kernel/debug/tracing/trace > /tmp/trace.txt\n"
+ "# echo 0 > /sys/kernel/debug/tracing/tracing_enabled\n"
;
static ssize_t
@@ -2826,6 +2825,9 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp)
/* trace pipe does not show start of buffer */
cpumask_setall(iter->started);
+ if (trace_flags & TRACE_ITER_LATENCY_FMT)
+ iter->iter_flags |= TRACE_FILE_LAT_FMT;
+
iter->cpu_file = cpu_file;
iter->tr = &global_trace;
mutex_init(&iter->mutex);
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 6c81f9c2142..aa08be69a1b 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1050,12 +1050,13 @@ static void trace_module_remove_events(struct module *mod)
struct ftrace_event_call *call, *p;
bool found = false;
+ down_write(&trace_event_mutex);
list_for_each_entry_safe(call, p, &ftrace_events, list) {
if (call->mod == mod) {
found = true;
ftrace_event_enable_disable(call, 0);
if (call->event)
- unregister_ftrace_event(call->event);
+ __unregister_ftrace_event(call->event);
debugfs_remove_recursive(call->dir);
list_del(&call->list);
trace_destroy_fields(call);
@@ -1079,6 +1080,7 @@ static void trace_module_remove_events(struct module *mod)
*/
if (found)
tracing_reset_current_online_cpus();
+ up_write(&trace_event_mutex);
}
static int trace_module_notify(struct notifier_block *self,
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index a7430b16d24..db6e54bdb59 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -478,12 +478,12 @@ enum {
static int is_string_field(const char *type)
{
+ if (strstr(type, "__data_loc") && strstr(type, "char"))
+ return FILTER_DYN_STRING;
+
if (strchr(type, '[') && strstr(type, "char"))
return FILTER_STATIC_STRING;
- if (!strcmp(type, "__str_loc"))
- return FILTER_DYN_STRING;
-
return 0;
}
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 10f6ad7d85f..8b592418d8b 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -65,6 +65,12 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth)
if (!current->ret_stack)
return -EBUSY;
+ /*
+ * We must make sure the ret_stack is tested before we read
+ * anything else.
+ */
+ smp_rmb();
+
/* The return trace stack is full */
if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
atomic_inc(&current->trace_overrun);
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index c12d95db2f5..7938f3ae93e 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -14,9 +14,10 @@
/* must be a power of 2 */
#define EVENT_HASHSIZE 128
-static DECLARE_RWSEM(trace_event_mutex);
+DECLARE_RWSEM(trace_event_mutex);
DEFINE_PER_CPU(struct trace_seq, ftrace_event_seq);
+EXPORT_PER_CPU_SYMBOL(ftrace_event_seq);
static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
@@ -99,6 +100,38 @@ trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
}
EXPORT_SYMBOL_GPL(trace_seq_printf);
+/**
+ * trace_seq_vprintf - sequence printing of trace information
+ * @s: trace sequence descriptor
+ * @fmt: printf format string
+ *
+ * The tracer may use either sequence operations or its own
+ * copy to user routines. To simplify formating of a trace
+ * trace_seq_printf is used to store strings into a special
+ * buffer (@s). Then the output may be either used by
+ * the sequencer or pulled into another buffer.
+ */
+int
+trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
+{
+ int len = (PAGE_SIZE - 1) - s->len;
+ int ret;
+
+ if (!len)
+ return 0;
+
+ ret = vsnprintf(s->buffer + s->len, len, fmt, args);
+
+ /* If we can't write it all, don't bother writing anything */
+ if (ret >= len)
+ return 0;
+
+ s->len += ret;
+
+ return len;
+}
+EXPORT_SYMBOL_GPL(trace_seq_vprintf);
+
int trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)
{
int len = (PAGE_SIZE - 1) - s->len;
@@ -222,10 +255,9 @@ ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
{
unsigned long mask;
const char *str;
+ const char *ret = p->buffer + p->len;
int i;
- trace_seq_init(p);
-
for (i = 0; flag_array[i].name && flags; i++) {
mask = flag_array[i].mask;
@@ -248,16 +280,16 @@ ftrace_print_flags_seq(struct trace_seq *p, const char *delim,
trace_seq_putc(p, 0);
- return p->buffer;
+ return ret;
}
+EXPORT_SYMBOL(ftrace_print_flags_seq);
const char *
ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
const struct trace_print_flags *symbol_array)
{
int i;
-
- trace_seq_init(p);
+ const char *ret = p->buffer + p->len;
for (i = 0; symbol_array[i].name; i++) {
@@ -273,8 +305,9 @@ ftrace_print_symbols_seq(struct trace_seq *p, unsigned long val,
trace_seq_putc(p, 0);
- return p->buffer;
+ return ret;
}
+EXPORT_SYMBOL(ftrace_print_symbols_seq);
#ifdef CONFIG_KRETPROBES
static inline const char *kretprobed(const char *name)
@@ -386,17 +419,20 @@ seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
if (ip == ULONG_MAX || !ret)
break;
- if (i && ret)
- ret = trace_seq_puts(s, " <- ");
+ if (ret)
+ ret = trace_seq_puts(s, " => ");
if (!ip) {
if (ret)
ret = trace_seq_puts(s, "??");
+ if (ret)
+ ret = trace_seq_puts(s, "\n");
continue;
}
if (!ret)
break;
if (ret)
ret = seq_print_user_ip(s, mm, ip, sym_flags);
+ ret = trace_seq_puts(s, "\n");
}
if (mm)
@@ -666,6 +702,16 @@ int register_ftrace_event(struct trace_event *event)
}
EXPORT_SYMBOL_GPL(register_ftrace_event);
+/*
+ * Used by module code with the trace_event_mutex held for write.
+ */
+int __unregister_ftrace_event(struct trace_event *event)
+{
+ hlist_del(&event->node);
+ list_del(&event->list);
+ return 0;
+}
+
/**
* unregister_ftrace_event - remove a no longer used event
* @event: the event to remove
@@ -673,8 +719,7 @@ EXPORT_SYMBOL_GPL(register_ftrace_event);
int unregister_ftrace_event(struct trace_event *event)
{
down_write(&trace_event_mutex);
- hlist_del(&event->node);
- list_del(&event->list);
+ __unregister_ftrace_event(event);
up_write(&trace_event_mutex);
return 0;
@@ -972,16 +1017,16 @@ static enum print_line_t trace_stack_print(struct trace_iterator *iter,
trace_assign_type(field, iter->ent);
+ if (!trace_seq_puts(s, "<stack trace>\n"))
+ goto partial;
for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
- if (!field->caller[i])
+ if (!field->caller[i] || (field->caller[i] == ULONG_MAX))
break;
- if (i) {
- if (!trace_seq_puts(s, " <= "))
- goto partial;
+ if (!trace_seq_puts(s, " => "))
+ goto partial;
- if (!seq_print_ip_sym(s, field->caller[i], flags))
- goto partial;
- }
+ if (!seq_print_ip_sym(s, field->caller[i], flags))
+ goto partial;
if (!trace_seq_puts(s, "\n"))
goto partial;
}
@@ -1009,10 +1054,10 @@ static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
trace_assign_type(field, iter->ent);
- if (!seq_print_userip_objs(field, s, flags))
+ if (!trace_seq_puts(s, "<user stack trace>\n"))
goto partial;
- if (!trace_seq_putc(s, '\n'))
+ if (!seq_print_userip_objs(field, s, flags))
goto partial;
return TRACE_TYPE_HANDLED;
diff --git a/kernel/trace/trace_output.h b/kernel/trace/trace_output.h
index ac240e76eb0..d38bec4a9c3 100644
--- a/kernel/trace/trace_output.h
+++ b/kernel/trace/trace_output.h
@@ -27,6 +27,10 @@ extern struct trace_event *ftrace_find_event(int type);
extern enum print_line_t trace_nop_print(struct trace_iterator *iter,
int flags);
+/* used by module unregistering */
+extern int __unregister_ftrace_event(struct trace_event *event);
+extern struct rw_semaphore trace_event_mutex;
+
#define MAX_MEMHEX_BYTES 8
#define HEX_CHARS (MAX_MEMHEX_BYTES*2 + 1)
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index 1796f00524e..2d7aebd71db 100644
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -265,7 +265,7 @@ static int t_show(struct seq_file *m, void *v)
seq_printf(m, " Depth Size Location"
" (%d entries)\n"
" ----- ---- --------\n",
- max_stack_trace.nr_entries);
+ max_stack_trace.nr_entries - 1);
if (!stack_tracer_enabled && !max_stack_size)
print_disabled(m);
diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c
index e04b76cc238..f6693969287 100644
--- a/kernel/trace/trace_sysprof.c
+++ b/kernel/trace/trace_sysprof.c
@@ -203,7 +203,8 @@ static void start_stack_timer(void *unused)
hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
hrtimer->function = stack_trace_timer_fn;
- hrtimer_start(hrtimer, ns_to_ktime(sample_period), HRTIMER_MODE_REL);
+ hrtimer_start(hrtimer, ns_to_ktime(sample_period),
+ HRTIMER_MODE_REL_PINNED);
}
static void start_stack_timers(void)
generated by cgit (git 2.34.1) at 2024-11-19 00:46:31 +0000