#include <linux/percpu.h>
#include <linux/ctype.h>
#include <linux/init.h>
+#include <linux/poll.h>
#include <linux/gfp.h>
#include <linux/fs.h>
+#include <linux/kprobes.h>
+#include <linux/writeback.h>
+
+#include <linux/stacktrace.h>
#include "trace.h"
unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX;
unsigned long __read_mostly tracing_thresh;
-static long notrace
+static unsigned long __read_mostly tracing_nr_buffers;
+static cpumask_t __read_mostly tracing_buffer_mask;
+
+#define for_each_tracing_cpu(cpu) \
+ for_each_cpu_mask(cpu, tracing_buffer_mask)
+
+static int trace_alloc_page(void);
+static int trace_free_page(void);
+
+static int tracing_disabled = 1;
+
+static unsigned long tracing_pages_allocated;
+
+long
ns2usecs(cycle_t nsec)
{
nsec += 500;
return nsec;
}
-static atomic_t tracer_counter;
+cycle_t ftrace_now(int cpu)
+{
+ return cpu_clock(cpu);
+}
+
+/*
+ * The global_trace is the descriptor that holds the tracing
+ * buffers for the live tracing. For each CPU, it contains
+ * a link list of pages that will store trace entries. The
+ * page descriptor of the pages in the memory is used to hold
+ * the link list by linking the lru item in the page descriptor
+ * to each of the pages in the buffer per CPU.
+ *
+ * For each active CPU there is a data field that holds the
+ * pages for the buffer for that CPU. Each CPU has the same number
+ * of pages allocated for its buffer.
+ */
static struct trace_array global_trace;
static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu);
+/*
+ * The max_tr is used to snapshot the global_trace when a maximum
+ * latency is reached. Some tracers will use this to store a maximum
+ * trace while it continues examining live traces.
+ *
+ * The buffers for the max_tr are set up the same as the global_trace.
+ * When a snapshot is taken, the link list of the max_tr is swapped
+ * with the link list of the global_trace and the buffers are reset for
+ * the global_trace so the tracing can continue.
+ */
static struct trace_array max_tr;
static DEFINE_PER_CPU(struct trace_array_cpu, max_data);
-static int tracer_enabled;
-static unsigned long trace_nr_entries = 16384UL;
+/* tracer_enabled is used to toggle activation of a tracer */
+static int tracer_enabled = 1;
+/*
+ * trace_nr_entries is the number of entries that is allocated
+ * for a buffer. Note, the number of entries is always rounded
+ * to ENTRIES_PER_PAGE.
+ */
+static unsigned long trace_nr_entries = 65536UL;
+
+/* trace_types holds a link list of available tracers. */
static struct tracer *trace_types __read_mostly;
+
+/* current_trace points to the tracer that is currently active */
static struct tracer *current_trace __read_mostly;
+
+/*
+ * max_tracer_type_len is used to simplify the allocating of
+ * buffers to read userspace tracer names. We keep track of
+ * the longest tracer name registered.
+ */
static int max_tracer_type_len;
+/*
+ * trace_types_lock is used to protect the trace_types list.
+ * This lock is also used to keep user access serialized.
+ * Accesses from userspace will grab this lock while userspace
+ * activities happen inside the kernel.
+ */
static DEFINE_MUTEX(trace_types_lock);
+/* trace_wait is a waitqueue for tasks blocked on trace_poll */
+static DECLARE_WAIT_QUEUE_HEAD(trace_wait);
+
+/* trace_flags holds iter_ctrl options */
+unsigned long trace_flags = TRACE_ITER_PRINT_PARENT;
+
+static notrace void no_trace_init(struct trace_array *tr)
+{
+ int cpu;
+
+ if(tr->ctrl)
+ for_each_online_cpu(cpu)
+ tracing_reset(tr->data[cpu]);
+ tracer_enabled = 0;
+}
+
+/* dummy trace to disable tracing */
+static struct tracer no_tracer __read_mostly = {
+ .name = "none",
+ .init = no_trace_init
+};
+
+
+/**
+ * trace_wake_up - wake up tasks waiting for trace input
+ *
+ * Simply wakes up any task that is blocked on the trace_wait
+ * queue. These is used with trace_poll for tasks polling the trace.
+ */
+void trace_wake_up(void)
+{
+ /*
+ * The runqueue_is_locked() can fail, but this is the best we
+ * have for now:
+ */
+ if (!(trace_flags & TRACE_ITER_BLOCK) && !runqueue_is_locked())
+ wake_up(&trace_wait);
+}
+
#define ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(struct trace_entry))
static int __init set_nr_entries(char *str)
{
+ unsigned long nr_entries;
+ int ret;
+
if (!str)
return 0;
- trace_nr_entries = simple_strtoul(str, &str, 0);
+ ret = strict_strtoul(str, 0, &nr_entries);
+ /* nr_entries can not be zero */
+ if (ret < 0 || nr_entries == 0)
+ return 0;
+ trace_nr_entries = nr_entries;
return 1;
}
__setup("trace_entries=", set_nr_entries);
-enum trace_type {
- __TRACE_FIRST_TYPE = 0,
-
- TRACE_FN,
- TRACE_CTX,
-
- __TRACE_LAST_TYPE
-};
+unsigned long nsecs_to_usecs(unsigned long nsecs)
+{
+ return nsecs / 1000;
+}
+/*
+ * trace_flag_type is an enumeration that holds different
+ * states when a trace occurs. These are:
+ * IRQS_OFF - interrupts were disabled
+ * NEED_RESCED - reschedule is requested
+ * HARDIRQ - inside an interrupt handler
+ * SOFTIRQ - inside a softirq handler
+ */
enum trace_flag_type {
TRACE_FLAG_IRQS_OFF = 0x01,
TRACE_FLAG_NEED_RESCHED = 0x02,
TRACE_FLAG_SOFTIRQ = 0x08,
};
-enum trace_iterator_flags {
- TRACE_ITER_PRINT_PARENT = 0x01,
- TRACE_ITER_SYM_OFFSET = 0x02,
- TRACE_ITER_SYM_ADDR = 0x04,
- TRACE_ITER_VERBOSE = 0x08,
-};
-
+/*
+ * TRACE_ITER_SYM_MASK masks the options in trace_flags that
+ * control the output of kernel symbols.
+ */
#define TRACE_ITER_SYM_MASK \
(TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
-/* These must match the bit postions above */
+/* These must match the bit postions in trace_iterator_flags */
static const char *trace_options[] = {
"print-parent",
"sym-offset",
"sym-addr",
"verbose",
+ "raw",
+ "hex",
+ "bin",
+ "block",
+ "stacktrace",
+ "sched-tree",
NULL
};
-static unsigned trace_flags;
-
-static DEFINE_SPINLOCK(ftrace_max_lock);
+/*
+ * ftrace_max_lock is used to protect the swapping of buffers
+ * when taking a max snapshot. The buffers themselves are
+ * protected by per_cpu spinlocks. But the action of the swap
+ * needs its own lock.
+ *
+ * This is defined as a raw_spinlock_t in order to help
+ * with performance when lockdep debugging is enabled.
+ */
+static raw_spinlock_t ftrace_max_lock =
+ (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
/*
* 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)
*/
-static void notrace
+static void
__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
{
struct trace_array_cpu *data = tr->data[cpu];
tracing_record_cmdline(current);
}
-notrace void
+#define CHECK_COND(cond) \
+ if (unlikely(cond)) { \
+ tracing_disabled = 1; \
+ WARN_ON(1); \
+ return -1; \
+ }
+
+/**
+ * check_pages - integrity check of trace buffers
+ *
+ * As a safty measure we check to make sure the data pages have not
+ * been corrupted.
+ */
+int check_pages(struct trace_array_cpu *data)
+{
+ struct page *page, *tmp;
+
+ CHECK_COND(data->trace_pages.next->prev != &data->trace_pages);
+ CHECK_COND(data->trace_pages.prev->next != &data->trace_pages);
+
+ list_for_each_entry_safe(page, tmp, &data->trace_pages, lru) {
+ CHECK_COND(page->lru.next->prev != &page->lru);
+ CHECK_COND(page->lru.prev->next != &page->lru);
+ }
+
+ return 0;
+}
+
+/**
+ * head_page - page address of the first page in per_cpu buffer.
+ *
+ * head_page returns the page address of the first page in
+ * a per_cpu buffer. This also preforms various consistency
+ * checks to make sure the buffer has not been corrupted.
+ */
+void *head_page(struct trace_array_cpu *data)
+{
+ struct page *page;
+
+ if (list_empty(&data->trace_pages))
+ return NULL;
+
+ page = list_entry(data->trace_pages.next, struct page, lru);
+ BUG_ON(&page->lru == &data->trace_pages);
+
+ return page_address(page);
+}
+
+/**
+ * trace_seq_printf - 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_printf(struct trace_seq *s, const char *fmt, ...)
+{
+ int len = (PAGE_SIZE - 1) - s->len;
+ va_list ap;
+ int ret;
+
+ if (!len)
+ return 0;
+
+ va_start(ap, fmt);
+ ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
+ va_end(ap);
+
+ /* If we can't write it all, don't bother writing anything */
+ if (ret >= len)
+ return 0;
+
+ s->len += ret;
+
+ return len;
+}
+
+/**
+ * trace_seq_puts - trace sequence printing of simple string
+ * @s: trace sequence descriptor
+ * @str: simple string to record
+ *
+ * The tracer may use either the sequence operations or its own
+ * copy to user routines. This function records a simple string
+ * into a special buffer (@s) for later retrieval by a sequencer
+ * or other mechanism.
+ */
+static int
+trace_seq_puts(struct trace_seq *s, const char *str)
+{
+ int len = strlen(str);
+
+ if (len > ((PAGE_SIZE - 1) - s->len))
+ return 0;
+
+ memcpy(s->buffer + s->len, str, len);
+ s->len += len;
+
+ return len;
+}
+
+static int
+trace_seq_putc(struct trace_seq *s, unsigned char c)
+{
+ if (s->len >= (PAGE_SIZE - 1))
+ return 0;
+
+ s->buffer[s->len++] = c;
+
+ return 1;
+}
+
+static int
+trace_seq_putmem(struct trace_seq *s, void *mem, size_t len)
+{
+ if (len > ((PAGE_SIZE - 1) - s->len))
+ return 0;
+
+ memcpy(s->buffer + s->len, mem, len);
+ s->len += len;
+
+ return len;
+}
+
+#define HEX_CHARS 17
+static const char hex2asc[] = "0123456789abcdef";
+
+static int
+trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len)
+{
+ unsigned char hex[HEX_CHARS];
+ unsigned char *data = mem;
+ unsigned char byte;
+ int i, j;
+
+ BUG_ON(len >= HEX_CHARS);
+
+#ifdef __BIG_ENDIAN
+ for (i = 0, j = 0; i < len; i++) {
+#else
+ for (i = len-1, j = 0; i >= 0; i--) {
+#endif
+ byte = data[i];
+
+ hex[j++] = hex2asc[byte & 0x0f];
+ hex[j++] = hex2asc[byte >> 4];
+ }
+ hex[j++] = ' ';
+
+ return trace_seq_putmem(s, hex, j);
+}
+
+static void
+trace_seq_reset(struct trace_seq *s)
+{
+ s->len = 0;
+ s->readpos = 0;
+}
+
+ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt)
+{
+ int len;
+ int ret;
+
+ if (s->len <= s->readpos)
+ return -EBUSY;
+
+ len = s->len - s->readpos;
+ if (cnt > len)
+ cnt = len;
+ ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt);
+ if (ret)
+ return -EFAULT;
+
+ s->readpos += len;
+ return cnt;
+}
+
+static void
+trace_print_seq(struct seq_file *m, struct trace_seq *s)
+{
+ int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len;
+
+ s->buffer[len] = 0;
+ seq_puts(m, s->buffer);
+
+ trace_seq_reset(s);
+}
+
+/*
+ * flip the trace buffers between two trace descriptors.
+ * This usually is the buffers between the global_trace and
+ * the max_tr to record a snapshot of a current trace.
+ *
+ * The ftrace_max_lock must be held.
+ */
+static void
+flip_trace(struct trace_array_cpu *tr1, struct trace_array_cpu *tr2)
+{
+ struct list_head flip_pages;
+
+ INIT_LIST_HEAD(&flip_pages);
+
+ memcpy(&tr1->trace_head_idx, &tr2->trace_head_idx,
+ sizeof(struct trace_array_cpu) -
+ offsetof(struct trace_array_cpu, trace_head_idx));
+
+ check_pages(tr1);
+ check_pages(tr2);
+ list_splice_init(&tr1->trace_pages, &flip_pages);
+ list_splice_init(&tr2->trace_pages, &tr1->trace_pages);
+ list_splice_init(&flip_pages, &tr2->trace_pages);
+ BUG_ON(!list_empty(&flip_pages));
+ check_pages(tr1);
+ check_pages(tr2);
+}
+
+/**
+ * update_max_tr - snapshot all trace buffers from global_trace to max_tr
+ * @tr: tracer
+ * @tsk: the task with the latency
+ * @cpu: The cpu that initiated the trace.
+ *
+ * Flip the buffers between the @tr and the max_tr and record information
+ * about which task was the cause of this latency.
+ */
+void
update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
{
struct trace_array_cpu *data;
- void *save_trace;
- struct list_head save_pages;
int i;
WARN_ON_ONCE(!irqs_disabled());
- spin_lock(&ftrace_max_lock);
+ __raw_spin_lock(&ftrace_max_lock);
/* clear out all the previous traces */
- for_each_possible_cpu(i) {
+ for_each_tracing_cpu(i) {
data = tr->data[i];
- save_trace = max_tr.data[i]->trace;
- save_pages = max_tr.data[i]->trace_pages;
- memcpy(max_tr.data[i], data, sizeof(*data));
- data->trace = save_trace;
- data->trace_pages = save_pages;
+ flip_trace(max_tr.data[i], data);
+ tracing_reset(data);
}
__update_max_tr(tr, tsk, cpu);
- spin_unlock(&ftrace_max_lock);
+ __raw_spin_unlock(&ftrace_max_lock);
}
/**
* @tr - tracer
* @tsk - task with the latency
* @cpu - the cpu of the buffer to copy.
+ *
+ * Flip the trace of a single CPU buffer between the @tr and the max_tr.
*/
-notrace void
+void
update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
{
struct trace_array_cpu *data = tr->data[cpu];
- void *save_trace;
- struct list_head save_pages;
int i;
WARN_ON_ONCE(!irqs_disabled());
- spin_lock(&ftrace_max_lock);
- for_each_possible_cpu(i)
+ __raw_spin_lock(&ftrace_max_lock);
+ for_each_tracing_cpu(i)
tracing_reset(max_tr.data[i]);
- save_trace = max_tr.data[cpu]->trace;
- save_pages = max_tr.data[cpu]->trace_pages;
- memcpy(max_tr.data[cpu], data, sizeof(*data));
- data->trace = save_trace;
- data->trace_pages = save_pages;
+ flip_trace(max_tr.data[cpu], data);
+ tracing_reset(data);
__update_max_tr(tr, tsk, cpu);
- spin_unlock(&ftrace_max_lock);
+ __raw_spin_unlock(&ftrace_max_lock);
}
+/**
+ * register_tracer - register a tracer with the ftrace system.
+ * @type - the plugin for the tracer
+ *
+ * Register a new plugin tracer.
+ */
int register_tracer(struct tracer *type)
{
struct tracer *t;
}
}
+#ifdef CONFIG_FTRACE_STARTUP_TEST
+ if (type->selftest) {
+ struct tracer *saved_tracer = current_trace;
+ struct trace_array_cpu *data;
+ struct trace_array *tr = &global_trace;
+ int saved_ctrl = tr->ctrl;
+ int i;
+ /*
+ * Run a selftest on this tracer.
+ * Here we reset the trace buffer, and set the current
+ * tracer to be this tracer. The tracer can then run some
+ * internal tracing to verify that everything is in order.
+ * If we fail, we do not register this tracer.
+ */
+ for_each_tracing_cpu(i) {
+ data = tr->data[i];
+ if (!head_page(data))
+ continue;
+ tracing_reset(data);
+ }
+ current_trace = type;
+ tr->ctrl = 0;
+ /* the test is responsible for initializing and enabling */
+ pr_info("Testing tracer %s: ", type->name);
+ ret = type->selftest(type, tr);
+ /* the test is responsible for resetting too */
+ current_trace = saved_tracer;
+ tr->ctrl = saved_ctrl;
+ if (ret) {
+ printk(KERN_CONT "FAILED!\n");
+ goto out;
+ }
+ /* Only reset on passing, to avoid touching corrupted buffers */
+ for_each_tracing_cpu(i) {
+ data = tr->data[i];
+ if (!head_page(data))
+ continue;
+ tracing_reset(data);
+ }
+ printk(KERN_CONT "PASSED\n");
+ }
+#endif
+
type->next = trace_types;
trace_types = type;
len = strlen(type->name);
if (len > max_tracer_type_len)
max_tracer_type_len = len;
+
out:
mutex_unlock(&trace_types_lock);
mutex_unlock(&trace_types_lock);
}
-void notrace tracing_reset(struct trace_array_cpu *data)
+void tracing_reset(struct trace_array_cpu *data)
{
data->trace_idx = 0;
- data->trace_current = data->trace;
- data->trace_current_idx = 0;
-}
-
-#ifdef CONFIG_FTRACE
-static void notrace
-function_trace_call(unsigned long ip, unsigned long parent_ip)
-{
- struct trace_array *tr = &global_trace;
- struct trace_array_cpu *data;
- unsigned long flags;
- long disabled;
- int cpu;
-
- if (unlikely(!tracer_enabled))
- return;
-
- raw_local_irq_save(flags);
- cpu = raw_smp_processor_id();
- data = tr->data[cpu];
- disabled = atomic_inc_return(&data->disabled);
-
- if (likely(disabled == 1))
- ftrace(tr, data, ip, parent_ip, flags);
-
- atomic_dec(&data->disabled);
- raw_local_irq_restore(flags);
-}
-
-static struct ftrace_ops trace_ops __read_mostly =
-{
- .func = function_trace_call,
-};
-#endif
-
-notrace void tracing_start_function_trace(void)
-{
- register_ftrace_function(&trace_ops);
-}
-
-notrace void tracing_stop_function_trace(void)
-{
- unregister_ftrace_function(&trace_ops);
+ data->overrun = 0;
+ data->trace_head = data->trace_tail = head_page(data);
+ data->trace_head_idx = 0;
+ data->trace_tail_idx = 0;
}
#define SAVED_CMDLINES 128
static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN];
static int cmdline_idx;
static DEFINE_SPINLOCK(trace_cmdline_lock);
-atomic_t trace_record_cmdline_disabled;
+
+/* temporary disable recording */
+atomic_t trace_record_cmdline_disabled __read_mostly;
static void trace_init_cmdlines(void)
{
cmdline_idx = 0;
}
-notrace void trace_stop_cmdline_recording(void);
+void trace_stop_cmdline_recording(void);
-static void notrace trace_save_cmdline(struct task_struct *tsk)
+static void trace_save_cmdline(struct task_struct *tsk)
{
unsigned map;
unsigned idx;
spin_unlock(&trace_cmdline_lock);
}
-static notrace char *trace_find_cmdline(int pid)
+static char *trace_find_cmdline(int pid)
{
char *cmdline = "<...>";
unsigned map;
return cmdline;
}
-notrace void tracing_record_cmdline(struct task_struct *tsk)
+void tracing_record_cmdline(struct task_struct *tsk)
{
if (atomic_read(&trace_record_cmdline_disabled))
return;
trace_save_cmdline(tsk);
}
-static inline notrace struct trace_entry *
-tracing_get_trace_entry(struct trace_array *tr,
- struct trace_array_cpu *data)
+static inline struct list_head *
+trace_next_list(struct trace_array_cpu *data, struct list_head *next)
+{
+ /*
+ * Roundrobin - but skip the head (which is not a real page):
+ */
+ next = next->next;
+ if (unlikely(next == &data->trace_pages))
+ next = next->next;
+ BUG_ON(next == &data->trace_pages);
+
+ return next;
+}
+
+static inline void *
+trace_next_page(struct trace_array_cpu *data, void *addr)
+{
+ struct list_head *next;
+ struct page *page;
+
+ page = virt_to_page(addr);
+
+ next = trace_next_list(data, &page->lru);
+ page = list_entry(next, struct page, lru);
+
+ return page_address(page);
+}
+
+static inline struct trace_entry *
+tracing_get_trace_entry(struct trace_array *tr, struct trace_array_cpu *data)
{
unsigned long idx, idx_next;
struct trace_entry *entry;
- struct page *page;
- struct list_head *next;
data->trace_idx++;
- idx = data->trace_current_idx;
+ idx = data->trace_head_idx;
idx_next = idx + 1;
- entry = data->trace_current + idx * TRACE_ENTRY_SIZE;
+ BUG_ON(idx * TRACE_ENTRY_SIZE >= PAGE_SIZE);
+
+ entry = data->trace_head + idx * TRACE_ENTRY_SIZE;
if (unlikely(idx_next >= ENTRIES_PER_PAGE)) {
- page = virt_to_page(data->trace_current);
- if (unlikely(&page->lru == data->trace_pages.prev))
- next = data->trace_pages.next;
- else
- next = page->lru.next;
- page = list_entry(next, struct page, lru);
- data->trace_current = page_address(page);
+ data->trace_head = trace_next_page(data, data->trace_head);
idx_next = 0;
}
- data->trace_current_idx = idx_next;
+ if (data->trace_head == data->trace_tail &&
+ idx_next == data->trace_tail_idx) {
+ /* overrun */
+ data->overrun++;
+ data->trace_tail_idx++;
+ if (data->trace_tail_idx >= ENTRIES_PER_PAGE) {
+ data->trace_tail =
+ trace_next_page(data, data->trace_tail);
+ data->trace_tail_idx = 0;
+ }
+ }
+
+ data->trace_head_idx = idx_next;
+
+ return entry;
+}
+
+static inline void
+tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags)
+{
+ struct task_struct *tsk = current;
+ unsigned long pc;
+
+ pc = preempt_count();
+
+ entry->preempt_count = pc & 0xff;
+ entry->pid = (tsk) ? tsk->pid : 0;
+ entry->t = ftrace_now(raw_smp_processor_id());
+ entry->flags = (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
+ ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
+ ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
+ (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0);
+}
+
+void
+trace_function(struct trace_array *tr, struct trace_array_cpu *data,
+ unsigned long ip, unsigned long parent_ip, unsigned long flags)
+{
+ struct trace_entry *entry;
+ unsigned long irq_flags;
+
+ raw_local_irq_save(irq_flags);
+ __raw_spin_lock(&data->lock);
+ entry = tracing_get_trace_entry(tr, data);
+ tracing_generic_entry_update(entry, flags);
+ entry->type = TRACE_FN;
+ entry->fn.ip = ip;
+ entry->fn.parent_ip = parent_ip;
+ __raw_spin_unlock(&data->lock);
+ raw_local_irq_restore(irq_flags);
+}
+
+void
+ftrace(struct trace_array *tr, struct trace_array_cpu *data,
+ unsigned long ip, unsigned long parent_ip, unsigned long flags)
+{
+ if (likely(!atomic_read(&data->disabled)))
+ trace_function(tr, data, ip, parent_ip, flags);
+}
+
+void __trace_stack(struct trace_array *tr,
+ struct trace_array_cpu *data,
+ unsigned long flags,
+ int skip)
+{
+ struct trace_entry *entry;
+ struct stack_trace trace;
+
+ if (!(trace_flags & TRACE_ITER_STACKTRACE))
+ return;
+
+ entry = tracing_get_trace_entry(tr, data);
+ tracing_generic_entry_update(entry, flags);
+ entry->type = TRACE_STACK;
+
+ memset(&entry->stack, 0, sizeof(entry->stack));
+
+ trace.nr_entries = 0;
+ trace.max_entries = FTRACE_STACK_ENTRIES;
+ trace.skip = skip;
+ trace.entries = entry->stack.caller;
+
+ save_stack_trace(&trace);
+}
+
+void
+__trace_special(void *__tr, void *__data,
+ unsigned long arg1, unsigned long arg2, unsigned long arg3)
+{
+ struct trace_array_cpu *data = __data;
+ struct trace_array *tr = __tr;
+ struct trace_entry *entry;
+ unsigned long irq_flags;
+
+ raw_local_irq_save(irq_flags);
+ __raw_spin_lock(&data->lock);
+ entry = tracing_get_trace_entry(tr, data);
+ tracing_generic_entry_update(entry, 0);
+ entry->type = TRACE_SPECIAL;
+ entry->special.arg1 = arg1;
+ entry->special.arg2 = arg2;
+ entry->special.arg3 = arg3;
+ __trace_stack(tr, data, irq_flags, 4);
+ __raw_spin_unlock(&data->lock);
+ raw_local_irq_restore(irq_flags);
+
+ trace_wake_up();
+}
+
+void
+tracing_sched_switch_trace(struct trace_array *tr,
+ struct trace_array_cpu *data,
+ struct task_struct *prev,
+ struct task_struct *next,
+ unsigned long flags)
+{
+ struct trace_entry *entry;
+ unsigned long irq_flags;
+
+ raw_local_irq_save(irq_flags);
+ __raw_spin_lock(&data->lock);
+ entry = tracing_get_trace_entry(tr, data);
+ tracing_generic_entry_update(entry, flags);
+ entry->type = TRACE_CTX;
+ entry->ctx.prev_pid = prev->pid;
+ entry->ctx.prev_prio = prev->prio;
+ entry->ctx.prev_state = prev->state;
+ entry->ctx.next_pid = next->pid;
+ entry->ctx.next_prio = next->prio;
+ entry->ctx.next_state = next->state;
+ __trace_stack(tr, data, flags, 5);
+ __raw_spin_unlock(&data->lock);
+ raw_local_irq_restore(irq_flags);
+}
+
+void
+tracing_sched_wakeup_trace(struct trace_array *tr,
+ struct trace_array_cpu *data,
+ struct task_struct *wakee,
+ struct task_struct *curr,
+ unsigned long flags)
+{
+ struct trace_entry *entry;
+ unsigned long irq_flags;
+
+ raw_local_irq_save(irq_flags);
+ __raw_spin_lock(&data->lock);
+ entry = tracing_get_trace_entry(tr, data);
+ tracing_generic_entry_update(entry, flags);
+ entry->type = TRACE_WAKE;
+ entry->ctx.prev_pid = curr->pid;
+ entry->ctx.prev_prio = curr->prio;
+ entry->ctx.prev_state = curr->state;
+ entry->ctx.next_pid = wakee->pid;
+ entry->ctx.next_prio = wakee->prio;
+ entry->ctx.next_state = wakee->state;
+ __trace_stack(tr, data, flags, 6);
+ __raw_spin_unlock(&data->lock);
+ raw_local_irq_restore(irq_flags);
+
+ trace_wake_up();
+}
+
+void
+ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3)
+{
+ struct trace_array *tr = &global_trace;
+ struct trace_array_cpu *data;
+ unsigned long flags;
+ long disabled;
+ int cpu;
+
+ if (tracing_disabled || current_trace == &no_tracer || !tr->ctrl)
+ return;
+
+ local_irq_save(flags);
+ cpu = raw_smp_processor_id();
+ data = tr->data[cpu];
+ disabled = atomic_inc_return(&data->disabled);
+
+ if (likely(disabled == 1))
+ __trace_special(tr, data, arg1, arg2, arg3);
- return entry;
+ atomic_dec(&data->disabled);
+ local_irq_restore(flags);
}
-static inline notrace void
-tracing_generic_entry_update(struct trace_entry *entry,
- unsigned long flags)
+#ifdef CONFIG_FTRACE
+static void
+function_trace_call(unsigned long ip, unsigned long parent_ip)
{
- struct task_struct *tsk = current;
- unsigned long pc;
+ struct trace_array *tr = &global_trace;
+ struct trace_array_cpu *data;
+ unsigned long flags;
+ long disabled;
+ int cpu;
- pc = preempt_count();
+ if (unlikely(!tracer_enabled))
+ return;
- entry->idx = atomic_inc_return(&tracer_counter);
- entry->preempt_count = pc & 0xff;
- entry->pid = tsk->pid;
- entry->t = now(raw_smp_processor_id());
- entry->flags = (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
- ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
- ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
- (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0);
+ if (skip_trace(ip))
+ return;
+
+ local_irq_save(flags);
+ cpu = raw_smp_processor_id();
+ data = tr->data[cpu];
+ disabled = atomic_inc_return(&data->disabled);
+
+ if (likely(disabled == 1))
+ trace_function(tr, data, ip, parent_ip, flags);
+
+ atomic_dec(&data->disabled);
+ local_irq_restore(flags);
}
-notrace void
-ftrace(struct trace_array *tr, struct trace_array_cpu *data,
- unsigned long ip, unsigned long parent_ip,
- unsigned long flags)
+static struct ftrace_ops trace_ops __read_mostly =
{
- struct trace_entry *entry;
+ .func = function_trace_call,
+};
- entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, flags);
- entry->type = TRACE_FN;
- entry->fn.ip = ip;
- entry->fn.parent_ip = parent_ip;
+void tracing_start_function_trace(void)
+{
+ register_ftrace_function(&trace_ops);
}
-notrace void
-tracing_sched_switch_trace(struct trace_array *tr,
- struct trace_array_cpu *data,
- struct task_struct *prev, struct task_struct *next,
- unsigned long flags)
+void tracing_stop_function_trace(void)
{
- struct trace_entry *entry;
-
- entry = tracing_get_trace_entry(tr, data);
- tracing_generic_entry_update(entry, flags);
- entry->type = TRACE_CTX;
- entry->ctx.prev_pid = prev->pid;
- entry->ctx.prev_prio = prev->prio;
- entry->ctx.prev_state = prev->state;
- entry->ctx.next_pid = next->pid;
- entry->ctx.next_prio = next->prio;
+ unregister_ftrace_function(&trace_ops);
}
+#endif
enum trace_file_type {
TRACE_FILE_LAT_FMT = 1,
struct trace_entry *array;
if (iter->next_idx[cpu] >= tr->entries ||
- iter->next_idx[cpu] >= data->trace_idx)
+ iter->next_idx[cpu] >= data->trace_idx ||
+ (data->trace_head == data->trace_tail &&
+ data->trace_head_idx == data->trace_tail_idx))
return NULL;
if (!iter->next_page[cpu]) {
- /*
- * Initialize. If the count of elements in
- * this buffer is greater than the max entries
- * we had an underrun. Which means we looped around.
- * We can simply use the current pointer as our
- * starting point.
- */
- if (data->trace_idx >= tr->entries) {
- page = virt_to_page(data->trace_current);
- iter->next_page[cpu] = &page->lru;
- iter->next_page_idx[cpu] = data->trace_current_idx;
- } else {
- iter->next_page[cpu] = data->trace_pages.next;
- iter->next_page_idx[cpu] = 0;
- }
+ /* Initialize the iterator for this cpu trace buffer */
+ WARN_ON(!data->trace_tail);
+ page = virt_to_page(data->trace_tail);
+ iter->next_page[cpu] = &page->lru;
+ iter->next_page_idx[cpu] = data->trace_tail_idx;
}
page = list_entry(iter->next_page[cpu], struct page, lru);
+ BUG_ON(&data->trace_pages == &page->lru);
+
array = page_address(page);
+ WARN_ON(iter->next_page_idx[cpu] >= ENTRIES_PER_PAGE);
return &array[iter->next_page_idx[cpu]];
}
-static struct notrace trace_entry *
+static struct trace_entry *
find_next_entry(struct trace_iterator *iter, int *ent_cpu)
{
struct trace_array *tr = iter->tr;
int next_cpu = -1;
int cpu;
- for_each_possible_cpu(cpu) {
- if (!tr->data[cpu]->trace)
+ for_each_tracing_cpu(cpu) {
+ if (!head_page(tr->data[cpu]))
continue;
ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu);
- if (ent &&
- (!next || (long)(next->idx - ent->idx) > 0)) {
+ /*
+ * Pick the entry with the smallest timestamp:
+ */
+ if (ent && (!next || ent->t < next->t)) {
next = ent;
next_cpu = cpu;
}
return next;
}
+static void trace_iterator_increment(struct trace_iterator *iter)
+{
+ iter->idx++;
+ iter->next_idx[iter->cpu]++;
+ iter->next_page_idx[iter->cpu]++;
+
+ if (iter->next_page_idx[iter->cpu] >= ENTRIES_PER_PAGE) {
+ struct trace_array_cpu *data = iter->tr->data[iter->cpu];
+
+ iter->next_page_idx[iter->cpu] = 0;
+ iter->next_page[iter->cpu] =
+ trace_next_list(data, iter->next_page[iter->cpu]);
+ }
+}
+
+static void trace_consume(struct trace_iterator *iter)
+{
+ struct trace_array_cpu *data = iter->tr->data[iter->cpu];
+
+ data->trace_tail_idx++;
+ if (data->trace_tail_idx >= ENTRIES_PER_PAGE) {
+ data->trace_tail = trace_next_page(data, data->trace_tail);
+ data->trace_tail_idx = 0;
+ }
+
+ /* Check if we empty it, then reset the index */
+ if (data->trace_head == data->trace_tail &&
+ data->trace_head_idx == data->trace_tail_idx)
+ data->trace_idx = 0;
+}
+
static void *find_next_entry_inc(struct trace_iterator *iter)
{
struct trace_entry *next;
next = find_next_entry(iter, &next_cpu);
- if (next) {
- iter->idx++;
- iter->next_idx[next_cpu]++;
- iter->next_page_idx[next_cpu]++;
- if (iter->next_page_idx[next_cpu] >= ENTRIES_PER_PAGE) {
- struct trace_array_cpu *data = iter->tr->data[next_cpu];
-
- iter->next_page_idx[next_cpu] = 0;
- iter->next_page[next_cpu] =
- iter->next_page[next_cpu]->next;
- if (iter->next_page[next_cpu] == &data->trace_pages)
- iter->next_page[next_cpu] =
- data->trace_pages.next;
- }
- }
+ iter->prev_ent = iter->ent;
+ iter->prev_cpu = iter->cpu;
+
iter->ent = next;
iter->cpu = next_cpu;
+ if (next)
+ trace_iterator_increment(iter);
+
return next ? iter : NULL;
}
-static void notrace *
-s_next(struct seq_file *m, void *v, loff_t *pos)
+static void *s_next(struct seq_file *m, void *v, loff_t *pos)
{
struct trace_iterator *iter = m->private;
- void *ent;
void *last_ent = iter->ent;
int i = (int)*pos;
+ void *ent;
(*pos)++;
mutex_lock(&trace_types_lock);
- if (!current_trace || current_trace != iter->trace)
+ if (!current_trace || current_trace != iter->trace) {
+ mutex_unlock(&trace_types_lock);
return NULL;
+ }
atomic_inc(&trace_record_cmdline_disabled);
iter->ent = NULL;
iter->cpu = 0;
iter->idx = -1;
+ iter->prev_ent = NULL;
+ iter->prev_cpu = -1;
- for_each_possible_cpu(i) {
+ for_each_tracing_cpu(i) {
iter->next_idx[i] = 0;
iter->next_page[i] = NULL;
}
mutex_unlock(&trace_types_lock);
}
-static void
-seq_print_sym_short(struct seq_file *m, const char *fmt, unsigned long address)
+#define KRETPROBE_MSG "[unknown/kretprobe'd]"
+
+#ifdef CONFIG_KRETPROBES
+static inline int kretprobed(unsigned long addr)
+{
+ return addr == (unsigned long)kretprobe_trampoline;
+}
+#else
+static inline int kretprobed(unsigned long addr)
+{
+ return 0;
+}
+#endif /* CONFIG_KRETPROBES */
+
+static int
+seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
{
#ifdef CONFIG_KALLSYMS
char str[KSYM_SYMBOL_LEN];
kallsyms_lookup(address, NULL, NULL, NULL, str);
- seq_printf(m, fmt, str);
+ return trace_seq_printf(s, fmt, str);
#endif
+ return 1;
}
-static void
-seq_print_sym_offset(struct seq_file *m, const char *fmt, unsigned long address)
+static int
+seq_print_sym_offset(struct trace_seq *s, const char *fmt,
+ unsigned long address)
{
#ifdef CONFIG_KALLSYMS
char str[KSYM_SYMBOL_LEN];
sprint_symbol(str, address);
- seq_printf(m, fmt, str);
+ return trace_seq_printf(s, fmt, str);
#endif
+ return 1;
}
#ifndef CONFIG_64BIT
# define IP_FMT "%016lx"
#endif
-static void notrace
-seq_print_ip_sym(struct seq_file *m, unsigned long ip, unsigned long sym_flags)
+static int
+seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
{
- if (!ip) {
- seq_printf(m, "0");
- return;
- }
+ int ret;
+
+ if (!ip)
+ return trace_seq_printf(s, "0");
if (sym_flags & TRACE_ITER_SYM_OFFSET)
- seq_print_sym_offset(m, "%s", ip);
+ ret = seq_print_sym_offset(s, "%s", ip);
else
- seq_print_sym_short(m, "%s", ip);
+ ret = seq_print_sym_short(s, "%s", ip);
+
+ if (!ret)
+ return 0;
if (sym_flags & TRACE_ITER_SYM_ADDR)
- seq_printf(m, " <" IP_FMT ">", ip);
+ ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
+ return ret;
}
-static void notrace print_lat_help_header(struct seq_file *m)
+static void print_lat_help_header(struct seq_file *m)
{
seq_puts(m, "# _------=> CPU# \n");
seq_puts(m, "# / _-----=> irqs-off \n");
seq_puts(m, "# \\ / ||||| \\ | / \n");
}
-static void notrace print_func_help_header(struct seq_file *m)
+static void print_func_help_header(struct seq_file *m)
{
seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n");
seq_puts(m, "# | | | | |\n");
}
-static void notrace
+static void
print_trace_header(struct seq_file *m, struct trace_iterator *iter)
{
unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
if (type)
name = type->name;
- for_each_possible_cpu(cpu) {
- if (tr->data[cpu]->trace) {
+ for_each_tracing_cpu(cpu) {
+ if (head_page(tr->data[cpu])) {
total += tr->data[cpu]->trace_idx;
if (tr->data[cpu]->trace_idx > tr->entries)
entries += tr->entries;
"---------------------------------\n");
seq_printf(m, " latency: %lu us, #%lu/%lu, CPU#%d |"
" (M:%s VP:%d, KP:%d, SP:%d HP:%d",
- data->saved_latency,
+ nsecs_to_usecs(data->saved_latency),
entries,
total,
tr->cpu,
if (data->critical_start) {
seq_puts(m, " => started at: ");
- seq_print_ip_sym(m, data->critical_start, sym_flags);
+ seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags);
+ trace_print_seq(m, &iter->seq);
seq_puts(m, "\n => ended at: ");
- seq_print_ip_sym(m, data->critical_end, sym_flags);
+ seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags);
+ trace_print_seq(m, &iter->seq);
seq_puts(m, "\n");
}
seq_puts(m, "\n");
}
-unsigned long nsecs_to_usecs(unsigned long nsecs)
-{
- return nsecs / 1000;
-}
-
-static void notrace
-lat_print_generic(struct seq_file *m, struct trace_entry *entry, int cpu)
+static void
+lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)
{
int hardirq, softirq;
char *comm;
comm = trace_find_cmdline(entry->pid);
- seq_printf(m, "%8.8s-%-5d ", comm, entry->pid);
- seq_printf(m, "%d", cpu);
- seq_printf(m, "%c%c",
- (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.',
- ((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.'));
+ trace_seq_printf(s, "%8.8s-%-5d ", comm, entry->pid);
+ trace_seq_printf(s, "%d", cpu);
+ trace_seq_printf(s, "%c%c",
+ (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.',
+ ((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.'));
hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
- if (hardirq && softirq)
- seq_putc(m, 'H');
- else {
- if (hardirq)
- seq_putc(m, 'h');
- else {
+ if (hardirq && softirq) {
+ trace_seq_putc(s, 'H');
+ } else {
+ if (hardirq) {
+ trace_seq_putc(s, 'h');
+ } else {
if (softirq)
- seq_putc(m, 's');
+ trace_seq_putc(s, 's');
else
- seq_putc(m, '.');
+ trace_seq_putc(s, '.');
}
}
if (entry->preempt_count)
- seq_printf(m, "%x", entry->preempt_count);
+ trace_seq_printf(s, "%x", entry->preempt_count);
else
- seq_puts(m, ".");
+ trace_seq_puts(s, ".");
}
unsigned long preempt_mark_thresh = 100;
-static void notrace
-lat_print_timestamp(struct seq_file *m, unsigned long long abs_usecs,
+static void
+lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs,
unsigned long rel_usecs)
{
- seq_printf(m, " %4lldus", abs_usecs);
+ trace_seq_printf(s, " %4lldus", abs_usecs);
if (rel_usecs > preempt_mark_thresh)
- seq_puts(m, "!: ");
+ trace_seq_puts(s, "!: ");
else if (rel_usecs > 1)
- seq_puts(m, "+: ");
+ trace_seq_puts(s, "+: ");
else
- seq_puts(m, " : ");
+ trace_seq_puts(s, " : ");
}
static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
-static void notrace
-print_lat_fmt(struct seq_file *m, struct trace_iterator *iter,
- unsigned int trace_idx, int cpu)
+static int
+print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu)
{
+ struct trace_seq *s = &iter->seq;
unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
struct trace_entry *next_entry = find_next_entry(iter, NULL);
unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
unsigned long abs_usecs;
unsigned long rel_usecs;
char *comm;
- int S;
+ int S, T;
+ int i;
+ unsigned state;
if (!next_entry)
next_entry = entry;
if (verbose) {
comm = trace_find_cmdline(entry->pid);
- seq_printf(m, "%16s %5d %d %d %08x %08x [%08lx]"
- " %ld.%03ldms (+%ld.%03ldms): ",
- comm,
- entry->pid, cpu, entry->flags,
- entry->preempt_count, trace_idx,
- ns2usecs(entry->t),
- abs_usecs/1000,
- abs_usecs % 1000, rel_usecs/1000, rel_usecs % 1000);
+ trace_seq_printf(s, "%16s %5d %d %d %08x %08x [%08lx]"
+ " %ld.%03ldms (+%ld.%03ldms): ",
+ comm,
+ entry->pid, cpu, entry->flags,
+ entry->preempt_count, trace_idx,
+ ns2usecs(entry->t),
+ abs_usecs/1000,
+ abs_usecs % 1000, rel_usecs/1000,
+ rel_usecs % 1000);
} else {
- lat_print_generic(m, entry, cpu);
- lat_print_timestamp(m, abs_usecs, rel_usecs);
+ lat_print_generic(s, entry, cpu);
+ lat_print_timestamp(s, abs_usecs, rel_usecs);
}
switch (entry->type) {
case TRACE_FN:
- seq_print_ip_sym(m, entry->fn.ip, sym_flags);
- seq_puts(m, " (");
- seq_print_ip_sym(m, entry->fn.parent_ip, sym_flags);
- seq_puts(m, ")\n");
+ seq_print_ip_sym(s, entry->fn.ip, sym_flags);
+ trace_seq_puts(s, " (");
+ if (kretprobed(entry->fn.parent_ip))
+ trace_seq_puts(s, KRETPROBE_MSG);
+ else
+ seq_print_ip_sym(s, entry->fn.parent_ip, sym_flags);
+ trace_seq_puts(s, ")\n");
break;
case TRACE_CTX:
- S = entry->ctx.prev_state < sizeof(state_to_char) ?
- state_to_char[entry->ctx.prev_state] : 'X';
+ case TRACE_WAKE:
+ T = entry->ctx.next_state < sizeof(state_to_char) ?
+ state_to_char[entry->ctx.next_state] : 'X';
+
+ state = entry->ctx.prev_state ? __ffs(entry->ctx.prev_state) + 1 : 0;
+ S = state < sizeof(state_to_char) - 1 ? state_to_char[state] : 'X';
comm = trace_find_cmdline(entry->ctx.next_pid);
- seq_printf(m, " %d:%d:%c --> %d:%d %s\n",
- entry->ctx.prev_pid,
- entry->ctx.prev_prio,
- S,
- entry->ctx.next_pid,
- entry->ctx.next_prio,
- comm);
+ trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d:%c %s\n",
+ entry->ctx.prev_pid,
+ entry->ctx.prev_prio,
+ S, entry->type == TRACE_CTX ? "==>" : " +",
+ entry->ctx.next_pid,
+ entry->ctx.next_prio,
+ T, comm);
+ break;
+ case TRACE_SPECIAL:
+ trace_seq_printf(s, "# %ld %ld %ld\n",
+ entry->special.arg1,
+ entry->special.arg2,
+ entry->special.arg3);
break;
+ case TRACE_STACK:
+ for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
+ if (i)
+ trace_seq_puts(s, " <= ");
+ seq_print_ip_sym(s, entry->stack.caller[i], sym_flags);
+ }
+ trace_seq_puts(s, "\n");
+ break;
+ default:
+ trace_seq_printf(s, "Unknown type %d\n", entry->type);
}
+ return 1;
}
-static void notrace
-print_trace_fmt(struct seq_file *m, struct trace_iterator *iter)
+static int print_trace_fmt(struct trace_iterator *iter)
{
+ struct trace_seq *s = &iter->seq;
unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
- struct trace_entry *entry = iter->ent;
+ struct trace_entry *entry;
unsigned long usec_rem;
unsigned long long t;
unsigned long secs;
char *comm;
- int S;
+ int ret;
+ int S, T;
+ int i;
+
+ entry = iter->ent;
comm = trace_find_cmdline(iter->ent->pid);
usec_rem = do_div(t, 1000000ULL);
secs = (unsigned long)t;
- seq_printf(m, "%16s-%-5d ", comm, entry->pid);
- seq_printf(m, "[%02d] ", iter->cpu);
- seq_printf(m, "%5lu.%06lu: ", secs, usec_rem);
+ ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid);
+ if (!ret)
+ return 0;
+ ret = trace_seq_printf(s, "[%02d] ", iter->cpu);
+ if (!ret)
+ return 0;
+ ret = trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem);
+ if (!ret)
+ return 0;
switch (entry->type) {
case TRACE_FN:
- seq_print_ip_sym(m, entry->fn.ip, sym_flags);
+ ret = seq_print_ip_sym(s, entry->fn.ip, sym_flags);
+ if (!ret)
+ return 0;
if ((sym_flags & TRACE_ITER_PRINT_PARENT) &&
entry->fn.parent_ip) {
- seq_printf(m, " <-");
- seq_print_ip_sym(m, entry->fn.parent_ip, sym_flags);
+ ret = trace_seq_printf(s, " <-");
+ if (!ret)
+ return 0;
+ if (kretprobed(entry->fn.parent_ip))
+ ret = trace_seq_puts(s, KRETPROBE_MSG);
+ else
+ ret = seq_print_ip_sym(s, entry->fn.parent_ip,
+ sym_flags);
+ if (!ret)
+ return 0;
+ }
+ ret = trace_seq_printf(s, "\n");
+ if (!ret)
+ return 0;
+ break;
+ case TRACE_CTX:
+ case TRACE_WAKE:
+ S = entry->ctx.prev_state < sizeof(state_to_char) ?
+ state_to_char[entry->ctx.prev_state] : 'X';
+ T = entry->ctx.next_state < sizeof(state_to_char) ?
+ state_to_char[entry->ctx.next_state] : 'X';
+ ret = trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d:%c\n",
+ entry->ctx.prev_pid,
+ entry->ctx.prev_prio,
+ S,
+ entry->type == TRACE_CTX ? "==>" : " +",
+ entry->ctx.next_pid,
+ entry->ctx.next_prio,
+ T);
+ if (!ret)
+ return 0;
+ break;
+ case TRACE_SPECIAL:
+ ret = trace_seq_printf(s, "# %ld %ld %ld\n",
+ entry->special.arg1,
+ entry->special.arg2,
+ entry->special.arg3);
+ if (!ret)
+ return 0;
+ break;
+ case TRACE_STACK:
+ for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
+ if (i) {
+ ret = trace_seq_puts(s, " <= ");
+ if (!ret)
+ return 0;
+ }
+ ret = seq_print_ip_sym(s, entry->stack.caller[i],
+ sym_flags);
+ if (!ret)
+ return 0;
}
+ ret = trace_seq_puts(s, "\n");
+ if (!ret)
+ return 0;
+ break;
+ }
+ return 1;
+}
+
+static int print_raw_fmt(struct trace_iterator *iter)
+{
+ struct trace_seq *s = &iter->seq;
+ struct trace_entry *entry;
+ int ret;
+ int S, T;
+
+ entry = iter->ent;
+
+ ret = trace_seq_printf(s, "%d %d %llu ",
+ entry->pid, iter->cpu, entry->t);
+ if (!ret)
+ return 0;
+
+ switch (entry->type) {
+ case TRACE_FN:
+ ret = trace_seq_printf(s, "%x %x\n",
+ entry->fn.ip, entry->fn.parent_ip);
+ if (!ret)
+ return 0;
+ break;
+ case TRACE_CTX:
+ case TRACE_WAKE:
+ S = entry->ctx.prev_state < sizeof(state_to_char) ?
+ state_to_char[entry->ctx.prev_state] : 'X';
+ T = entry->ctx.next_state < sizeof(state_to_char) ?
+ state_to_char[entry->ctx.next_state] : 'X';
+ if (entry->type == TRACE_WAKE)
+ S = '+';
+ ret = trace_seq_printf(s, "%d %d %c %d %d %c\n",
+ entry->ctx.prev_pid,
+ entry->ctx.prev_prio,
+ S,
+ entry->ctx.next_pid,
+ entry->ctx.next_prio,
+ T);
+ if (!ret)
+ return 0;
+ break;
+ case TRACE_SPECIAL:
+ case TRACE_STACK:
+ ret = trace_seq_printf(s, "# %ld %ld %ld\n",
+ entry->special.arg1,
+ entry->special.arg2,
+ entry->special.arg3);
+ if (!ret)
+ return 0;
+ break;
+ }
+ return 1;
+}
+
+#define SEQ_PUT_FIELD_RET(s, x) \
+do { \
+ if (!trace_seq_putmem(s, &(x), sizeof(x))) \
+ return 0; \
+} while (0)
+
+#define SEQ_PUT_HEX_FIELD_RET(s, x) \
+do { \
+ if (!trace_seq_putmem_hex(s, &(x), sizeof(x))) \
+ return 0; \
+} while (0)
+
+static int print_hex_fmt(struct trace_iterator *iter)
+{
+ struct trace_seq *s = &iter->seq;
+ unsigned char newline = '\n';
+ struct trace_entry *entry;
+ int S, T;
+
+ entry = iter->ent;
+
+ SEQ_PUT_HEX_FIELD_RET(s, entry->pid);
+ SEQ_PUT_HEX_FIELD_RET(s, iter->cpu);
+ SEQ_PUT_HEX_FIELD_RET(s, entry->t);
+
+ switch (entry->type) {
+ case TRACE_FN:
+ SEQ_PUT_HEX_FIELD_RET(s, entry->fn.ip);
+ SEQ_PUT_HEX_FIELD_RET(s, entry->fn.parent_ip);
break;
case TRACE_CTX:
+ case TRACE_WAKE:
S = entry->ctx.prev_state < sizeof(state_to_char) ?
state_to_char[entry->ctx.prev_state] : 'X';
- seq_printf(m, " %d:%d:%c ==> %d:%d\n",
- entry->ctx.prev_pid,
- entry->ctx.prev_prio,
- S,
- entry->ctx.next_pid,
- entry->ctx.next_prio);
+ T = entry->ctx.next_state < sizeof(state_to_char) ?
+ state_to_char[entry->ctx.next_state] : 'X';
+ if (entry->type == TRACE_WAKE)
+ S = '+';
+ SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.prev_pid);
+ SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.prev_prio);
+ SEQ_PUT_HEX_FIELD_RET(s, S);
+ SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.next_pid);
+ SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.next_prio);
+ SEQ_PUT_HEX_FIELD_RET(s, entry->fn.parent_ip);
+ SEQ_PUT_HEX_FIELD_RET(s, T);
+ break;
+ case TRACE_SPECIAL:
+ case TRACE_STACK:
+ SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg1);
+ SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg2);
+ SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg3);
+ break;
+ }
+ SEQ_PUT_FIELD_RET(s, newline);
+
+ return 1;
+}
+
+static int print_bin_fmt(struct trace_iterator *iter)
+{
+ struct trace_seq *s = &iter->seq;
+ struct trace_entry *entry;
+
+ entry = iter->ent;
+
+ SEQ_PUT_FIELD_RET(s, entry->pid);
+ SEQ_PUT_FIELD_RET(s, entry->cpu);
+ SEQ_PUT_FIELD_RET(s, entry->t);
+
+ switch (entry->type) {
+ case TRACE_FN:
+ SEQ_PUT_FIELD_RET(s, entry->fn.ip);
+ SEQ_PUT_FIELD_RET(s, entry->fn.parent_ip);
+ break;
+ case TRACE_CTX:
+ SEQ_PUT_FIELD_RET(s, entry->ctx.prev_pid);
+ SEQ_PUT_FIELD_RET(s, entry->ctx.prev_prio);
+ SEQ_PUT_FIELD_RET(s, entry->ctx.prev_state);
+ SEQ_PUT_FIELD_RET(s, entry->ctx.next_pid);
+ SEQ_PUT_FIELD_RET(s, entry->ctx.next_prio);
+ SEQ_PUT_FIELD_RET(s, entry->ctx.next_state);
+ break;
+ case TRACE_SPECIAL:
+ case TRACE_STACK:
+ SEQ_PUT_FIELD_RET(s, entry->special.arg1);
+ SEQ_PUT_FIELD_RET(s, entry->special.arg2);
+ SEQ_PUT_FIELD_RET(s, entry->special.arg3);
break;
}
- seq_printf(m, "\n");
+ return 1;
}
static int trace_empty(struct trace_iterator *iter)
struct trace_array_cpu *data;
int cpu;
- for_each_possible_cpu(cpu) {
+ for_each_tracing_cpu(cpu) {
data = iter->tr->data[cpu];
- if (data->trace &&
- data->trace_idx)
+ if (head_page(data) && data->trace_idx &&
+ (data->trace_tail != data->trace_head ||
+ data->trace_tail_idx != data->trace_head_idx))
return 0;
}
return 1;
}
+static int print_trace_line(struct trace_iterator *iter)
+{
+ if (iter->trace && iter->trace->print_line)
+ return iter->trace->print_line(iter);
+
+ if (trace_flags & TRACE_ITER_BIN)
+ return print_bin_fmt(iter);
+
+ if (trace_flags & TRACE_ITER_HEX)
+ return print_hex_fmt(iter);
+
+ if (trace_flags & TRACE_ITER_RAW)
+ return print_raw_fmt(iter);
+
+ if (iter->iter_flags & TRACE_FILE_LAT_FMT)
+ return print_lat_fmt(iter, iter->idx, iter->cpu);
+
+ return print_trace_fmt(iter);
+}
+
static int s_show(struct seq_file *m, void *v)
{
struct trace_iterator *iter = v;
print_func_help_header(m);
}
} else {
- if (iter->iter_flags & TRACE_FILE_LAT_FMT)
- print_lat_fmt(m, iter, iter->idx, iter->cpu);
- else
- print_trace_fmt(m, iter);
+ print_trace_line(iter);
+ trace_print_seq(m, &iter->seq);
}
return 0;
}
static struct seq_operations tracer_seq_ops = {
- .start = s_start,
- .next = s_next,
- .stop = s_stop,
- .show = s_show,
+ .start = s_start,
+ .next = s_next,
+ .stop = s_stop,
+ .show = s_show,
};
-static struct trace_iterator notrace *
+static struct trace_iterator *
__tracing_open(struct inode *inode, struct file *file, int *ret)
{
struct trace_iterator *iter;
+ if (tracing_disabled) {
+ *ret = -ENODEV;
+ return NULL;
+ }
+
iter = kzalloc(sizeof(*iter), GFP_KERNEL);
if (!iter) {
*ret = -ENOMEM;
int tracing_open_generic(struct inode *inode, struct file *filp)
{
+ if (tracing_disabled)
+ return -ENODEV;
+
filp->private_data = inode->i_private;
return 0;
}
}
-static void notrace *
+static void *
t_next(struct seq_file *m, void *v, loff_t *pos)
{
struct tracer *t = m->private;
}
static struct seq_operations show_traces_seq_ops = {
- .start = t_start,
- .next = t_next,
- .stop = t_stop,
- .show = t_show,
+ .start = t_start,
+ .next = t_next,
+ .stop = t_stop,
+ .show = t_show,
};
static int show_traces_open(struct inode *inode, struct file *file)
{
int ret;
+ if (tracing_disabled)
+ return -ENODEV;
+
ret = seq_open(file, &show_traces_seq_ops);
if (!ret) {
struct seq_file *m = file->private_data;
}
static struct file_operations tracing_fops = {
- .open = tracing_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = tracing_release,
+ .open = tracing_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = tracing_release,
};
static struct file_operations tracing_lt_fops = {
- .open = tracing_lt_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = tracing_release,
+ .open = tracing_lt_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = tracing_release,
};
-static struct file_operations show_traces_fops = {
- .open = show_traces_open,
- .read = seq_read,
- .release = seq_release,
+static struct file_operations show_traces_fops = {
+ .open = show_traces_open,
+ .read = seq_read,
+ .release = seq_release,
+};
+
+/*
+ * Only trace on a CPU if the bitmask is set:
+ */
+static cpumask_t tracing_cpumask = CPU_MASK_ALL;
+
+/*
+ * When tracing/tracing_cpu_mask is modified then this holds
+ * the new bitmask we are about to install:
+ */
+static cpumask_t tracing_cpumask_new;
+
+/*
+ * The tracer itself will not take this lock, but still we want
+ * to provide a consistent cpumask to user-space:
+ */
+static DEFINE_MUTEX(tracing_cpumask_update_lock);
+
+/*
+ * Temporary storage for the character representation of the
+ * CPU bitmask (and one more byte for the newline):
+ */
+static char mask_str[NR_CPUS + 1];
+
+static ssize_t
+tracing_cpumask_read(struct file *filp, char __user *ubuf,
+ size_t count, loff_t *ppos)
+{
+ int len;
+
+ mutex_lock(&tracing_cpumask_update_lock);
+
+ len = cpumask_scnprintf(mask_str, count, tracing_cpumask);
+ if (count - len < 2) {
+ count = -EINVAL;
+ goto out_err;
+ }
+ len += sprintf(mask_str + len, "\n");
+ count = simple_read_from_buffer(ubuf, count, ppos, mask_str, NR_CPUS+1);
+
+out_err:
+ mutex_unlock(&tracing_cpumask_update_lock);
+
+ return count;
+}
+
+static ssize_t
+tracing_cpumask_write(struct file *filp, const char __user *ubuf,
+ size_t count, loff_t *ppos)
+{
+ int err, cpu;
+
+ mutex_lock(&tracing_cpumask_update_lock);
+ err = cpumask_parse_user(ubuf, count, tracing_cpumask_new);
+ if (err)
+ goto err_unlock;
+
+ raw_local_irq_disable();
+ __raw_spin_lock(&ftrace_max_lock);
+ for_each_tracing_cpu(cpu) {
+ /*
+ * Increase/decrease the disabled counter if we are
+ * about to flip a bit in the cpumask:
+ */
+ if (cpu_isset(cpu, tracing_cpumask) &&
+ !cpu_isset(cpu, tracing_cpumask_new)) {
+ atomic_inc(&global_trace.data[cpu]->disabled);
+ }
+ if (!cpu_isset(cpu, tracing_cpumask) &&
+ cpu_isset(cpu, tracing_cpumask_new)) {
+ atomic_dec(&global_trace.data[cpu]->disabled);
+ }
+ }
+ __raw_spin_unlock(&ftrace_max_lock);
+ raw_local_irq_enable();
+
+ tracing_cpumask = tracing_cpumask_new;
+
+ mutex_unlock(&tracing_cpumask_update_lock);
+
+ return count;
+
+err_unlock:
+ mutex_unlock(&tracing_cpumask_update_lock);
+
+ return err;
+}
+
+static struct file_operations tracing_cpumask_fops = {
+ .open = tracing_open_generic,
+ .read = tracing_cpumask_read,
+ .write = tracing_cpumask_write,
};
static ssize_t
r += sprintf(buf + r, "\n");
WARN_ON(r >= len + 2);
- r = simple_read_from_buffer(ubuf, cnt, ppos,
- buf, r);
+ r = simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
kfree(buf);
int neg = 0;
int i;
- if (cnt > 63)
- cnt = 63;
+ if (cnt >= sizeof(buf))
+ return -EINVAL;
if (copy_from_user(&buf, ubuf, cnt))
return -EFAULT;
break;
}
}
+ /*
+ * If no option could be set, return an error:
+ */
+ if (!trace_options[i])
+ return -EINVAL;
filp->f_pos += cnt;
}
static struct file_operations tracing_iter_fops = {
- .open = tracing_open_generic,
- .read = tracing_iter_ctrl_read,
- .write = tracing_iter_ctrl_write,
+ .open = tracing_open_generic,
+ .read = tracing_iter_ctrl_read,
+ .write = tracing_iter_ctrl_write,
+};
+
+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"
+ "wakeup preemptirqsoff preemptoff irqsoff ftrace sched_switch none\n\n"
+ "# cat /debug/tracing/current_tracer\n"
+ "none\n"
+ "# echo sched_switch > /debug/tracing/current_tracer\n"
+ "# cat /debug/tracing/current_tracer\n"
+ "sched_switch\n"
+ "# cat /debug/tracing/iter_ctrl\n"
+ "noprint-parent nosym-offset nosym-addr noverbose\n"
+ "# echo print-parent > /debug/tracing/iter_ctrl\n"
+ "# echo 1 > /debug/tracing/tracing_enabled\n"
+ "# cat /debug/tracing/trace > /tmp/trace.txt\n"
+ "echo 0 > /debug/tracing/tracing_enabled\n"
+;
+
+static ssize_t
+tracing_readme_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ return simple_read_from_buffer(ubuf, cnt, ppos,
+ readme_msg, strlen(readme_msg));
+}
+
+static struct file_operations tracing_readme_fops = {
+ .open = tracing_open_generic,
+ .read = tracing_readme_read,
};
static ssize_t
int r;
r = sprintf(buf, "%ld\n", tr->ctrl);
- return simple_read_from_buffer(ubuf, cnt, ppos,
- buf, r);
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
}
static ssize_t
size_t cnt, loff_t *ppos)
{
struct trace_array *tr = filp->private_data;
- long val;
char buf[64];
+ long val;
+ int ret;
- if (cnt > 63)
- cnt = 63;
+ if (cnt >= sizeof(buf))
+ return -EINVAL;
if (copy_from_user(&buf, ubuf, cnt))
return -EFAULT;
buf[cnt] = 0;
- val = simple_strtoul(buf, NULL, 10);
+ ret = strict_strtoul(buf, 10, &val);
+ if (ret < 0)
+ return ret;
val = !!val;
r = sprintf(buf, "\n");
mutex_unlock(&trace_types_lock);
- return simple_read_from_buffer(ubuf, cnt, ppos,
- buf, r);
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
}
static ssize_t
char buf[64];
int r;
- r = snprintf(buf, 64, "%ld\n",
+ r = snprintf(buf, sizeof(buf), "%ld\n",
*ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr));
- if (r > 64)
- r = 64;
- return simple_read_from_buffer(ubuf, cnt, ppos,
- buf, r);
+ if (r > sizeof(buf))
+ r = sizeof(buf);
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
}
static ssize_t
size_t cnt, loff_t *ppos)
{
long *ptr = filp->private_data;
- long val;
char buf[64];
+ long val;
+ int ret;
- if (cnt > 63)
- cnt = 63;
+ if (cnt >= sizeof(buf))
+ return -EINVAL;
if (copy_from_user(&buf, ubuf, cnt))
return -EFAULT;
buf[cnt] = 0;
- val = simple_strtoul(buf, NULL, 10);
+ ret = strict_strtoul(buf, 10, &val);
+ if (ret < 0)
+ return ret;
*ptr = val * 1000;
return cnt;
}
+static atomic_t tracing_reader;
+
+static int tracing_open_pipe(struct inode *inode, struct file *filp)
+{
+ struct trace_iterator *iter;
+
+ if (tracing_disabled)
+ return -ENODEV;
+
+ /* We only allow for reader of the pipe */
+ if (atomic_inc_return(&tracing_reader) != 1) {
+ atomic_dec(&tracing_reader);
+ return -EBUSY;
+ }
+
+ /* create a buffer to store the information to pass to userspace */
+ iter = kzalloc(sizeof(*iter), GFP_KERNEL);
+ if (!iter)
+ return -ENOMEM;
+
+ mutex_lock(&trace_types_lock);
+ iter->tr = &global_trace;
+ iter->trace = current_trace;
+ filp->private_data = iter;
+
+ if (iter->trace->pipe_open)
+ iter->trace->pipe_open(iter);
+ mutex_unlock(&trace_types_lock);
+
+ return 0;
+}
+
+static int tracing_release_pipe(struct inode *inode, struct file *file)
+{
+ struct trace_iterator *iter = file->private_data;
+
+ kfree(iter);
+ atomic_dec(&tracing_reader);
+
+ return 0;
+}
+
+static unsigned int
+tracing_poll_pipe(struct file *filp, poll_table *poll_table)
+{
+ struct trace_iterator *iter = filp->private_data;
+
+ if (trace_flags & TRACE_ITER_BLOCK) {
+ /*
+ * Always select as readable when in blocking mode
+ */
+ return POLLIN | POLLRDNORM;
+ } else {
+ if (!trace_empty(iter))
+ return POLLIN | POLLRDNORM;
+ poll_wait(filp, &trace_wait, poll_table);
+ if (!trace_empty(iter))
+ return POLLIN | POLLRDNORM;
+
+ return 0;
+ }
+}
+
+/*
+ * Consumer reader.
+ */
+static ssize_t
+tracing_read_pipe(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ struct trace_iterator *iter = filp->private_data;
+ struct trace_array_cpu *data;
+ static cpumask_t mask;
+ unsigned long flags;
+#ifdef CONFIG_FTRACE
+ int ftrace_save;
+#endif
+ int cpu;
+ ssize_t sret;
+
+ /* return any leftover data */
+ sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
+ if (sret != -EBUSY)
+ return sret;
+ sret = 0;
+
+ trace_seq_reset(&iter->seq);
+
+ mutex_lock(&trace_types_lock);
+ if (iter->trace->read) {
+ sret = iter->trace->read(iter, filp, ubuf, cnt, ppos);
+ if (sret)
+ goto out;
+ }
+
+ while (trace_empty(iter)) {
+
+ if ((filp->f_flags & O_NONBLOCK)) {
+ sret = -EAGAIN;
+ goto out;
+ }
+
+ /*
+ * This is a make-shift waitqueue. The reason we don't use
+ * an actual wait queue is because:
+ * 1) we only ever have one waiter
+ * 2) the tracing, traces all functions, we don't want
+ * the overhead of calling wake_up and friends
+ * (and tracing them too)
+ * Anyway, this is really very primitive wakeup.
+ */
+ set_current_state(TASK_INTERRUPTIBLE);
+ iter->tr->waiter = current;
+
+ mutex_unlock(&trace_types_lock);
+
+ /* sleep for 100 msecs, and try again. */
+ schedule_timeout(HZ/10);
+
+ mutex_lock(&trace_types_lock);
+
+ iter->tr->waiter = NULL;
+
+ if (signal_pending(current)) {
+ sret = -EINTR;
+ goto out;
+ }
+
+ if (iter->trace != current_trace)
+ goto out;
+
+ /*
+ * We block until we read something and tracing is disabled.
+ * We still block if tracing is disabled, but we have never
+ * read anything. This allows a user to cat this file, and
+ * then enable tracing. But after we have read something,
+ * we give an EOF when tracing is again disabled.
+ *
+ * iter->pos will be 0 if we haven't read anything.
+ */
+ if (!tracer_enabled && iter->pos)
+ break;
+
+ continue;
+ }
+
+ /* stop when tracing is finished */
+ if (trace_empty(iter))
+ goto out;
+
+ if (cnt >= PAGE_SIZE)
+ cnt = PAGE_SIZE - 1;
+
+ /* reset all but tr, trace, and overruns */
+ memset(&iter->seq, 0,
+ sizeof(struct trace_iterator) -
+ offsetof(struct trace_iterator, seq));
+ iter->pos = -1;
+
+ /*
+ * We need to stop all tracing on all CPUS to read the
+ * the next buffer. This is a bit expensive, but is
+ * not done often. We fill all what we can read,
+ * and then release the locks again.
+ */
+
+ cpus_clear(mask);
+ local_irq_save(flags);
+#ifdef CONFIG_FTRACE
+ ftrace_save = ftrace_enabled;
+ ftrace_enabled = 0;
+#endif
+ smp_wmb();
+ for_each_tracing_cpu(cpu) {
+ data = iter->tr->data[cpu];
+
+ if (!head_page(data) || !data->trace_idx)
+ continue;
+
+ atomic_inc(&data->disabled);
+ cpu_set(cpu, mask);
+ }
+
+ for_each_cpu_mask(cpu, mask) {
+ data = iter->tr->data[cpu];
+ __raw_spin_lock(&data->lock);
+
+ if (data->overrun > iter->last_overrun[cpu])
+ iter->overrun[cpu] +=
+ data->overrun - iter->last_overrun[cpu];
+ iter->last_overrun[cpu] = data->overrun;
+ }
+
+ while (find_next_entry_inc(iter) != NULL) {
+ int ret;
+ int len = iter->seq.len;
+
+ ret = print_trace_line(iter);
+ if (!ret) {
+ /* don't print partial lines */
+ iter->seq.len = len;
+ break;
+ }
+
+ trace_consume(iter);
+
+ if (iter->seq.len >= cnt)
+ break;
+ }
+
+ for_each_cpu_mask(cpu, mask) {
+ data = iter->tr->data[cpu];
+ __raw_spin_unlock(&data->lock);
+ }
+
+ for_each_cpu_mask(cpu, mask) {
+ data = iter->tr->data[cpu];
+ atomic_dec(&data->disabled);
+ }
+#ifdef CONFIG_FTRACE
+ ftrace_enabled = ftrace_save;
+#endif
+ local_irq_restore(flags);
+
+ /* Now copy what we have to the user */
+ sret = trace_seq_to_user(&iter->seq, ubuf, cnt);
+ if (iter->seq.readpos >= iter->seq.len)
+ trace_seq_reset(&iter->seq);
+ if (sret == -EBUSY)
+ sret = 0;
+
+out:
+ mutex_unlock(&trace_types_lock);
+
+ return sret;
+}
+
+static ssize_t
+tracing_entries_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ struct trace_array *tr = filp->private_data;
+ char buf[64];
+ int r;
+
+ r = sprintf(buf, "%lu\n", tr->entries);
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
+}
+
+static ssize_t
+tracing_entries_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ unsigned long val;
+ char buf[64];
+ int i, ret;
+
+ if (cnt >= sizeof(buf))
+ return -EINVAL;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = 0;
+
+ ret = strict_strtoul(buf, 10, &val);
+ if (ret < 0)
+ return ret;
+
+ /* must have at least 1 entry */
+ if (!val)
+ return -EINVAL;
+
+ mutex_lock(&trace_types_lock);
+
+ if (current_trace != &no_tracer) {
+ cnt = -EBUSY;
+ pr_info("ftrace: set current_tracer to none"
+ " before modifying buffer size\n");
+ goto out;
+ }
+
+ if (val > global_trace.entries) {
+ long pages_requested;
+ unsigned long freeable_pages;
+
+ /* make sure we have enough memory before mapping */
+ pages_requested =
+ (val + (ENTRIES_PER_PAGE-1)) / ENTRIES_PER_PAGE;
+
+ /* account for each buffer (and max_tr) */
+ pages_requested *= tracing_nr_buffers * 2;
+
+ /* Check for overflow */
+ if (pages_requested < 0) {
+ cnt = -ENOMEM;
+ goto out;
+ }
+
+ freeable_pages = determine_dirtyable_memory();
+
+ /* we only allow to request 1/4 of useable memory */
+ if (pages_requested >
+ ((freeable_pages + tracing_pages_allocated) / 4)) {
+ cnt = -ENOMEM;
+ goto out;
+ }
+
+ while (global_trace.entries < val) {
+ if (trace_alloc_page()) {
+ cnt = -ENOMEM;
+ goto out;
+ }
+ /* double check that we don't go over the known pages */
+ if (tracing_pages_allocated > pages_requested)
+ break;
+ }
+
+ } else {
+ /* include the number of entries in val (inc of page entries) */
+ while (global_trace.entries > val + (ENTRIES_PER_PAGE - 1))
+ trace_free_page();
+ }
+
+ /* check integrity */
+ for_each_tracing_cpu(i)
+ check_pages(global_trace.data[i]);
+
+ filp->f_pos += cnt;
+
+ /* If check pages failed, return ENOMEM */
+ if (tracing_disabled)
+ cnt = -ENOMEM;
+ out:
+ max_tr.entries = global_trace.entries;
+ mutex_unlock(&trace_types_lock);
+
+ return cnt;
+}
+
static struct file_operations tracing_max_lat_fops = {
- .open = tracing_open_generic,
- .read = tracing_max_lat_read,
- .write = tracing_max_lat_write,
+ .open = tracing_open_generic,
+ .read = tracing_max_lat_read,
+ .write = tracing_max_lat_write,
};
static struct file_operations tracing_ctrl_fops = {
- .open = tracing_open_generic,
- .read = tracing_ctrl_read,
- .write = tracing_ctrl_write,
+ .open = tracing_open_generic,
+ .read = tracing_ctrl_read,
+ .write = tracing_ctrl_write,
};
static struct file_operations set_tracer_fops = {
- .open = tracing_open_generic,
- .read = tracing_set_trace_read,
- .write = tracing_set_trace_write,
+ .open = tracing_open_generic,
+ .read = tracing_set_trace_read,
+ .write = tracing_set_trace_write,
+};
+
+static struct file_operations tracing_pipe_fops = {
+ .open = tracing_open_pipe,
+ .poll = tracing_poll_pipe,
+ .read = tracing_read_pipe,
+ .release = tracing_release_pipe,
+};
+
+static struct file_operations tracing_entries_fops = {
+ .open = tracing_open_generic,
+ .read = tracing_entries_read,
+ .write = tracing_entries_write,
};
#ifdef CONFIG_DYNAMIC_FTRACE
int r;
r = sprintf(buf, "%ld\n", *p);
- return simple_read_from_buffer(ubuf, cnt, ppos,
- buf, r);
+
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
}
static struct file_operations tracing_read_long_fops = {
- .open = tracing_open_generic,
- .read = tracing_read_long,
+ .open = tracing_open_generic,
+ .read = tracing_read_long,
};
#endif
return d_tracer;
}
+#ifdef CONFIG_FTRACE_SELFTEST
+/* Let selftest have access to static functions in this file */
+#include "trace_selftest.c"
+#endif
+
static __init void tracer_init_debugfs(void)
{
struct dentry *d_tracer;
if (!entry)
pr_warning("Could not create debugfs 'iter_ctrl' entry\n");
+ entry = debugfs_create_file("tracing_cpumask", 0644, d_tracer,
+ NULL, &tracing_cpumask_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs 'tracing_cpumask' entry\n");
+
entry = debugfs_create_file("latency_trace", 0444, d_tracer,
&global_trace, &tracing_lt_fops);
if (!entry)
if (!entry)
pr_warning("Could not create debugfs "
"'tracing_threash' entry\n");
+ entry = debugfs_create_file("README", 0644, d_tracer,
+ NULL, &tracing_readme_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs 'README' entry\n");
+
+ entry = debugfs_create_file("trace_pipe", 0644, d_tracer,
+ NULL, &tracing_pipe_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs "
+ "'tracing_threash' entry\n");
+
+ entry = debugfs_create_file("trace_entries", 0644, d_tracer,
+ &global_trace, &tracing_entries_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs "
+ "'tracing_threash' entry\n");
#ifdef CONFIG_DYNAMIC_FTRACE
entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer,
#endif
}
-/* dummy trace to disable tracing */
-static struct tracer no_tracer __read_mostly =
-{
- .name = "none",
-};
-
static int trace_alloc_page(void)
{
struct trace_array_cpu *data;
- void *array;
struct page *page, *tmp;
LIST_HEAD(pages);
+ void *array;
+ unsigned pages_allocated = 0;
int i;
/* first allocate a page for each CPU */
- for_each_possible_cpu(i) {
+ for_each_tracing_cpu(i) {
array = (void *)__get_free_page(GFP_KERNEL);
if (array == NULL) {
printk(KERN_ERR "tracer: failed to allocate page"
goto free_pages;
}
+ pages_allocated++;
page = virt_to_page(array);
list_add(&page->lru, &pages);
"for trace buffer!\n");
goto free_pages;
}
+ pages_allocated++;
page = virt_to_page(array);
list_add(&page->lru, &pages);
#endif
}
/* Now that we successfully allocate a page per CPU, add them */
- for_each_possible_cpu(i) {
+ for_each_tracing_cpu(i) {
data = global_trace.data[i];
page = list_entry(pages.next, struct page, lru);
- list_del(&page->lru);
+ list_del_init(&page->lru);
list_add_tail(&page->lru, &data->trace_pages);
ClearPageLRU(page);
#ifdef CONFIG_TRACER_MAX_TRACE
data = max_tr.data[i];
page = list_entry(pages.next, struct page, lru);
- list_del(&page->lru);
+ list_del_init(&page->lru);
list_add_tail(&page->lru, &data->trace_pages);
SetPageLRU(page);
#endif
}
+ tracing_pages_allocated += pages_allocated;
global_trace.entries += ENTRIES_PER_PAGE;
return 0;
free_pages:
list_for_each_entry_safe(page, tmp, &pages, lru) {
- list_del(&page->lru);
+ list_del_init(&page->lru);
__free_page(page);
}
return -ENOMEM;
}
+static int trace_free_page(void)
+{
+ struct trace_array_cpu *data;
+ struct page *page;
+ struct list_head *p;
+ int i;
+ int ret = 0;
+
+ /* free one page from each buffer */
+ for_each_tracing_cpu(i) {
+ data = global_trace.data[i];
+ p = data->trace_pages.next;
+ if (p == &data->trace_pages) {
+ /* should never happen */
+ WARN_ON(1);
+ tracing_disabled = 1;
+ ret = -1;
+ break;
+ }
+ page = list_entry(p, struct page, lru);
+ ClearPageLRU(page);
+ list_del(&page->lru);
+ tracing_pages_allocated--;
+ tracing_pages_allocated--;
+ __free_page(page);
+
+ tracing_reset(data);
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ data = max_tr.data[i];
+ p = data->trace_pages.next;
+ if (p == &data->trace_pages) {
+ /* should never happen */
+ WARN_ON(1);
+ tracing_disabled = 1;
+ ret = -1;
+ break;
+ }
+ page = list_entry(p, struct page, lru);
+ ClearPageLRU(page);
+ list_del(&page->lru);
+ __free_page(page);
+
+ tracing_reset(data);
+#endif
+ }
+ global_trace.entries -= ENTRIES_PER_PAGE;
+
+ return ret;
+}
+
__init static int tracer_alloc_buffers(void)
{
struct trace_array_cpu *data;
void *array;
struct page *page;
int pages = 0;
+ int ret = -ENOMEM;
int i;
+ /* TODO: make the number of buffers hot pluggable with CPUS */
+ tracing_nr_buffers = num_possible_cpus();
+ tracing_buffer_mask = cpu_possible_map;
+
/* Allocate the first page for all buffers */
- for_each_possible_cpu(i) {
+ for_each_tracing_cpu(i) {
data = global_trace.data[i] = &per_cpu(global_trace_cpu, i);
max_tr.data[i] = &per_cpu(max_data, i);
"for trace buffer!\n");
goto free_buffers;
}
- data->trace = array;
/* set the array to the list */
INIT_LIST_HEAD(&data->trace_pages);
/* use the LRU flag to differentiate the two buffers */
ClearPageLRU(page);
+ data->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
+ max_tr.data[i]->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
+
/* Only allocate if we are actually using the max trace */
#ifdef CONFIG_TRACER_MAX_TRACE
array = (void *)__get_free_page(GFP_KERNEL);
"for trace buffer!\n");
goto free_buffers;
}
- max_tr.data[i]->trace = array;
INIT_LIST_HEAD(&max_tr.data[i]->trace_pages);
page = virt_to_page(array);
* round up a bit.
*/
global_trace.entries = ENTRIES_PER_PAGE;
- max_tr.entries = global_trace.entries;
pages++;
while (global_trace.entries < trace_nr_entries) {
break;
pages++;
}
+ max_tr.entries = global_trace.entries;
- pr_info("tracer: %d pages allocated for %ld",
- pages, trace_nr_entries);
- pr_info(" entries of %ld bytes\n", (long)TRACE_ENTRY_SIZE);
+ pr_info("tracer: %d pages allocated for %ld entries of %ld bytes\n",
+ pages, trace_nr_entries, (long)TRACE_ENTRY_SIZE);
pr_info(" actual entries %ld\n", global_trace.entries);
tracer_init_debugfs();
register_tracer(&no_tracer);
current_trace = &no_tracer;
+ /* All seems OK, enable tracing */
+ global_trace.ctrl = tracer_enabled;
+ tracing_disabled = 0;
+
return 0;
free_buffers:
struct page *page, *tmp;
struct trace_array_cpu *data = global_trace.data[i];
- if (data && data->trace) {
+ if (data) {
list_for_each_entry_safe(page, tmp,
&data->trace_pages, lru) {
- list_del(&page->lru);
+ list_del_init(&page->lru);
__free_page(page);
}
- data->trace = NULL;
}
#ifdef CONFIG_TRACER_MAX_TRACE
data = max_tr.data[i];
- if (data && data->trace) {
+ if (data) {
list_for_each_entry_safe(page, tmp,
&data->trace_pages, lru) {
- list_del(&page->lru);
+ list_del_init(&page->lru);
__free_page(page);
}
- data->trace = NULL;
}
#endif
}
- return -ENOMEM;
+ return ret;
}
-
-device_initcall(tracer_alloc_buffers);
+fs_initcall(tracer_alloc_buffers);
projects / linux-2.6 / blobdiff