#include <linux/poll.h>
#include <linux/gfp.h>
#include <linux/fs.h>
+#include <linux/kprobes.h>
+#include <linux/writeback.h>
#include <linux/stacktrace.h>
#define for_each_tracing_cpu(cpu) \
for_each_cpu_mask(cpu, tracing_buffer_mask)
-/* dummy trace to disable tracing */
-static struct tracer no_tracer __read_mostly = {
- .name = "none",
-};
-
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)
{
/* 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
*
tracing_record_cmdline(current);
}
+#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. TODO: configure to disable this because it adds
- * a bit of overhead.
+ * been corrupted.
*/
-void check_pages(struct trace_array_cpu *data)
+int check_pages(struct trace_array_cpu *data)
{
struct page *page, *tmp;
- BUG_ON(data->trace_pages.next->prev != &data->trace_pages);
- BUG_ON(data->trace_pages.prev->next != &data->trace_pages);
+ 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) {
- BUG_ON(page->lru.next->prev != &page->lru);
- BUG_ON(page->lru.prev->next != &page->lru);
+ CHECK_COND(page->lru.next->prev != &page->lru);
+ CHECK_COND(page->lru.prev->next != &page->lru);
}
+
+ return 0;
}
/**
{
struct page *page;
- check_pages(data);
if (list_empty(&data->trace_pages))
return NULL;
static int cmdline_idx;
static DEFINE_SPINLOCK(trace_cmdline_lock);
-/* trace in all context switches */
-atomic_t trace_record_cmdline_enabled __read_mostly;
-
/* temporary disable recording */
atomic_t trace_record_cmdline_disabled __read_mostly;
entry->ctx.next_pid = next->pid;
entry->ctx.next_prio = next->prio;
entry->ctx.next_state = next->state;
- __trace_stack(tr, data, flags, 4);
+ __trace_stack(tr, data, flags, 5);
__raw_spin_unlock(&data->lock);
raw_local_irq_restore(irq_flags);
}
entry->ctx.next_pid = wakee->pid;
entry->ctx.next_prio = wakee->prio;
entry->ctx.next_state = wakee->state;
- __trace_stack(tr, data, flags, 5);
+ __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);
+
+ atomic_dec(&data->disabled);
+ local_irq_restore(flags);
+}
+
#ifdef CONFIG_FTRACE
static void
function_trace_call(unsigned long ip, unsigned long parent_ip)
mutex_unlock(&trace_types_lock);
}
+#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)
{
case TRACE_FN:
seq_print_ip_sym(s, entry->fn.ip, sym_flags);
trace_seq_puts(s, " (");
- seq_print_ip_sym(s, entry->fn.parent_ip, sym_flags);
+ 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:
ret = trace_seq_printf(s, " <-");
if (!ret)
return 0;
- ret = seq_print_ip_sym(s, entry->fn.parent_ip,
- sym_flags);
+ 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;
}
{
unsigned long val;
char buf[64];
- int ret;
+ int i, ret;
if (cnt >= sizeof(buf))
return -EINVAL;
}
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);
struct page *page, *tmp;
LIST_HEAD(pages);
void *array;
+ unsigned pages_allocated = 0;
int i;
/* first allocate a page for each CPU */
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
SetPageLRU(page);
#endif
}
+ tracing_pages_allocated += pages_allocated;
global_trace.entries += ENTRIES_PER_PAGE;
return 0;
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);
int ret = -ENOMEM;
int i;
- global_trace.ctrl = tracer_enabled;
-
/* TODO: make the number of buffers hot pluggable with CPUS */
tracing_nr_buffers = num_possible_cpus();
tracing_buffer_mask = cpu_possible_map;
}
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();
current_trace = &no_tracer;
/* All seems OK, enable tracing */
+ global_trace.ctrl = tracer_enabled;
tracing_disabled = 0;
return 0;
projects / linux-2.6 / blobdiff