bool noboot;
};
-
-/* Only current can touch trace_recursion */
-
-/*
- * For function tracing recursion:
- * The order of these bits are important.
- *
- * When function tracing occurs, the following steps are made:
- * If arch does not support a ftrace feature:
- * call internal function (uses INTERNAL bits) which calls...
- * If callback is registered to the "global" list, the list
- * function is called and recursion checks the GLOBAL bits.
- * then this function calls...
- * The function callback, which can use the FTRACE bits to
- * check for recursion.
- *
- * Now if the arch does not support a feature, and it calls
- * the global list function which calls the ftrace callback
- * all three of these steps will do a recursion protection.
- * There's no reason to do one if the previous caller already
- * did. The recursion that we are protecting against will
- * go through the same steps again.
- *
- * To prevent the multiple recursion checks, if a recursion
- * bit is set that is higher than the MAX bit of the current
- * check, then we know that the check was made by the previous
- * caller, and we can skip the current check.
- */
-enum {
- /* Function recursion bits */
- TRACE_FTRACE_BIT,
- TRACE_FTRACE_NMI_BIT,
- TRACE_FTRACE_IRQ_BIT,
- TRACE_FTRACE_SIRQ_BIT,
-
- /* INTERNAL_BITs must be greater than FTRACE_BITs */
- TRACE_INTERNAL_BIT,
- TRACE_INTERNAL_NMI_BIT,
- TRACE_INTERNAL_IRQ_BIT,
- TRACE_INTERNAL_SIRQ_BIT,
-
- TRACE_BRANCH_BIT,
-/*
- * Abuse of the trace_recursion.
- * As we need a way to maintain state if we are tracing the function
- * graph in irq because we want to trace a particular function that
- * was called in irq context but we have irq tracing off. Since this
- * can only be modified by current, we can reuse trace_recursion.
- */
- TRACE_IRQ_BIT,
-
- /* Set if the function is in the set_graph_function file */
- TRACE_GRAPH_BIT,
-
- /*
- * In the very unlikely case that an interrupt came in
- * at a start of graph tracing, and we want to trace
- * the function in that interrupt, the depth can be greater
- * than zero, because of the preempted start of a previous
- * trace. In an even more unlikely case, depth could be 2
- * if a softirq interrupted the start of graph tracing,
- * followed by an interrupt preempting a start of graph
- * tracing in the softirq, and depth can even be 3
- * if an NMI came in at the start of an interrupt function
- * that preempted a softirq start of a function that
- * preempted normal context!!!! Luckily, it can't be
- * greater than 3, so the next two bits are a mask
- * of what the depth is when we set TRACE_GRAPH_BIT
- */
-
- TRACE_GRAPH_DEPTH_START_BIT,
- TRACE_GRAPH_DEPTH_END_BIT,
-
- /*
- * To implement set_graph_notrace, if this bit is set, we ignore
- * function graph tracing of called functions, until the return
- * function is called to clear it.
- */
- TRACE_GRAPH_NOTRACE_BIT,
-
- /*
- * When transitioning between context, the preempt_count() may
- * not be correct. Allow for a single recursion to cover this case.
- */
- TRACE_TRANSITION_BIT,
-};
-
-#define trace_recursion_set(bit) do { (current)->trace_recursion |= (1<<(bit)); } while (0)
-#define trace_recursion_clear(bit) do { (current)->trace_recursion &= ~(1<<(bit)); } while (0)
-#define trace_recursion_test(bit) ((current)->trace_recursion & (1<<(bit)))
-
-#define trace_recursion_depth() \
- (((current)->trace_recursion >> TRACE_GRAPH_DEPTH_START_BIT) & 3)
-#define trace_recursion_set_depth(depth) \
- do { \
- current->trace_recursion &= \
- ~(3 << TRACE_GRAPH_DEPTH_START_BIT); \
- current->trace_recursion |= \
- ((depth) & 3) << TRACE_GRAPH_DEPTH_START_BIT; \
- } while (0)
-
-#define TRACE_CONTEXT_BITS 4
-
-#define TRACE_FTRACE_START TRACE_FTRACE_BIT
-#define TRACE_FTRACE_MAX ((1 << (TRACE_FTRACE_START + TRACE_CONTEXT_BITS)) - 1)
-
-#define TRACE_LIST_START TRACE_INTERNAL_BIT
-#define TRACE_LIST_MAX ((1 << (TRACE_LIST_START + TRACE_CONTEXT_BITS)) - 1)
-
-#define TRACE_CONTEXT_MASK TRACE_LIST_MAX
-
-static __always_inline int trace_get_context_bit(void)
-{
- int bit;
-
- if (in_interrupt()) {
- if (in_nmi())
- bit = 0;
-
- else if (in_irq())
- bit = 1;
- else
- bit = 2;
- } else
- bit = 3;
-
- return bit;
-}
-
-static __always_inline int trace_test_and_set_recursion(int start, int max)
-{
- unsigned int val = current->trace_recursion;
- int bit;
-
- /* A previous recursion check was made */
- if ((val & TRACE_CONTEXT_MASK) > max)
- return 0;
-
- bit = trace_get_context_bit() + start;
- if (unlikely(val & (1 << bit))) {
- /*
- * It could be that preempt_count has not been updated during
- * a switch between contexts. Allow for a single recursion.
- */
- bit = TRACE_TRANSITION_BIT;
- if (trace_recursion_test(bit))
- return -1;
- trace_recursion_set(bit);
- barrier();
- return bit + 1;
- }
-
- /* Normal check passed, clear the transition to allow it again */
- trace_recursion_clear(TRACE_TRANSITION_BIT);
-
- val |= 1 << bit;
- current->trace_recursion = val;
- barrier();
-
- return bit + 1;
-}
-
-static __always_inline void trace_clear_recursion(int bit)
-{
- unsigned int val = current->trace_recursion;
-
- if (!bit)
- return;
-
- bit--;
- bit = 1 << bit;
- val &= ~bit;
-
- barrier();
- current->trace_recursion = val;
-}
-
static inline struct ring_buffer_iter *
trace_buffer_iter(struct trace_iterator *iter, int cpu)
{
extern bool tracing_selftest_disabled;
#ifdef CONFIG_FTRACE_STARTUP_TEST
+extern void __init disable_tracing_selftest(const char *reason);
+
extern int trace_selftest_startup_function(struct tracer *trace,
struct trace_array *tr);
extern int trace_selftest_startup_function_graph(struct tracer *trace,
*/
#define __tracer_data __refdata
#else
+static inline void __init disable_tracing_selftest(const char *reason)
+{
+}
/* Tracers are seldom changed. Optimize when selftests are disabled. */
#define __tracer_data __read_mostly
#endif /* CONFIG_FTRACE_STARTUP_TEST */
projects / linux-2.6-microblaze.git / blobdiff