tracing: Fix function-graph build warning on 32-bit
[pandora-kernel.git] / kernel / trace / trace_functions_graph.c
index 6bff236..ef49e93 100644 (file)
 #include "trace.h"
 #include "trace_output.h"
 
+/* When set, irq functions will be ignored */
+static int ftrace_graph_skip_irqs;
+
 struct fgraph_cpu_data {
        pid_t           last_pid;
        int             depth;
+       int             depth_irq;
        int             ignore;
        unsigned long   enter_funcs[FTRACE_RETFUNC_DEPTH];
 };
 
 struct fgraph_data {
-       struct fgraph_cpu_data          *cpu_data;
+       struct fgraph_cpu_data __percpu *cpu_data;
 
        /* Place to preserve last processed entry. */
        struct ftrace_graph_ent_entry   ent;
@@ -41,6 +45,7 @@ struct fgraph_data {
 #define TRACE_GRAPH_PRINT_PROC         0x8
 #define TRACE_GRAPH_PRINT_DURATION     0x10
 #define TRACE_GRAPH_PRINT_ABS_TIME     0x20
+#define TRACE_GRAPH_PRINT_IRQS         0x40
 
 static struct tracer_opt trace_opts[] = {
        /* Display overruns? (for self-debug purpose) */
@@ -55,13 +60,15 @@ static struct tracer_opt trace_opts[] = {
        { TRACER_OPT(funcgraph-duration, TRACE_GRAPH_PRINT_DURATION) },
        /* Display absolute time of an entry */
        { TRACER_OPT(funcgraph-abstime, TRACE_GRAPH_PRINT_ABS_TIME) },
+       /* Display interrupts */
+       { TRACER_OPT(funcgraph-irqs, TRACE_GRAPH_PRINT_IRQS) },
        { } /* Empty entry */
 };
 
 static struct tracer_flags tracer_flags = {
        /* Don't display overruns and proc by default */
        .val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD |
-              TRACE_GRAPH_PRINT_DURATION,
+              TRACE_GRAPH_PRINT_DURATION | TRACE_GRAPH_PRINT_IRQS,
        .opts = trace_opts
 };
 
@@ -204,6 +211,14 @@ int __trace_graph_entry(struct trace_array *tr,
        return 1;
 }
 
+static inline int ftrace_graph_ignore_irqs(void)
+{
+       if (!ftrace_graph_skip_irqs)
+               return 0;
+
+       return in_irq();
+}
+
 int trace_graph_entry(struct ftrace_graph_ent *trace)
 {
        struct trace_array *tr = graph_array;
@@ -218,7 +233,8 @@ int trace_graph_entry(struct ftrace_graph_ent *trace)
                return 0;
 
        /* trace it when it is-nested-in or is a function enabled. */
-       if (!(trace->depth || ftrace_graph_addr(trace->func)))
+       if (!(trace->depth || ftrace_graph_addr(trace->func)) ||
+             ftrace_graph_ignore_irqs())
                return 0;
 
        local_irq_save(flags);
@@ -507,7 +523,15 @@ get_return_for_leaf(struct trace_iterator *iter,
                         * if the output fails.
                         */
                        data->ent = *curr;
-                       data->ret = *next;
+                       /*
+                        * If the next event is not a return type, then
+                        * we only care about what type it is. Otherwise we can
+                        * safely copy the entire event.
+                        */
+                       if (next->ent.type == TRACE_GRAPH_RET)
+                               data->ret = *next;
+                       else
+                               data->ret.ent.type = next->ent.type;
                }
        }
 
@@ -641,8 +665,9 @@ trace_print_graph_duration(unsigned long long duration, struct trace_seq *s)
 
        /* Print nsecs (we don't want to exceed 7 numbers) */
        if (len < 7) {
-               snprintf(nsecs_str, min(sizeof(nsecs_str), 8UL - len), "%03lu",
-                        nsecs_rem);
+               size_t slen = min_t(size_t, sizeof(nsecs_str), 8UL - len);
+
+               snprintf(nsecs_str, slen, "%03lu", nsecs_rem);
                ret = trace_seq_printf(s, ".%s", nsecs_str);
                if (!ret)
                        return TRACE_TYPE_PARTIAL_LINE;
@@ -847,6 +872,92 @@ print_graph_prologue(struct trace_iterator *iter, struct trace_seq *s,
        return 0;
 }
 
+/*
+ * Entry check for irq code
+ *
+ * returns 1 if
+ *  - we are inside irq code
+ *  - we just extered irq code
+ *
+ * retunns 0 if
+ *  - funcgraph-interrupts option is set
+ *  - we are not inside irq code
+ */
+static int
+check_irq_entry(struct trace_iterator *iter, u32 flags,
+               unsigned long addr, int depth)
+{
+       int cpu = iter->cpu;
+       struct fgraph_data *data = iter->private;
+       int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
+
+       if (flags & TRACE_GRAPH_PRINT_IRQS)
+               return 0;
+
+       /*
+        * We are inside the irq code
+        */
+       if (*depth_irq >= 0)
+               return 1;
+
+       if ((addr < (unsigned long)__irqentry_text_start) ||
+           (addr >= (unsigned long)__irqentry_text_end))
+               return 0;
+
+       /*
+        * We are entering irq code.
+        */
+       *depth_irq = depth;
+       return 1;
+}
+
+/*
+ * Return check for irq code
+ *
+ * returns 1 if
+ *  - we are inside irq code
+ *  - we just left irq code
+ *
+ * returns 0 if
+ *  - funcgraph-interrupts option is set
+ *  - we are not inside irq code
+ */
+static int
+check_irq_return(struct trace_iterator *iter, u32 flags, int depth)
+{
+       int cpu = iter->cpu;
+       struct fgraph_data *data = iter->private;
+       int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
+
+       if (flags & TRACE_GRAPH_PRINT_IRQS)
+               return 0;
+
+       /*
+        * We are not inside the irq code.
+        */
+       if (*depth_irq == -1)
+               return 0;
+
+       /*
+        * We are inside the irq code, and this is returning entry.
+        * Let's not trace it and clear the entry depth, since
+        * we are out of irq code.
+        *
+        * This condition ensures that we 'leave the irq code' once
+        * we are out of the entry depth. Thus protecting us from
+        * the RETURN entry loss.
+        */
+       if (*depth_irq >= depth) {
+               *depth_irq = -1;
+               return 1;
+       }
+
+       /*
+        * We are inside the irq code, and this is not the entry.
+        */
+       return 1;
+}
+
 static enum print_line_t
 print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
                        struct trace_iterator *iter, u32 flags)
@@ -857,6 +968,9 @@ print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
        static enum print_line_t ret;
        int cpu = iter->cpu;
 
+       if (check_irq_entry(iter, flags, call->func, call->depth))
+               return TRACE_TYPE_HANDLED;
+
        if (print_graph_prologue(iter, s, TRACE_GRAPH_ENT, call->func, flags))
                return TRACE_TYPE_PARTIAL_LINE;
 
@@ -894,6 +1008,9 @@ print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
        int ret;
        int i;
 
+       if (check_irq_return(iter, flags, trace->depth))
+               return TRACE_TYPE_HANDLED;
+
        if (data) {
                struct fgraph_cpu_data *cpu_data;
                int cpu = iter->cpu;
@@ -1202,9 +1319,12 @@ void graph_trace_open(struct trace_iterator *iter)
                pid_t *pid = &(per_cpu_ptr(data->cpu_data, cpu)->last_pid);
                int *depth = &(per_cpu_ptr(data->cpu_data, cpu)->depth);
                int *ignore = &(per_cpu_ptr(data->cpu_data, cpu)->ignore);
+               int *depth_irq = &(per_cpu_ptr(data->cpu_data, cpu)->depth_irq);
+
                *pid = -1;
                *depth = 0;
                *ignore = 0;
+               *depth_irq = -1;
        }
 
        iter->private = data;
@@ -1227,6 +1347,14 @@ void graph_trace_close(struct trace_iterator *iter)
        }
 }
 
+static int func_graph_set_flag(u32 old_flags, u32 bit, int set)
+{
+       if (bit == TRACE_GRAPH_PRINT_IRQS)
+               ftrace_graph_skip_irqs = !set;
+
+       return 0;
+}
+
 static struct trace_event_functions graph_functions = {
        .trace          = print_graph_function_event,
 };
@@ -1253,6 +1381,7 @@ static struct tracer graph_trace __read_mostly = {
        .print_line     = print_graph_function,
        .print_header   = print_graph_headers,
        .flags          = &tracer_flags,
+       .set_flag       = func_graph_set_flag,
 #ifdef CONFIG_FTRACE_SELFTEST
        .selftest       = trace_selftest_startup_function_graph,
 #endif