1 files changed, 829 insertions, 0 deletions

diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
new file mode 100644
index 000000000000..1a4e144a9f8f
--- /dev/null
+++ b/kernel/trace/trace_output.c
@@ -0,0 +1,829 @@
+/*
+ * trace_output.c
+ *
+ * Copyright (C) 2008 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/ftrace.h>
+
+#include "trace_output.h"
+
+/* must be a power of 2 */
+#define EVENT_HASHSIZE  128
+
+static DEFINE_MUTEX(trace_event_mutex);
+static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly;
+
+static int next_event_type = __TRACE_LAST_TYPE + 1;
+
+/**
+ * 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.
+ */
+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;
+}
+
+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;
+}
+
+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;
+}
+
+int trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len)
+{
+        unsigned char hex[HEX_CHARS];
+        unsigned char *data = mem;
+        int i, j;
+
+#ifdef __BIG_ENDIAN
+        for (i = 0, j = 0; i < len; i++) {
+#else
+        for (i = len-1, j = 0; i >= 0; i--) {
+#endif
+                hex[j++] = hex_asc_hi(data[i]);
+                hex[j++] = hex_asc_lo(data[i]);
+        }
+        hex[j++] = ' ';
+
+        return trace_seq_putmem(s, hex, j);
+}
+
+int trace_seq_path(struct trace_seq *s, struct path *path)
+{
+        unsigned char *p;
+
+        if (s->len >= (PAGE_SIZE - 1))
+                return 0;
+        p = d_path(path, s->buffer + s->len, PAGE_SIZE - s->len);
+        if (!IS_ERR(p)) {
+                p = mangle_path(s->buffer + s->len, p, "\n");
+                if (p) {
+                        s->len = p - s->buffer;
+                        return 1;
+                }
+        } else {
+                s->buffer[s->len++] = '?';
+                return 1;
+        }
+
+        return 0;
+}
+
+#ifdef CONFIG_KRETPROBES
+static inline const char *kretprobed(const char *name)
+{
+        static const char tramp_name[] = "kretprobe_trampoline";
+        int size = sizeof(tramp_name);
+
+        if (strncmp(tramp_name, name, size) == 0)
+                return "[unknown/kretprobe'd]";
+        return name;
+}
+#else
+static inline const char *kretprobed(const char *name)
+{
+        return name;
+}
+#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];
+        const char *name;
+
+        kallsyms_lookup(address, NULL, NULL, NULL, str);
+
+        name = kretprobed(str);
+
+        return trace_seq_printf(s, fmt, name);
+#endif
+        return 1;
+}
+
+static int
+seq_print_sym_offset(struct trace_seq *s, const char *fmt,
+                     unsigned long address)
+{
+#ifdef CONFIG_KALLSYMS
+        char str[KSYM_SYMBOL_LEN];
+        const char *name;
+
+        sprint_symbol(str, address);
+        name = kretprobed(str);
+
+        return trace_seq_printf(s, fmt, name);
+#endif
+        return 1;
+}
+
+#ifndef CONFIG_64BIT
+# define IP_FMT "%08lx"
+#else
+# define IP_FMT "%016lx"
+#endif
+
+int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
+                      unsigned long ip, unsigned long sym_flags)
+{
+        struct file *file = NULL;
+        unsigned long vmstart = 0;
+        int ret = 1;
+
+        if (mm) {
+                const struct vm_area_struct *vma;
+
+                down_read(&mm->mmap_sem);
+                vma = find_vma(mm, ip);
+                if (vma) {
+                        file = vma->vm_file;
+                        vmstart = vma->vm_start;
+                }
+                if (file) {
+                        ret = trace_seq_path(s, &file->f_path);
+                        if (ret)
+                                ret = trace_seq_printf(s, "[+0x%lx]",
+                                                       ip - vmstart);
+                }
+                up_read(&mm->mmap_sem);
+        }
+        if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
+                ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
+        return ret;
+}
+
+int
+seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
+                      unsigned long sym_flags)
+{
+        struct mm_struct *mm = NULL;
+        int ret = 1;
+        unsigned int i;
+
+        if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
+                struct task_struct *task;
+                /*
+                 * we do the lookup on the thread group leader,
+                 * since individual threads might have already quit!
+                 */
+                rcu_read_lock();
+                task = find_task_by_vpid(entry->ent.tgid);
+                if (task)
+                        mm = get_task_mm(task);
+                rcu_read_unlock();
+        }
+
+        for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
+                unsigned long ip = entry->caller[i];
+
+                if (ip == ULONG_MAX || !ret)
+                        break;
+                if (i && ret)
+                        ret = trace_seq_puts(s, " <- ");
+                if (!ip) {
+                        if (ret)
+                                ret = trace_seq_puts(s, "??");
+                        continue;
+                }
+                if (!ret)
+                        break;
+                if (ret)
+                        ret = seq_print_user_ip(s, mm, ip, sym_flags);
+        }
+
+        if (mm)
+                mmput(mm);
+        return ret;
+}
+
+int
+seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
+{
+        int ret;
+
+        if (!ip)
+                return trace_seq_printf(s, "0");
+
+        if (sym_flags & TRACE_ITER_SYM_OFFSET)
+                ret = seq_print_sym_offset(s, "%s", ip);
+        else
+                ret = seq_print_sym_short(s, "%s", ip);
+
+        if (!ret)
+                return 0;
+
+        if (sym_flags & TRACE_ITER_SYM_ADDR)
+                ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
+        return ret;
+}
+
+static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
+
+static int task_state_char(unsigned long state)
+{
+        int bit = state ? __ffs(state) + 1 : 0;
+
+        return bit < sizeof(state_to_char) - 1 ? state_to_char[bit] : '?';
+}
+
+/**
+ * ftrace_find_event - find a registered event
+ * @type: the type of event to look for
+ *
+ * Returns an event of type @type otherwise NULL
+ */
+struct trace_event *ftrace_find_event(int type)
+{
+        struct trace_event *event;
+        struct hlist_node *n;
+        unsigned key;
+
+        key = type & (EVENT_HASHSIZE - 1);
+
+        hlist_for_each_entry_rcu(event, n, &event_hash[key], node) {
+                if (event->type == type)
+                        return event;
+        }
+
+        return NULL;
+}
+
+/**
+ * register_ftrace_event - register output for an event type
+ * @event: the event type to register
+ *
+ * Event types are stored in a hash and this hash is used to
+ * find a way to print an event. If the @event->type is set
+ * then it will use that type, otherwise it will assign a
+ * type to use.
+ *
+ * If you assign your own type, please make sure it is added
+ * to the trace_type enum in trace.h, to avoid collisions
+ * with the dynamic types.
+ *
+ * Returns the event type number or zero on error.
+ */
+int register_ftrace_event(struct trace_event *event)
+{
+        unsigned key;
+        int ret = 0;
+
+        mutex_lock(&trace_event_mutex);
+
+        if (!event->type)
+                event->type = next_event_type++;
+        else if (event->type > __TRACE_LAST_TYPE) {
+                printk(KERN_WARNING "Need to add type to trace.h\n");
+                WARN_ON(1);
+        }
+
+        if (ftrace_find_event(event->type))
+                goto out;
+
+        key = event->type & (EVENT_HASHSIZE - 1);
+
+        hlist_add_head_rcu(&event->node, &event_hash[key]);
+
+        ret = event->type;
+ out:
+        mutex_unlock(&trace_event_mutex);
+
+        return ret;
+}
+
+/**
+ * unregister_ftrace_event - remove a no longer used event
+ * @event: the event to remove
+ */
+int unregister_ftrace_event(struct trace_event *event)
+{
+        mutex_lock(&trace_event_mutex);
+        hlist_del(&event->node);
+        mutex_unlock(&trace_event_mutex);
+
+        return 0;
+}
+
+/*
+ * Standard events
+ */
+
+int
+trace_nop_print(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+        return 0;
+}
+
+/* TRACE_FN */
+static int
+trace_fn_latency(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+        struct ftrace_entry *field;
+
+        trace_assign_type(field, entry);
+
+        if (!seq_print_ip_sym(s, field->ip, flags))
+                goto partial;
+        if (!trace_seq_puts(s, " ("))
+                goto partial;
+        if (!seq_print_ip_sym(s, field->parent_ip, flags))
+                goto partial;
+        if (!trace_seq_puts(s, ")\n"))
+                goto partial;
+
+        return 0;
+
+ partial:
+        return TRACE_TYPE_PARTIAL_LINE;
+}
+
+static int
+trace_fn_trace(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+        struct ftrace_entry *field;
+
+        trace_assign_type(field, entry);
+
+        if (!seq_print_ip_sym(s, field->ip, flags))
+                goto partial;
+
+        if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
+                if (!trace_seq_printf(s, " <-"))
+                        goto partial;
+                if (!seq_print_ip_sym(s,
+                                      field->parent_ip,
+                                      flags))
+                        goto partial;
+        }
+        if (!trace_seq_printf(s, "\n"))
+                goto partial;
+
+        return 0;
+
+ partial:
+        return TRACE_TYPE_PARTIAL_LINE;
+}
+
+static int
+trace_fn_raw(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+        struct ftrace_entry *field;
+
+        trace_assign_type(field, entry);
+
+        if (!trace_seq_printf(s, "%lx %lx\n",
+                              field->ip,
+                              field->parent_ip))
+                return TRACE_TYPE_PARTIAL_LINE;
+
+        return 0;
+}
+
+static int
+trace_fn_hex(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+        struct ftrace_entry *field;
+
+        trace_assign_type(field, entry);
+
+        SEQ_PUT_HEX_FIELD_RET(s, field->ip);
+        SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
+
+        return 0;
+}
+
+static int
+trace_fn_bin(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+        struct ftrace_entry *field;
+
+        trace_assign_type(field, entry);
+
+        SEQ_PUT_FIELD_RET(s, field->ip);
+        SEQ_PUT_FIELD_RET(s, field->parent_ip);
+
+        return 0;
+}
+
+static struct trace_event trace_fn_event = {
+        .type           = TRACE_FN,
+        .trace          = trace_fn_trace,
+        .latency_trace  = trace_fn_latency,
+        .raw            = trace_fn_raw,
+        .hex            = trace_fn_hex,
+        .binary         = trace_fn_bin,
+};
+
+/* TRACE_CTX an TRACE_WAKE */
+static int
+trace_ctxwake_print(struct trace_seq *s, struct trace_entry *entry, int flags,
+                    char *delim)
+{
+        struct ctx_switch_entry *field;
+        char *comm;
+        int S, T;
+
+        trace_assign_type(field, entry);
+
+        T = task_state_char(field->next_state);
+        S = task_state_char(field->prev_state);
+        comm = trace_find_cmdline(field->next_pid);
+        if (!trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
+                              field->prev_pid,
+                              field->prev_prio,
+                              S, delim,
+                              field->next_cpu,
+                              field->next_pid,
+                              field->next_prio,
+                              T, comm))
+                return TRACE_TYPE_PARTIAL_LINE;
+
+        return 0;
+}
+
+static int
+trace_ctx_print(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+        return trace_ctxwake_print(s, entry, flags, "==>");
+}
+
+static int
+trace_wake_print(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+        return trace_ctxwake_print(s, entry, flags, "  +");
+}
+
+static int
+trace_ctxwake_raw(struct trace_seq *s, struct trace_entry *entry, int flags,
+                  char S)
+{
+        struct ctx_switch_entry *field;
+        int T;
+
+        trace_assign_type(field, entry);
+
+        if (!S)
+                task_state_char(field->prev_state);
+        T = task_state_char(field->next_state);
+        if (!trace_seq_printf(s, "%d %d %c %d %d %d %c\n",
+                              field->prev_pid,
+                              field->prev_prio,
+                              S,
+                              field->next_cpu,
+                              field->next_pid,
+                              field->next_prio,
+                              T))
+                return TRACE_TYPE_PARTIAL_LINE;
+
+        return 0;
+}
+
+static int
+trace_ctx_raw(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+        return trace_ctxwake_raw(s, entry, flags, 0);
+}
+
+static int
+trace_wake_raw(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+        return trace_ctxwake_raw(s, entry, flags, '+');
+}
+
+
+static int
+trace_ctxwake_hex(struct trace_seq *s, struct trace_entry *entry, int flags,
+                  char S)
+{
+        struct ctx_switch_entry *field;
+        int T;
+
+        trace_assign_type(field, entry);
+
+        if (!S)
+                task_state_char(field->prev_state);
+        T = task_state_char(field->next_state);
+
+        SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
+        SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
+        SEQ_PUT_HEX_FIELD_RET(s, S);
+        SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
+        SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
+        SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
+        SEQ_PUT_HEX_FIELD_RET(s, T);
+
+        return 0;
+}
+
+static int
+trace_ctx_hex(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+        return trace_ctxwake_hex(s, entry, flags, 0);
+}
+
+static int
+trace_wake_hex(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+        return trace_ctxwake_hex(s, entry, flags, '+');
+}
+
+static int
+trace_ctxwake_bin(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+        struct ctx_switch_entry *field;
+
+        trace_assign_type(field, entry);
+
+        SEQ_PUT_FIELD_RET(s, field->prev_pid);
+        SEQ_PUT_FIELD_RET(s, field->prev_prio);
+        SEQ_PUT_FIELD_RET(s, field->prev_state);
+        SEQ_PUT_FIELD_RET(s, field->next_pid);
+        SEQ_PUT_FIELD_RET(s, field->next_prio);
+        SEQ_PUT_FIELD_RET(s, field->next_state);
+
+        return 0;
+}
+
+static struct trace_event trace_ctx_event = {
+        .type           = TRACE_CTX,
+        .trace          = trace_ctx_print,
+        .latency_trace  = trace_ctx_print,
+        .raw            = trace_ctx_raw,
+        .hex            = trace_ctx_hex,
+        .binary         = trace_ctxwake_bin,
+};
+
+static struct trace_event trace_wake_event = {
+        .type           = TRACE_WAKE,
+        .trace          = trace_wake_print,
+        .latency_trace  = trace_wake_print,
+        .raw            = trace_wake_raw,
+        .hex            = trace_wake_hex,
+        .binary         = trace_ctxwake_bin,
+};
+
+/* TRACE_SPECIAL */
+static int
+trace_special_print(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+        struct special_entry *field;
+
+        trace_assign_type(field, entry);
+
+        if (!trace_seq_printf(s, "# %ld %ld %ld\n",
+                              field->arg1,
+                              field->arg2,
+                              field->arg3))
+                return TRACE_TYPE_PARTIAL_LINE;
+
+        return 0;
+}
+
+static int
+trace_special_hex(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+        struct special_entry *field;
+
+        trace_assign_type(field, entry);
+
+        SEQ_PUT_HEX_FIELD_RET(s, field->arg1);
+        SEQ_PUT_HEX_FIELD_RET(s, field->arg2);
+        SEQ_PUT_HEX_FIELD_RET(s, field->arg3);
+
+        return 0;
+}
+
+static int
+trace_special_bin(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+        struct special_entry *field;
+
+        trace_assign_type(field, entry);
+
+        SEQ_PUT_FIELD_RET(s, field->arg1);
+        SEQ_PUT_FIELD_RET(s, field->arg2);
+        SEQ_PUT_FIELD_RET(s, field->arg3);
+
+        return 0;
+}
+
+static struct trace_event trace_special_event = {
+        .type           = TRACE_SPECIAL,
+        .trace          = trace_special_print,
+        .latency_trace  = trace_special_print,
+        .raw            = trace_special_print,
+        .hex            = trace_special_hex,
+        .binary         = trace_special_bin,
+};
+
+/* TRACE_STACK */
+
+static int
+trace_stack_print(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+        struct stack_entry *field;
+        int i;
+
+        trace_assign_type(field, entry);
+
+        for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
+                if (i) {
+                        if (!trace_seq_puts(s, " <= "))
+                                goto partial;
+
+                        if (!seq_print_ip_sym(s, field->caller[i], flags))
+                                goto partial;
+                }
+                if (!trace_seq_puts(s, "\n"))
+                        goto partial;
+        }
+
+        return 0;
+
+ partial:
+        return TRACE_TYPE_PARTIAL_LINE;
+}
+
+static struct trace_event trace_stack_event = {
+        .type           = TRACE_STACK,
+        .trace          = trace_stack_print,
+        .latency_trace  = trace_stack_print,
+        .raw            = trace_special_print,
+        .hex            = trace_special_hex,
+        .binary         = trace_special_bin,
+};
+
+/* TRACE_USER_STACK */
+static int
+trace_user_stack_print(struct trace_seq *s, struct trace_entry *entry,
+                       int flags)
+{
+        struct userstack_entry *field;
+
+        trace_assign_type(field, entry);
+
+        if (!seq_print_userip_objs(field, s, flags))
+                goto partial;
+
+        if (!trace_seq_putc(s, '\n'))
+                goto partial;
+
+        return 0;
+
+ partial:
+        return TRACE_TYPE_PARTIAL_LINE;
+}
+
+static struct trace_event trace_user_stack_event = {
+        .type           = TRACE_USER_STACK,
+        .trace          = trace_user_stack_print,
+        .latency_trace  = trace_user_stack_print,
+        .raw            = trace_special_print,
+        .hex            = trace_special_hex,
+        .binary         = trace_special_bin,
+};
+
+/* TRACE_PRINT */
+static int
+trace_print_print(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+        struct print_entry *field;
+
+        trace_assign_type(field, entry);
+
+        if (!seq_print_ip_sym(s, field->ip, flags))
+                goto partial;
+
+        if (!trace_seq_printf(s, ": %s", field->buf))
+                goto partial;
+
+        return 0;
+
+ partial:
+        return TRACE_TYPE_PARTIAL_LINE;
+}
+
+static int
+trace_print_raw(struct trace_seq *s, struct trace_entry *entry, int flags)
+{
+        struct print_entry *field;
+
+        trace_assign_type(field, entry);
+
+        if (!trace_seq_printf(s, "# %lx %s", field->ip, field->buf))
+                goto partial;
+
+        return 0;
+
+ partial:
+        return TRACE_TYPE_PARTIAL_LINE;
+}
+
+static struct trace_event trace_print_event = {
+        .type           = TRACE_PRINT,
+        .trace          = trace_print_print,
+        .latency_trace  = trace_print_print,
+        .raw            = trace_print_raw,
+        .hex            = trace_nop_print,
+        .binary         = trace_nop_print,
+};
+
+static struct trace_event *events[] __initdata = {
+        &trace_fn_event,
+        &trace_ctx_event,
+        &trace_wake_event,
+        &trace_special_event,
+        &trace_stack_event,
+        &trace_user_stack_event,
+        &trace_print_event,
+        NULL
+};
+
+__init static int init_events(void)
+{
+        struct trace_event *event;
+        int i, ret;
+
+        for (i = 0; events[i]; i++) {
+                event = events[i];
+
+                ret = register_ftrace_event(event);
+                if (!ret) {
+                        printk(KERN_WARNING "event %d failed to register\n",
+                               event->type);
+                        WARN_ON_ONCE(1);
+                }
+        }
+
+        return 0;
+}
+device_initcall(init_events);