1 files changed, 732 insertions, 0 deletions

diff --git a/tools/lib/traceevent/kbuffer-parse.c b/tools/lib/traceevent/kbuffer-parse.c
new file mode 100644
index 000000000000..dcc665228c71
--- /dev/null
+++ b/tools/lib/traceevent/kbuffer-parse.c
@@ -0,0 +1,732 @@
+/*
+ * Copyright (C) 2009, 2010 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License (not later!)
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "kbuffer.h"
+
+#define MISSING_EVENTS (1 << 31)
+#define MISSING_STORED (1 << 30)
+
+#define COMMIT_MASK ((1 << 27) - 1)
+
+enum {
+        KBUFFER_FL_HOST_BIG_ENDIAN      = (1<<0),
+        KBUFFER_FL_BIG_ENDIAN           = (1<<1),
+        KBUFFER_FL_LONG_8               = (1<<2),
+        KBUFFER_FL_OLD_FORMAT           = (1<<3),
+};
+
+#define ENDIAN_MASK (KBUFFER_FL_HOST_BIG_ENDIAN | KBUFFER_FL_BIG_ENDIAN)
+
+/** kbuffer
+ * @timestamp           - timestamp of current event
+ * @lost_events         - # of lost events between this subbuffer and previous
+ * @flags               - special flags of the kbuffer
+ * @subbuffer           - pointer to the sub-buffer page
+ * @data                - pointer to the start of data on the sub-buffer page
+ * @index               - index from @data to the @curr event data
+ * @curr                - offset from @data to the start of current event
+ *                         (includes metadata)
+ * @next                - offset from @data to the start of next event
+ * @size                - The size of data on @data
+ * @start               - The offset from @subbuffer where @data lives
+ *
+ * @read_4              - Function to read 4 raw bytes (may swap)
+ * @read_8              - Function to read 8 raw bytes (may swap)
+ * @read_long           - Function to read a long word (4 or 8 bytes with needed swap)
+ */
+struct kbuffer {
+        unsigned long long      timestamp;
+        long long               lost_events;
+        unsigned long           flags;
+        void                    *subbuffer;
+        void                    *data;
+        unsigned int            index;
+        unsigned int            curr;
+        unsigned int            next;
+        unsigned int            size;
+        unsigned int            start;
+
+        unsigned int (*read_4)(void *ptr);
+        unsigned long long (*read_8)(void *ptr);
+        unsigned long long (*read_long)(struct kbuffer *kbuf, void *ptr);
+        int (*next_event)(struct kbuffer *kbuf);
+};
+
+static void *zmalloc(size_t size)
+{
+        return calloc(1, size);
+}
+
+static int host_is_bigendian(void)
+{
+        unsigned char str[] = { 0x1, 0x2, 0x3, 0x4 };
+        unsigned int *ptr;
+
+        ptr = (unsigned int *)str;
+        return *ptr == 0x01020304;
+}
+
+static int do_swap(struct kbuffer *kbuf)
+{
+        return ((kbuf->flags & KBUFFER_FL_HOST_BIG_ENDIAN) + kbuf->flags) &
+                ENDIAN_MASK;
+}
+
+static unsigned long long __read_8(void *ptr)
+{
+        unsigned long long data = *(unsigned long long *)ptr;
+
+        return data;
+}
+
+static unsigned long long __read_8_sw(void *ptr)
+{
+        unsigned long long data = *(unsigned long long *)ptr;
+        unsigned long long swap;
+
+        swap = ((data & 0xffULL) << 56) |
+                ((data & (0xffULL << 8)) << 40) |
+                ((data & (0xffULL << 16)) << 24) |
+                ((data & (0xffULL << 24)) << 8) |
+                ((data & (0xffULL << 32)) >> 8) |
+                ((data & (0xffULL << 40)) >> 24) |
+                ((data & (0xffULL << 48)) >> 40) |
+                ((data & (0xffULL << 56)) >> 56);
+
+        return swap;
+}
+
+static unsigned int __read_4(void *ptr)
+{
+        unsigned int data = *(unsigned int *)ptr;
+
+        return data;
+}
+
+static unsigned int __read_4_sw(void *ptr)
+{
+        unsigned int data = *(unsigned int *)ptr;
+        unsigned int swap;
+
+        swap = ((data & 0xffULL) << 24) |
+                ((data & (0xffULL << 8)) << 8) |
+                ((data & (0xffULL << 16)) >> 8) |
+                ((data & (0xffULL << 24)) >> 24);
+
+        return swap;
+}
+
+static unsigned long long read_8(struct kbuffer *kbuf, void *ptr)
+{
+        return kbuf->read_8(ptr);
+}
+
+static unsigned int read_4(struct kbuffer *kbuf, void *ptr)
+{
+        return kbuf->read_4(ptr);
+}
+
+static unsigned long long __read_long_8(struct kbuffer *kbuf, void *ptr)
+{
+        return kbuf->read_8(ptr);
+}
+
+static unsigned long long __read_long_4(struct kbuffer *kbuf, void *ptr)
+{
+        return kbuf->read_4(ptr);
+}
+
+static unsigned long long read_long(struct kbuffer *kbuf, void *ptr)
+{
+        return kbuf->read_long(kbuf, ptr);
+}
+
+static int calc_index(struct kbuffer *kbuf, void *ptr)
+{
+        return (unsigned long)ptr - (unsigned long)kbuf->data;
+}
+
+static int __next_event(struct kbuffer *kbuf);
+
+/**
+ * kbuffer_alloc - allocat a new kbuffer
+ * @size;       enum to denote size of word
+ * @endian:     enum to denote endianness
+ *
+ * Allocates and returns a new kbuffer.
+ */
+struct kbuffer *
+kbuffer_alloc(enum kbuffer_long_size size, enum kbuffer_endian endian)
+{
+        struct kbuffer *kbuf;
+        int flags = 0;
+
+        switch (size) {
+        case KBUFFER_LSIZE_4:
+                break;
+        case KBUFFER_LSIZE_8:
+                flags |= KBUFFER_FL_LONG_8;
+                break;
+        default:
+                return NULL;
+        }
+
+        switch (endian) {
+        case KBUFFER_ENDIAN_LITTLE:
+                break;
+        case KBUFFER_ENDIAN_BIG:
+                flags |= KBUFFER_FL_BIG_ENDIAN;
+                break;
+        default:
+                return NULL;
+        }
+
+        kbuf = zmalloc(sizeof(*kbuf));
+        if (!kbuf)
+                return NULL;
+
+        kbuf->flags = flags;
+
+        if (host_is_bigendian())
+                kbuf->flags |= KBUFFER_FL_HOST_BIG_ENDIAN;
+
+        if (do_swap(kbuf)) {
+                kbuf->read_8 = __read_8_sw;
+                kbuf->read_4 = __read_4_sw;
+        } else {
+                kbuf->read_8 = __read_8;
+                kbuf->read_4 = __read_4;
+        }
+
+        if (kbuf->flags & KBUFFER_FL_LONG_8)
+                kbuf->read_long = __read_long_8;
+        else
+                kbuf->read_long = __read_long_4;
+
+        /* May be changed by kbuffer_set_old_format() */
+        kbuf->next_event = __next_event;
+
+        return kbuf;
+}
+
+/** kbuffer_free - free an allocated kbuffer
+ * @kbuf:       The kbuffer to free
+ *
+ * Can take NULL as a parameter.
+ */
+void kbuffer_free(struct kbuffer *kbuf)
+{
+        free(kbuf);
+}
+
+static unsigned int type4host(struct kbuffer *kbuf,
+                              unsigned int type_len_ts)
+{
+        if (kbuf->flags & KBUFFER_FL_BIG_ENDIAN)
+                return (type_len_ts >> 29) & 3;
+        else
+                return type_len_ts & 3;
+}
+
+static unsigned int len4host(struct kbuffer *kbuf,
+                             unsigned int type_len_ts)
+{
+        if (kbuf->flags & KBUFFER_FL_BIG_ENDIAN)
+                return (type_len_ts >> 27) & 7;
+        else
+                return (type_len_ts >> 2) & 7;
+}
+
+static unsigned int type_len4host(struct kbuffer *kbuf,
+                                  unsigned int type_len_ts)
+{
+        if (kbuf->flags & KBUFFER_FL_BIG_ENDIAN)
+                return (type_len_ts >> 27) & ((1 << 5) - 1);
+        else
+                return type_len_ts & ((1 << 5) - 1);
+}
+
+static unsigned int ts4host(struct kbuffer *kbuf,
+                            unsigned int type_len_ts)
+{
+        if (kbuf->flags & KBUFFER_FL_BIG_ENDIAN)
+                return type_len_ts & ((1 << 27) - 1);
+        else
+                return type_len_ts >> 5;
+}
+
+/*
+ * Linux 2.6.30 and earlier (not much ealier) had a different
+ * ring buffer format. It should be obsolete, but we handle it anyway.
+ */
+enum old_ring_buffer_type {
+        OLD_RINGBUF_TYPE_PADDING,
+        OLD_RINGBUF_TYPE_TIME_EXTEND,
+        OLD_RINGBUF_TYPE_TIME_STAMP,
+        OLD_RINGBUF_TYPE_DATA,
+};
+
+static unsigned int old_update_pointers(struct kbuffer *kbuf)
+{
+        unsigned long long extend;
+        unsigned int type_len_ts;
+        unsigned int type;
+        unsigned int len;
+        unsigned int delta;
+        unsigned int length;
+        void *ptr = kbuf->data + kbuf->curr;
+
+        type_len_ts = read_4(kbuf, ptr);
+        ptr += 4;
+
+        type = type4host(kbuf, type_len_ts);
+        len = len4host(kbuf, type_len_ts);
+        delta = ts4host(kbuf, type_len_ts);
+
+        switch (type) {
+        case OLD_RINGBUF_TYPE_PADDING:
+                kbuf->next = kbuf->size;
+                return 0;
+
+        case OLD_RINGBUF_TYPE_TIME_EXTEND:
+                extend = read_4(kbuf, ptr);
+                extend <<= TS_SHIFT;
+                extend += delta;
+                delta = extend;
+                ptr += 4;
+                break;
+
+        case OLD_RINGBUF_TYPE_TIME_STAMP:
+                /* should never happen! */
+                kbuf->curr = kbuf->size;
+                kbuf->next = kbuf->size;
+                kbuf->index = kbuf->size;
+                return -1;
+        default:
+                if (len)
+                        length = len * 4;
+                else {
+                        length = read_4(kbuf, ptr);
+                        length -= 4;
+                        ptr += 4;
+                }
+                break;
+        }
+
+        kbuf->timestamp += delta;
+        kbuf->index = calc_index(kbuf, ptr);
+        kbuf->next = kbuf->index + length;
+
+        return type;
+}
+
+static int __old_next_event(struct kbuffer *kbuf)
+{
+        int type;
+
+        do {
+                kbuf->curr = kbuf->next;
+                if (kbuf->next >= kbuf->size)
+                        return -1;
+                type = old_update_pointers(kbuf);
+        } while (type == OLD_RINGBUF_TYPE_TIME_EXTEND || type == OLD_RINGBUF_TYPE_PADDING);
+
+        return 0;
+}
+
+static unsigned int
+translate_data(struct kbuffer *kbuf, void *data, void **rptr,
+               unsigned long long *delta, int *length)
+{
+        unsigned long long extend;
+        unsigned int type_len_ts;
+        unsigned int type_len;
+
+        type_len_ts = read_4(kbuf, data);
+        data += 4;
+
+        type_len = type_len4host(kbuf, type_len_ts);
+        *delta = ts4host(kbuf, type_len_ts);
+
+        switch (type_len) {
+        case KBUFFER_TYPE_PADDING:
+                *length = read_4(kbuf, data);
+                data += *length;
+                break;
+
+        case KBUFFER_TYPE_TIME_EXTEND:
+                extend = read_4(kbuf, data);
+                data += 4;
+                extend <<= TS_SHIFT;
+                extend += *delta;
+                *delta = extend;
+                *length = 0;
+                break;
+
+        case KBUFFER_TYPE_TIME_STAMP:
+                data += 12;
+                *length = 0;
+                break;
+        case 0:
+                *length = read_4(kbuf, data) - 4;
+                *length = (*length + 3) & ~3;
+                data += 4;
+                break;
+        default:
+                *length = type_len * 4;
+                break;
+        }
+
+        *rptr = data;
+
+        return type_len;
+}
+
+static unsigned int update_pointers(struct kbuffer *kbuf)
+{
+        unsigned long long delta;
+        unsigned int type_len;
+        int length;
+        void *ptr = kbuf->data + kbuf->curr;
+
+        type_len = translate_data(kbuf, ptr, &ptr, &delta, &length);
+
+        kbuf->timestamp += delta;
+        kbuf->index = calc_index(kbuf, ptr);
+        kbuf->next = kbuf->index + length;
+
+        return type_len;
+}
+
+/**
+ * kbuffer_translate_data - read raw data to get a record
+ * @swap:       Set to 1 if bytes in words need to be swapped when read
+ * @data:       The raw data to read
+ * @size:       Address to store the size of the event data.
+ *
+ * Returns a pointer to the event data. To determine the entire
+ * record size (record metadata + data) just add the difference between
+ * @data and the returned value to @size.
+ */
+void *kbuffer_translate_data(int swap, void *data, unsigned int *size)
+{
+        unsigned long long delta;
+        struct kbuffer kbuf;
+        int type_len;
+        int length;
+        void *ptr;
+
+        if (swap) {
+                kbuf.read_8 = __read_8_sw;
+                kbuf.read_4 = __read_4_sw;
+                kbuf.flags = host_is_bigendian() ? 0 : KBUFFER_FL_BIG_ENDIAN;
+        } else {
+                kbuf.read_8 = __read_8;
+                kbuf.read_4 = __read_4;
+                kbuf.flags = host_is_bigendian() ? KBUFFER_FL_BIG_ENDIAN: 0;
+        }
+
+        type_len = translate_data(&kbuf, data, &ptr, &delta, &length);
+        switch (type_len) {
+        case KBUFFER_TYPE_PADDING:
+        case KBUFFER_TYPE_TIME_EXTEND:
+        case KBUFFER_TYPE_TIME_STAMP:
+                return NULL;
+        };
+
+        *size = length;
+
+        return ptr;
+}
+
+static int __next_event(struct kbuffer *kbuf)
+{
+        int type;
+
+        do {
+                kbuf->curr = kbuf->next;
+                if (kbuf->next >= kbuf->size)
+                        return -1;
+                type = update_pointers(kbuf);
+        } while (type == KBUFFER_TYPE_TIME_EXTEND || type == KBUFFER_TYPE_PADDING);
+
+        return 0;
+}
+
+static int next_event(struct kbuffer *kbuf)
+{
+        return kbuf->next_event(kbuf);
+}
+
+/**
+ * kbuffer_next_event - increment the current pointer
+ * @kbuf:       The kbuffer to read
+ * @ts:         Address to store the next record's timestamp (may be NULL to ignore)
+ *
+ * Increments the pointers into the subbuffer of the kbuffer to point to the
+ * next event so that the next kbuffer_read_event() will return a
+ * new event.
+ *
+ * Returns the data of the next event if a new event exists on the subbuffer,
+ * NULL otherwise.
+ */
+void *kbuffer_next_event(struct kbuffer *kbuf, unsigned long long *ts)
+{
+        int ret;
+
+        if (!kbuf || !kbuf->subbuffer)
+                return NULL;
+
+        ret = next_event(kbuf);
+        if (ret < 0)
+                return NULL;
+
+        if (ts)
+                *ts = kbuf->timestamp;
+
+        return kbuf->data + kbuf->index;
+}
+
+/**
+ * kbuffer_load_subbuffer - load a new subbuffer into the kbuffer
+ * @kbuf:       The kbuffer to load
+ * @subbuffer:  The subbuffer to load into @kbuf.
+ *
+ * Load a new subbuffer (page) into @kbuf. This will reset all
+ * the pointers and update the @kbuf timestamp. The next read will
+ * return the first event on @subbuffer.
+ *
+ * Returns 0 on succes, -1 otherwise.
+ */
+int kbuffer_load_subbuffer(struct kbuffer *kbuf, void *subbuffer)
+{
+        unsigned long long flags;
+        void *ptr = subbuffer;
+
+        if (!kbuf || !subbuffer)
+                return -1;
+
+        kbuf->subbuffer = subbuffer;
+
+        kbuf->timestamp = read_8(kbuf, ptr);
+        ptr += 8;
+
+        kbuf->curr = 0;
+
+        if (kbuf->flags & KBUFFER_FL_LONG_8)
+                kbuf->start = 16;
+        else
+                kbuf->start = 12;
+
+        kbuf->data = subbuffer + kbuf->start;
+
+        flags = read_long(kbuf, ptr);
+        kbuf->size = (unsigned int)flags & COMMIT_MASK;
+
+        if (flags & MISSING_EVENTS) {
+                if (flags & MISSING_STORED) {
+                        ptr = kbuf->data + kbuf->size;
+                        kbuf->lost_events = read_long(kbuf, ptr);
+                } else
+                        kbuf->lost_events = -1;
+        } else
+                kbuf->lost_events = 0;
+
+        kbuf->index = 0;
+        kbuf->next = 0;
+
+        next_event(kbuf);
+
+        return 0;
+}
+
+/**
+ * kbuffer_read_event - read the next event in the kbuffer subbuffer
+ * @kbuf:       The kbuffer to read from
+ * @ts:         The address to store the timestamp of the event (may be NULL to ignore)
+ *
+ * Returns a pointer to the data part of the current event.
+ * NULL if no event is left on the subbuffer.
+ */
+void *kbuffer_read_event(struct kbuffer *kbuf, unsigned long long *ts)
+{
+        if (!kbuf || !kbuf->subbuffer)
+                return NULL;
+
+        if (kbuf->curr >= kbuf->size)
+                return NULL;
+
+        if (ts)
+                *ts = kbuf->timestamp;
+        return kbuf->data + kbuf->index;
+}
+
+/**
+ * kbuffer_timestamp - Return the timestamp of the current event
+ * @kbuf:       The kbuffer to read from
+ *
+ * Returns the timestamp of the current (next) event.
+ */
+unsigned long long kbuffer_timestamp(struct kbuffer *kbuf)
+{
+        return kbuf->timestamp;
+}
+
+/**
+ * kbuffer_read_at_offset - read the event that is at offset
+ * @kbuf:       The kbuffer to read from
+ * @offset:     The offset into the subbuffer
+ * @ts:         The address to store the timestamp of the event (may be NULL to ignore)
+ *
+ * The @offset must be an index from the @kbuf subbuffer beginning.
+ * If @offset is bigger than the stored subbuffer, NULL will be returned.
+ *
+ * Returns the data of the record that is at @offset. Note, @offset does
+ * not need to be the start of the record, the offset just needs to be
+ * in the record (or beginning of it).
+ *
+ * Note, the kbuf timestamp and pointers are updated to the
+ * returned record. That is, kbuffer_read_event() will return the same
+ * data and timestamp, and kbuffer_next_event() will increment from
+ * this record.
+ */
+void *kbuffer_read_at_offset(struct kbuffer *kbuf, int offset,
+                             unsigned long long *ts)
+{
+        void *data;
+
+        if (offset < kbuf->start)
+                offset = 0;
+        else
+                offset -= kbuf->start;
+
+        /* Reset the buffer */
+        kbuffer_load_subbuffer(kbuf, kbuf->subbuffer);
+
+        while (kbuf->curr < offset) {
+                data = kbuffer_next_event(kbuf, ts);
+                if (!data)
+                        break;
+        }
+
+        return data;
+}
+
+/**
+ * kbuffer_subbuffer_size - the size of the loaded subbuffer
+ * @kbuf:       The kbuffer to read from
+ *
+ * Returns the size of the subbuffer. Note, this size is
+ * where the last event resides. The stored subbuffer may actually be
+ * bigger due to padding and such.
+ */
+int kbuffer_subbuffer_size(struct kbuffer *kbuf)
+{
+        return kbuf->size;
+}
+
+/**
+ * kbuffer_curr_index - Return the index of the record
+ * @kbuf:       The kbuffer to read from
+ *
+ * Returns the index from the start of the data part of
+ * the subbuffer to the current location. Note this is not
+ * from the start of the subbuffer. An index of zero will
+ * point to the first record. Use kbuffer_curr_offset() for
+ * the actually offset (that can be used by kbuffer_read_at_offset())
+ */
+int kbuffer_curr_index(struct kbuffer *kbuf)
+{
+        return kbuf->curr;
+}
+
+/**
+ * kbuffer_curr_offset - Return the offset of the record
+ * @kbuf:       The kbuffer to read from
+ *
+ * Returns the offset from the start of the subbuffer to the
+ * current location.
+ */
+int kbuffer_curr_offset(struct kbuffer *kbuf)
+{
+        return kbuf->curr + kbuf->start;
+}
+
+/**
+ * kbuffer_event_size - return the size of the event data
+ * @kbuf:       The kbuffer to read
+ *
+ * Returns the size of the event data (the payload not counting
+ * the meta data of the record) of the current event.
+ */
+int kbuffer_event_size(struct kbuffer *kbuf)
+{
+        return kbuf->next - kbuf->index;
+}
+
+/**
+ * kbuffer_curr_size - return the size of the entire record
+ * @kbuf:       The kbuffer to read
+ *
+ * Returns the size of the entire record (meta data and payload)
+ * of the current event.
+ */
+int kbuffer_curr_size(struct kbuffer *kbuf)
+{
+        return kbuf->next - kbuf->curr;
+}
+
+/**
+ * kbuffer_missed_events - return the # of missed events from last event.
+ * @kbuf:       The kbuffer to read from
+ *
+ * Returns the # of missed events (if recorded) before the current
+ * event. Note, only events on the beginning of a subbuffer can
+ * have missed events, all other events within the buffer will be
+ * zero.
+ */
+int kbuffer_missed_events(struct kbuffer *kbuf)
+{
+        /* Only the first event can have missed events */
+        if (kbuf->curr)
+                return 0;
+
+        return kbuf->lost_events;
+}
+
+/**
+ * kbuffer_set_old_forma - set the kbuffer to use the old format parsing
+ * @kbuf:       The kbuffer to set
+ *
+ * This is obsolete (or should be). The first kernels to use the
+ * new ring buffer had a slightly different ring buffer format
+ * (2.6.30 and earlier). It is still somewhat supported by kbuffer,
+ * but should not be counted on in the future.
+ */
+void kbuffer_set_old_format(struct kbuffer *kbuf)
+{
+        kbuf->flags |= KBUFFER_FL_OLD_FORMAT;
+
+        kbuf->next_event = __old_next_event;
+}