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    Subject[038/102] perf tools: Fix endian conversion reading event attr from file header
    3.0-stable review patch.  If anyone has any objections, please let us know.

    ------------------

    From: David Ahern <dsahern@gmail.com>

    commit eda3913bb70ecebac13adccffe1e7f96e93cee02 upstream.

    The perf_event_attr struct has two __u32's at the top and
    they need to be swapped individually.

    With this change I was able to analyze a perf.data collected in a
    32-bit PPC VM on an x86 system. I tested both 32-bit and 64-bit
    binaries for the Intel analysis side; both read the PPC perf.data
    file correctly.

    -v2:
    - changed the existing perf_event__attr_swap() to swap only elements
    of perf_event_attr and exported it for use in swapping the
    attributes in the file header
    - updated swap_ops used for processing events

    Signed-off-by: David Ahern <dsahern@gmail.com>
    Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
    Cc: acme@ghostprotocols.net
    Cc: peterz@infradead.org
    Cc: paulus@samba.org
    Link: http://lkml.kernel.org/r/1310754849-12474-1-git-send-email-dsahern@gmail.com
    Signed-off-by: Ingo Molnar <mingo@elte.hu>
    Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

    ---
    tools/perf/util/header.c | 5 ++++-
    tools/perf/util/session.c | 30 ++++++++++++++++++------------
    tools/perf/util/session.h | 1 +
    3 files changed, 23 insertions(+), 13 deletions(-)

    --- a/tools/perf/util/header.c
    +++ b/tools/perf/util/header.c
    @@ -877,9 +877,12 @@ int perf_session__read_header(struct per
    struct perf_evsel *evsel;
    off_t tmp;

    - if (perf_header__getbuffer64(header, fd, &f_attr, sizeof(f_attr)))
    + if (readn(fd, &f_attr, sizeof(f_attr)) <= 0)
    goto out_errno;

    + if (header->needs_swap)
    + perf_event__attr_swap(&f_attr.attr);
    +
    tmp = lseek(fd, 0, SEEK_CUR);
    evsel = perf_evsel__new(&f_attr.attr, i);

    --- a/tools/perf/util/session.c
    +++ b/tools/perf/util/session.c
    @@ -407,20 +407,26 @@ static void perf_event__read_swap(union
    event->read.id = bswap_64(event->read.id);
    }

    -static void perf_event__attr_swap(union perf_event *event)
    +/* exported for swapping attributes in file header */
    +void perf_event__attr_swap(struct perf_event_attr *attr)
    +{
    + attr->type = bswap_32(attr->type);
    + attr->size = bswap_32(attr->size);
    + attr->config = bswap_64(attr->config);
    + attr->sample_period = bswap_64(attr->sample_period);
    + attr->sample_type = bswap_64(attr->sample_type);
    + attr->read_format = bswap_64(attr->read_format);
    + attr->wakeup_events = bswap_32(attr->wakeup_events);
    + attr->bp_type = bswap_32(attr->bp_type);
    + attr->bp_addr = bswap_64(attr->bp_addr);
    + attr->bp_len = bswap_64(attr->bp_len);
    +}
    +
    +static void perf_event__hdr_attr_swap(union perf_event *event)
    {
    size_t size;

    - event->attr.attr.type = bswap_32(event->attr.attr.type);
    - event->attr.attr.size = bswap_32(event->attr.attr.size);
    - event->attr.attr.config = bswap_64(event->attr.attr.config);
    - event->attr.attr.sample_period = bswap_64(event->attr.attr.sample_period);
    - event->attr.attr.sample_type = bswap_64(event->attr.attr.sample_type);
    - event->attr.attr.read_format = bswap_64(event->attr.attr.read_format);
    - event->attr.attr.wakeup_events = bswap_32(event->attr.attr.wakeup_events);
    - event->attr.attr.bp_type = bswap_32(event->attr.attr.bp_type);
    - event->attr.attr.bp_addr = bswap_64(event->attr.attr.bp_addr);
    - event->attr.attr.bp_len = bswap_64(event->attr.attr.bp_len);
    + perf_event__attr_swap(&event->attr.attr);

    size = event->header.size;
    size -= (void *)&event->attr.id - (void *)event;
    @@ -448,7 +454,7 @@ static perf_event__swap_op perf_event__s
    [PERF_RECORD_LOST] = perf_event__all64_swap,
    [PERF_RECORD_READ] = perf_event__read_swap,
    [PERF_RECORD_SAMPLE] = perf_event__all64_swap,
    - [PERF_RECORD_HEADER_ATTR] = perf_event__attr_swap,
    + [PERF_RECORD_HEADER_ATTR] = perf_event__hdr_attr_swap,
    [PERF_RECORD_HEADER_EVENT_TYPE] = perf_event__event_type_swap,
    [PERF_RECORD_HEADER_TRACING_DATA] = perf_event__tracing_data_swap,
    [PERF_RECORD_HEADER_BUILD_ID] = NULL,
    --- a/tools/perf/util/session.h
    +++ b/tools/perf/util/session.h
    @@ -112,6 +112,7 @@ int perf_session__set_kallsyms_ref_reloc
    u64 addr);

    void mem_bswap_64(void *src, int byte_size);
    +void perf_event__attr_swap(struct perf_event_attr *attr);

    int perf_session__create_kernel_maps(struct perf_session *self);




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