Re: [RFC][PATCH 07/11] perf: Provide PERF_SAMPLE_REGS

[Stephane Eranian <eranian@google.com>]

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This assumes struct pt_regs is somehow exported to userland.Is that the case?
I would clearly spell out that the REGS are the interrupted REGS,not the overflow REGS. Maybe PERF_SAMPLE_IREGS.
On Wed, Mar 3, 2010 at 8:39 AM, Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:> Simply copy out the provided pt_regs in a u64 aligned fashion.>> XXX: do task_pt_regs() and get_irq_regs() always clear everything or>     are we now leaking data?>> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>> --->  include/linux/perf_event.h |    5 ++++->  kernel/perf_event.c        |   17 +++++++++++++++++>  2 files changed, 21 insertions(+), 1 deletion(-)>> Index: linux-2.6/include/linux/perf_event.h> ===================================================================> --- linux-2.6.orig/include/linux/perf_event.h> +++ linux-2.6/include/linux/perf_event.h> @@ -125,8 +125,9 @@ enum perf_event_sample_format {>        PERF_SAMPLE_PERIOD                      = 1U << 8,>        PERF_SAMPLE_STREAM_ID                   = 1U << 9,>        PERF_SAMPLE_RAW                         = 1U << 10,> +       PERF_SAMPLE_REGS                        = 1U << 11,>> -       PERF_SAMPLE_MAX = 1U << 11,             /* non-ABI */> +       PERF_SAMPLE_MAX = 1U << 12,             /* non-ABI */>  };>>  /*> @@ -392,6 +393,7 @@ enum perf_event_type {>         *      { u64                   period;   } && PERF_SAMPLE_PERIOD>         *>         *      { struct read_format    values;   } && PERF_SAMPLE_READ> +        *      { struct pt_regs        regs;     } && PERF_SAMPLE_REGS>         *>         *      { u64                   nr,>         *        u64                   ips[nr];  } && PERF_SAMPLE_CALLCHAIN> @@ -800,6 +802,7 @@ struct perf_sample_data {>        u64                             period;>        struct perf_callchain_entry     *callchain;>        struct perf_raw_record          *raw;> +       struct pt_regs                  *regs;>  };>>  static inline> Index: linux-2.6/kernel/perf_event.c> ===================================================================> --- linux-2.6.orig/kernel/perf_event.c> +++ linux-2.6/kernel/perf_event.c> @@ -3176,6 +3176,17 @@ void perf_output_sample(struct perf_outp>        if (sample_type & PERF_SAMPLE_READ)>                perf_output_read(handle, event);>> +       if (sample_type & PERF_SAMPLE_REGS) {> +               int size = DIV_ROUND_UP(sizeof(struct pt_regs), sizeof(u64)) -> +                          sizeof(struct pt_regs);> +> +               perf_output_put(handle, *data->regs);> +               if (size) {> +                       u64 zero = 0;> +                       perf_output_copy(handle, &zero, size);> +               }> +       }> +>        if (sample_type & PERF_SAMPLE_CALLCHAIN) {>                if (data->callchain) {>                        int size = 1;> @@ -3273,6 +3284,12 @@ void perf_prepare_sample(struct perf_eve>        if (sample_type & PERF_SAMPLE_READ)>                header->size += perf_event_read_size(event);>> +       if (sample_type & PERF_SAMPLE_REGS) {> +               data->regs = regs;> +               header->size += DIV_ROUND_UP(sizeof(struct pt_regs),> +                                            sizeof(u64));> +       }> +>        if (sample_type & PERF_SAMPLE_CALLCHAIN) {>                int size = 1;>>> -->>


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