From d4ae42139289cbe38d5b84fa1558161d330d6e54 Mon Sep 17 00:00:00 2001 From: Wang Nan Date: Sat, 18 Apr 2015 17:50:20 +0200 Subject: [PATCH] perf data: Fix signedness of value When converting int values, perf first extractes it to a ulonglong, then feeds it to babeltrace as a signed value. For negative 32 bit values (for example, return values of failed syscalls), the extracted data should be something like 0xfffffffe (-2). It becomes a large int64 value. Babeltrace denies to insert it with bt_ctf_field_signed_integer_set_value() because it is larger than 0x7fffffff, the largest positive value a 32 bit int can be. This patch introduces adjust_signedness(), which fills high bits of ulonglong with 1 if the value is negative. Signed-off-by: Wang Nan Cc: David Ahern Cc: Frederic Weisbecker Cc: He Kuang Cc: Jeremie Galarneau Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Sebastian Andrzej Siewior Cc: Tom Zanussi Link: http://lkml.kernel.org/r/1429372220-6406-8-git-send-email-jolsa@kernel.org Signed-off-by: Jiri Olsa [ s/signess/signedness/g ] Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/data-convert-bt.c | 64 +++++++++++++++++++++++++------ 1 file changed, 52 insertions(+), 12 deletions(-) diff --git a/tools/perf/util/data-convert-bt.c b/tools/perf/util/data-convert-bt.c index 8eda4ed628e7..5bfc1198ab46 100644 --- a/tools/perf/util/data-convert-bt.c +++ b/tools/perf/util/data-convert-bt.c @@ -166,6 +166,43 @@ get_tracepoint_field_type(struct ctf_writer *cw, struct format_field *field) return cw->data.u32; } +static unsigned long long adjust_signedness(unsigned long long value_int, int size) +{ + unsigned long long value_mask; + + /* + * value_mask = (1 << (size * 8 - 1)) - 1. + * Directly set value_mask for code readers. + */ + switch (size) { + case 1: + value_mask = 0x7fULL; + break; + case 2: + value_mask = 0x7fffULL; + break; + case 4: + value_mask = 0x7fffffffULL; + break; + case 8: + /* + * For 64 bit value, return it self. There is no need + * to fill high bit. + */ + /* Fall through */ + default: + /* BUG! */ + return value_int; + } + + /* If it is a positive value, don't adjust. */ + if ((value_int & (~0ULL - value_mask)) == 0) + return value_int; + + /* Fill upper part of value_int with 1 to make it a negative long long. */ + return (value_int & value_mask) | ~value_mask; +} + static int add_tracepoint_field_value(struct ctf_writer *cw, struct bt_ctf_event_class *event_class, struct bt_ctf_event *event, @@ -177,7 +214,6 @@ static int add_tracepoint_field_value(struct ctf_writer *cw, struct bt_ctf_field *field; const char *name = fmtf->name; void *data = sample->raw_data; - unsigned long long value_int; unsigned long flags = fmtf->flags; unsigned int n_items; unsigned int i; @@ -222,11 +258,6 @@ static int add_tracepoint_field_value(struct ctf_writer *cw, type = get_tracepoint_field_type(cw, fmtf); for (i = 0; i < n_items; i++) { - if (!(flags & FIELD_IS_STRING)) - value_int = pevent_read_number( - fmtf->event->pevent, - data + offset + i * len, len); - if (flags & FIELD_IS_ARRAY) field = bt_ctf_field_array_get_field(array_field, i); else @@ -240,12 +271,21 @@ static int add_tracepoint_field_value(struct ctf_writer *cw, if (flags & FIELD_IS_STRING) ret = bt_ctf_field_string_set_value(field, data + offset + i * len); - else if (!(flags & FIELD_IS_SIGNED)) - ret = bt_ctf_field_unsigned_integer_set_value( - field, value_int); - else - ret = bt_ctf_field_signed_integer_set_value( - field, value_int); + else { + unsigned long long value_int; + + value_int = pevent_read_number( + fmtf->event->pevent, + data + offset + i * len, len); + + if (!(flags & FIELD_IS_SIGNED)) + ret = bt_ctf_field_unsigned_integer_set_value( + field, value_int); + else + ret = bt_ctf_field_signed_integer_set_value( + field, adjust_signedness(value_int, len)); + } + if (ret) { pr_err("failed to set file value %s\n", name); goto err_put_field; -- 2.20.1