[PATCH v1 1/4] perf cs-etm: Generate branch sample for exception packet
The exception packet appears as one element with 'elem_type' ==
OCSD_GEN_TRC_ELEM_EXCEPTION or OCSD_GEN_TRC_ELEM_EXCEPTION_RET,
which present for exception entry and exit respectively. The decoder
set packet fields 'packet->exc' and 'packet->exc_ret' to indicate the
exception packets; but exception packets don't have dedicated sample
type and shares the same sample type CS_ETM_RANGE with normal
instruction packets.
As result, the exception packets are taken as normal instruction packets
and this introduces confusion to mix different packet types.
Furthermore, these instruction range packets will be processed for
branch sample only when 'packet->last_instr_taken_branch' is true,
otherwise they will be omitted, this can introduce mess for exception
and exception returning due we don't have complete address range info
for context switching.
To process exception packets properly, this patch introduce two new
sample type: CS_ETM_EXCEPTION and CS_ETM_EXCEPTION_RET; for these two
kind packets, they will be handled by cs_etm__exception(). The func
cs_etm__exception() forces to set previous CS_ETM_RANGE packet flag
'prev_packet->last_instr_taken_branch' to true, this matches well with
the program flow when the exception is trapped from user space to kernel
space, no matter if the most recent flow has branch taken or not; this
is also safe for returning to user space after exception handling.
After exception packets have their own sample type, the packet fields
'packet->exc' and 'packet->exc_ret' aren't needed anymore, so remove
them.
Signed-off-by: Leo Yan
---
tools/perf/util/cs-etm-decoder/cs-etm-decoder.c | 26 +--
tools/perf/util/cs-etm-decoder/cs-etm-decoder.h | 10 -
tools/perf/util/cs-etm.c| 28 +
3 files changed, 53 insertions(+), 11 deletions(-)
diff --git a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c
b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c
index 5efb616..0f29534 100644
--- a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c
+++ b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c
@@ -269,8 +269,6 @@ static void cs_etm_decoder__clear_buffer(struct
cs_etm_decoder *decoder)
decoder->packet_buffer[i].instr_count = 0;
decoder->packet_buffer[i].last_instr_taken_branch = false;
decoder->packet_buffer[i].last_instr_size = 0;
- decoder->packet_buffer[i].exc = false;
- decoder->packet_buffer[i].exc_ret = false;
decoder->packet_buffer[i].cpu = INT_MIN;
}
}
@@ -298,8 +296,6 @@ cs_etm_decoder__buffer_packet(struct cs_etm_decoder
*decoder,
decoder->packet_buffer[et].sample_type = sample_type;
decoder->packet_buffer[et].isa = CS_ETM_ISA_UNKNOWN;
- decoder->packet_buffer[et].exc = false;
- decoder->packet_buffer[et].exc_ret = false;
decoder->packet_buffer[et].cpu = *((int *)inode->priv);
decoder->packet_buffer[et].start_addr = CS_ETM_INVAL_ADDR;
decoder->packet_buffer[et].end_addr = CS_ETM_INVAL_ADDR;
@@ -376,6 +372,22 @@ cs_etm_decoder__buffer_trace_on(struct cs_etm_decoder
*decoder,
CS_ETM_TRACE_ON);
}
+static ocsd_datapath_resp_t
+cs_etm_decoder__buffer_exception(struct cs_etm_decoder *decoder,
+const uint8_t trace_chan_id)
+{
+ return cs_etm_decoder__buffer_packet(decoder, trace_chan_id,
+CS_ETM_EXCEPTION);
+}
+
+static ocsd_datapath_resp_t
+cs_etm_decoder__buffer_exception_ret(struct cs_etm_decoder *decoder,
+const uint8_t trace_chan_id)
+{
+ return cs_etm_decoder__buffer_packet(decoder, trace_chan_id,
+CS_ETM_EXCEPTION_RET);
+}
+
static ocsd_datapath_resp_t cs_etm_decoder__gen_trace_elem_printer(
const void *context,
const ocsd_trc_index_t indx __maybe_unused,
@@ -401,10 +413,12 @@ static ocsd_datapath_resp_t
cs_etm_decoder__gen_trace_elem_printer(
trace_chan_id);
break;
case OCSD_GEN_TRC_ELEM_EXCEPTION:
- decoder->packet_buffer[decoder->tail].exc = true;
+ resp = cs_etm_decoder__buffer_exception(decoder,
+ trace_chan_id);
break;
case OCSD_GEN_TRC_ELEM_EXCEPTION_RET:
- decoder->packet_buffer[decoder->tail].exc_ret = true;
+ resp = cs_etm_decoder__buffer_exception_ret(decoder,
+ trace_chan_id);
break;
case OCSD_GEN_TRC_ELEM_PE_CONTEXT:
case OCSD_GEN_TRC_ELEM_EO_TRACE:
diff --git a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.h
b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.h
index
[PATCH v1 1/4] perf cs-etm: Generate branch sample for exception packet
The exception packet appears as one element with 'elem_type' ==
OCSD_GEN_TRC_ELEM_EXCEPTION or OCSD_GEN_TRC_ELEM_EXCEPTION_RET,
which present for exception entry and exit respectively. The decoder
set packet fields 'packet->exc' and 'packet->exc_ret' to indicate the
exception packets; but exception packets don't have dedicated sample
type and shares the same sample type CS_ETM_RANGE with normal
instruction packets.
As result, the exception packets are taken as normal instruction packets
and this introduces confusion to mix different packet types.
Furthermore, these instruction range packets will be processed for
branch sample only when 'packet->last_instr_taken_branch' is true,
otherwise they will be omitted, this can introduce mess for exception
and exception returning due we don't have complete address range info
for context switching.
To process exception packets properly, this patch introduce two new
sample type: CS_ETM_EXCEPTION and CS_ETM_EXCEPTION_RET; for these two
kind packets, they will be handled by cs_etm__exception(). The func
cs_etm__exception() forces to set previous CS_ETM_RANGE packet flag
'prev_packet->last_instr_taken_branch' to true, this matches well with
the program flow when the exception is trapped from user space to kernel
space, no matter if the most recent flow has branch taken or not; this
is also safe for returning to user space after exception handling.
After exception packets have their own sample type, the packet fields
'packet->exc' and 'packet->exc_ret' aren't needed anymore, so remove
them.
Signed-off-by: Leo Yan
---
tools/perf/util/cs-etm-decoder/cs-etm-decoder.c | 26 +--
tools/perf/util/cs-etm-decoder/cs-etm-decoder.h | 10 -
tools/perf/util/cs-etm.c| 28 +
3 files changed, 53 insertions(+), 11 deletions(-)
diff --git a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c
b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c
index 5efb616..0f29534 100644
--- a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c
+++ b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c
@@ -269,8 +269,6 @@ static void cs_etm_decoder__clear_buffer(struct
cs_etm_decoder *decoder)
decoder->packet_buffer[i].instr_count = 0;
decoder->packet_buffer[i].last_instr_taken_branch = false;
decoder->packet_buffer[i].last_instr_size = 0;
- decoder->packet_buffer[i].exc = false;
- decoder->packet_buffer[i].exc_ret = false;
decoder->packet_buffer[i].cpu = INT_MIN;
}
}
@@ -298,8 +296,6 @@ cs_etm_decoder__buffer_packet(struct cs_etm_decoder
*decoder,
decoder->packet_buffer[et].sample_type = sample_type;
decoder->packet_buffer[et].isa = CS_ETM_ISA_UNKNOWN;
- decoder->packet_buffer[et].exc = false;
- decoder->packet_buffer[et].exc_ret = false;
decoder->packet_buffer[et].cpu = *((int *)inode->priv);
decoder->packet_buffer[et].start_addr = CS_ETM_INVAL_ADDR;
decoder->packet_buffer[et].end_addr = CS_ETM_INVAL_ADDR;
@@ -376,6 +372,22 @@ cs_etm_decoder__buffer_trace_on(struct cs_etm_decoder
*decoder,
CS_ETM_TRACE_ON);
}
+static ocsd_datapath_resp_t
+cs_etm_decoder__buffer_exception(struct cs_etm_decoder *decoder,
+const uint8_t trace_chan_id)
+{
+ return cs_etm_decoder__buffer_packet(decoder, trace_chan_id,
+CS_ETM_EXCEPTION);
+}
+
+static ocsd_datapath_resp_t
+cs_etm_decoder__buffer_exception_ret(struct cs_etm_decoder *decoder,
+const uint8_t trace_chan_id)
+{
+ return cs_etm_decoder__buffer_packet(decoder, trace_chan_id,
+CS_ETM_EXCEPTION_RET);
+}
+
static ocsd_datapath_resp_t cs_etm_decoder__gen_trace_elem_printer(
const void *context,
const ocsd_trc_index_t indx __maybe_unused,
@@ -401,10 +413,12 @@ static ocsd_datapath_resp_t
cs_etm_decoder__gen_trace_elem_printer(
trace_chan_id);
break;
case OCSD_GEN_TRC_ELEM_EXCEPTION:
- decoder->packet_buffer[decoder->tail].exc = true;
+ resp = cs_etm_decoder__buffer_exception(decoder,
+ trace_chan_id);
break;
case OCSD_GEN_TRC_ELEM_EXCEPTION_RET:
- decoder->packet_buffer[decoder->tail].exc_ret = true;
+ resp = cs_etm_decoder__buffer_exception_ret(decoder,
+ trace_chan_id);
break;
case OCSD_GEN_TRC_ELEM_PE_CONTEXT:
case OCSD_GEN_TRC_ELEM_EO_TRACE:
diff --git a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.h
b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.h
index
