[PATCH 15/24] gtrace: Only copy AUX data from the path sink
Zane Leung
liangzhen at linux.spacemit.com
Thu Oct 22 20:14:56 PDT 2026
gtrace_path_copyto_auxbuf() walked the path and copied from the first
component implementing copyto_auxbuf(). For a linksink like ETF used as
a link, this picked the wrong component. Call the sink's callback
directly via gtrace_path_sink() and pass the perf handle so the sink
can set AUX flags itself.
Signed-off-by: Zane Leung <liangzhen at linux.spacemit.com>
---
drivers/hwtracing/gtrace/gtrace-core.c | 39 ++++++++++------------
drivers/hwtracing/gtrace/gtrace-perf.c | 13 ++------
drivers/hwtracing/gtrace/rvtrace-ramsink.c | 10 ++++--
include/linux/gtrace.h | 10 +++---
4 files changed, 34 insertions(+), 38 deletions(-)
diff --git a/drivers/hwtracing/gtrace/gtrace-core.c b/drivers/hwtracing/gtrace/gtrace-core.c
index 231d06218d8e..a42b1844da29 100644
--- a/drivers/hwtracing/gtrace/gtrace-core.c
+++ b/drivers/hwtracing/gtrace/gtrace-core.c
@@ -806,14 +806,14 @@ int gtrace_path_stop(struct gtrace_path *path)
EXPORT_SYMBOL_GPL(gtrace_path_stop);
int gtrace_path_copyto_auxbuf(struct gtrace_path *path,
+ struct perf_output_handle *handle,
struct gtrace_perf_auxbuf *buf,
- size_t *bytes_copied, u64 *format)
+ size_t *bytes_copied)
{
- struct gtrace_comp_priv *sink = to_gtrace_comp_priv(gtrace_path_sink(path));
- const struct gtrace_driver *gtdrv;
- struct gtrace_component *comp;
- struct gtrace_path_node *node;
- int ret = -EOPNOTSUPP;
+ struct gtrace_component *sink = gtrace_path_sink(path);
+ struct gtrace_comp_priv *spriv = to_gtrace_comp_priv(sink);
+ const struct gtrace_driver *sinkdrv = to_gtrace_driver(sink->dev.driver);
+ int ret = 0;
unsigned long flags;
/*
@@ -823,25 +823,20 @@ int gtrace_path_copyto_auxbuf(struct gtrace_path *path,
* sink's lock also stops another path from starting the sink before copy
* completes.
*/
- raw_spin_lock_irqsave(&sink->lock, flags);
- if (sink->start_count) {
- *bytes_copied = 0;
- ret = 0;
- goto out;
- }
-
- list_for_each_entry(node, &path->comp_list, head) {
- comp = node->comp;
- gtdrv = to_gtrace_driver(comp->dev.driver);
- if (!gtdrv || !gtdrv->copyto_auxbuf)
- continue;
+ raw_spin_lock_irqsave(&spriv->lock, flags);
+ if (!spriv->start_count) {
+ if (!sinkdrv) {
+ ret = -ENODEV;
+ goto out;
+ }
- *bytes_copied = gtdrv->copyto_auxbuf(comp, buf, format);
- ret = 0;
- break;
+ if (sinkdrv->copyto_auxbuf) {
+ *bytes_copied = sinkdrv->copyto_auxbuf(sink, handle, buf);
+ ret = 0;
+ }
}
out:
- raw_spin_unlock_irqrestore(&sink->lock, flags);
+ raw_spin_unlock_irqrestore(&spriv->lock, flags);
return ret;
}
EXPORT_SYMBOL_GPL(gtrace_path_copyto_auxbuf);
diff --git a/drivers/hwtracing/gtrace/gtrace-perf.c b/drivers/hwtracing/gtrace/gtrace-perf.c
index 604b673a29d5..3c8b620df5a8 100644
--- a/drivers/hwtracing/gtrace/gtrace-perf.c
+++ b/drivers/hwtracing/gtrace/gtrace-perf.c
@@ -243,7 +243,6 @@ static void gtrace_event_stop(struct perf_event *event, int mode)
{
struct gtrace_ctxt *ctxt = this_cpu_ptr(>race_ctxt);
struct perf_output_handle *handle = &ctxt->handle;
- u64 format = PERF_AUX_FLAG_GTRACE_FORMAT_UNKNOWN;
struct gtrace_event_data *event_data;
int ret, cpu = smp_processor_id();
struct gtrace_path *path;
@@ -280,17 +279,11 @@ static void gtrace_event_stop(struct perf_event *event, int mode)
if (handle->event && (mode & PERF_EF_UPDATE)) {
if (WARN_ON_ONCE(handle->event != event))
return;
- ret = gtrace_path_copyto_auxbuf(path, &event_data->buf, &size, &format);
+ ret = gtrace_path_copyto_auxbuf(path, handle, &event_data->buf, &size);
WARN_ON_ONCE(ret);
- if (READ_ONCE(handle->event)) {
- /* Tag the AUX data with the source's trace format. */
- perf_aux_output_flag(handle, format);
- if (size > handle->size) {
- size = handle->size;
- perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
- }
+ if (READ_ONCE(handle->event))
perf_aux_output_end(handle, size);
- } else
+ else
WARN_ON(size);
}
diff --git a/drivers/hwtracing/gtrace/rvtrace-ramsink.c b/drivers/hwtracing/gtrace/rvtrace-ramsink.c
index 9588c32c5b13..e0826d3f0d60 100644
--- a/drivers/hwtracing/gtrace/rvtrace-ramsink.c
+++ b/drivers/hwtracing/gtrace/rvtrace-ramsink.c
@@ -11,6 +11,7 @@
#include <linux/minmax.h>
#include <linux/types.h>
#include <linux/sizes.h>
+#include <linux/perf_event.h>
#include <uapi/linux/perf_event.h>
#include "rvtrace.h"
@@ -147,8 +148,8 @@ static void tbuf_to_pbuf_copy(struct trace_buf *src, struct trace_buf *dst, size
}
static size_t rvtrace_ramsink_copyto_auxbuf(struct gtrace_component *comp,
- struct gtrace_perf_auxbuf *buf,
- u64 *format)
+ struct perf_output_handle *handle,
+ struct gtrace_perf_auxbuf *buf)
{
struct rvtrace_ramsink_priv *priv = dev_get_drvdata(&comp->dev);
struct trace_buf src, dst;
@@ -181,6 +182,11 @@ static size_t rvtrace_ramsink_copyto_auxbuf(struct gtrace_component *comp,
priv->prev_wp = wp;
}
+ if (bytes > handle->size) {
+ bytes = handle->size;
+ perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
+ }
+
tbuf_to_pbuf_copy(&src, &dst, bytes);
dev_dbg(&comp->dev, "Copied %zu bytes\n", bytes);
return bytes;
diff --git a/include/linux/gtrace.h b/include/linux/gtrace.h
index e9210b0a73b5..39ae13701615 100644
--- a/include/linux/gtrace.h
+++ b/include/linux/gtrace.h
@@ -13,6 +13,7 @@
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/types.h>
+#include <linux/perf_event.h>
#define GTRACE_PMU_ATTR_CFG_CONTEXT_SHIFT 1
#define GTRACE_PMU_ATTR_CFG_SYNCMODE_MASK GENMASK(3, 2)
@@ -363,15 +364,16 @@ struct gtrace_perf_auxbuf {
};
int gtrace_path_copyto_auxbuf(struct gtrace_path *path,
+ struct perf_output_handle *handle,
struct gtrace_perf_auxbuf *buf,
- size_t *bytes_copied, u64 *format);
+ size_t *bytes_copied);
/**
* struct gtrace_driver - Representation of a trace driver.
* @id_table: Table to match components handled by the driver.
* @copyto_auxbuf: Callback to copy data into perf AUX buffer. The driver
* reports the PMU specific trace format of the copied data
- * via @format (see PERF_AUX_FLAG_PMU_FORMAT_TYPE_MASK).
+ * via @handle (see PERF_AUX_FLAG_PMU_FORMAT_TYPE_MASK).
* @start: Callback to start tracing.
* @stop: Callback to stop tracing.
* @start_port: Callback to start a specific component port.
@@ -385,8 +387,8 @@ int gtrace_path_copyto_auxbuf(struct gtrace_path *path,
struct gtrace_driver {
const struct gtrace_component_id *id_table;
size_t (*copyto_auxbuf)(struct gtrace_component *comp,
- struct gtrace_perf_auxbuf *buf,
- u64 *format);
+ struct perf_output_handle *handle,
+ struct gtrace_perf_auxbuf *buf);
int (*start)(struct gtrace_component *comp);
int (*stop)(struct gtrace_component *comp);
int (*start_port)(struct gtrace_component *comp,
--
2.34.1
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