[PATCH v3 1/4] devcoredump: Add dev_coredump_put()

From: José Roberto de Souza
Date: Mon Mar 04 2024 - 09:39:30 EST


It is useful for modules that do not want to keep coredump available
after its unload.
Otherwise, the coredump would only be removed after DEVCD_TIMEOUT
seconds.

v2:
- dev_coredump_put() documentation updated (Mukesh)

Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
Cc: Mukesh Ojha <quic_mojha@xxxxxxxxxxx>
Cc: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
Cc: Jonathan Cavitt <jonathan.cavitt@xxxxxxxxx>
Acked-by: Jonathan Cavitt <jonathan.cavitt@xxxxxxxxx>
Signed-off-by: José Roberto de Souza <jose.souza@xxxxxxxxx>
---
drivers/base/devcoredump.c | 23 +++++++++++++++++++++++
include/linux/devcoredump.h | 5 +++++
2 files changed, 28 insertions(+)

diff --git a/drivers/base/devcoredump.c b/drivers/base/devcoredump.c
index 7e2d1f0d903a6..82aeb09b3d1b5 100644
--- a/drivers/base/devcoredump.c
+++ b/drivers/base/devcoredump.c
@@ -304,6 +304,29 @@ static ssize_t devcd_read_from_sgtable(char *buffer, loff_t offset,
offset);
}

+/**
+ * dev_coredump_put - remove device coredump
+ * @dev: the struct device for the crashed device
+ *
+ * dev_coredump_put() removes coredump, if exists, for a given device from
+ * the file system and free its associated data otherwise, does nothing.
+ *
+ * It is useful for modules that do not want to keep coredump
+ * available after its unload.
+ */
+void dev_coredump_put(struct device *dev)
+{
+ struct device *existing;
+
+ existing = class_find_device(&devcd_class, NULL, dev,
+ devcd_match_failing);
+ if (existing) {
+ devcd_free(existing, NULL);
+ put_device(existing);
+ }
+}
+EXPORT_SYMBOL_GPL(dev_coredump_put);
+
/**
* dev_coredumpm - create device coredump with read/free methods
* @dev: the struct device for the crashed device
diff --git a/include/linux/devcoredump.h b/include/linux/devcoredump.h
index c008169ed2c6f..c8f7eb6cc1915 100644
--- a/include/linux/devcoredump.h
+++ b/include/linux/devcoredump.h
@@ -63,6 +63,8 @@ void dev_coredumpm(struct device *dev, struct module *owner,

void dev_coredumpsg(struct device *dev, struct scatterlist *table,
size_t datalen, gfp_t gfp);
+
+void dev_coredump_put(struct device *dev);
#else
static inline void dev_coredumpv(struct device *dev, void *data,
size_t datalen, gfp_t gfp)
@@ -85,6 +87,9 @@ static inline void dev_coredumpsg(struct device *dev, struct scatterlist *table,
{
_devcd_free_sgtable(table);
}
+static inline void dev_coredump_put(struct device *dev)
+{
+}
#endif /* CONFIG_DEV_COREDUMP */

#endif /* __DEVCOREDUMP_H */
--
2.44.0