[PATCH v5 1/2] devcoredump: Add dev_coredumpm_timeout()

José Roberto de Souza
2024-06-10T16:11:43Z

Add function to set a custom coredump timeout.

For Xe driver usage, current 5 minutes timeout may be too short for
users to search and understand what needs to be done to capture
coredump to report bugs.

We have plans to automate(distribute a udev script) it but at the end
will be up to distros and users to pack it so having a option to
increase the timeout is a safer option.

v2:
- replace dev_coredump_timeout_set() by dev_coredumpm_timeout() (Mukesh)

v3:
- make dev_coredumpm() static inline (Johannes)

v5:
- rename DEVCOREDUMP_TIMEOUT -> DEVCD_TIMEOUT to avoid redefinition
in include/net/bluetooth/coredump.h

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Mukesh Ojha <quic_mojha@quicinc.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Jonathan Cavitt <jonathan.cavitt@intel.com>
Acked-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
---
drivers/base/devcoredump.c | 23 ++++++++--------
include/linux/devcoredump.h | 54 ++++++++++++++++++++++++++++---------
2 files changed, 54 insertions(+), 23 deletions(-)

diff --git a/drivers/base/devcoredump.c b/drivers/base/devcoredump.c
index 82aeb09b3d1b5..c795edad1b969 100644
--- a/drivers/base/devcoredump.c
+++ b/drivers/base/devcoredump.c
@@ -18,9 +18,6 @@ static struct class devcd_class;
/* global disable flag, for security purposes */
static bool devcd_disabled;

-/* if data isn't read by userspace after 5 minutes then delete it */
-#define DEVCD_TIMEOUT (HZ * 60 * 5)
-
struct devcd_entry {
struct device devcd_dev;
void *data;
@@ -328,7 +325,8 @@ void dev_coredump_put(struct device *dev)
EXPORT_SYMBOL_GPL(dev_coredump_put);

/**
- * dev_coredumpm - create device coredump with read/free methods
+ * dev_coredumpm_timeout - create device coredump with read/free methods with a
+ * custom timeout.
* @dev: the struct device for the crashed device
* @owner: the module that contains the read/free functions, use %THIS_MODULE
* @data: data cookie for the @read/@free functions
@@ -336,17 +334,20 @@ EXPORT_SYMBOL_GPL(dev_coredump_put);
* @gfp: allocation flags
* @read: function to read from the given buffer
* @free: function to free the given buffer
+ * @timeout: time in jiffies to remove coredump
*
* Creates a new device coredump for the given device. If a previous one hasn't
* been read yet, the new coredump is discarded. The data lifetime is determined
* by the device coredump framework and when it is no longer needed the @free
* function will be called to free the data.
*/
-void dev_coredumpm(struct device *dev, struct module *owner,
- void *data, size_t datalen, gfp_t gfp,
- ssize_t (*read)(char *buffer, loff_t offset, size_t count,
- void *data, size_t datalen),
- void (*free)(void *data))
+void dev_coredumpm_timeout(struct device *dev, struct module *owner,
+ void *data, size_t datalen, gfp_t gfp,
+ ssize_t (*read)(char *buffer, loff_t offset,
+ size_t count, void *data,
+ size_t datalen),
+ void (*free)(void *data),
+ unsigned long timeout)
{
static atomic_t devcd_count = ATOMIC_INIT(0);
struct devcd_entry *devcd;
@@ -403,7 +404,7 @@ void dev_coredumpm(struct device *dev, struct module *owner,
dev_set_uevent_suppress(&devcd->devcd_dev, false);
kobject_uevent(&devcd->devcd_dev.kobj, KOBJ_ADD);
INIT_DELAYED_WORK(&devcd->del_wk, devcd_del);
- schedule_delayed_work(&devcd->del_wk, DEVCD_TIMEOUT);
+ schedule_delayed_work(&devcd->del_wk, timeout);
mutex_unlock(&devcd->mutex);
return;
put_device:
@@ -414,7 +415,7 @@ void dev_coredumpm(struct device *dev, struct module *owner,
free:
free(data);
}
-EXPORT_SYMBOL_GPL(dev_coredumpm);
+EXPORT_SYMBOL_GPL(dev_coredumpm_timeout);

/**
* dev_coredumpsg - create device coredump that uses scatterlist as data
diff --git a/include/linux/devcoredump.h b/include/linux/devcoredump.h
index c8f7eb6cc1915..e3de1e545a4a5 100644
--- a/include/linux/devcoredump.h
+++ b/include/linux/devcoredump.h
@@ -12,6 +12,9 @@
#include <linux/scatterlist.h>
#include <linux/slab.h>

+/* if data isn't read by userspace after 5 minutes then delete it */
+#define DEVCD_TIMEOUT (HZ * 60 * 5)
+
/*
* _devcd_free_sgtable - free all the memory of the given scatterlist table
* (i.e. both pages and scatterlist instances)
@@ -50,16 +53,17 @@ static inline void _devcd_free_sgtable(struct scatterlist *table)
kfree(delete_iter);
}

-
#ifdef CONFIG_DEV_COREDUMP
void dev_coredumpv(struct device *dev, void *data, size_t datalen,
gfp_t gfp);

-void dev_coredumpm(struct device *dev, struct module *owner,
- void *data, size_t datalen, gfp_t gfp,
- ssize_t (*read)(char *buffer, loff_t offset, size_t count,
- void *data, size_t datalen),
- void (*free)(void *data));
+void dev_coredumpm_timeout(struct device *dev, struct module *owner,
+ void *data, size_t datalen, gfp_t gfp,
+ ssize_t (*read)(char *buffer, loff_t offset,
+ size_t count, void *data,
+ size_t datalen),
+ void (*free)(void *data),
+ unsigned long timeout);

void dev_coredumpsg(struct device *dev, struct scatterlist *table,
size_t datalen, gfp_t gfp);
@@ -72,12 +76,13 @@ static inline void dev_coredumpv(struct device *dev, void *data,
vfree(data);
}

-static inline void
-dev_coredumpm(struct device *dev, struct module *owner,
- void *data, size_t datalen, gfp_t gfp,
- ssize_t (*read)(char *buffer, loff_t offset, size_t count,
- void *data, size_t datalen),
- void (*free)(void *data))
+void dev_coredumpm_timeout(struct device *dev, struct module *owner,
+ void *data, size_t datalen, gfp_t gfp,
+ ssize_t (*read)(char *buffer, loff_t offset,
+ size_t count, void *data,
+ size_t datalen),
+ void (*free)(void *data),
+ unsigned long timeout)
{
free(data);
}
@@ -92,4 +97,29 @@ static inline void dev_coredump_put(struct device *dev)
}
#endif /* CONFIG_DEV_COREDUMP */

+/**
+ * dev_coredumpm - create device coredump with read/free methods
+ * @dev: the struct device for the crashed device
+ * @owner: the module that contains the read/free functions, use %THIS_MODULE
+ * @data: data cookie for the @read/@free functions
+ * @datalen: length of the data
+ * @gfp: allocation flags
+ * @read: function to read from the given buffer
+ * @free: function to free the given buffer
+ *
+ * Creates a new device coredump for the given device. If a previous one hasn't
+ * been read yet, the new coredump is discarded. The data lifetime is determined
+ * by the device coredump framework and when it is no longer needed the @free
+ * function will be called to free the data.
+ */
+static inline void dev_coredumpm(struct device *dev, struct module *owner,
+ void *data, size_t datalen, gfp_t gfp,
+ ssize_t (*read)(char *buffer, loff_t offset, size_t count,
+ void *data, size_t datalen),
+ void (*free)(void *data))
+{
+ dev_coredumpm_timeout(dev, owner, data, datalen, gfp, read, free,
+ DEVCD_TIMEOUT);
+}
+
#endif /* __DEVCOREDUMP_H */
--
2.45.2