devcoredump: Add dev_coredumpm_timeout()

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

v6:
- fix definition of dev_coredumpm_timeout() when CONFIG_DEV_COREDUMP
is disabled

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>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20240611174716.72660-1-jose.souza@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

1 files changed, 42 insertions, 11 deletions

diff --git a/include/linux/devcoredump.h b/include/linux/devcoredump.h
index c8f7eb6cc191..377892604ff4 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);
@@ -73,11 +77,13 @@ static inline void dev_coredumpv(struct device *dev, void *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(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 +98,29 @@ 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 */