From a2b992c828f7651db369ba8f0eb0818d70232636 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 9 Jul 2020 17:42:44 -0700 Subject: debugfs: make sure we can remove u32_array files cleanly debugfs_create_u32_array() allocates a small structure to wrap the data and size information about the array. If users ever try to remove the file this leads to a leak since nothing ever frees this wrapper. That said there are no upstream users of debugfs_create_u32_array() that'd remove a u32 array file (we only have one u32 array user in CMA), so there is no real bug here. Make callers pass a wrapper they allocated. This way the lifetime management of the wrapper is on the caller, and we can avoid the potential leak in debugfs. CC: Chucheng Luo Signed-off-by: Jakub Kicinski Reviewed-by: Greg Kroah-Hartman Signed-off-by: David S. Miller --- Documentation/filesystems/debugfs.rst | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'Documentation/filesystems') diff --git a/Documentation/filesystems/debugfs.rst b/Documentation/filesystems/debugfs.rst index 1da7a4b7383d..728ab57a611a 100644 --- a/Documentation/filesystems/debugfs.rst +++ b/Documentation/filesystems/debugfs.rst @@ -185,13 +185,17 @@ byte offsets over a base for the register block. If you want to dump an u32 array in debugfs, you can create file with:: + struct debugfs_u32_array { + u32 *array; + u32 n_elements; + }; + void debugfs_create_u32_array(const char *name, umode_t mode, struct dentry *parent, - u32 *array, u32 elements); + struct debugfs_u32_array *array); -The "array" argument provides data, and the "elements" argument is -the number of elements in the array. Note: Once array is created its -size can not be changed. +The "array" argument wraps a pointer to the array's data and the number +of its elements. Note: Once array is created its size can not be changed. There is a helper function to create device related seq_file:: -- cgit v1.2.3