Hi Souptick, On Thu, Feb 07, 2019 at 09:19:47PM +0530, Souptick Joarder wrote: > Hi Mike, > > Just thought to take opinion for documentation before placing it in v3. > Does it looks fine ? Overall looks good to me. Several minor points below. > +/** > + * __vm_insert_range - insert range of kernel pages into user vma > + * @vma: user vma to map to > + * @pages: pointer to array of source kernel pages > + * @num: number of pages in page array > + * @offset: user's requested vm_pgoff > + * > + * This allow drivers to insert range of kernel pages into a user vma. allows > + * > + * Return: 0 on success and error code otherwise. > + */ > +static int __vm_insert_range(struct vm_area_struct *vma, struct page **pages, > + unsigned long num, unsigned long offset) > > > +/** > + * vm_insert_range - insert range of kernel pages starts with non zero offset > + * @vma: user vma to map to > + * @pages: pointer to array of source kernel pages > + * @num: number of pages in page array > + * > + * Maps an object consisting of `num' `pages', catering for the user's @num pages > + * requested vm_pgoff > + * > + * If we fail to insert any page into the vma, the function will return > + * immediately leaving any previously inserted pages present. Callers > + * from the mmap handler may immediately return the error as their caller > + * will destroy the vma, removing any successfully inserted pages. Other > + * callers should make their own arrangements for calling unmap_region(). > + * > + * Context: Process context. Called by mmap handlers. > + * Return: 0 on success and error code otherwise. > + */ > +int vm_insert_range(struct vm_area_struct *vma, struct page **pages, > + unsigned long num) > > > +/** > + * vm_insert_range_buggy - insert range of kernel pages starts with zero offset > + * @vma: user vma to map to > + * @pages: pointer to array of source kernel pages > + * @num: number of pages in page array > + * > + * Similar to vm_insert_range(), except that it explicitly sets @vm_pgoff to the offset > + * 0. This function is intended for the drivers that did not consider > + * @vm_pgoff. > + * > + * Context: Process context. Called by mmap handlers. > + * Return: 0 on success and error code otherwise. > + */ > +int vm_insert_range_buggy(struct vm_area_struct *vma, struct page **pages, > + unsigned long num) > -- Sincerely yours, Mike.