From 331843c845d15413e9d89fd91cdcfa6912e291c3 Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Wed, 4 Jun 2025 17:23:37 -0700 Subject: scatterlist: fix extraneous '@'-sign kernel-doc notation Using "@argname@" in kernel-doc produces "argname****" (with "argname" in bold) in the generated html output, so use the expected kernel-doc notation of just "@argname" instead. "Fixes:" lines are added in case Matthew's patch [1] is backported. Link: https://lkml.kernel.org/r/20250605002337.2842659-1-rdunlap@infradead.org Link: https://lore.kernel.org/linux-doc/3bc4e779-7a79-42c1-8867-024f643a22fc@infradead.org/T/#m5d2bd9d21fb34f297aa4e7db069f09bc27b89007 [1] Fixes: 0db9299f48eb ("SG: Move functions to lib/scatterlist.c and add sg chaining allocator helpers") Fixes: 8d1d4b538bb1 ("scatterlist: inline sg_next()") Fixes: 18dabf473e15 ("Change table chaining layout") Signed-off-by: Randy Dunlap Reviewed-by: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton --- include/linux/scatterlist.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index 0cdbfc42f153..6f8a4965f9b9 100644 --- a/include/linux/scatterlist.h +++ b/include/linux/scatterlist.h @@ -99,7 +99,7 @@ static inline bool sg_is_last(struct scatterlist *sg) * @sg: The current sg entry * * Description: - * Usually the next entry will be @sg@ + 1, but if this sg element is part + * Usually the next entry will be @sg + 1, but if this sg element is part * of a chained scatterlist, it could jump to the start of a new * scatterlist array. * @@ -254,7 +254,7 @@ static inline void __sg_chain(struct scatterlist *chain_sg, * @sgl: Second scatterlist * * Description: - * Links @prv@ and @sgl@ together, to form a longer scatterlist. + * Links @prv and @sgl together, to form a longer scatterlist. * **/ static inline void sg_chain(struct scatterlist *prv, unsigned int prv_nents, -- cgit v1.2.3 From bb666b7c27073b986b75699e51a7102910f58060 Mon Sep 17 00:00:00 2001 From: Lorenzo Stoakes Date: Mon, 9 Jun 2025 17:57:49 +0100 Subject: mm: add mmap_prepare() compatibility layer for nested file systems Nested file systems, that is those which invoke call_mmap() within their own f_op->mmap() handlers, may encounter underlying file systems which provide the f_op->mmap_prepare() hook introduced by commit c84bf6dd2b83 ("mm: introduce new .mmap_prepare() file callback"). We have a chicken-and-egg scenario here - until all file systems are converted to using .mmap_prepare(), we cannot convert these nested handlers, as we can't call f_op->mmap from an .mmap_prepare() hook. So we have to do it the other way round - invoke the .mmap_prepare() hook from an .mmap() one. in order to do so, we need to convert VMA state into a struct vm_area_desc descriptor, invoking the underlying file system's f_op->mmap_prepare() callback passing a pointer to this, and then setting VMA state accordingly and safely. This patch achieves this via the compat_vma_mmap_prepare() function, which we invoke from call_mmap() if f_op->mmap_prepare() is specified in the passed in file pointer. We place the fundamental logic into mm/vma.h where VMA manipulation belongs. We also update the VMA userland tests to accommodate the changes. The compat_vma_mmap_prepare() function and its associated machinery is temporary, and will be removed once the conversion of file systems is complete. We carefully place this code so it can be used with CONFIG_MMU and also with cutting edge nommu silicon. [akpm@linux-foundation.org: export compat_vma_mmap_prepare tp fix build] [lorenzo.stoakes@oracle.com: remove unused declarations] Link: https://lkml.kernel.org/r/ac3ae324-4c65-432a-8c6d-2af988b18ac8@lucifer.local Link: https://lkml.kernel.org/r/20250609165749.344976-1-lorenzo.stoakes@oracle.com Fixes: c84bf6dd2b83 ("mm: introduce new .mmap_prepare() file callback"). Signed-off-by: Lorenzo Stoakes Reported-by: Jann Horn Closes: https://lore.kernel.org/linux-mm/CAG48ez04yOEVx1ekzOChARDDBZzAKwet8PEoPM4Ln3_rk91AzQ@mail.gmail.com/ Reviewed-by: Pedro Falcato Reviewed-by: Vlastimil Babka Cc: Al Viro Cc: Christian Brauner Cc: Jan Kara Cc: Jann Horn Cc: Liam Howlett Signed-off-by: Andrew Morton --- include/linux/fs.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/fs.h b/include/linux/fs.h index 96c7925a6551..4ec77da65f14 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2274,10 +2274,12 @@ static inline bool file_has_valid_mmap_hooks(struct file *file) return true; } +int compat_vma_mmap_prepare(struct file *file, struct vm_area_struct *vma); + static inline int call_mmap(struct file *file, struct vm_area_struct *vma) { - if (WARN_ON_ONCE(file->f_op->mmap_prepare)) - return -EINVAL; + if (file->f_op->mmap_prepare) + return compat_vma_mmap_prepare(file, vma); return file->f_op->mmap(file, vma); } -- cgit v1.2.3