diff options
Diffstat (limited to 'mm/util.c')
| -rw-r--r-- | mm/util.c | 146 |
1 files changed, 135 insertions, 11 deletions
diff --git a/mm/util.c b/mm/util.c index 8989d5767528..97cae40c0209 100644 --- a/mm/util.c +++ b/mm/util.c @@ -1135,7 +1135,7 @@ EXPORT_SYMBOL(flush_dcache_folio); #endif /** - * __compat_vma_mmap_prepare() - See description for compat_vma_mmap_prepare() + * __compat_vma_mmap() - See description for compat_vma_mmap() * for details. This is the same operation, only with a specific file operations * struct which may or may not be the same as vma->vm_file->f_op. * @f_op: The file operations whose .mmap_prepare() hook is specified. @@ -1143,7 +1143,7 @@ EXPORT_SYMBOL(flush_dcache_folio); * @vma: The VMA to apply the .mmap_prepare() hook to. * Returns: 0 on success or error. */ -int __compat_vma_mmap_prepare(const struct file_operations *f_op, +int __compat_vma_mmap(const struct file_operations *f_op, struct file *file, struct vm_area_struct *vma) { struct vm_area_desc desc = { @@ -1156,21 +1156,24 @@ int __compat_vma_mmap_prepare(const struct file_operations *f_op, .vm_file = vma->vm_file, .vm_flags = vma->vm_flags, .page_prot = vma->vm_page_prot, + + .action.type = MMAP_NOTHING, /* Default */ }; int err; err = f_op->mmap_prepare(&desc); if (err) return err; - set_vma_from_desc(vma, &desc); - return 0; + mmap_action_prepare(&desc.action, &desc); + set_vma_from_desc(vma, &desc); + return mmap_action_complete(&desc.action, vma); } -EXPORT_SYMBOL(__compat_vma_mmap_prepare); +EXPORT_SYMBOL(__compat_vma_mmap); /** - * compat_vma_mmap_prepare() - Apply the file's .mmap_prepare() hook to an - * existing VMA. + * compat_vma_mmap() - Apply the file's .mmap_prepare() hook to an + * existing VMA and execute any requested actions. * @file: The file which possesss an f_op->mmap_prepare() hook. * @vma: The VMA to apply the .mmap_prepare() hook to. * @@ -1185,7 +1188,7 @@ EXPORT_SYMBOL(__compat_vma_mmap_prepare); * .mmap_prepare() hook, as we are in a different context when we invoke the * .mmap() hook, already having a VMA to deal with. * - * compat_vma_mmap_prepare() is a compatibility function that takes VMA state, + * compat_vma_mmap() is a compatibility function that takes VMA state, * establishes a struct vm_area_desc descriptor, passes to the underlying * .mmap_prepare() hook and applies any changes performed by it. * @@ -1194,11 +1197,11 @@ EXPORT_SYMBOL(__compat_vma_mmap_prepare); * * Returns: 0 on success or error. */ -int compat_vma_mmap_prepare(struct file *file, struct vm_area_struct *vma) +int compat_vma_mmap(struct file *file, struct vm_area_struct *vma) { - return __compat_vma_mmap_prepare(file->f_op, file, vma); + return __compat_vma_mmap(file->f_op, file, vma); } -EXPORT_SYMBOL(compat_vma_mmap_prepare); +EXPORT_SYMBOL(compat_vma_mmap); static void set_ps_flags(struct page_snapshot *ps, const struct folio *folio, const struct page *page) @@ -1280,6 +1283,127 @@ again: } } +static int mmap_action_finish(struct mmap_action *action, + const struct vm_area_struct *vma, int err) +{ + /* + * If an error occurs, unmap the VMA altogether and return an error. We + * only clear the newly allocated VMA, since this function is only + * invoked if we do NOT merge, so we only clean up the VMA we created. + */ + if (err) { + const size_t len = vma_pages(vma) << PAGE_SHIFT; + + do_munmap(current->mm, vma->vm_start, len, NULL); + + if (action->error_hook) { + /* We may want to filter the error. */ + err = action->error_hook(err); + + /* The caller should not clear the error. */ + VM_WARN_ON_ONCE(!err); + } + return err; + } + + if (action->success_hook) + return action->success_hook(vma); + + return 0; +} + +#ifdef CONFIG_MMU +/** + * mmap_action_prepare - Perform preparatory setup for an VMA descriptor + * action which need to be performed. + * @desc: The VMA descriptor to prepare for @action. + * @action: The action to perform. + */ +void mmap_action_prepare(struct mmap_action *action, + struct vm_area_desc *desc) +{ + switch (action->type) { + case MMAP_NOTHING: + break; + case MMAP_REMAP_PFN: + remap_pfn_range_prepare(desc, action->remap.start_pfn); + break; + case MMAP_IO_REMAP_PFN: + io_remap_pfn_range_prepare(desc, action->remap.start_pfn, + action->remap.size); + break; + } +} +EXPORT_SYMBOL(mmap_action_prepare); + +/** + * mmap_action_complete - Execute VMA descriptor action. + * @action: The action to perform. + * @vma: The VMA to perform the action upon. + * + * Similar to mmap_action_prepare(). + * + * Return: 0 on success, or error, at which point the VMA will be unmapped. + */ +int mmap_action_complete(struct mmap_action *action, + struct vm_area_struct *vma) +{ + int err = 0; + + switch (action->type) { + case MMAP_NOTHING: + break; + case MMAP_REMAP_PFN: + err = remap_pfn_range_complete(vma, action->remap.start, + action->remap.start_pfn, action->remap.size, + action->remap.pgprot); + break; + case MMAP_IO_REMAP_PFN: + err = io_remap_pfn_range_complete(vma, action->remap.start, + action->remap.start_pfn, action->remap.size, + action->remap.pgprot); + break; + } + + return mmap_action_finish(action, vma, err); +} +EXPORT_SYMBOL(mmap_action_complete); +#else +void mmap_action_prepare(struct mmap_action *action, + struct vm_area_desc *desc) +{ + switch (action->type) { + case MMAP_NOTHING: + break; + case MMAP_REMAP_PFN: + case MMAP_IO_REMAP_PFN: + WARN_ON_ONCE(1); /* nommu cannot handle these. */ + break; + } +} +EXPORT_SYMBOL(mmap_action_prepare); + +int mmap_action_complete(struct mmap_action *action, + struct vm_area_struct *vma) +{ + int err = 0; + + switch (action->type) { + case MMAP_NOTHING: + break; + case MMAP_REMAP_PFN: + case MMAP_IO_REMAP_PFN: + WARN_ON_ONCE(1); /* nommu cannot handle this. */ + + err = -EINVAL; + break; + } + + return mmap_action_finish(action, vma, err); +} +EXPORT_SYMBOL(mmap_action_complete); +#endif + #ifdef CONFIG_MMU /** * folio_pte_batch - detect a PTE batch for a large folio |