From c0b293b38bb29b83372128b61dea61ae30d9c42c Mon Sep 17 00:00:00 2001 From: "Liam R. Howlett" Date: Tue, 15 Nov 2022 10:25:26 -0500 Subject: [PATCH] mmap: Clean up mmap_region() unrolling Move logic of unrolling to the error path as apposed to duplicating it within the function body. This reduces the potential of missing an update to one path when making changes. Cc: Li Zetao Signed-off-by: Liam R. Howlett --- mm/mmap.c | 45 ++++++++++++++++++--------------------------- 1 file changed, 18 insertions(+), 27 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index 8d792a65426c..be9ba141cb6f 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2659,12 +2659,11 @@ cannot_expand: * Expansion is handled above, merging is handled below. * Drivers should not alter the address of the VMA. */ - if (WARN_ON((addr != vma->vm_start))) { - error = -EINVAL; + error = -EINVAL; + if (WARN_ON((addr != vma->vm_start))) goto close_and_free_vma; - } - vma_iter_set(&vmi, addr); + vma_iter_set(&vmi, addr); /* * If vm_flags changed after call_mmap(), we should try merge * vma again as we may succeed this time. @@ -2701,25 +2700,13 @@ cannot_expand: } /* Allow architectures to sanity-check the vm_flags */ - if (!arch_validate_flags(vma->vm_flags)) { - error = -EINVAL; - if (file) - goto close_and_free_vma; - else if (vma->vm_file) - goto unmap_and_free_vma; - else - goto free_vma; - } + error = -EINVAL; + if (!arch_validate_flags(vma->vm_flags)) + goto close_and_free_vma; - if (vma_iter_prealloc(&vmi, vma)) { - error = -ENOMEM; - if (file) - goto close_and_free_vma; - else if (vma->vm_file) - goto unmap_and_free_vma; - else - goto free_vma; - } + error = -ENOMEM; + if (vma_iter_prealloc(&vmi, vma)) + goto close_and_free_vma; if (vma->vm_file) i_mmap_lock_write(vma->vm_file->f_mapping); @@ -2778,14 +2765,18 @@ expanded: return addr; close_and_free_vma: - if (vma->vm_ops && vma->vm_ops->close) + if (file && vma->vm_ops && vma->vm_ops->close) vma->vm_ops->close(vma); + + if (file || vma->vm_file) { unmap_and_free_vma: - fput(vma->vm_file); - vma->vm_file = NULL; + fput(vma->vm_file); + vma->vm_file = NULL; - /* Undo any partial mapping done by a device driver. */ - unmap_region(mm, &mm->mm_mt, vma, prev, next, vma->vm_start, vma->vm_end); + /* Undo any partial mapping done by a device driver. */ + unmap_region(mm, &mm->mm_mt, vma, prev, next, vma->vm_start, + vma->vm_end); + } if (file && (vm_flags & VM_SHARED)) mapping_unmap_writable(file->f_mapping); free_vma: -- 2.49.0