From cc8cb3697a8d8eabe1fb9acb8768b11c1ab607d8 Mon Sep 17 00:00:00 2001 From: Lorenzo Stoakes Date: Fri, 30 Aug 2024 19:10:21 +0100 Subject: mm: refactor vma_merge() into modify-only vma_merge_existing_range() The existing vma_merge() function is no longer required to handle what were previously referred to as cases 1-3 (i.e. the merging of a new VMA), as this is now handled by vma_merge_new_vma(). Additionally, simplify the convoluted control flow of the original, maintaining identical logic only expressed more clearly and doing away with a complicated set of cases, rather logically examining each possible outcome - merging of both the previous and subsequent VMA, merging of the previous VMA and merging of the subsequent VMA alone. We now utilise the previously implemented commit_merge() function to share logic with vma_expand() de-duplicating code and providing less surface area for bugs and confusion. In order to do so, we adjust this function to accept parameters specific to merging existing ranges. Link: https://lkml.kernel.org/r/2cf6016b7bfcc4965fc3cde10827560c42e4f12c.1725040657.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes Cc: Liam R. Howlett Cc: Mark Brown Cc: Vlastimil Babka Cc: Bert Karwatzki Cc: Jeff Xu Cc: Jiri Olsa Cc: Kees Cook Cc: Lorenzo Stoakes Cc: Matthew Wilcox Cc: "Paul E. McKenney" Cc: Paul Moore Cc: Sidhartha Kumar Cc: Suren Baghdasaryan Signed-off-by: Andrew Morton --- tools/testing/vma/vma.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'tools/testing/vma') diff --git a/tools/testing/vma/vma.c b/tools/testing/vma/vma.c index b7cdafec09af..25a95d9901ea 100644 --- a/tools/testing/vma/vma.c +++ b/tools/testing/vma/vma.c @@ -112,7 +112,7 @@ static struct vm_area_struct *merge_new(struct vma_merge_struct *vmg) */ static struct vm_area_struct *merge_existing(struct vma_merge_struct *vmg) { - return vma_merge(vmg); + return vma_merge_existing_range(vmg); } /* @@ -752,7 +752,12 @@ static bool test_vma_merge_with_close(void) vmg.vma = vma; /* Make sure merge does not occur. */ ASSERT_EQ(merge_existing(&vmg), NULL); - ASSERT_EQ(vmg.state, VMA_MERGE_NOMERGE); + /* + * Initially this is misapprehended as an out of memory report, as the + * close() check is handled in the same way as anon_vma duplication + * failures, however a subsequent patch resolves this. + */ + ASSERT_EQ(vmg.state, VMA_MERGE_ERROR_NOMEM); cleanup_mm(&mm, &vmi); return true; -- cgit v1.2.3