diff options
Diffstat (limited to 'tools/testing/vma/vma.c')
| -rw-r--r-- | tools/testing/vma/vma.c | 166 |
1 files changed, 128 insertions, 38 deletions
diff --git a/tools/testing/vma/vma.c b/tools/testing/vma/vma.c index 25a95d9901ea..c53f220eb6cc 100644 --- a/tools/testing/vma/vma.c +++ b/tools/testing/vma/vma.c @@ -387,6 +387,9 @@ static bool test_merge_new(void) struct anon_vma_chain dummy_anon_vma_chain_d = { .anon_vma = &dummy_anon_vma, }; + const struct vm_operations_struct vm_ops = { + .close = dummy_close, + }; int count; struct vm_area_struct *vma, *vma_a, *vma_b, *vma_c, *vma_d; bool merged; @@ -430,6 +433,7 @@ static bool test_merge_new(void) * 0123456789abc * AA*B DD CC */ + vma_a->vm_ops = &vm_ops; /* This should have no impact. */ vma_b->anon_vma = &dummy_anon_vma; vma = try_merge_new_vma(&mm, &vmg, 0x2000, 0x3000, 2, flags, &merged); ASSERT_EQ(vma, vma_a); @@ -466,6 +470,7 @@ static bool test_merge_new(void) * AAAAA *DD CC */ vma_d->anon_vma = &dummy_anon_vma; + vma_d->vm_ops = &vm_ops; /* This should have no impact. */ vma = try_merge_new_vma(&mm, &vmg, 0x6000, 0x7000, 6, flags, &merged); ASSERT_EQ(vma, vma_d); /* Prepend. */ @@ -483,6 +488,7 @@ static bool test_merge_new(void) * 0123456789abc * AAAAA*DDD CC */ + vma_d->vm_ops = NULL; /* This would otherwise degrade the merge. */ vma = try_merge_new_vma(&mm, &vmg, 0x5000, 0x6000, 5, flags, &merged); ASSERT_EQ(vma, vma_a); /* Merge with A, delete D. */ @@ -640,13 +646,11 @@ static bool test_vma_merge_with_close(void) const struct vm_operations_struct vm_ops = { .close = dummy_close, }; - struct vm_area_struct *vma_next = - alloc_and_link_vma(&mm, 0x2000, 0x3000, 2, flags); - struct vm_area_struct *vma; + struct vm_area_struct *vma_prev, *vma_next, *vma; /* - * When we merge VMAs we sometimes have to delete others as part of the - * operation. + * When merging VMAs we are not permitted to remove any VMA that has a + * vm_ops->close() hook. * * Considering the two possible adjacent VMAs to which a VMA can be * merged: @@ -697,28 +701,52 @@ static bool test_vma_merge_with_close(void) * would be set too, and thus scenario A would pick this up. */ - ASSERT_NE(vma_next, NULL); - /* - * SCENARIO A + * The only case of a new VMA merge that results in a VMA being deleted + * is one where both the previous and next VMAs are merged - in this + * instance the next VMA is deleted, and the previous VMA is extended. * - * 0123 - * *N + * If we are unable to do so, we reduce the operation to simply + * extending the prev VMA and not merging next. + * + * 0123456789 + * PPP**NNNN + * -> + * 0123456789 + * PPPPPPNNN */ - /* Make the next VMA have a close() callback. */ + vma_prev = alloc_and_link_vma(&mm, 0, 0x3000, 0, flags); + vma_next = alloc_and_link_vma(&mm, 0x5000, 0x9000, 5, flags); vma_next->vm_ops = &vm_ops; - /* Our proposed VMA has characteristics that would otherwise be merged. */ - vmg_set_range(&vmg, 0x1000, 0x2000, 1, flags); + vmg_set_range(&vmg, 0x3000, 0x5000, 3, flags); + ASSERT_EQ(merge_new(&vmg), vma_prev); + ASSERT_EQ(vmg.state, VMA_MERGE_SUCCESS); + ASSERT_EQ(vma_prev->vm_start, 0); + ASSERT_EQ(vma_prev->vm_end, 0x5000); + ASSERT_EQ(vma_prev->vm_pgoff, 0); - /* The next VMA having a close() operator should cause the merge to fail.*/ - ASSERT_EQ(merge_new(&vmg), NULL); - ASSERT_EQ(vmg.state, VMA_MERGE_NOMERGE); + ASSERT_EQ(cleanup_mm(&mm, &vmi), 2); - /* Now create the VMA so we can merge via modified flags */ - vmg_set_range(&vmg, 0x1000, 0x2000, 1, flags); - vma = alloc_and_link_vma(&mm, 0x1000, 0x2000, 1, flags); + /* + * When modifying an existing VMA there are further cases where we + * delete VMAs. + * + * <> + * 0123456789 + * PPPVV + * + * In this instance, if vma has a close hook, the merge simply cannot + * proceed. + */ + + vma_prev = alloc_and_link_vma(&mm, 0, 0x3000, 0, flags); + vma = alloc_and_link_vma(&mm, 0x3000, 0x5000, 3, flags); + vma->vm_ops = &vm_ops; + + vmg_set_range(&vmg, 0x3000, 0x5000, 3, flags); + vmg.prev = vma_prev; vmg.vma = vma; /* @@ -728,38 +756,90 @@ static bool test_vma_merge_with_close(void) ASSERT_EQ(merge_existing(&vmg), NULL); ASSERT_EQ(vmg.state, VMA_MERGE_NOMERGE); - /* SCENARIO B + ASSERT_EQ(cleanup_mm(&mm, &vmi), 2); + + /* + * This case is mirrored if merging with next. * - * 0123 - * P* + * <> + * 0123456789 + * VVNNNN * - * In order for this scenario to trigger, the VMA currently being - * modified must also have a .close(). + * In this instance, if vma has a close hook, the merge simply cannot + * proceed. */ - /* Reset VMG state. */ - vmg_set_range(&vmg, 0x1000, 0x2000, 1, flags); - /* - * Make next unmergeable, and don't let the scenario A check pick this - * up, we want to reproduce scenario B only. - */ - vma_next->vm_ops = NULL; - vma_next->__vm_flags &= ~VM_MAYWRITE; - /* Allocate prev. */ - vmg.prev = alloc_and_link_vma(&mm, 0, 0x1000, 0, flags); - /* Assign a vm_ops->close() function to VMA explicitly. */ + vma = alloc_and_link_vma(&mm, 0x3000, 0x5000, 3, flags); + vma_next = alloc_and_link_vma(&mm, 0x5000, 0x9000, 5, flags); vma->vm_ops = &vm_ops; + + vmg_set_range(&vmg, 0x3000, 0x5000, 3, flags); vmg.vma = vma; - /* Make sure merge does not occur. */ ASSERT_EQ(merge_existing(&vmg), NULL); /* * 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); + ASSERT_EQ(vmg.state, VMA_MERGE_NOMERGE); + + ASSERT_EQ(cleanup_mm(&mm, &vmi), 2); + + /* + * Finally, we consider two variants of the case where we modify a VMA + * to merge with both the previous and next VMAs. + * + * The first variant is where vma has a close hook. In this instance, no + * merge can proceed. + * + * <> + * 0123456789 + * PPPVVNNNN + */ + + vma_prev = alloc_and_link_vma(&mm, 0, 0x3000, 0, flags); + vma = alloc_and_link_vma(&mm, 0x3000, 0x5000, 3, flags); + vma_next = alloc_and_link_vma(&mm, 0x5000, 0x9000, 5, flags); + vma->vm_ops = &vm_ops; + + vmg_set_range(&vmg, 0x3000, 0x5000, 3, flags); + vmg.prev = vma_prev; + vmg.vma = vma; + + ASSERT_EQ(merge_existing(&vmg), NULL); + ASSERT_EQ(vmg.state, VMA_MERGE_NOMERGE); + + ASSERT_EQ(cleanup_mm(&mm, &vmi), 3); + + /* + * The second variant is where next has a close hook. In this instance, + * we reduce the operation to a merge between prev and vma. + * + * <> + * 0123456789 + * PPPVVNNNN + * -> + * 0123456789 + * PPPPPNNNN + */ + + vma_prev = alloc_and_link_vma(&mm, 0, 0x3000, 0, flags); + vma = alloc_and_link_vma(&mm, 0x3000, 0x5000, 3, flags); + vma_next = alloc_and_link_vma(&mm, 0x5000, 0x9000, 5, flags); + vma_next->vm_ops = &vm_ops; + + vmg_set_range(&vmg, 0x3000, 0x5000, 3, flags); + vmg.prev = vma_prev; + vmg.vma = vma; + + ASSERT_EQ(merge_existing(&vmg), vma_prev); + ASSERT_EQ(vmg.state, VMA_MERGE_SUCCESS); + ASSERT_EQ(vma_prev->vm_start, 0); + ASSERT_EQ(vma_prev->vm_end, 0x5000); + ASSERT_EQ(vma_prev->vm_pgoff, 0); + + ASSERT_EQ(cleanup_mm(&mm, &vmi), 2); - cleanup_mm(&mm, &vmi); return true; } @@ -828,6 +908,9 @@ static bool test_merge_existing(void) .mm = &mm, .vmi = &vmi, }; + const struct vm_operations_struct vm_ops = { + .close = dummy_close, + }; /* * Merge right case - partial span. @@ -840,7 +923,9 @@ static bool test_merge_existing(void) * VNNNNNN */ vma = alloc_and_link_vma(&mm, 0x2000, 0x6000, 2, flags); + vma->vm_ops = &vm_ops; /* This should have no impact. */ vma_next = alloc_and_link_vma(&mm, 0x6000, 0x9000, 6, flags); + vma_next->vm_ops = &vm_ops; /* This should have no impact. */ vmg_set_range(&vmg, 0x3000, 0x6000, 3, flags); vmg.vma = vma; vmg.prev = vma; @@ -873,6 +958,7 @@ static bool test_merge_existing(void) */ vma = alloc_and_link_vma(&mm, 0x2000, 0x6000, 2, flags); vma_next = alloc_and_link_vma(&mm, 0x6000, 0x9000, 6, flags); + vma_next->vm_ops = &vm_ops; /* This should have no impact. */ vmg_set_range(&vmg, 0x2000, 0x6000, 2, flags); vmg.vma = vma; vma->anon_vma = &dummy_anon_vma; @@ -899,7 +985,9 @@ static bool test_merge_existing(void) * PPPPPPV */ vma_prev = alloc_and_link_vma(&mm, 0, 0x3000, 0, flags); + vma_prev->vm_ops = &vm_ops; /* This should have no impact. */ vma = alloc_and_link_vma(&mm, 0x3000, 0x7000, 3, flags); + vma->vm_ops = &vm_ops; /* This should have no impact. */ vmg_set_range(&vmg, 0x3000, 0x6000, 3, flags); vmg.prev = vma_prev; vmg.vma = vma; @@ -932,6 +1020,7 @@ static bool test_merge_existing(void) * PPPPPPP */ vma_prev = alloc_and_link_vma(&mm, 0, 0x3000, 0, flags); + vma_prev->vm_ops = &vm_ops; /* This should have no impact. */ vma = alloc_and_link_vma(&mm, 0x3000, 0x7000, 3, flags); vmg_set_range(&vmg, 0x3000, 0x7000, 3, flags); vmg.prev = vma_prev; @@ -960,6 +1049,7 @@ static bool test_merge_existing(void) * PPPPPPPPPP */ vma_prev = alloc_and_link_vma(&mm, 0, 0x3000, 0, flags); + vma_prev->vm_ops = &vm_ops; /* This should have no impact. */ vma = alloc_and_link_vma(&mm, 0x3000, 0x7000, 3, flags); vma_next = alloc_and_link_vma(&mm, 0x7000, 0x9000, 7, flags); vmg_set_range(&vmg, 0x3000, 0x7000, 3, flags); |