From: Liam R. Howlett <Liam.Howlett@Oracle.com>
Date: Tue, 22 Dec 2020 01:59:08 +0000 (-0500)
Subject: linked list mess
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=126aa09dbc6aff9f80c388d559d1d12e1cffc83f;p=users%2Fjedix%2Flinux-maple.git

linked list mess

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---

diff --git a/ipc/shm.c b/ipc/shm.c
index 02f4c9413690..4ad878835209 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -1703,13 +1703,14 @@ long ksys_shmdt(char __user *shmaddr)
 	 * prevent overflows and make comparisons vs. equal-width types.
 	 */
 	size = PAGE_ALIGN(size);
-
-	mas_for_each(&mas, vma, size) {
+	while (vma && (loff_t)(vma->vm_end - addr) <= size) {
 		/* finding a matching vma now does not alter retval */
 		if ((vma->vm_ops == &shm_vm_ops) &&
 		    ((vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) &&
 		    (vma->vm_file == file))
 			do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, NULL);
+
+		vma = mas_find(&mas, addr + size - 1);
 	}
 
 #else	/* CONFIG_MMU */
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 710727741538..1cb3a245ffd8 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2781,7 +2781,6 @@ static void task_numa_work(struct callback_head *work)
 	vma = mas_walk(&mas);
 	if (!vma) {
 		reset_ptenuma_scan(p);
-		mas_reset(&mas);
 		start = 0;
 		mas_set(&mas, start);
 	}
diff --git a/mm/ksm.c b/mm/ksm.c
index 2e9e685c588f..defe9c3eb9a9 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -979,6 +979,7 @@ static int unmerge_and_remove_all_rmap_items(void)
 			mm_slot != &ksm_mm_head; mm_slot = ksm_scan.mm_slot) {
 		mm = mm_slot->mm;
 		mmap_read_lock(mm);
+		mas_set(&mas, 0);
 		mas_for_each(&mas, vma, ULONG_MAX) {
 			if (ksm_test_exit(mm))
 				break;
@@ -2290,12 +2291,9 @@ next_mm:
 	mm = slot->mm;
 	mmap_read_lock(mm);
 	if (ksm_test_exit(mm))
-		vma = NULL;
-	else {
-		mas_set(&mas, ksm_scan.address);
-		vma = mas_find(&mas, ULONG_MAX);
-	}
+		goto no_vmas;
 
+	mas_set(&mas, ksm_scan.address);
 	mas_for_each(&mas, vma, ULONG_MAX) {
 		if (!(vma->vm_flags & VM_MERGEABLE))
 			continue;
@@ -2334,6 +2332,7 @@ next_mm:
 	}
 
 	if (ksm_test_exit(mm)) {
+no_vmas:
 		ksm_scan.address = 0;
 		ksm_scan.rmap_list = &slot->rmap_list;
 	}
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 4757b7939920..e0b8e658f18e 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -820,7 +820,7 @@ static int mbind_range(struct mm_struct *mm, unsigned long start,
 	if (start > vma->vm_start)
 		prev = vma;
 
-	mas_for_each(&mas, vma, end) {
+	mas_for_each(&mas, vma, end - 1) {
 		next = vma_next(mm, vma);
 		vmstart = max(start, vma->vm_start);
 		vmend   = min(end, vma->vm_end);
@@ -850,6 +850,7 @@ static int mbind_range(struct mm_struct *mm, unsigned long start,
 			err = split_vma(vma->vm_mm, vma, vmend, 0);
 			if (err)
 				goto out;
+			mas_pause(&mas);
 		}
  replace:
 		err = vma_replace_policy(vma, new_pol);
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 5492833af73b..a6208b872336 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -550,11 +550,12 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
 	if ((pkey != -1) && !mm_pkey_is_allocated(current->mm, pkey))
 		goto out;
 
+	mas_set(&mas, start);
 	vma = mas_walk(&mas);
 	error = -ENOMEM;
 	if (!vma)
 		goto out;
-	prev = vma_prev(vma->vm_mm, vma);
+	prev = mas_prev(&mas, 0);
 	if (unlikely(grows & PROT_GROWSDOWN)) {
 		if (vma->vm_start >= end)
 			goto out;