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Diffstat (limited to 'arch/x86/mm/kmmio.c')
-rw-r--r--arch/x86/mm/kmmio.c13
1 files changed, 11 insertions, 2 deletions
diff --git a/arch/x86/mm/kmmio.c b/arch/x86/mm/kmmio.c
index 6a92d9111b64..93b1797666cb 100644
--- a/arch/x86/mm/kmmio.c
+++ b/arch/x86/mm/kmmio.c
@@ -351,11 +351,19 @@ static void release_kmmio_fault_page(unsigned long page,
}
}
+/*
+ * With page-unaligned ioremaps, one or two armed pages may contain
+ * addresses from outside the intended mapping. Events for these addresses
+ * are currently silently dropped. The events may result only from programming
+ * mistakes by accessing addresses before the beginning or past the end of a
+ * mapping.
+ */
int register_kmmio_probe(struct kmmio_probe *p)
{
unsigned long flags;
int ret = 0;
unsigned long size = 0;
+ const unsigned long size_lim = p->len + (p->addr & ~PAGE_MASK);
spin_lock_irqsave(&kmmio_lock, flags);
if (get_kmmio_probe(p->addr)) {
@@ -364,7 +372,7 @@ int register_kmmio_probe(struct kmmio_probe *p)
}
kmmio_count++;
list_add_rcu(&p->list, &kmmio_probes);
- while (size < p->len) {
+ while (size < size_lim) {
if (add_kmmio_fault_page(p->addr + size))
pr_err("kmmio: Unable to set page fault.\n");
size += PAGE_SIZE;
@@ -436,11 +444,12 @@ void unregister_kmmio_probe(struct kmmio_probe *p)
{
unsigned long flags;
unsigned long size = 0;
+ const unsigned long size_lim = p->len + (p->addr & ~PAGE_MASK);
struct kmmio_fault_page *release_list = NULL;
struct kmmio_delayed_release *drelease;
spin_lock_irqsave(&kmmio_lock, flags);
- while (size < p->len) {
+ while (size < size_lim) {
release_kmmio_fault_page(p->addr + size, &release_list);
size += PAGE_SIZE;
}
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