x86 mmiotrace: fix page-unaligned ioremaps

mmiotrace_ioremap() expects to receive the original unaligned map phys address
and size. Also fix {un,}register_kmmio_probe() to deal properly with
unaligned size.

Signed-off-by: Pekka Paalanen <pq@iki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 8927c87..a7c80a6 100644 (file)
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -123,6 +123,8 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr,
 {
        unsigned long pfn, offset, vaddr;
        resource_size_t last_addr;
+       const resource_size_t unaligned_phys_addr = phys_addr;
+       const unsigned long unaligned_size = size;
        struct vm_struct *area;
        unsigned long new_prot_val;
        pgprot_t prot;
@@ -236,7 +238,7 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr,
        }
 
        ret_addr = (void __iomem *) (vaddr + offset);
-       mmiotrace_ioremap(phys_addr, size, ret_addr);
+       mmiotrace_ioremap(unaligned_phys_addr, unaligned_size, ret_addr);
 
        return ret_addr;
 }

diff --git a/arch/x86/mm/kmmio.c b/arch/x86/mm/kmmio.c
index 6a92d91..93b1797 100644 (file)
--- 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;
        }

diff --git a/arch/x86/mm/mmio-mod.c b/arch/x86/mm/mmio-mod.c
index a8d2a00..278998c 100644 (file)
--- a/arch/x86/mm/mmio-mod.c
+++ b/arch/x86/mm/mmio-mod.c
@@ -280,6 +280,7 @@ static void ioremap_trace_core(unsigned long offset, unsigned long size,
 {
        static atomic_t next_id;
        struct remap_trace *trace = kmalloc(sizeof(*trace), GFP_KERNEL);
+       /* These are page-unaligned. */
        struct mmiotrace_map map = {
                .phys = offset,
                .virt = (unsigned long)addr,