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-rw-r--r--arch/x86/mm/kmmio.c88
1 files changed, 59 insertions, 29 deletions
diff --git a/arch/x86/mm/kmmio.c b/arch/x86/mm/kmmio.c
index 637ab34..ddb2244 100644
--- a/arch/x86/mm/kmmio.c
+++ b/arch/x86/mm/kmmio.c
@@ -33,7 +33,7 @@
struct kmmio_fault_page {
struct list_head list;
struct kmmio_fault_page *release_next;
- unsigned long page; /* location of the fault page */
+ unsigned long addr; /* the requested address */
pteval_t old_presence; /* page presence prior to arming */
bool armed;
@@ -70,9 +70,16 @@ unsigned int kmmio_count;
static struct list_head kmmio_page_table[KMMIO_PAGE_TABLE_SIZE];
static LIST_HEAD(kmmio_probes);
-static struct list_head *kmmio_page_list(unsigned long page)
+static struct list_head *kmmio_page_list(unsigned long addr)
{
- return &kmmio_page_table[hash_long(page, KMMIO_PAGE_HASH_BITS)];
+ unsigned int l;
+ pte_t *pte = lookup_address(addr, &l);
+
+ if (!pte)
+ return NULL;
+ addr &= page_level_mask(l);
+
+ return &kmmio_page_table[hash_long(addr, KMMIO_PAGE_HASH_BITS)];
}
/* Accessed per-cpu */
@@ -98,15 +105,19 @@ static struct kmmio_probe *get_kmmio_probe(unsigned long addr)
}
/* You must be holding RCU read lock. */
-static struct kmmio_fault_page *get_kmmio_fault_page(unsigned long page)
+static struct kmmio_fault_page *get_kmmio_fault_page(unsigned long addr)
{
struct list_head *head;
struct kmmio_fault_page *f;
+ unsigned int l;
+ pte_t *pte = lookup_address(addr, &l);
- page &= PAGE_MASK;
- head = kmmio_page_list(page);
+ if (!pte)
+ return NULL;
+ addr &= page_level_mask(l);
+ head = kmmio_page_list(addr);
list_for_each_entry_rcu(f, head, list) {
- if (f->page == page)
+ if (f->addr == addr)
return f;
}
return NULL;
@@ -137,10 +148,10 @@ static void clear_pte_presence(pte_t *pte, bool clear, pteval_t *old)
static int clear_page_presence(struct kmmio_fault_page *f, bool clear)
{
unsigned int level;
- pte_t *pte = lookup_address(f->page, &level);
+ pte_t *pte = lookup_address(f->addr, &level);
if (!pte) {
- pr_err("no pte for page 0x%08lx\n", f->page);
+ pr_err("no pte for addr 0x%08lx\n", f->addr);
return -1;
}
@@ -156,7 +167,7 @@ static int clear_page_presence(struct kmmio_fault_page *f, bool clear)
return -1;
}
- __flush_tlb_one(f->page);
+ __flush_tlb_one(f->addr);
return 0;
}
@@ -176,12 +187,12 @@ static int arm_kmmio_fault_page(struct kmmio_fault_page *f)
int ret;
WARN_ONCE(f->armed, KERN_ERR pr_fmt("kmmio page already armed.\n"));
if (f->armed) {
- pr_warning("double-arm: page 0x%08lx, ref %d, old %d\n",
- f->page, f->count, !!f->old_presence);
+ pr_warning("double-arm: addr 0x%08lx, ref %d, old %d\n",
+ f->addr, f->count, !!f->old_presence);
}
ret = clear_page_presence(f, true);
- WARN_ONCE(ret < 0, KERN_ERR pr_fmt("arming 0x%08lx failed.\n"),
- f->page);
+ WARN_ONCE(ret < 0, KERN_ERR pr_fmt("arming at 0x%08lx failed.\n"),
+ f->addr);
f->armed = true;
return ret;
}
@@ -191,7 +202,7 @@ static void disarm_kmmio_fault_page(struct kmmio_fault_page *f)
{
int ret = clear_page_presence(f, false);
WARN_ONCE(ret < 0,
- KERN_ERR "kmmio disarming 0x%08lx failed.\n", f->page);
+ KERN_ERR "kmmio disarming at 0x%08lx failed.\n", f->addr);
f->armed = false;
}
@@ -215,6 +226,12 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr)
struct kmmio_context *ctx;
struct kmmio_fault_page *faultpage;
int ret = 0; /* default to fault not handled */
+ unsigned long page_base = addr;
+ unsigned int l;
+ pte_t *pte = lookup_address(addr, &l);
+ if (!pte)
+ return -EINVAL;
+ page_base &= page_level_mask(l);
/*
* Preemption is now disabled to prevent process switch during
@@ -227,7 +244,7 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr)
preempt_disable();
rcu_read_lock();
- faultpage = get_kmmio_fault_page(addr);
+ faultpage = get_kmmio_fault_page(page_base);
if (!faultpage) {
/*
* Either this page fault is not caused by kmmio, or
@@ -239,7 +256,7 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr)
ctx = &get_cpu_var(kmmio_ctx);
if (ctx->active) {
- if (addr == ctx->addr) {
+ if (page_base == ctx->addr) {
/*
* A second fault on the same page means some other
* condition needs handling by do_page_fault(), the
@@ -267,9 +284,9 @@ int kmmio_handler(struct pt_regs *regs, unsigned long addr)
ctx->active++;
ctx->fpage = faultpage;
- ctx->probe = get_kmmio_probe(addr);
+ ctx->probe = get_kmmio_probe(page_base);
ctx->saved_flags = (regs->flags & (X86_EFLAGS_TF | X86_EFLAGS_IF));
- ctx->addr = addr;
+ ctx->addr = page_base;
if (ctx->probe && ctx->probe->pre_handler)
ctx->probe->pre_handler(ctx->probe, regs, addr);
@@ -354,12 +371,11 @@ out:
}
/* You must be holding kmmio_lock. */
-static int add_kmmio_fault_page(unsigned long page)
+static int add_kmmio_fault_page(unsigned long addr)
{
struct kmmio_fault_page *f;
- page &= PAGE_MASK;
- f = get_kmmio_fault_page(page);
+ f = get_kmmio_fault_page(addr);
if (f) {
if (!f->count)
arm_kmmio_fault_page(f);
@@ -372,26 +388,25 @@ static int add_kmmio_fault_page(unsigned long page)
return -1;
f->count = 1;
- f->page = page;
+ f->addr = addr;
if (arm_kmmio_fault_page(f)) {
kfree(f);
return -1;
}
- list_add_rcu(&f->list, kmmio_page_list(f->page));
+ list_add_rcu(&f->list, kmmio_page_list(f->addr));
return 0;
}
/* You must be holding kmmio_lock. */
-static void release_kmmio_fault_page(unsigned long page,
+static void release_kmmio_fault_page(unsigned long addr,
struct kmmio_fault_page **release_list)
{
struct kmmio_fault_page *f;
- page &= PAGE_MASK;
- f = get_kmmio_fault_page(page);
+ f = get_kmmio_fault_page(addr);
if (!f)
return;
@@ -420,18 +435,27 @@ int register_kmmio_probe(struct kmmio_probe *p)
int ret = 0;
unsigned long size = 0;
const unsigned long size_lim = p->len + (p->addr & ~PAGE_MASK);
+ unsigned int l;
+ pte_t *pte;
spin_lock_irqsave(&kmmio_lock, flags);
if (get_kmmio_probe(p->addr)) {
ret = -EEXIST;
goto out;
}
+
+ pte = lookup_address(p->addr, &l);
+ if (!pte) {
+ ret = -EINVAL;
+ goto out;
+ }
+
kmmio_count++;
list_add_rcu(&p->list, &kmmio_probes);
while (size < size_lim) {
if (add_kmmio_fault_page(p->addr + size))
pr_err("Unable to set page fault.\n");
- size += PAGE_SIZE;
+ size += page_level_size(l);
}
out:
spin_unlock_irqrestore(&kmmio_lock, flags);
@@ -506,11 +530,17 @@ void unregister_kmmio_probe(struct kmmio_probe *p)
const unsigned long size_lim = p->len + (p->addr & ~PAGE_MASK);
struct kmmio_fault_page *release_list = NULL;
struct kmmio_delayed_release *drelease;
+ unsigned int l;
+ pte_t *pte;
+
+ pte = lookup_address(p->addr, &l);
+ if (!pte)
+ return;
spin_lock_irqsave(&kmmio_lock, flags);
while (size < size_lim) {
release_kmmio_fault_page(p->addr + size, &release_list);
- size += PAGE_SIZE;
+ size += page_level_size(l);
}
list_del_rcu(&p->list);
kmmio_count--;
generated by cgit v0.10.2 at 2024-11-01 19:02:32 (GMT)