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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] Introduce some finer-grained locking to prevent calling
# HG changeset patch
# User kaf24@xxxxxxxxxxxxxxxxxxxx
# Node ID 42a70a5297531270612557e49908597e5ddb9ba3
# Parent 1449c89adb8b2221cc49b67c0015ff03d09e4da4
Introduce some finer-grained locking to prevent calling
copy_from/to_user while preventing interrupts and fix allocation of
memory from within a task and other issues.
Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxx>
diff -r 1449c89adb8b -r 42a70a529753
linux-2.6-xen-sparse/drivers/xen/tpmback/common.h
--- a/linux-2.6-xen-sparse/drivers/xen/tpmback/common.h Wed May 03 10:59:54
2006 +0100
+++ b/linux-2.6-xen-sparse/drivers/xen/tpmback/common.h Wed May 03 11:00:57
2006 +0100
@@ -50,6 +50,8 @@ typedef struct tpmif_st {
grant_handle_t shmem_handle;
grant_ref_t shmem_ref;
struct page *pagerange;
+
+ char devname[20];
} tpmif_t;
void tpmif_disconnect_complete(tpmif_t * tpmif);
diff -r 1449c89adb8b -r 42a70a529753
linux-2.6-xen-sparse/drivers/xen/tpmback/interface.c
--- a/linux-2.6-xen-sparse/drivers/xen/tpmback/interface.c Wed May 03
10:59:54 2006 +0100
+++ b/linux-2.6-xen-sparse/drivers/xen/tpmback/interface.c Wed May 03
11:00:57 2006 +0100
@@ -32,6 +32,7 @@ static tpmif_t *alloc_tpmif(domid_t domi
tpmif->domid = domid;
tpmif->status = DISCONNECTED;
tpmif->tpm_instance = instance;
+ snprintf(tpmif->devname, sizeof(tpmif->devname), "tpmif%d", domid);
atomic_set(&tpmif->refcnt, 1);
tpmif->pagerange = balloon_alloc_empty_page_range(TPMIF_TX_RING_SIZE);
@@ -144,7 +145,7 @@ int tpmif_map(tpmif_t *tpmif, unsigned l
tpmif->tx = (tpmif_tx_interface_t *)tpmif->tx_area->addr;
tpmif->irq = bind_evtchn_to_irqhandler(
- tpmif->evtchn, tpmif_be_int, 0, "tpmif-backend", tpmif);
+ tpmif->evtchn, tpmif_be_int, 0, tpmif->devname, tpmif);
tpmif->shmem_ref = shared_page;
tpmif->active = 1;
diff -r 1449c89adb8b -r 42a70a529753
linux-2.6-xen-sparse/drivers/xen/tpmback/tpmback.c
--- a/linux-2.6-xen-sparse/drivers/xen/tpmback/tpmback.c Wed May 03
10:59:54 2006 +0100
+++ b/linux-2.6-xen-sparse/drivers/xen/tpmback/tpmback.c Wed May 03
11:00:57 2006 +0100
@@ -28,7 +28,8 @@ struct data_exchange {
struct list_head pending_pak;
struct list_head current_pak;
unsigned int copied_so_far;
- u8 has_opener;
+ u8 has_opener:1;
+ u8 aborted:1;
rwlock_t pak_lock; // protects all of the previous fields
wait_queue_head_t wait_queue;
};
@@ -101,6 +102,16 @@ static inline int copy_to_buffer(void *t
return 0;
}
+
+static void dataex_init(struct data_exchange *dataex)
+{
+ INIT_LIST_HEAD(&dataex->pending_pak);
+ INIT_LIST_HEAD(&dataex->current_pak);
+ dataex->has_opener = 0;
+ rwlock_init(&dataex->pak_lock);
+ init_waitqueue_head(&dataex->wait_queue);
+}
+
/***************************************************************
Packet-related functions
***************************************************************/
@@ -148,11 +159,12 @@ static struct packet *packet_alloc(tpmif
u32 size, u8 req_tag, u8 flags)
{
struct packet *pak = NULL;
- pak = kzalloc(sizeof (struct packet), GFP_KERNEL);
+ pak = kzalloc(sizeof (struct packet), GFP_ATOMIC);
if (NULL != pak) {
if (tpmif) {
pak->tpmif = tpmif;
pak->tpm_instance = tpmif->tpm_instance;
+ tpmif_get(tpmif);
}
pak->data_len = size;
pak->req_tag = req_tag;
@@ -180,6 +192,9 @@ static void packet_free(struct packet *p
if (timer_pending(&pak->processing_timer)) {
BUG();
}
+
+ if (pak->tpmif)
+ tpmif_put(pak->tpmif);
kfree(pak->data_buffer);
/*
* cannot do tpmif_put(pak->tpmif); bad things happen
@@ -271,7 +286,6 @@ int _packet_write(struct packet *pak,
struct gnttab_map_grant_ref map_op;
struct gnttab_unmap_grant_ref unmap_op;
tpmif_tx_request_t *tx;
- unsigned long pfn, mfn, mfn_orig;
tx = &tpmif->tx->ring[i].req;
@@ -294,12 +308,6 @@ int _packet_write(struct packet *pak,
DPRINTK(" Grant table operation failure !\n");
return 0;
}
-
- pfn = __pa(MMAP_VADDR(tpmif, i)) >> PAGE_SHIFT;
- mfn = FOREIGN_FRAME(map_op.dev_bus_addr >> PAGE_SHIFT);
- mfn_orig = pfn_to_mfn(pfn);
-
- set_phys_to_machine(pfn, mfn);
tocopy = MIN(size - offset, PAGE_SIZE);
@@ -310,8 +318,6 @@ int _packet_write(struct packet *pak,
return -EFAULT;
}
tx->size = tocopy;
-
- set_phys_to_machine(pfn, mfn_orig);
gnttab_set_unmap_op(&unmap_op, MMAP_VADDR(tpmif, i),
GNTMAP_host_map, handle);
@@ -514,27 +520,41 @@ static ssize_t vtpm_op_read(struct file
unsigned long flags;
write_lock_irqsave(&dataex.pak_lock, flags);
+ if (dataex.aborted) {
+ dataex.aborted = 0;
+ dataex.copied_so_far = 0;
+ write_unlock_irqrestore(&dataex.pak_lock, flags);
+ return -EIO;
+ }
if (list_empty(&dataex.pending_pak)) {
write_unlock_irqrestore(&dataex.pak_lock, flags);
wait_event_interruptible(dataex.wait_queue,
!list_empty(&dataex.pending_pak));
write_lock_irqsave(&dataex.pak_lock, flags);
+ dataex.copied_so_far = 0;
}
if (!list_empty(&dataex.pending_pak)) {
unsigned int left;
+
pak = list_entry(dataex.pending_pak.next, struct packet, next);
-
left = pak->data_len - dataex.copied_so_far;
+ list_del(&pak->next);
+ write_unlock_irqrestore(&dataex.pak_lock, flags);
DPRINTK("size given by app: %d, available: %d\n", size, left);
ret_size = MIN(size, left);
ret_size = packet_read(pak, ret_size, data, size, 1);
+
+ write_lock_irqsave(&dataex.pak_lock, flags);
+
if (ret_size < 0) {
- ret_size = -EFAULT;
+ del_singleshot_timer_sync(&pak->processing_timer);
+ packet_free(pak);
+ dataex.copied_so_far = 0;
} else {
DPRINTK("Copied %d bytes to user buffer\n", ret_size);
@@ -545,7 +565,6 @@ static ssize_t vtpm_op_read(struct file
del_singleshot_timer_sync(&pak->
processing_timer);
- list_del(&pak->next);
list_add_tail(&pak->next, &dataex.current_pak);
/*
* The more fontends that are handled at the
same time,
@@ -554,6 +573,8 @@ static ssize_t vtpm_op_read(struct file
mod_timer(&pak->processing_timer,
jiffies + (num_frontends * 60 * HZ));
dataex.copied_so_far = 0;
+ } else {
+ list_add(&pak->next, &dataex.pending_pak);
}
}
}
@@ -601,8 +622,8 @@ static ssize_t vtpm_op_write(struct file
if (pak == NULL) {
write_unlock_irqrestore(&dataex.pak_lock, flags);
- printk(KERN_ALERT "No associated packet! (inst=%d)\n",
- ntohl(vrh.instance_no));
+ DPRINTK(KERN_ALERT "No associated packet! (inst=%d)\n",
+ ntohl(vrh.instance_no));
return -EFAULT;
}
@@ -784,15 +805,17 @@ static int tpm_send_fail_message(struct
return rc;
}
-static void _vtpm_release_packets(struct list_head *head,
- tpmif_t * tpmif, int send_msgs)
-{
+static int _vtpm_release_packets(struct list_head *head,
+ tpmif_t * tpmif, int send_msgs)
+{
+ int aborted = 0;
+ int c = 0;
struct packet *pak;
- struct list_head *pos,
- *tmp;
+ struct list_head *pos, *tmp;
list_for_each_safe(pos, tmp, head) {
pak = list_entry(pos, struct packet, next);
+ c += 1;
if (tpmif == NULL || pak->tpmif == tpmif) {
int can_send = 0;
@@ -808,8 +831,11 @@ static void _vtpm_release_packets(struct
tpm_send_fail_message(pak, pak->req_tag);
}
packet_free(pak);
- }
- }
+ if (c == 1)
+ aborted = 1;
+ }
+ }
+ return aborted;
}
int vtpm_release_packets(tpmif_t * tpmif, int send_msgs)
@@ -818,7 +844,9 @@ int vtpm_release_packets(tpmif_t * tpmif
write_lock_irqsave(&dataex.pak_lock, flags);
- _vtpm_release_packets(&dataex.pending_pak, tpmif, send_msgs);
+ dataex.aborted = _vtpm_release_packets(&dataex.pending_pak,
+ tpmif,
+ send_msgs);
_vtpm_release_packets(&dataex.current_pak, tpmif, send_msgs);
write_unlock_irqrestore(&dataex.pak_lock, flags);
@@ -1020,11 +1048,7 @@ static int __init tpmback_init(void)
return rc;
}
- INIT_LIST_HEAD(&dataex.pending_pak);
- INIT_LIST_HEAD(&dataex.current_pak);
- dataex.has_opener = 0;
- rwlock_init(&dataex.pak_lock);
- init_waitqueue_head(&dataex.wait_queue);
+ dataex_init(&dataex);
spin_lock_init(&tpm_schedule_list_lock);
INIT_LIST_HEAD(&tpm_schedule_list);
@@ -1041,6 +1065,7 @@ module_init(tpmback_init);
static void __exit tpmback_exit(void)
{
+ vtpm_release_packets(NULL, 0);
tpmif_xenbus_exit();
tpmif_interface_exit();
misc_deregister(&vtpms_miscdevice);
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