I''ve had these sitting around for a while and only just got round to
posting them.
The second fixes a crash which I''ve only observed on the pvops netback
backported to the XCP kernel but which I believe is valid for upstream
too.
Ian.
The following changes since commit 37089b13602b0ccf44616324fa3a8abd77b610b4:
Bastian Blank (1):
xen/netback: Fix null-pointer access in netback_uevent
are available in the git repository at:
git://xenbits.xensource.com/people/ianc/linux-2.6.git for-jeremy/netback
Ian Campbell (2):
xen: netback: do not unleash netback threads until initialisation is
complete
xen: netback: check if foreign pages are actually netback-created foreign
pages.
drivers/xen/netback/netback.c | 60 ++++++++++++++++++++++++++++------------
1 files changed, 42 insertions(+), 18 deletions(-)
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Ian Campbell
2010-Jul-30 14:16 UTC
[Xen-devel] [PATCH] xen: netback: do not unleash netback threads until initialisation is complete
Otherwise netbk_action_thread can reference &netbk->net_schedule_list
(via tx_work_todo) before it is initialised. Until now it was zeroed
which is probably safe but not exactly robust.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Xu, Dongxiao <dongxiao.xu@intel.com>
Cc: Paul Durrant <Paul.Durrant@citrix.com>
---
drivers/xen/netback/netback.c | 4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)
diff --git a/drivers/xen/netback/netback.c b/drivers/xen/netback/netback.c
index 4121062..0ed7e61 100644
--- a/drivers/xen/netback/netback.c
+++ b/drivers/xen/netback/netback.c
@@ -1781,7 +1781,6 @@ static int __init netback_init(void)
if (!IS_ERR(netbk->kthread.task)) {
kthread_bind(netbk->kthread.task, group);
- wake_up_process(netbk->kthread.task);
} else {
printk(KERN_ALERT
"kthread_run() fails at netback\n");
@@ -1807,6 +1806,9 @@ static int __init netback_init(void)
spin_lock_init(&netbk->net_schedule_list_lock);
atomic_set(&netbk->netfront_count, 0);
+
+ if (MODPARM_netback_kthread)
+ wake_up_process(netbk->kthread.task);
}
netbk_copy_skb_mode = NETBK_DONT_COPY_SKB;
--
1.5.6.5
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Ian Campbell
2010-Jul-30 14:16 UTC
[Xen-devel] [PATCH] xen: netback: check if foreign pages are actually netback-created foreign pages.
020ba906 "xen/netback: Multiple tasklets support." changed
netbk_gop_frag_copy to attempt to lookup a pending_tx_info for any
foreign page, regardless of whether the page was a netback-foreign
page.
In the case of non-netback pages this can lead to dereferencing a NULL
src_pend->netif.
Restore the behaviour of netif_page_index prior toa3031942
"xen/netback: Introduce a new struct type page_ext" by performing
tests to ensure that page is a netback page and extend the same checks
to netif_page_group.
Actually combine netif_page_{index,group} in to a single function
since they are always called together and it saves duplicating all the
checks.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Xu, Dongxiao <dongxiao.xu@intel.com>
---
drivers/xen/netback/netback.c | 56 ++++++++++++++++++++++++++++------------
1 files changed, 39 insertions(+), 17 deletions(-)
diff --git a/drivers/xen/netback/netback.c b/drivers/xen/netback/netback.c
index 0ed7e61..ed7cd65 100644
--- a/drivers/xen/netback/netback.c
+++ b/drivers/xen/netback/netback.c
@@ -89,18 +89,37 @@ static inline void netif_set_page_ext(struct page *pg,
unsigned int group,
pg->mapping = ext.mapping;
}
-static inline unsigned int netif_page_group(const struct page *pg)
+static inline int netif_get_page_ext(struct page *pg, unsigned int *_group,
unsigned int *_idx)
{
union page_ext ext = { .mapping = pg->mapping };
+ struct xen_netbk *netbk;
+ unsigned int group, idx;
- return ext.e.group - 1;
-}
+ if (!PageForeign(pg))
+ return 0;
-static inline unsigned int netif_page_index(const struct page *pg)
-{
- union page_ext ext = { .mapping = pg->mapping };
+ group = ext.e.group - 1;
+
+ if (group < 0 || group >= xen_netbk_group_nr)
+ return 0;
+
+ netbk = &xen_netbk[group];
+
+ if (netbk->mmap_pages == NULL)
+ return 0;
- return ext.e.idx;
+ idx = ext.e.idx;
+
+ if ((idx < 0) || (idx >= MAX_PENDING_REQS))
+ return 0;
+
+ if (netbk->mmap_pages[idx] != pg)
+ return 0;
+
+ *_group = group;
+ *_idx = idx;
+
+ return 1;
}
/*
@@ -386,8 +405,12 @@ static void netbk_gop_frag_copy(struct xen_netif *netif,
{
struct gnttab_copy *copy_gop;
struct netbk_rx_meta *meta;
- int group = netif_page_group(page);
- int idx = netif_page_index(page);
+ /*
+ * These variables a used iff netif_get_page_ext returns true,
+ * in which case they are guaranteed to be initialized.
+ */
+ unsigned int uninitialized_var(group), uninitialized_var(idx);
+ int foreign = netif_get_page_ext(page, &group, &idx);
unsigned long bytes;
/* Data must not cross a page boundary. */
@@ -445,7 +468,7 @@ static void netbk_gop_frag_copy(struct xen_netif *netif,
copy_gop = npo->copy + npo->copy_prod++;
copy_gop->flags = GNTCOPY_dest_gref;
- if (PageForeign(page)) {
+ if (foreign) {
struct xen_netbk *netbk = &xen_netbk[group];
struct pending_tx_info *src_pend;
@@ -1546,14 +1569,13 @@ static void netif_idx_release(struct xen_netbk *netbk,
u16 pending_idx)
static void netif_page_release(struct page *page, unsigned int order)
{
- int group = netif_page_group(page);
- int idx = netif_page_index(page);
- struct xen_netbk *netbk = &xen_netbk[group];
+ unsigned int group, idx;
+ int foreign = netif_get_page_ext(page, &group, &idx);
+
+ BUG_ON(!foreign);
BUG_ON(order);
- BUG_ON(group < 0 || group >= xen_netbk_group_nr);
- BUG_ON(idx < 0 || idx >= MAX_PENDING_REQS);
- BUG_ON(netbk->mmap_pages[idx] != page);
- netif_idx_release(netbk, idx);
+
+ netif_idx_release(&xen_netbk[group], idx);
}
irqreturn_t netif_be_int(int irq, void *dev_id)
--
1.5.6.5
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