We are not checking whether the requested device identifier fits into
the device table memory or not. The function its_create_device()
assumes that enough memory has been allocated for whole DevID space
(reported by ITS_TYPER.Devbits) during the ITS probe() and continues
to initialize ITS hardware.
This assumption is not perfect, sometimes we reduce memory size either
because of its size crossing MAX_ORDER-1 or BASERn max size limit. The
MAPD command fails if 'Device ID' is outside of device table range.
Add a simple validation check to avoid MAPD failures since we are
not handling ITS command errors. This change also helps to return an
error -ENOMEM instead of success to caller.
Signed-off-by: Shanker Donthineni <[email protected]>
---
[v3]->[v4]
Cleanup code based on Marc's comments, remove the variable
'device_table' and extend validation check to cover case ITS
HW with on-chip device table memory.
[v2]->[v3]
Fix typo.
[v1]->[v2]
Rebase to v4.5-rc6, edit commit text and simplify code changes.
drivers/irqchip/irq-gic-v3-its.c | 42 ++++++++++++++++++++++++++++++++++++----
1 file changed, 38 insertions(+), 4 deletions(-)
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 43dfd15..d50d837 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -55,6 +55,16 @@ struct its_collection {
};
/*
+ * The ITS_BASER structure - contains memory information and cached
+ * value of BASER register configuration.
+ */
+struct its_baser {
+ void *base;
+ u64 val;
+ u32 order;
+};
+
+/*
* The ITS structure - contains most of the infrastructure, with the
* top-level MSI domain, the command queue, the collections, and the
* list of devices writing to it.
@@ -66,14 +76,12 @@ struct its_node {
unsigned long phys_base;
struct its_cmd_block *cmd_base;
struct its_cmd_block *cmd_write;
- struct {
- void *base;
- u32 order;
- } tables[GITS_BASER_NR_REGS];
+ struct its_baser tables[GITS_BASER_NR_REGS];
struct its_collection *collections;
struct list_head its_device_list;
u64 flags;
u32 ite_size;
+ u32 device_ids;
};
#define ITS_ITT_ALIGN SZ_256
@@ -839,6 +847,8 @@ static int its_alloc_tables(const char *node_name, struct its_node *its)
ids = GITS_TYPER_DEVBITS(typer);
}
+ its->device_ids = ids;
+
for (i = 0; i < GITS_BASER_NR_REGS; i++) {
u64 val = readq_relaxed(its->base + GITS_BASER + i * 8);
u64 type = GITS_BASER_TYPE(val);
@@ -914,6 +924,7 @@ retry_baser:
}
val |= alloc_pages - 1;
+ its->tables[i].val = val;
writeq_relaxed(val, its->base + GITS_BASER + i * 8);
tmp = readq_relaxed(its->base + GITS_BASER + i * 8);
@@ -1139,9 +1150,22 @@ static struct its_device *its_find_device(struct its_node *its, u32 dev_id)
return its_dev;
}
+static struct its_baser *its_get_baser(struct its_node *its, u32 type)
+{
+ int i;
+
+ for (i = 0; i < GITS_BASER_NR_REGS; i++) {
+ if (GITS_BASER_TYPE(its->tables[i].val) == type)
+ return &its->tables[i];
+ }
+
+ return NULL;
+}
+
static struct its_device *its_create_device(struct its_node *its, u32 dev_id,
int nvecs)
{
+ struct its_baser *baser;
struct its_device *dev;
unsigned long *lpi_map;
unsigned long flags;
@@ -1152,6 +1176,16 @@ static struct its_device *its_create_device(struct its_node *its, u32 dev_id,
int nr_ites;
int sz;
+ baser = its_get_baser(its, GITS_BASER_TYPE_DEVICE);
+
+ /* Don't allow 'dev_id' that exceeds single, flat table limit */
+ if (baser) {
+ if (dev_id >= (PAGE_ORDER_TO_SIZE(baser->order) /
+ GITS_BASER_ENTRY_SIZE(baser->val)))
+ return NULL;
+ } else if (ilog2(dev_id) >= its->device_ids)
+ return NULL;
+
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
/*
* At least one bit of EventID is being used, hence a minimum
--
Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project
On 17/03/16 15:18, Shanker Donthineni wrote:
> We are not checking whether the requested device identifier fits into
> the device table memory or not. The function its_create_device()
> assumes that enough memory has been allocated for whole DevID space
> (reported by ITS_TYPER.Devbits) during the ITS probe() and continues
> to initialize ITS hardware.
>
> This assumption is not perfect, sometimes we reduce memory size either
> because of its size crossing MAX_ORDER-1 or BASERn max size limit. The
> MAPD command fails if 'Device ID' is outside of device table range.
>
> Add a simple validation check to avoid MAPD failures since we are
> not handling ITS command errors. This change also helps to return an
> error -ENOMEM instead of success to caller.
>
> Signed-off-by: Shanker Donthineni <[email protected]>
Is there any difference between this patch and the one you posted on
March 10th?
Thanks,
M.
--
Jazz is not dead. It just smells funny...
Hi Marc,
Sorry, absolutely It was my mistake sending the same patch second time.
On 03/17/2016 10:34 AM, Marc Zyngier wrote:
> On 17/03/16 15:18, Shanker Donthineni wrote:
>> We are not checking whether the requested device identifier fits into
>> the device table memory or not. The function its_create_device()
>> assumes that enough memory has been allocated for whole DevID space
>> (reported by ITS_TYPER.Devbits) during the ITS probe() and continues
>> to initialize ITS hardware.
>>
>> This assumption is not perfect, sometimes we reduce memory size either
>> because of its size crossing MAX_ORDER-1 or BASERn max size limit. The
>> MAPD command fails if 'Device ID' is outside of device table range.
>>
>> Add a simple validation check to avoid MAPD failures since we are
>> not handling ITS command errors. This change also helps to return an
>> error -ENOMEM instead of success to caller.
>>
>> Signed-off-by: Shanker Donthineni <[email protected]>
> Is there any difference between this patch and the one you posted on
> March 10th?
>
> Thanks,
>
> M.
--
Shanker Donthineni
Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project