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. Reviewed-by: Eric Auger <[email protected]> Signed-off-by: Shanker Donthineni <[email protected]> --- [v1]->[v2] Rebase to v4.5-rc6, edit commit text and simplify code changes. [v2]->[v3] Fix typo. drivers/irqchip/irq-gic-v3-its.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index 43dfd15..6d986ac 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 table + * entry size in bytes. + */ +struct its_baser { + void *base; + u32 order; + u32 entry_size; +}; + +/* * 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; + struct its_baser *device_table; }; #define ITS_ITT_ALIGN SZ_256 @@ -860,6 +868,7 @@ static int its_alloc_tables(const char *node_name, struct its_node *its) * For other tables, only allocate a single page. */ if (type == GITS_BASER_TYPE_DEVICE) { + its->device_table = &its->tables[i]; /* * 'order' was initialized earlier to the default page * granule of the the ITS. We can't have an allocation @@ -874,6 +883,7 @@ static int its_alloc_tables(const char *node_name, struct its_node *its) node_name, order); } } + its->tables[i].entry_size = entry_size; retry_alloc_baser: alloc_pages = (PAGE_ORDER_TO_SIZE(order) / psz); @@ -1152,6 +1162,12 @@ static struct its_device *its_create_device(struct its_node *its, u32 dev_id, int nr_ites; int sz; + /* Don't allow 'dev_id' that exceeds single, flat table limit */ + if (its->device_table && + (dev_id >= (PAGE_ORDER_TO_SIZE(its->device_table->order) / + its->device_table->entry_size))) + 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
