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Commit 466b7d16 authored by Shanker Donthineni's avatar Shanker Donthineni Committed by Marc Zyngier
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irqchip/gicv3-its: Don't allow devices whose ID is outside range 



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: default avatarShanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 8cb17b5e

drivers/irqchip/irq-gic-v3-its.c

+38 −4
Original line number Diff line number Diff line
@@ -54,6 +54,16 @@ struct its_collection { 
	u16			col_id;

};



/*

 * 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
@@ -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
@@ -838,6 +846,8 @@ 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);
@@ -913,6 +923,7 @@ static int its_alloc_tables(const char *node_name, struct its_node *its) 
		}



		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);
@@ -1138,9 +1149,22 @@ 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;
@@ -1151,6 +1175,16 @@ 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