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Commit 310adfdd authored by Muli Ben-Yehuda's avatar Muli Ben-Yehuda Committed by Andi Kleen
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[PATCH] x86-64: robustify bad_dma_address handling 



- set bad_dma_address explicitly to 0x0
- reserve 32 pages from bad_dma_address and up
- WARN_ON() a driver feeding us bad_dma_address

Thanks to Leo Duran <leo.duran@amd.com> for the suggestion.

Signed-off-by: default avatarMuli Ben-Yehuda <muli@il.ibm.com>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Cc: Leo Duran <leo.duran@amd.com>
Cc: Job Mason <jdmason@kudzu.us>
parent 2fa8a050

arch/x86_64/kernel/pci-calgary.c

+15 −2
Original line number Diff line number Diff line
@@ -138,6 +138,8 @@ static const unsigned long phb_debug_offsets[] = { 


#define PHB_DEBUG_STUFF_OFFSET	0x0020



#define EMERGENCY_PAGES 32 /* = 128KB */



unsigned int specified_table_size = TCE_TABLE_SIZE_UNSPECIFIED;

static int translate_empty_slots __read_mostly = 0;

static int calgary_detected __read_mostly = 0;
@@ -296,6 +298,16 @@ static void __iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr, 
{

	unsigned long entry;

	unsigned long badbit;

	unsigned long badend;



	/* were we called with bad_dma_address? */

	badend = bad_dma_address + (EMERGENCY_PAGES * PAGE_SIZE);

	if (unlikely((dma_addr >= bad_dma_address) && (dma_addr < badend))) {

		printk(KERN_ERR "Calgary: driver tried unmapping bad DMA "

		       "address 0x%Lx\n", dma_addr);

		WARN_ON(1);

		return;

	}



	entry = dma_addr >> PAGE_SHIFT;
@@ -656,8 +668,8 @@ static void __init calgary_reserve_regions(struct pci_dev *dev) 
	u64 start;

	struct iommu_table *tbl = dev->sysdata;



	/* reserve bad_dma_address in case it's a legal address */

	iommu_range_reserve(tbl, bad_dma_address, 1);

	/* reserve EMERGENCY_PAGES from bad_dma_address and up */

	iommu_range_reserve(tbl, bad_dma_address, EMERGENCY_PAGES);



	/* avoid the BIOS/VGA first 640KB-1MB region */

	start = (640 * 1024);
@@ -1176,6 +1188,7 @@ int __init calgary_iommu_init(void) 
	}



	force_iommu = 1;

	bad_dma_address = 0x0;

	dma_ops = &calgary_dma_ops;



	return 0;