From 310adfdd9153f6ae818981a38a48dd2330990d8d Mon Sep 17 00:00:00 2001 From: Muli Ben-Yehuda Date: Tue, 13 Feb 2007 13:26:24 +0100 Subject: [PATCH] [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 for the suggestion. Signed-off-by: Muli Ben-Yehuda Signed-off-by: Andi Kleen Cc: Leo Duran Cc: Job Mason --- arch/x86_64/kernel/pci-calgary.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/arch/x86_64/kernel/pci-calgary.c b/arch/x86_64/kernel/pci-calgary.c index 3d65b1d4c2b3..04480c3b68f5 100644 --- a/arch/x86_64/kernel/pci-calgary.c +++ b/arch/x86_64/kernel/pci-calgary.c @@ -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;