From akpm@linux-foundation.org Mon Nov 26 15:01:06 2007 From: Fenghua Yu Date: Wed, 21 Nov 2007 15:07:14 -0800 Subject: PCI: More Sanity checks for DMAR To: greg@kroah.com Cc: akpm@linux-foundation.org, fenghua.yu@intel.com, mgross@linux.intel.com Message-ID: <200711212307.lALN7EOX013921@imap1.linux-foundation.org> From: Fenghua Yu Add and changes a few sanity checks in dmar.c. 1. The haw field in ACPI DMAR table in VT-d spec doesn't describe the range of haw. But since DMA page size is 4KB in DMA remapping, haw should be at least 4KB. The current VT-d code in dmar.c returns failure when haw==0. This sanity check is not accurate and execution can pass when haw is less than one page size 4KB. This patch changes the haw sanity check to validate if haw is less than 4KB. 2. Add dmar_rmrr_units verification. 3. Add parse_dmar_table() verification. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Fenghua Yu Acked-by: mark gross Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- drivers/pci/dmar.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) --- a/drivers/pci/dmar.c +++ b/drivers/pci/dmar.c @@ -25,6 +25,7 @@ #include #include +#include "iova.h" #undef PREFIX #define PREFIX "DMAR:" @@ -263,8 +264,8 @@ parse_dmar_table(void) if (!dmar) return -ENODEV; - if (!dmar->width) { - printk (KERN_WARNING PREFIX "Zero: Invalid DMAR haw\n"); + if (dmar->width < PAGE_SHIFT_4K - 1) { + printk(KERN_WARNING PREFIX "Invalid DMAR haw\n"); return -EINVAL; } @@ -301,11 +302,24 @@ parse_dmar_table(void) int __init dmar_table_init(void) { - parse_dmar_table(); + int ret; + + ret = parse_dmar_table(); + if (ret) { + printk(KERN_INFO PREFIX "parse DMAR table failure.\n"); + return ret; + } + if (list_empty(&dmar_drhd_units)) { printk(KERN_INFO PREFIX "No DMAR devices found\n"); return -ENODEV; } + + if (list_empty(&dmar_rmrr_units)) { + printk(KERN_INFO PREFIX "No RMRR found\n"); + return -ENODEV; + } + return 0; }