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Commit e523b38e authored by David Woodhouse's avatar David Woodhouse
Browse files

intel-iommu: Avoid panic() for DRHD at address zero. 



If the BIOS does something obviously stupid, like claiming that the
registers for the IOMMU are at physical address zero, then print a nasty
message and abort, rather than trying to set up the IOMMU and then later
panicking.

It's becoming more and more obvious that trusting this stuff to the BIOS
was a mistake.

Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent 31d3568d

drivers/pci/dmar.c

+10 −1
Original line number Diff line number Diff line
@@ -173,12 +173,21 @@ dmar_parse_one_drhd(struct acpi_dmar_header *header) 
	struct dmar_drhd_unit *dmaru;

	int ret = 0;



	drhd = (struct acpi_dmar_hardware_unit *)header;

	if (!drhd->address) {

		/* Promote an attitude of violence to a BIOS engineer today */

		WARN(1, "Your BIOS is broken; DMAR reported at address zero!\n"

		     "BIOS vendor: %s; Ver: %s; Product Version: %s\n",

		     dmi_get_system_info(DMI_BIOS_VENDOR),

		     dmi_get_system_info(DMI_BIOS_VERSION),

		     dmi_get_system_info(DMI_PRODUCT_VERSION));

		return -ENODEV;

	}

	dmaru = kzalloc(sizeof(*dmaru), GFP_KERNEL);

	if (!dmaru)

		return -ENOMEM;



	dmaru->hdr = header;

	drhd = (struct acpi_dmar_hardware_unit *)header;

	dmaru->reg_base_addr = drhd->address;

	dmaru->segment = drhd->segment;

	dmaru->include_all = drhd->flags & 0x1; /* BIT0: INCLUDE_ALL */