From b68f007ad8ec30e567b42f839268e89ad2cabd63 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Tue, 5 May 2009 09:25:28 +0100 Subject: [PATCH] intel-iommu: Avoid panic() for DRHD at address zero. (cherry picked from commit e523b38e2f568af58baa13120a994cbf24e6dee0) 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: David Woodhouse Signed-off-by: Greg Kroah-Hartman --- drivers/pci/dmar.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/pci/dmar.c b/drivers/pci/dmar.c index 26c536b51c5ac..8a011207b154d 100644 --- a/drivers/pci/dmar.c +++ b/drivers/pci/dmar.c @@ -170,12 +170,21 @@ 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->include_all = drhd->flags & 0x1; /* BIT0: INCLUDE_ALL */ -- 2.47.2