| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <86802c440709212349l3d968d1bgdc89e7c7415b54da@mail.gmail.com>
Date: Fri, 21 Sep 2007 23:49:19 -0700
From: "Yinghai Lu" <yhlu.kernel@...il.com>
To: "Andi Kleen" <ak@...e.de>
Cc: hancockr@...w.ca, rajesh.shah@...el.com, jbarnes@...tuousgeek.org,
greg@...ah.com, patches@...-64.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] [9/50] i386: validate against ACPI motherboard resources
On 9/21/07, Andi Kleen <ak@...e.de> wrote:
>
> From: Robert Hancock <hancockr@...w.ca>
>
> This path adds validation of the MMCONFIG table against the ACPI reserved
> motherboard resources. If the MMCONFIG table is found to be reserved in
> ACPI, we don't bother checking the E820 table. The PCI Express firmware
> spec apparently tells BIOS developers that reservation in ACPI is required
> and E820 reservation is optional, so checking against ACPI first makes
> sense. Many BIOSes don't reserve the MMCONFIG region in E820 even though
> it is perfectly functional, the existing check needlessly disables MMCONFIG
> in these cases.
>
> In order to do this, MMCONFIG setup has been split into two phases. If PCI
> configuration type 1 is not available then MMCONFIG is enabled early as
> before. Otherwise, it is enabled later after the ACPI interpreter is
> enabled, since we need to be able to execute control methods in order to
> check the ACPI reserved resources. Presently this is just triggered off
> the end of ACPI interpreter initialization.
>
> There are a few other behavioral changes here:
>
> - Validate all MMCONFIG configurations provided, not just the first one.
>
> - Validate the entire required length of each configuration according to
> the provided ending bus number is reserved, not just the minimum required
> allocation.
>
> - Validate that the area is reserved even if we read it from the chipset
> directly and not from the MCFG table. This catches the case where the
> BIOS didn't set the location properly in the chipset and has mapped it
> over other things it shouldn't have.
>
> This also cleans up the MMCONFIG initialization functions so that they
> simply do nothing if MMCONFIG is not compiled in.
>
> Based on an original patch by Rajesh Shah from Intel.
>
> [akpm@...ux-foundation.org: many fixes and cleanups]
> Signed-off-by: Robert Hancock <hancockr@...w.ca>
> Signed-off-by: Andi Kleen <ak@...e.de>
> Cc: Rajesh Shah <rajesh.shah@...el.com>
> Cc: Jesse Barnes <jbarnes@...tuousgeek.org>
> Acked-by: Linus Torvalds <torvalds@...ux-foundation.org>
> Cc: Andi Kleen <ak@...e.de>
> Cc: Greg KH <greg@...ah.com>
> Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
> ---
>
> arch/i386/pci/init.c | 4 -
> arch/i386/pci/mmconfig-shared.c | 151 +++++++++++++++++++++++++++++++++++-----
> arch/i386/pci/pci.h | 1
> drivers/acpi/bus.c | 2
> include/linux/pci.h | 8 ++
> 5 files changed, 144 insertions(+), 22 deletions(-)
>
> Index: linux/arch/i386/pci/init.c
> ===================================================================
> --- linux.orig/arch/i386/pci/init.c
> +++ linux/arch/i386/pci/init.c
> @@ -11,9 +11,7 @@ static __init int pci_access_init(void)
> #ifdef CONFIG_PCI_DIRECT
> type = pci_direct_probe();
> #endif
> -#ifdef CONFIG_PCI_MMCONFIG
> - pci_mmcfg_init(type);
> -#endif
> + pci_mmcfg_early_init(type);
> if (raw_pci_ops)
> return 0;
> #ifdef CONFIG_PCI_BIOS
> Index: linux/arch/i386/pci/mmconfig-shared.c
> ===================================================================
> --- linux.orig/arch/i386/pci/mmconfig-shared.c
> +++ linux/arch/i386/pci/mmconfig-shared.c
> @@ -206,9 +206,78 @@ static void __init pci_mmcfg_insert_reso
> pci_mmcfg_resources_inserted = 1;
> }
>
> -static void __init pci_mmcfg_reject_broken(int type)
> +static acpi_status __init check_mcfg_resource(struct acpi_resource *res,
> + void *data)
> +{
> + struct resource *mcfg_res = data;
> + struct acpi_resource_address64 address;
> + acpi_status status;
> +
> + if (res->type == ACPI_RESOURCE_TYPE_FIXED_MEMORY32) {
> + struct acpi_resource_fixed_memory32 *fixmem32 =
> + &res->data.fixed_memory32;
> + if (!fixmem32)
> + return AE_OK;
> + if ((mcfg_res->start >= fixmem32->address) &&
> + (mcfg_res->end < (fixmem32->address +
> + fixmem32->address_length))) {
> + mcfg_res->flags = 1;
> + return AE_CTRL_TERMINATE;
> + }
> + }
> + if ((res->type != ACPI_RESOURCE_TYPE_ADDRESS32) &&
> + (res->type != ACPI_RESOURCE_TYPE_ADDRESS64))
> + return AE_OK;
> +
> + status = acpi_resource_to_address64(res, &address);
> + if (ACPI_FAILURE(status) ||
> + (address.address_length <= 0) ||
> + (address.resource_type != ACPI_MEMORY_RANGE))
> + return AE_OK;
> +
> + if ((mcfg_res->start >= address.minimum) &&
> + (mcfg_res->end < (address.minimum + address.address_length))) {
> + mcfg_res->flags = 1;
> + return AE_CTRL_TERMINATE;
> + }
> + return AE_OK;
> +}
> +
> +static acpi_status __init find_mboard_resource(acpi_handle handle, u32 lvl,
> + void *context, void **rv)
> +{
> + struct resource *mcfg_res = context;
> +
> + acpi_walk_resources(handle, METHOD_NAME__CRS,
> + check_mcfg_resource, context);
> +
> + if (mcfg_res->flags)
> + return AE_CTRL_TERMINATE;
> +
> + return AE_OK;
> +}
> +
> +static int __init is_acpi_reserved(unsigned long start, unsigned long end)
> +{
> + struct resource mcfg_res;
> +
> + mcfg_res.start = start;
> + mcfg_res.end = end;
> + mcfg_res.flags = 0;
> +
> + acpi_get_devices("PNP0C01", find_mboard_resource, &mcfg_res, NULL);
> +
> + if (!mcfg_res.flags)
> + acpi_get_devices("PNP0C02", find_mboard_resource, &mcfg_res,
> + NULL);
> +
> + return mcfg_res.flags;
> +}
> +
> +static void __init pci_mmcfg_reject_broken(void)
> {
> typeof(pci_mmcfg_config[0]) *cfg;
> + int i;
>
> if ((pci_mmcfg_config_num == 0) ||
> (pci_mmcfg_config == NULL) ||
> @@ -229,17 +298,37 @@ static void __init pci_mmcfg_reject_brok
> goto reject;
> }
>
> - /*
> - * Only do this check when type 1 works. If it doesn't work
> - * assume we run on a Mac and always use MCFG
> - */
> - if (type == 1 && !e820_all_mapped(cfg->address,
> - cfg->address + MMCONFIG_APER_MIN,
> - E820_RESERVED)) {
> - printk(KERN_ERR "PCI: BIOS Bug: MCFG area at %Lx is not"
> - " E820-reserved\n", cfg->address);
> - goto reject;
> + for (i = 0; i < pci_mmcfg_config_num; i++) {
> + u32 size = (cfg->end_bus_number + 1) << 20;
> + cfg = &pci_mmcfg_config[i];
> + printk(KERN_NOTICE "PCI: MCFG configuration %d: base %lu "
> + "segment %hu buses %u - %u\n",
> + i, (unsigned long)cfg->address, cfg->pci_segment,
> + (unsigned int)cfg->start_bus_number,
> + (unsigned int)cfg->end_bus_number);
> + if (is_acpi_reserved(cfg->address, cfg->address + size - 1)) {
> + printk(KERN_NOTICE "PCI: MCFG area at %Lx reserved "
> + "in ACPI motherboard resources\n",
> + cfg->address);
> + } else {
> + printk(KERN_ERR "PCI: BIOS Bug: MCFG area at %Lx is not"
> + " reserved in ACPI motherboard resources\n",
> + cfg->address);
> + /* Don't try to do this check unless configuration
> + type 1 is available. */
> + if ((pci_probe & PCI_PROBE_CONF1) &&
> + e820_all_mapped(cfg->address,
> + cfg->address + size - 1,
> + E820_RESERVED))
> + printk(KERN_NOTICE
> + "PCI: MCFG area at %Lx reserved in "
> + "E820\n",
> + cfg->address);
> + else
> + goto reject;
> + }
> }
> +
> return;
>
> reject:
> @@ -249,20 +338,46 @@ reject:
> pci_mmcfg_config_num = 0;
> }
>
> -void __init pci_mmcfg_init(int type)
> +void __init pci_mmcfg_early_init(int type)
> +{
> + if ((pci_probe & PCI_PROBE_MMCONF) == 0)
> + return;
> +
> + /* If type 1 access is available, no need to enable MMCONFIG yet, we can
> + defer until later when the ACPI interpreter is available to better
> + validate things. */
> + if (type == 1)
> + return;
> +
> + acpi_table_parse(ACPI_SIG_MCFG, acpi_parse_mcfg);
> +
> + if ((pci_mmcfg_config_num == 0) ||
> + (pci_mmcfg_config == NULL) ||
> + (pci_mmcfg_config[0].address == 0))
> + return;
> +
> + if (pci_mmcfg_arch_init())
> + pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
> +}
> +
> +void __init pci_mmcfg_late_init(void)
> {
> int known_bridge = 0;
>
> + /* MMCONFIG disabled */
> if ((pci_probe & PCI_PROBE_MMCONF) == 0)
> return;
>
> - if (type == 1 && pci_mmcfg_check_hostbridge())
> - known_bridge = 1;
> + /* MMCONFIG already enabled */
> + if (!(pci_probe & PCI_PROBE_MASK & ~PCI_PROBE_MMCONF))
> + return;
>
> - if (!known_bridge) {
> + if ((pci_probe & PCI_PROBE_CONF1) && pci_mmcfg_check_hostbridge())
> + known_bridge = 1;
> + else
> acpi_table_parse(ACPI_SIG_MCFG, acpi_parse_mcfg);
> - pci_mmcfg_reject_broken(type);
> - }
> +
> + pci_mmcfg_reject_broken();
>
> if ((pci_mmcfg_config_num == 0) ||
> (pci_mmcfg_config == NULL) ||
> @@ -270,7 +385,7 @@ void __init pci_mmcfg_init(int type)
> return;
>
> if (pci_mmcfg_arch_init()) {
> - if (type == 1)
> + if (pci_probe & PCI_PROBE_CONF1)
> unreachable_devices();
> if (known_bridge)
> pci_mmcfg_insert_resources(IORESOURCE_BUSY);
> Index: linux/arch/i386/pci/pci.h
> ===================================================================
> --- linux.orig/arch/i386/pci/pci.h
> +++ linux/arch/i386/pci/pci.h
> @@ -91,7 +91,6 @@ extern int pci_conf1_read(unsigned int s
> extern int pci_direct_probe(void);
> extern void pci_direct_init(int type);
> extern void pci_pcbios_init(void);
> -extern void pci_mmcfg_init(int type);
> extern void pcibios_sort(void);
>
> /* pci-mmconfig.c */
> Index: linux/drivers/acpi/bus.c
> ===================================================================
> --- linux.orig/drivers/acpi/bus.c
> +++ linux/drivers/acpi/bus.c
> @@ -35,6 +35,7 @@
> #ifdef CONFIG_X86
> #include <asm/mpspec.h>
> #endif
> +#include <linux/pci.h>
> #include <acpi/acpi_bus.h>
> #include <acpi/acpi_drivers.h>
>
> @@ -757,6 +758,7 @@ static int __init acpi_init(void)
> result = acpi_bus_init();
>
> if (!result) {
> + pci_mmcfg_late_init();
No!
MMCONFIG will not work with acpi=off any more.
because acpi_init==>pci_mmcfg_late_init==>pci_mmcfg_check_hostbridge...
can you move pci_mmcfg_later_init out of acpi_init and just call
somewhere after acpi_init...
or put pci_mmcfg_check_hostbridge back to pci_mmcfg_early_init?
YH
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists