From 5ec5d38a1c8af255ffc481c81eef13e9155524b3 Mon Sep 17 00:00:00 2001 From: Len Brown Date: Tue, 3 Feb 2009 22:52:12 -0500 Subject: [PATCH] ACPI: make some IO ports off-limits to AML ACPICA exports acpi_os_validate_address() so the OS can prevent BIOS AML from accessing specified addresses. Start using this interface to prevent AML from accessing some well known IO addresses that the OS "owns". Signed-off-by: Len Brown --- drivers/acpi/osl.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c index 6729a4992f2..4fb01b0133c 100644 --- a/drivers/acpi/osl.c +++ b/drivers/acpi/osl.c @@ -1317,6 +1317,54 @@ acpi_os_validate_interface (char *interface) return AE_SUPPORT; } +#ifdef CONFIG_X86 + +struct aml_port_desc { + uint start; + uint end; + char* name; + char warned; +}; + +static struct aml_port_desc aml_invalid_port_list[] = { + {0x20, 0x21, "PIC0", 0}, + {0xA0, 0xA1, "PIC1", 0}, + {0x4D0, 0x4D1, "ELCR", 0} +}; + +/* + * valid_aml_io_address() + * + * if valid, return true + * else invalid, warn once, return false + */ +static bool valid_aml_io_address(uint address, uint length) +{ + int i; + int entries = sizeof(aml_invalid_port_list) / sizeof(struct aml_port_desc); + + for (i = 0; i < entries; ++i) { + if ((address >= aml_invalid_port_list[i].start && + address <= aml_invalid_port_list[i].end) || + (address + length >= aml_invalid_port_list[i].start && + address + length <= aml_invalid_port_list[i].end)) + { + if (!aml_invalid_port_list[i].warned) + { + printk(KERN_ERR "ACPI: Denied BIOS AML access" + " to invalid port 0x%x+0x%x (%s)\n", + address, length, + aml_invalid_port_list[i].name); + aml_invalid_port_list[i].warned = 1; + } + return false; /* invalid */ + } + } + return true; /* valid */ +} +#else +static inline bool valid_aml_io_address(uint address, uint length) { return true; } +#endif /****************************************************************************** * * FUNCTION: acpi_os_validate_address @@ -1346,6 +1394,8 @@ acpi_os_validate_address ( switch (space_id) { case ACPI_ADR_SPACE_SYSTEM_IO: + if (!valid_aml_io_address(address, length)) + return AE_AML_ILLEGAL_ADDRESS; case ACPI_ADR_SPACE_SYSTEM_MEMORY: /* Only interference checks against SystemIO and SytemMemory are needed */ -- 2.41.0