diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/Kconfig | 26 | ||||
| -rw-r--r-- | arch/x86/kernel/setup.c | 80 |
2 files changed, 83 insertions, 23 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 1bb52e2ca02..cbee4199689 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -201,9 +201,6 @@ config X86_TRAMPOLINE depends on X86_SMP || (X86_VOYAGER && SMP) || (64BIT && ACPI_SLEEP) default y -config X86_CHECK_BIOS_CORRUPTION - def_bool y - config KTIME_SCALAR def_bool X86_32 source "init/Kconfig" @@ -1062,6 +1059,29 @@ config HIGHPTE low memory. Setting this option will put user-space page table entries in high memory. +config X86_CHECK_BIOS_CORRUPTION + bool "Check for low memory corruption" + default y + help + Periodically check for memory corruption in low memory, which + is suspected to be caused by BIOS. Even when enabled in the + configuration, it is disabled at runtime. Enable it by + setting "memory_corruption_check=1" on the kernel command + line. By default it scans the low 64k of memory every 60 + seconds; see the memory_corruption_check_size and + memory_corruption_check_period parameters in + Documentation/kernel-parameters.txt to adjust this. + + When enabled with the default parameters, this option has + almost no overhead, as it reserves a relatively small amount + of memory and scans it infrequently. It both detects corruption + and prevents it from affecting the running system. + + It is, however, intended as a diagnostic tool; if repeatable + BIOS-originated corruption always affects the same memory, + you can use memmap= to prevent the kernel from using that + memory. + config MATH_EMULATION bool prompt "Math emulation" if X86_32 diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index c239b378097..27ae9128885 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -586,22 +586,71 @@ struct x86_quirks *x86_quirks __initdata = &default_x86_quirks; */ #ifdef CONFIG_X86_CHECK_BIOS_CORRUPTION #define MAX_SCAN_AREAS 8 + +static int __read_mostly memory_corruption_check = 0; +static unsigned __read_mostly corruption_check_size = 64*1024; +static unsigned __read_mostly corruption_check_period = 60; /* seconds */ + static struct e820entry scan_areas[MAX_SCAN_AREAS]; static int num_scan_areas; + +static int set_corruption_check(char *arg) +{ + char *end; + + memory_corruption_check = simple_strtol(arg, &end, 10); + + return (*end == 0) ? 0 : -EINVAL; +} +early_param("memory_corruption_check", set_corruption_check); + +static int set_corruption_check_period(char *arg) +{ + char *end; + + corruption_check_period = simple_strtoul(arg, &end, 10); + + return (*end == 0) ? 0 : -EINVAL; +} +early_param("memory_corruption_check_period", set_corruption_check_period); + +static int set_corruption_check_size(char *arg) +{ + char *end; + unsigned size; + + size = memparse(arg, &end); + + if (*end == '\0') + corruption_check_size = size; + + return (size == corruption_check_size) ? 0 : -EINVAL; +} +early_param("memory_corruption_check_size", set_corruption_check_size); + + static void __init setup_bios_corruption_check(void) { u64 addr = PAGE_SIZE; /* assume first page is reserved anyway */ - while(addr < 0x10000 && num_scan_areas < MAX_SCAN_AREAS) { + if (corruption_check_size == 0) + memory_corruption_check = 0; + + if (!memory_corruption_check) + return; + + corruption_check_size = round_up(corruption_check_size, PAGE_SIZE); + + while(addr < corruption_check_size && num_scan_areas < MAX_SCAN_AREAS) { u64 size; addr = find_e820_area_size(addr, &size, PAGE_SIZE); if (addr == 0) break; - if ((addr + size) > 0x10000) - size = 0x10000 - addr; + if ((addr + size) > corruption_check_size) + size = corruption_check_size - addr; if (size == 0) break; @@ -617,12 +666,11 @@ static void __init setup_bios_corruption_check(void) addr += size; } - printk(KERN_INFO "scanning %d areas for BIOS corruption\n", + printk(KERN_INFO "Scanning %d areas for low memory corruption\n", num_scan_areas); update_e820(); } -static int __read_mostly bios_corruption_check = 1; static struct timer_list periodic_check_timer; void check_for_bios_corruption(void) @@ -630,7 +678,7 @@ void check_for_bios_corruption(void) int i; int corruption = 0; - if (!bios_corruption_check) + if (!memory_corruption_check) return; for(i = 0; i < num_scan_areas; i++) { @@ -647,35 +695,27 @@ void check_for_bios_corruption(void) } } - if (corruption) - dump_stack(); + WARN(corruption, KERN_ERR "Memory corruption detected in low memory\n"); } static void periodic_check_for_corruption(unsigned long data) { check_for_bios_corruption(); - mod_timer(&periodic_check_timer, jiffies + 60*HZ); + mod_timer(&periodic_check_timer, jiffies + corruption_check_period*HZ); } void start_periodic_check_for_corruption(void) { - if (!bios_corruption_check) + if (!memory_corruption_check || corruption_check_period == 0) return; + printk(KERN_INFO "Scanning for low memory corruption every %d seconds\n", + corruption_check_period); + init_timer(&periodic_check_timer); periodic_check_timer.function = &periodic_check_for_corruption; periodic_check_for_corruption(0); } - -static int set_bios_corruption_check(char *arg) -{ - char *end; - - bios_corruption_check = simple_strtol(arg, &end, 10); - - return (*end == 0) ? 0 : -EINVAL; -} -early_param("bios_corruption_check", set_bios_corruption_check); #endif /* |