From 39b8931b5cad9a7cbcd2394a40a088311e783a82 Mon Sep 17 00:00:00 2001 From: Fenghua Yu Date: Mon, 9 Jun 2008 16:48:18 -0700 Subject: ACPI: handle invalid ACPI SLIT table This is a SLIT sanity checking patch. It moves slit_valid() function to generic ACPI code and does sanity checking for both x86 and ia64. It sets up node_distance with LOCAL_DISTANCE and REMOTE_DISTANCE when hitting invalid SLIT table on ia64. It also cleans up unused variable localities in acpi_parse_slit() on x86. Signed-off-by: Fenghua Yu Signed-off-by: Andrew Morton Signed-off-by: Len Brown --- drivers/acpi/numa.c | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/numa.c b/drivers/acpi/numa.c index 5d59cb33b1a5..658e5f3abae0 100644 --- a/drivers/acpi/numa.c +++ b/drivers/acpi/numa.c @@ -140,19 +140,42 @@ acpi_table_print_srat_entry(struct acpi_subtable_header *header) } } +/* + * A lot of BIOS fill in 10 (= no distance) everywhere. This messes + * up the NUMA heuristics which wants the local node to have a smaller + * distance than the others. + * Do some quick checks here and only use the SLIT if it passes. + */ +static __init int slit_valid(struct acpi_table_slit *slit) +{ + int i, j; + int d = slit->locality_count; + for (i = 0; i < d; i++) { + for (j = 0; j < d; j++) { + u8 val = slit->entry[d*i + j]; + if (i == j) { + if (val != LOCAL_DISTANCE) + return 0; + } else if (val <= LOCAL_DISTANCE) + return 0; + } + } + return 1; +} + static int __init acpi_parse_slit(struct acpi_table_header *table) { struct acpi_table_slit *slit; - u32 localities; if (!table) return -EINVAL; slit = (struct acpi_table_slit *)table; - /* downcast just for %llu vs %lu for i386/ia64 */ - localities = (u32) slit->locality_count; - + if (!slit_valid(slit)) { + printk(KERN_INFO "ACPI: SLIT table looks invalid. Not used.\n"); + return -EINVAL; + } acpi_numa_slit_init(slit); return 0; -- cgit v1.2.3