[PATCH] Handle invalid ACPI SLIT table

Fenghua Yu
2008-05-02T22:27:15Z

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 <fenghua.yu@intel.com>

---

arch/ia64/kernel/acpi.c | 9 +++++++--
arch/x86/mm/srat_64.c | 27 ---------------------------
drivers/acpi/numa.c | 31 +++++++++++++++++++++++++++----
3 files changed, 34 insertions(+), 33 deletions(-)

diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c
index c7467f8..4f156f4 100644
--- a/arch/ia64/kernel/acpi.c
+++ b/arch/ia64/kernel/acpi.c
@@ -460,7 +460,6 @@ void __init acpi_numa_slit_init(struct acpi_table_slit *slit)
printk(KERN_ERR
"ACPI 2.0 SLIT: size mismatch: %d expected, %d actual\n",
len, slit->header.length);
- memset(numa_slit, 10, sizeof(numa_slit));
return;
}
slit_table = slit;
@@ -569,8 +568,14 @@ void __init acpi_numa_arch_fixup(void)
printk(KERN_INFO "Number of memory chunks in system = %d\n",
num_node_memblks);

- if (!slit_table)
+ if (!slit_table) {
+ for (i = 0; i < MAX_NUMNODES; i++)
+ for (j = 0; j < MAX_NUMNODES; j++)
+ node_distance(i, j) = i == j ? LOCAL_DISTANCE :
+ REMOTE_DISTANCE;
return;
+ }
+
memset(numa_slit, -1, sizeof(numa_slit));
for (i = 0; i < slit_table->locality_count; i++) {
if (!pxm_bit_test(i))
diff --git a/arch/x86/mm/srat_64.c b/arch/x86/mm/srat_64.c
index 3890234..99649dc 100644
--- a/arch/x86/mm/srat_64.c
+++ b/arch/x86/mm/srat_64.c
@@ -97,36 +97,9 @@ static __init inline int srat_disabled(void)
return numa_off || acpi_numa < 0;
}

-/*
- * 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;
-}
-
/* Callback for SLIT parsing */
void __init acpi_numa_slit_init(struct acpi_table_slit *slit)
{
- if (!slit_valid(slit)) {
- printk(KERN_INFO "ACPI: SLIT table looks invalid. Not used.\n");
- return;
- }
acpi_slit = slit;
}

diff --git a/drivers/acpi/numa.c b/drivers/acpi/numa.c
index 5d59cb3..658e5f3 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;