acpi/x86: introduce __apci_map_table, v4
to prevent wrongly overwriting fixmap that still want to use.
ACPI used to rely on low mappings being all linearly mapped and
grew a habit: it never really unmapped certain kinds of tables
after use.
This can cause problems - for example the hypothetical case
when some spurious access still references it.
v2: remove prev_map and prev_size in __apci_map_table
v3: let acpi_os_unmap_memory() call early_iounmap too, so remove extral calling to
early_acpi_os_unmap_memory
v4: fix typo in one acpi_get_table_with_size calling
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Acked-by: Len Brown <len.brown@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
index a885295..fec1ae3 100644
--- a/drivers/acpi/tables.c
+++ b/drivers/acpi/tables.c
@@ -181,14 +181,15 @@
struct acpi_subtable_header *entry;
unsigned int count = 0;
unsigned long table_end;
+ acpi_size tbl_size;
if (!handler)
return -EINVAL;
if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
- acpi_get_table(id, acpi_apic_instance, &table_header);
+ acpi_get_table_with_size(id, acpi_apic_instance, &table_header, &tbl_size);
else
- acpi_get_table(id, 0, &table_header);
+ acpi_get_table_with_size(id, 0, &table_header, &tbl_size);
if (!table_header) {
printk(KERN_WARNING PREFIX "%4.4s not present\n", id);
@@ -206,8 +207,10 @@
table_end) {
if (entry->type == entry_id
&& (!max_entries || count++ < max_entries))
- if (handler(entry, table_end))
+ if (handler(entry, table_end)) {
+ early_acpi_os_unmap_memory((char *)table_header, tbl_size);
return -EINVAL;
+ }
entry = (struct acpi_subtable_header *)
((unsigned long)entry + entry->length);
@@ -217,6 +220,7 @@
"%i found\n", id, entry_id, count - max_entries, count);
}
+ early_acpi_os_unmap_memory((char *)table_header, tbl_size);
return count;
}
@@ -241,17 +245,19 @@
int __init acpi_table_parse(char *id, acpi_table_handler handler)
{
struct acpi_table_header *table = NULL;
+ acpi_size tbl_size;
if (!handler)
return -EINVAL;
if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
- acpi_get_table(id, acpi_apic_instance, &table);
+ acpi_get_table_with_size(id, acpi_apic_instance, &table, &tbl_size);
else
- acpi_get_table(id, 0, &table);
+ acpi_get_table_with_size(id, 0, &table, &tbl_size);
if (table) {
handler(table);
+ early_acpi_os_unmap_memory(table, tbl_size);
return 0;
} else
return 1;
@@ -265,8 +271,9 @@
static void __init check_multiple_madt(void)
{
struct acpi_table_header *table = NULL;
+ acpi_size tbl_size;
- acpi_get_table(ACPI_SIG_MADT, 2, &table);
+ acpi_get_table_with_size(ACPI_SIG_MADT, 2, &table, &tbl_size);
if (table) {
printk(KERN_WARNING PREFIX
"BIOS bug: multiple APIC/MADT found,"
@@ -275,6 +282,7 @@
"If \"acpi_apic_instance=%d\" works better, "
"notify linux-acpi@vger.kernel.org\n",
acpi_apic_instance ? 0 : 2);
+ early_acpi_os_unmap_memory(table, tbl_size);
} else
acpi_apic_instance = 0;
