The following regression is reported when the table length is very large:
WARNING: CPU: 0 PID: 0 at mm/early_ioremap.c:136 __early_ioremap+0x11f/0x1f2()
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 3.15.0-rc1-00017-g86dfc6f3-dirty #298
Hardware name: Intel Corporation S2600CP/S2600CP, BIOS SE5C600.86B.99.99.x036.091920111209 09/19/2011
0000000000000009 ffffffff81b75c40 ffffffff817c627b 0000000000000000
ffffffff81b75c78 ffffffff81067b5d 000000000000007b 8000000000000563
00000000b96b20dc 0000000000000001 ffffffffff300e0c ffffffff81b75c88
Call Trace:
[<ffffffff817c627b>] dump_stack+0x45/0x56
[<ffffffff81067b5d>] warn_slowpath_common+0x7d/0xa0
[<ffffffff81067c3a>] warn_slowpath_null+0x1a/0x20
[<ffffffff81d4b9d5>] __early_ioremap+0x11f/0x1f2
[<ffffffff81d4bc5b>] early_ioremap+0x13/0x15
[<ffffffff81d2b8f3>] __acpi_map_table+0x13/0x18
[<ffffffff817b8d1a>] acpi_os_map_memory+0x26/0x14e
[<ffffffff813ff018>] acpi_tb_acquire_table+0x42/0x70
[<ffffffff813ff086>] acpi_tb_validate_table+0x27/0x37
[<ffffffff813ff0e5>] acpi_tb_verify_table+0x22/0xd8
[<ffffffff813ff6a8>] acpi_tb_install_non_fixed_table+0x60/0x1c9
[<ffffffff81d61024>] acpi_tb_parse_root_table+0x218/0x26a
[<ffffffff81d1b120>] ? early_idt_handlers+0x120/0x120
[<ffffffff81d610cd>] acpi_initialize_tables+0x57/0x59
[<ffffffff81d5f25d>] acpi_table_init+0x1b/0x99
[<ffffffff81d2bca0>] acpi_boot_table_init+0x1e/0x85
[<ffffffff81d23043>] setup_arch+0x99d/0xcc6
[<ffffffff81d1b120>] ? early_idt_handlers+0x120/0x120
[<ffffffff81d1bbbe>] start_kernel+0x8b/0x415
[<ffffffff81d1b120>] ? early_idt_handlers+0x120/0x120
[<ffffffff81d1b5ee>] x86_64_start_reservations+0x2a/0x2c
[<ffffffff81d1b72e>] x86_64_start_kernel+0x13e/0x14d
---[ end trace 11ae599a1898f4e7 ]---
This is due to the size limitation of the x86 early IO mapping.
This patch fixes this issue by utilizing acpi_gbl_verify_table_checksum to
disable table mapping during early stage and enabling it again for the late
stage. In this way, the normal code path is not affected.
A new boot parameter - acpi_force_verify_table is introduced for platforms
that require checksum verification to stop loading bad tables.
Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx>
Reported-and-tested-by: Yuanhan Liu <yuanhan.liu@xxxxxxxxxxxxxxx>
Cc: <lkp@xxxxxxxxxxxxxxxxxxxx>
Cc: <x86@xxxxxxxxxx>
---
Documentation/kernel-parameters.txt | 5 +++++
drivers/acpi/bus.c | 3 +++
drivers/acpi/tables.c | 23 +++++++++++++++++++++++
3 files changed, 31 insertions(+)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 7a4802d..e5c3274 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -214,6 +214,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
unusable. The "log_buf_len" parameter may be useful
if you need to capture more output.
+ acpi_force_verify_table [HW,ACPI]
+ Enable table checksum verification during early stage.
+ By default, this is disabled due to x86 early mapping
+ size limitation.
+
acpi_irq_balance [HW,ACPI]
ACPI will balance active IRQs
default in APIC mode
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 4ce0ea1..c5bc8cf 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -489,6 +489,9 @@ void __init acpi_early_init(void)
printk(KERN_INFO PREFIX "Core revision %08x\n", ACPI_CA_VERSION);
+ /* It's safe to verify table checksums during late stage */
+ acpi_gbl_verify_table_checksum = TRUE;
+
/* enable workarounds, unless strict ACPI spec. compliance */
if (!acpi_strict)
acpi_gbl_enable_interpreter_slack = TRUE;
diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
index 2178229..204b746 100644
--- a/drivers/acpi/tables.c
+++ b/drivers/acpi/tables.c
@@ -44,6 +44,12 @@ static struct acpi_table_desc initial_tables[ACPI_MAX_TABLES] __initdata;
static int acpi_apic_instance __initdata;
+/*
+ * Disable table checksum verification for the early stage due to the size
+ * limitation of the current x86 early mapping implementation.
+ */
+static bool acpi_verify_table_checksum __initdata = false;
+
void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
{
if (!header)
@@ -333,6 +339,14 @@ int __init acpi_table_init(void)
{
acpi_status status;
+ if (!acpi_verify_table_checksum) {
+ pr_info("Early table checksum verification disabled\n");
+ acpi_gbl_verify_table_checksum = FALSE;
+ } else {
+ pr_info("Early table checksum verification enabled\n");
+ acpi_gbl_verify_table_checksum = TRUE;
+ }
+
status = acpi_initialize_tables(initial_tables, ACPI_MAX_TABLES, 0);
if (ACPI_FAILURE(status))
return -EINVAL;
@@ -354,3 +368,12 @@ static int __init acpi_parse_apic_instance(char *str)
}
early_param("acpi_apic_instance", acpi_parse_apic_instance);
+
+static int __init acpi_force_verify_table_setup(char *s)
+{
+ acpi_verify_table_checksum = true;
+
+ return 0;
+}
+
+early_param("acpi_force_verify_table", acpi_force_verify_table_setup);
--
1.7.10
--
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