[PATCH] ACPI: tables: FPDT: Don't call acpi_os_map_memory() on invalid phys address

[Hans de Goede <hdegoede@redhat.com>]

On a Packard Bell Dot SC (Intel Atom N2600 model) there is a FPDT table
which contains invalid physical addresses, with high bits set which fall
outside the range of the CPU-s supported physical address range.

Calling acpi_os_map_memory() on such an invalid phys address leads to
the below WARN_ON in ioremap triggering resulting in an oops/stacktrace.

Add code to verify the physical address before calling acpi_os_map_memory()
to fix / avoid the oops.

[    1.226900] ioremap: invalid physical address 3001000000000000
[    1.226949] ------------[ cut here ]------------
[    1.226962] WARNING: CPU: 1 PID: 1 at arch/x86/mm/ioremap.c:200 __ioremap_caller.cold+0x43/0x5f
[    1.226996] Modules linked in:
[    1.227016] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.0.0-rc3+ #490
[    1.227029] Hardware name: Packard Bell dot s/SJE01_CT, BIOS V1.10 07/23/2013
[    1.227038] RIP: 0010:__ioremap_caller.cold+0x43/0x5f
[    1.227054] Code: 96 00 00 e9 f8 af 24 ff 89 c6 48 c7 c7 d8 0c 84 99 e8 6a 96 00 00 e9 76 af 24 ff 48 89 fe 48 c7 c7 a8 0c 84 99 e8 56 96 00 00 <0f> 0b e9 60 af 24 ff 48 8b 34 24 48 c7 c7 40 0d 84 99 e8 3f 96 00
[    1.227067] RSP: 0000:ffffb18c40033d60 EFLAGS: 00010286
[    1.227084] RAX: 0000000000000032 RBX: 3001000000000000 RCX: 0000000000000000
[    1.227095] RDX: 0000000000000001 RSI: 00000000ffffdfff RDI: 00000000ffffffff
[    1.227105] RBP: 3001000000000000 R08: 0000000000000000 R09: ffffb18c40033c18
[    1.227115] R10: 0000000000000003 R11: ffffffff99d62fe8 R12: 0000000000000008
[    1.227124] R13: 0003001000000000 R14: 0000000000001000 R15: 3001000000000000
[    1.227135] FS:  0000000000000000(0000) GS:ffff913a3c080000(0000) knlGS:0000000000000000
[    1.227146] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    1.227156] CR2: 0000000000000000 CR3: 0000000018c26000 CR4: 00000000000006e0
[    1.227167] Call Trace:
[    1.227176]  <TASK>
[    1.227185]  ? acpi_os_map_iomem+0x1c9/0x1e0
[    1.227215]  ? kmem_cache_alloc_trace+0x187/0x370
[    1.227254]  acpi_os_map_iomem+0x1c9/0x1e0
[    1.227288]  acpi_init_fpdt+0xa8/0x253
[    1.227308]  ? acpi_debugfs_init+0x1f/0x1f
[    1.227339]  do_one_initcall+0x5a/0x300
[    1.227406]  ? rcu_read_lock_sched_held+0x3f/0x80
[    1.227442]  kernel_init_freeable+0x28b/0x2cc
[    1.227512]  ? rest_init+0x170/0x170
[    1.227538]  kernel_init+0x16/0x140
[    1.227552]  ret_from_fork+0x1f/0x30
[    1.227639]  </TASK>
[    1.227647] irq event stamp: 186819
[    1.227656] hardirqs last  enabled at (186825): [<ffffffff98184a6e>] __up_console_sem+0x5e/0x70
[    1.227672] hardirqs last disabled at (186830): [<ffffffff98184a53>] __up_console_sem+0x43/0x70
[    1.227686] softirqs last  enabled at (186576): [<ffffffff980fbc9d>] __irq_exit_rcu+0xed/0x160
[    1.227701] softirqs last disabled at (186569): [<ffffffff980fbc9d>] __irq_exit_rcu+0xed/0x160
[    1.227715] ---[ end trace 0000000000000000 ]---

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/acpi/acpi_fpdt.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/acpi/acpi_fpdt.c b/drivers/acpi/acpi_fpdt.c
index 6922a44b3ce7..a2056c4c8cb7 100644
--- a/drivers/acpi/acpi_fpdt.c
+++ b/drivers/acpi/acpi_fpdt.c
@@ -143,6 +143,23 @@ static const struct attribute_group boot_attr_group = {
 
 static struct kobject *fpdt_kobj;
 
+#if defined CONFIG_X86 && defined CONFIG_PHYS_ADDR_T_64BIT
+#include <linux/processor.h>
+static bool fpdt_address_valid(u64 address)
+{
+	/*
+	 * On some systems the table contains invalid addresses
+	 * with unsuppored high address bits set, check for this.
+	 */
+	return !(address >> boot_cpu_data.x86_phys_bits);
+}
+#else
+static bool fpdt_address_valid(u64 address)
+{
+	return true;
+}
+#endif
+
 static int fpdt_process_subtable(u64 address, u32 subtable_type)
 {
 	struct fpdt_subtable_header *subtable_header;
@@ -151,6 +168,11 @@ static int fpdt_process_subtable(u64 address, u32 subtable_type)
 	u32 length, offset;
 	int result;
 
+	if (!fpdt_address_valid(address)) {
+		pr_info(FW_BUG "invalid physical address: 0x%llx!\n", address);
+		return -EINVAL;
+	}
+
 	subtable_header = acpi_os_map_memory(address, sizeof(*subtable_header));
 	if (!subtable_header)
 		return -ENOMEM;
-- 
2.36.1