From: John Garry john.garry@huawei.com
[ Upstream commit a6dd255bdd7d00bbdbf78ba00bde9fc64f86c3a7 ]
Some released ACPI FW for Huawei boards describes incorrect the port IO address range for child devices, in that it tells us the IO port max range is 0x3fff for each child device, which is not correct. The address range should be [e4:e8) or similar. With this incorrect upper range, the child device IO port resources overlap.
As such, the kernel thinks that the LPC host serial device is a child of the IPMI device:
root@(none)$ more /proc/ioports [...] 00ffc0e3-00ffffff : hisi-lpc-ipmi.0.auto 00ffc0e3-00ffc0e3 : ipmi_si 00ffc0e4-00ffc0e4 : ipmi_si 00ffc0e5-00ffc0e5 : ipmi_si 00ffc2f7-00ffffff : serial8250.1.auto 00ffc2f7-00ffc2fe : serial root@(none)$
They should both be siblings. Note that these are logical PIO addresses, which have a direct mapping from the FW IO port ranges.
This shows up as a real issue when we enable CONFIG_KASAN and CONFIG_DEBUG_TEST_DRIVER_REMOVE - we see use-after-free warnings in the host removal path:
================================================================== BUG: KASAN: use-after-free in release_resource+0x38/0xc8 Read of size 8 at addr ffff0026accdbc38 by task swapper/0/1
CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.5.0-rc6-00001-g68e186e77b5c-dirty #1593 Hardware name: Huawei Taishan 2180 /D03, BIOS Hisilicon D03 IT20 Nemo 2.0 RC0 03/30/2018 Call trace: dump_backtrace+0x0/0x290 show_stack+0x14/0x20 dump_stack+0xf0/0x14c print_address_description.isra.9+0x6c/0x3b8 __kasan_report+0x12c/0x23c kasan_report+0xc/0x18 __asan_load8+0x94/0xb8 release_resource+0x38/0xc8 platform_device_del.part.10+0x80/0xe0 platform_device_unregister+0x20/0x38 hisi_lpc_acpi_remove_subdev+0x10/0x20 device_for_each_child+0xc8/0x128 hisi_lpc_acpi_remove+0x4c/0xa8 hisi_lpc_remove+0xbc/0xc0 platform_drv_remove+0x3c/0x68 really_probe+0x174/0x548 driver_probe_device+0x7c/0x148 device_driver_attach+0x94/0xa0 __driver_attach+0xa4/0x110 bus_for_each_dev+0xe8/0x158 driver_attach+0x30/0x40 bus_add_driver+0x234/0x2f0 driver_register+0xbc/0x1d0 __platform_driver_register+0x7c/0x88 hisi_lpc_driver_init+0x18/0x20 do_one_initcall+0xb4/0x258 kernel_init_freeable+0x248/0x2c0 kernel_init+0x10/0x118 ret_from_fork+0x10/0x1c
...
The issue here is that the kernel created an incorrect parent-child resource dependency between two devices, and references the false parent node when deleting the second child device, when it had been deleted already.
Fix up the child device resources from FW to create proper IO port resource relationships for broken FW.
With this, the IO port layout looks more healthy:
root@(none)$ more /proc/ioports [...] 00ffc0e3-00ffc0e7 : hisi-lpc-ipmi.0.auto 00ffc0e3-00ffc0e3 : ipmi_si 00ffc0e4-00ffc0e4 : ipmi_si 00ffc0e5-00ffc0e5 : ipmi_si 00ffc2f7-00ffc2ff : serial8250.1.auto 00ffc2f7-00ffc2fe : serial
Signed-off-by: John Garry john.garry@huawei.com Signed-off-by: Wei Xu xuwei5@hisilicon.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/bus/hisi_lpc.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-)
diff --git a/drivers/bus/hisi_lpc.c b/drivers/bus/hisi_lpc.c index 20c957185af20..2e9252d37a18f 100644 --- a/drivers/bus/hisi_lpc.c +++ b/drivers/bus/hisi_lpc.c @@ -358,6 +358,26 @@ static int hisi_lpc_acpi_xlat_io_res(struct acpi_device *adev, return 0; }
+/* + * Released firmware describes the IO port max address as 0x3fff, which is + * the max host bus address. Fixup to a proper range. This will probably + * never be fixed in firmware. + */ +static void hisi_lpc_acpi_fixup_child_resource(struct device *hostdev, + struct resource *r) +{ + if (r->end != 0x3fff) + return; + + if (r->start == 0xe4) + r->end = 0xe4 + 0x04 - 1; + else if (r->start == 0x2f8) + r->end = 0x2f8 + 0x08 - 1; + else + dev_warn(hostdev, "unrecognised resource %pR to fixup, ignoring\n", + r); +} + /* * hisi_lpc_acpi_set_io_res - set the resources for a child * @child: the device node to be updated the I/O resource @@ -419,8 +439,11 @@ static int hisi_lpc_acpi_set_io_res(struct device *child, return -ENOMEM; } count = 0; - list_for_each_entry(rentry, &resource_list, node) - resources[count++] = *rentry->res; + list_for_each_entry(rentry, &resource_list, node) { + resources[count] = *rentry->res; + hisi_lpc_acpi_fixup_child_resource(hostdev, &resources[count]); + count++; + }
acpi_dev_free_resource_list(&resource_list);