[PATCH v2 1/2] PCI ACPI: Avoid panic when PCI IO resource's size is not page aligned
From: Yisheng Xie
Date: Sat Mar 31 2018 - 03:23:38 EST
Zhou reported a bug on Hisilicon arm64 D06 platform with 64KB page size:
[ 2.470908] kernel BUG at lib/ioremap.c:72!
[ 2.475079] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
[ 2.480551] Modules linked in:
[ 2.483594] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.16.0-rc7-00062-g0b41260-dirty #23
[ 2.491756] Hardware name: Huawei D06/D06, BIOS Hisilicon D06 UEFI Nemo 2.0 RC0 - B120 03/23/2018
[ 2.500614] pstate: 80c00009 (Nzcv daif +PAN +UAO)
[ 2.505395] pc : ioremap_page_range+0x268/0x36c
[ 2.509912] lr : pci_remap_iospace+0xe4/0x100
[...]
[ 2.603733] Call trace:
[ 2.606168] ioremap_page_range+0x268/0x36c
[ 2.610337] pci_remap_iospace+0xe4/0x100
[ 2.614334] acpi_pci_probe_root_resources+0x1d4/0x214
[ 2.619460] pci_acpi_root_prepare_resources+0x18/0xa8
[ 2.624585] acpi_pci_root_create+0x98/0x214
[ 2.628843] pci_acpi_scan_root+0x124/0x20c
[ 2.633013] acpi_pci_root_add+0x224/0x494
[ 2.637096] acpi_bus_attach+0xf8/0x200
[ 2.640918] acpi_bus_attach+0x98/0x200
[ 2.644740] acpi_bus_attach+0x98/0x200
[ 2.648562] acpi_bus_scan+0x48/0x9c
[ 2.652125] acpi_scan_init+0x104/0x268
[ 2.655948] acpi_init+0x308/0x374
[ 2.659337] do_one_initcall+0x48/0x14c
[ 2.663160] kernel_init_freeable+0x19c/0x250
[ 2.667504] kernel_init+0x10/0x100
[ 2.670979] ret_from_fork+0x10/0x18
The cause is the size of PCI IO resource is 32KB, which is 4K aligned but
not 64KB aligned, however, ioremap_page_range() request the range as page
aligned or it will trigger a BUG_ON() on ioremap_pte_range() it calls, as
ioremap_pte_range increase the addr by PAGE_SIZE, which makes addr != end
until trigger BUG_ON, if its incoming end is not page aligned. More detail
trace is as following:
ioremap_page_range
-> ioremap_p4d_range
-> ioremap_p4d_range
-> ioremap_pud_range
-> ioremap_pmd_range
-> ioremap_pte_range
This patch fix the bug by align the size of PCI IO resource to PAGE_SIZE.
Reported-by: Zhou Wang <wangzhou1@xxxxxxxxxxxxx>
Tested-by: Xiaojun Tan <tanxiaojun@xxxxxxxxxx>
Signed-off-by: Yisheng Xie <xieyisheng1@xxxxxxxxxx>
---
I mark this as v2 for I have post a RFC version:
https://lkml.org/lkml/2018/3/30/8
v2:
* Let the caller of ioremap_page_range() align the request by PAGE_SIZE - per Toshi
Thanks
Yisheng
drivers/acpi/pci_root.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 6fc204a..b758ca3 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -746,7 +746,7 @@ static void acpi_pci_root_remap_iospace(struct resource_entry *entry)
goto err;
res->start = port;
- res->end = port + length - 1;
+ res->end = PAGE_ALIGN(port + length) - 1;
entry->offset = port - pci_addr;
if (pci_remap_iospace(res, cpu_addr) < 0)
--
1.7.12.4