[PATCH 5.16 050/285] PCI: endpoint: Fix alignment fault error in copy tests

Greg Kroah-Hartman
2022-04-12T07:45:48Z

From: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>

[ Upstream commit 829cc0e2ea2d61fb6c54bc3f8a17f86c56e11864 ]

The copy test uses the memcpy() to copy data between IO memory spaces.
This can trigger an alignment fault error (pasted the error logs below)
because memcpy() may use unaligned accesses on a mapped memory that is
just IO, which does not support unaligned memory accesses.

Fix it by using the correct memcpy API to copy from/to IO memory.

Alignment fault error logs:
Unable to handle kernel paging request at virtual address ffff8000101cd3c1
Mem abort info:
ESR = 0x96000021
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x21: alignment fault
Data abort info:
ISV = 0, ISS = 0x00000021
CM = 0, WnR = 0
swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000081773000
[ffff8000101cd3c1] pgd=1000000082410003, p4d=1000000082410003, pud=1000000082411003, pmd=1000000082412003, pte=0068004000001f13
Internal error: Oops: 96000021 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 6 Comm: kworker/0:0H Not tainted 5.15.0-rc1-next-20210914-dirty #2
Hardware name: LS1012A RDB Board (DT)
Workqueue: kpcitest pci_epf_test_cmd_handler
pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __memcpy+0x168/0x230
lr : pci_epf_test_cmd_handler+0x6f0/0xa68
sp : ffff80001003bce0
x29: ffff80001003bce0 x28: ffff800010135000 x27: ffff8000101e5000
x26: ffff8000101cd000 x25: ffff6cda941cf6c8 x24: 0000000000000000
x23: ffff6cda863f2000 x22: ffff6cda9096c800 x21: ffff800010135000
x20: ffff6cda941cf680 x19: ffffaf39fd999000 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000 x15: ffffaf39fd2b6000
x14: 0000000000000000 x13: 15f5c8fa2f984d57 x12: 604d132b60275454
x11: 065cee5e5fb428b6 x10: aae662eb17d0cf3e x9 : 1d97c9a1b4ddef37
x8 : 7541b65edebf928c x7 : e71937c4fc595de0 x6 : b8a0e09562430d1c
x5 : ffff8000101e5401 x4 : ffff8000101cd401 x3 : ffff8000101e5380
x2 : fffffffffffffff1 x1 : ffff8000101cd3c0 x0 : ffff8000101e5000
Call trace:
__memcpy+0x168/0x230
process_one_work+0x1ec/0x370
worker_thread+0x44/0x478
kthread+0x154/0x160
ret_from_fork+0x10/0x20
Code: a984346c a9c4342c f1010042 54fffee8 (a97c3c8e)
---[ end trace 568c28c7b6336335 ]---

Link: https://lore.kernel.org/r/20211217094708.28678-1-Zhiqiang.Hou@nxp.com
Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/pci/endpoint/functions/pci-epf-test.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
index 90d84d3bc868..c7e45633beaf 100644
--- a/drivers/pci/endpoint/functions/pci-epf-test.c
+++ b/drivers/pci/endpoint/functions/pci-epf-test.c
@@ -285,7 +285,17 @@ static int pci_epf_test_copy(struct pci_epf_test *epf_test)
if (ret)
dev_err(dev, "Data transfer failed\n");
} else {
- memcpy(dst_addr, src_addr, reg->size);
+ void *buf;
+
+ buf = kzalloc(reg->size, GFP_KERNEL);
+ if (!buf) {
+ ret = -ENOMEM;
+ goto err_map_addr;
+ }
+
+ memcpy_fromio(buf, src_addr, reg->size);
+ memcpy_toio(dst_addr, buf, reg->size);
+ kfree(buf);
}
ktime_get_ts64(&end);
pci_epf_test_print_rate("COPY", reg->size, &start, &end, use_dma);
--
2.35.1