On systems with OF_IMAP_OLDWORLD_MAC set in of_irq_workarounds, the
devicetree interrupt parsing code is different, causing unit tests of
devicetree interrupt nodes to fail. Due to a bug in unittest code, which
tries to dereference an uninitialized pointer, this results in a crash.
OF: /testcase-data/phandle-tests/consumer-a: arguments longer than property
Unable to handle kernel paging request for data at address 0x00bc616e
Faulting instruction address: 0xc08e9468
Oops: Kernel access of bad area, sig: 11 [#1]
BE PREEMPT PowerMac
Modules linked in:
CPU: 0 PID: 1 Comm: swapper Not tainted 4.14.72-rc1-yocto-standard+ #1
task: cf8e0000 task.stack: cf8da000
NIP: c08e9468 LR: c08ea5bc CTR: c08ea5ac
REGS: cf8dbb50 TRAP: 0300 Not tainted (4.14.72-rc1-yocto-standard+)
MSR: 00001032 <ME,IR,DR,RI> CR: 82004044 XER: 00000000
DAR: 00bc616e DSISR: 40000000
GPR00: c08ea5bc cf8dbc00 cf8e0000 c13ca517 c13ca517 c13ca8a0 00000066 00000002
GPR08: 00000063 00bc614e c0b05865 000affff 82004048 00000000 c00047f0 00000000
GPR16: c0a80000 c0a9cc34 c13ca517 c0ad1134 05ffffff 000affff c0b05860 c0abeef8
GPR24: cecec278 cecec278 c0a8c4d0 c0a885e0 c13ca8a0 05ffffff c13ca8a0 c13ca517
NIP [c08e9468] device_node_gen_full_name+0x30/0x15c
LR [c08ea5bc] device_node_string+0x190/0x3c8
Call Trace:
[cf8dbc00] [c007f670] trace_hardirqs_on_caller+0x118/0x1fc (unreliable)
[cf8dbc40] [c08ea5bc] device_node_string+0x190/0x3c8
[cf8dbcb0] [c08eb794] pointer+0x25c/0x4d0
[cf8dbd00] [c08ebcbc] vsnprintf+0x2b4/0x5ec
[cf8dbd60] [c08ec00c] vscnprintf+0x18/0x48
[cf8dbd70] [c008e268] vprintk_store+0x4c/0x22c
[cf8dbda0] [c008ecac] vprintk_emit+0x94/0x130
[cf8dbdd0] [c008ff54] printk+0x5c/0x6c
[cf8dbe10] [c0b8ddd4] of_unittest+0x2220/0x26f8
[cf8dbea0] [c0004434] do_one_initcall+0x4c/0x184
[cf8dbf00] [c0b4534c] kernel_init_freeable+0x13c/0x1d8
[cf8dbf30] [c0004814] kernel_init+0x24/0x118
[cf8dbf40] [c0013398] ret_from_kernel_thread+0x5c/0x64
The problem was observed when running a qemu test for the g3beige machine
with devicetree unittests enabled.
Disable interrupt node tests on affected systems to avoid both false
unittest failures and the crash.
Fixes: 53a42093d96ef ("of: Add device tree selftests")
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
The changes in of_unittest_platform_populate() are kept at the minimum;
I wanted to avoid changing the intendation.
An alternative fix might be to move the interrupt tests to a separate
function.
drivers/of/unittest.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
index 722537e14848..bd1d56cf1962 100644
--- a/drivers/of/unittest.c
+++ b/drivers/of/unittest.c
@@ -771,6 +771,9 @@ static void __init of_unittest_parse_interrupts(void)
struct of_phandle_args args;
int i, rc;
+ if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
+ return;
+
np = of_find_node_by_path("/testcase-data/interrupts/interrupts0");
if (!np) {
pr_err("missing testcase data\n");
@@ -845,6 +848,9 @@ static void __init of_unittest_parse_interrupts_extended(void)
struct of_phandle_args args;
int i, rc;
+ if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
+ return;
+
np = of_find_node_by_path("/testcase-data/interrupts/interrupts-extended0");
if (!np) {
pr_err("missing testcase data\n");
@@ -1001,6 +1007,9 @@ static void __init of_unittest_platform_populate(void)
pdev = of_find_device_by_node(np);
unittest(pdev, "device 1 creation failed\n");
+ if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
+ goto skip_irqtests;
+
irq = platform_get_irq(pdev, 0);
unittest(irq == -EPROBE_DEFER, "device deferred probe failed - %d\n", irq);
@@ -1011,6 +1020,7 @@ static void __init of_unittest_platform_populate(void)
irq = platform_get_irq(pdev, 0);
unittest(irq < 0 && irq != -EPROBE_DEFER, "device parsing error failed - %d\n", irq);
+skip_irqtests:
np = of_find_node_by_path("/testcase-data/platform-tests");
unittest(np, "No testcase data in device tree\n");
if (!np)
--
2.7.4
