4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Guenter Roeck linux@roeck-us.net
commit 8894891446c9380709451b99ab45c5c53adfd2fc upstream.
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.
With this patch in place, unittest on the affected system passes with the following message.
dt-test ### end of unittest - 144 passed, 0 failed
Fixes: 53a42093d96ef ("of: Add device tree selftests") Signed-off-by: Guenter Roeck linux@roeck-us.net Reviewed-by: Frank Rowand frank.rowand@sony.com Signed-off-by: Rob Herring robh@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/of/unittest.c | 28 +++++++++++++++++++--------- 1 file changed, 19 insertions(+), 9 deletions(-)
--- a/drivers/of/unittest.c +++ b/drivers/of/unittest.c @@ -553,6 +553,9 @@ static void __init of_unittest_parse_int 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"); @@ -627,6 +630,9 @@ static void __init of_unittest_parse_int 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"); @@ -778,15 +784,19 @@ static void __init of_unittest_platform_ pdev = of_find_device_by_node(np); unittest(pdev, "device 1 creation failed\n");
- irq = platform_get_irq(pdev, 0); - unittest(irq == -EPROBE_DEFER, "device deferred probe failed - %d\n", irq); - - /* Test that a parsing failure does not return -EPROBE_DEFER */ - np = of_find_node_by_path("/testcase-data/testcase-device2"); - pdev = of_find_device_by_node(np); - unittest(pdev, "device 2 creation failed\n"); - irq = platform_get_irq(pdev, 0); - unittest(irq < 0 && irq != -EPROBE_DEFER, "device parsing error failed - %d\n", irq); + if (!(of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)) { + irq = platform_get_irq(pdev, 0); + unittest(irq == -EPROBE_DEFER, + "device deferred probe failed - %d\n", irq); + + /* Test that a parsing failure does not return -EPROBE_DEFER */ + np = of_find_node_by_path("/testcase-data/testcase-device2"); + pdev = of_find_device_by_node(np); + unittest(pdev, "device 2 creation failed\n"); + irq = platform_get_irq(pdev, 0); + unittest(irq < 0 && irq != -EPROBE_DEFER, + "device parsing error failed - %d\n", irq); + }
np = of_find_node_by_path("/testcase-data/platform-tests"); unittest(np, "No testcase data in device tree\n");