On 6/13/2017 11:05 PM, Dan Williams wrote:
On Tue, Jun 13, 2017 at 7:41 PM, Yasunori Goto <[email protected]> wrote:
Hi, Dan-san, Linda-san,
I had chased the root cause of this panic problem, and maybe I found it.
Very good! Thank you!
-- ljk
Hmmm, though I made Fedora 25 environment, this panic still occurs...
I'll attach syslog and .config again.
[..]
[ 117.804948] general protection fault: 0000 [#1] SMP
[..]
[ 117.820866] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
[..]
[ 117.843262] Call Trace:
[ 117.843985] release_nodes+0x76/0x260
[ 117.845062] devres_release_all+0x3c/0x50
[ 117.846225] device_release_driver_internal+0x159/0x200
[ 117.847748] device_release_driver+0x12/0x20
[ 117.849029] bus_remove_device+0xfd/0x170
[ 117.850192] device_del+0x1e8/0x330
[ 117.851284] platform_device_del+0x28/0x90
[ 117.852485] platform_device_unregister+0x12/0x30
[ 117.853846] nfit_test_exit+0x2a/0x93b [nfit_test]
[ 117.855219] SyS_delete_module+0x171/0x250
[ 117.856403] entry_SYSCALL_64_fastpath+0x1a/0xa5
Can you also attach the qemu-kvm command line you are using?
ps aux | grep qemu
The cause of this problem is the num_pm of nfit_test1 is wrong.
Though 1 is specified for num_pm at nfit_test_init(), it must be 2.
----
static __init int nfit_test_init(void)
{
int rc, i;
:
:
case 1:
nfit_test->num_pm = 1; <---- !!!
nfit_test->dcr_idx = NUM_DCR;
-----
The num_pm affects size of devm_kcalloc() at nfit_test_probe().
----
static int nfit_test_probe(struct platform_device *pdev)
{
if (nfit_test->num_pm) {
int num = nfit_test->num_pm; <----!!!
nfit_test->spa_set = devm_kcalloc(dev, num, sizeof(void *),
GFP_KERNEL); <---!!!!
nfit_test->spa_set_dma = devm_kcalloc(dev, num,
sizeof(dma_addr_t), GFP_KERNEL);
-----
However, spa_set[] array needs 2 elements at nfit_test1_alloc().
---
static int nfit_test1_alloc(struct nfit_test *t)
{
:
t->spa_set[0] = test_alloc(t, SPA2_SIZE, &t->spa_set_dma[0]); <---
first element
if (!t->spa_set[0])
return -ENOMEM;
:
t->spa_set[1] = test_alloc(t, SPA_VCD_SIZE, &t->spa_set_dma[1]); <----
The second element!!!!
-----
This breaks other area, and the area is often the link list of devres.
As a result, the panic occured on release_nodes().
I confirmed that this panic never occurred with the following patch.
Wow!
---
diff --git a/tools/testing/nvdimm/test/nfit.c b/tools/testing/nvdimm/test/nfit.c
index c218717..548b6d4 100644
--- a/tools/testing/nvdimm/test/nfit.c
+++ b/tools/testing/nvdimm/test/nfit.c
@@ -1943,7 +1943,7 @@ static __init int nfit_test_init(void)
nfit_test->setup = nfit_test0_setup;
break;
case 1:
- nfit_test->num_pm = 1;
+ nfit_test->num_pm = 2;
nfit_test->dcr_idx = NUM_DCR;
nfit_test->num_dcr = 2;
nfit_test->alloc = nfit_test1_alloc;
This change looks correct to me. I'm going to try it out.
...but, "Wow!" again and a big "Thank You!".
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