在 2021/10/12 1:11, Bjorn Helgaas 写道:
For v2, please note "git log --oneline drivers/pci/msi.c" and make
your patch follow the style, including capitalization.
On Mon, Oct 11, 2021 at 05:15:28PM +0800, wanghai (M) wrote:
在 2021/10/11 16:52, Barry Song 写道:
On Mon, Oct 11, 2021 at 9:24 PM Wang Hai <wanghai38@xxxxxxxxxx> wrote:
I got a page fault report when doing fault injection test:
When you send v2, can you include information about how you injected
the fault? If it's easy, others can reproduce the failure that way.
Sorry, the reproduction needs to be based on the fault injection framework
provided by Hulk Robot. I don't know how the framework is implemented.
The way to reproduce this is to do a fault injection to make
'msi_attrs = kcalloc() in msi_populate_sysfs()' fail when insmod
9pnet_virtio.ko.
I sent v2 yesterday, can you help review it?
https://lore.kernel.org/linux-pci/20211011130837.766323-1-wanghai38@xxxxxxxxxx/
BUG: unable to handle page fault for address: fffffffffffffff4
...
RIP: 0010:sysfs_remove_groups+0x25/0x60
...
Call Trace:
msi_destroy_sysfs+0x30/0xa0
free_msi_irqs+0x11d/0x1b0
__pci_enable_msix_range+0x67f/0x760
pci_alloc_irq_vectors_affinity+0xe7/0x170
vp_find_vqs_msix+0x129/0x560
vp_find_vqs+0x52/0x230
vp_modern_find_vqs+0x47/0xb0
p9_virtio_probe+0xa1/0x460 [9pnet_virtio]
virtio_dev_probe+0x1ed/0x2e0
really_probe+0x1c7/0x400
__driver_probe_device+0xa4/0x120
driver_probe_device+0x32/0xe0
__driver_attach+0xbf/0x130
bus_for_each_dev+0xbb/0x110
driver_attach+0x27/0x30
bus_add_driver+0x1d9/0x270
driver_register+0xa9/0x180
register_virtio_driver+0x31/0x50
p9_virtio_init+0x3c/0x1000 [9pnet_virtio]
do_one_initcall+0x7b/0x380
do_init_module+0x5f/0x21e
load_module+0x265c/0x2c60
__do_sys_finit_module+0xb0/0xf0
__x64_sys_finit_module+0x1a/0x20
do_syscall_64+0x34/0xb0
entry_SYSCALL_64_after_hwframe+0x44/0xae
When populating msi_irqs sysfs failed in msi_capability_init() or
msix_capability_init(), dev->msi_irq_groups will point to ERR_PTR(...).
This will cause a page fault when destroying the wrong
dev->msi_irq_groups in free_msi_irqs().
Fix this by setting dev->msi_irq_groups to NULL when msi_populate_sysfs()
failed.
Fixes: 2f170814bdd2 ("genirq/msi: Move MSI sysfs handling from PCI to MSI core")
Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
What exactly was reported by the Hulk Robot? Did it really do the
fault injection and report the page fault?
Yes, it reported the error and provided a way to reproduce it
Signed-off-by: Wang Hai <wanghai38@xxxxxxxxxx>
Acked-by: Barry Song <song.bao.hua@xxxxxxxxxxxxx>
---
drivers/pci/msi.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 0099a00af361..6f75db9f3be7 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -561,6 +561,7 @@ static int msi_capability_init(struct pci_dev *dev, int nvec,
dev->msi_irq_groups = msi_populate_sysfs(&dev->dev);
if (IS_ERR(dev->msi_irq_groups)) {
ret = PTR_ERR(dev->msi_irq_groups);
+ dev->msi_irq_groups = NULL;
goto err;
}
@@ -733,6 +734,7 @@ static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries,
dev->msi_irq_groups = msi_populate_sysfs(&dev->dev);
if (IS_ERR(dev->msi_irq_groups)) {
ret = PTR_ERR(dev->msi_irq_groups);
+ dev->msi_irq_groups = NULL;
Can you define a temp variable and assign it to dev->msi_irq_groups if
the temp variable
is not PTR_ERR?
Of course, I will send a v2 patch.
goto out_free;
}
--
2.17.1
Thanks
Barry
.
--
Wang Hai
.
--
Wang Hai
