Commits
Tonghao Zhang committed f17c1795228
PCI/MSI: Warn and return error if driver enables MSI/MSI-X twice
[ Upstream commit 4c1ef72e9b71a19fb405ebfcd37c0a5e16fa44ca ]
It is a serious driver defect to enable MSI or MSI-X more than once. Doing
so may panic the kernel as in the stack trace below:
Call Trace:
sysfs_add_one+0xa5/0xd0
create_dir+0x7c/0xe0
sysfs_create_subdir+0x1c/0x20
internal_create_group+0x6d/0x290
sysfs_create_groups+0x4a/0xa0
populate_msi_sysfs+0x1cd/0x210
pci_enable_msix+0x31c/0x3e0
igbuio_pci_open+0x72/0x300 [igb_uio]
uio_open+0xcc/0x120 [uio]
chrdev_open+0xa1/0x1e0
[...]
do_sys_open+0xf3/0x1f0
SyS_open+0x1e/0x20
system_call_fastpath+0x16/0x1b
---[ end trace 11042e2848880209 ]---
Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffffa056b4fa
We want to keep the WARN_ON() and stack trace so the driver can be fixed,
but we can avoid the kernel panic by returning an error. We may still get
warnings like this:
Call Trace:
pci_enable_msix+0x3c9/0x3e0
igbuio_pci_open+0x72/0x300 [igb_uio]
uio_open+0xcc/0x120 [uio]
chrdev_open+0xa1/0x1e0
[...]
do_sys_open+0xf3/0x1f0
SyS_open+0x1e/0x20
system_call_fastpath+0x16/0x1b
------------[ cut here ]------------
WARNING: at fs/sysfs/dir.c:526 sysfs_add_one+0xa5/0xd0()
sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:03.0/0000:01:00.1/msi_irqs'
Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
[bhelgaas: changelog, fix patch whitespace, remove !!]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>