From: Michael Ellerman <mpe@ellerman.id.au>
To: stable@vger.kernel.org
Cc: grimm@linux.vnet.ibm.com, linuxppc-dev@ozlabs.org, imunsie@au.ibm.com
Subject: [PATCH 2/3] cxl: Fix device_node reference counting
Date: Mon, 23 Feb 2015 15:21:20 +1100 [thread overview]
Message-ID: <1424665281-25431-2-git-send-email-mpe@ellerman.id.au> (raw)
In-Reply-To: <1424665281-25431-1-git-send-email-mpe@ellerman.id.au>
From: Ryan Grimm <grimm@linux.vnet.ibm.com>
Commit 6f963ec2d6bf2476a16799eece920acb2100ff1c upstream.
When unbinding and rebinding the driver on a system with a card in PHB0, this
error condition is reached after a few attempts:
ERROR: Bad of_node_put() on /pciex@3fffe40000000
CPU: 0 PID: 3040 Comm: bash Not tainted 3.18.0-rc3-12545-g3627ffe #152
Call Trace:
[c000000721acb5c0] [c00000000086ef94] .dump_stack+0x84/0xb0 (unreliable)
[c000000721acb640] [c00000000073a0a8] .of_node_release+0xd8/0xe0
[c000000721acb6d0] [c00000000044bc44] .kobject_release+0x74/0xe0
[c000000721acb760] [c0000000007394fc] .of_node_put+0x1c/0x30
[c000000721acb7d0] [c000000000545cd8] .cxl_probe+0x1a98/0x1d50
[c000000721acb900] [c0000000004845a0] .local_pci_probe+0x40/0xc0
[c000000721acb980] [c000000000484998] .pci_device_probe+0x128/0x170
[c000000721acba30] [c00000000052400c] .driver_probe_device+0xac/0x2a0
[c000000721acbad0] [c000000000522468] .bind_store+0x108/0x160
[c000000721acbb70] [c000000000521448] .drv_attr_store+0x38/0x60
[c000000721acbbe0] [c000000000293840] .sysfs_kf_write+0x60/0xa0
[c000000721acbc50] [c000000000292500] .kernfs_fop_write+0x140/0x1d0
[c000000721acbcf0] [c000000000208648] .vfs_write+0xd8/0x260
[c000000721acbd90] [c000000000208b18] .SyS_write+0x58/0x100
[c000000721acbe30] [c000000000009258] syscall_exit+0x0/0x98
We are missing a call to of_node_get(). pnv_pci_to_phb_node() should
call of_node_get() otherwise np's reference count isn't incremented and
it might go away. Rename pnv_pci_to_phb_node() to pnv_pci_get_phb_node()
so it's clear it calls of_node_get().
Signed-off-by: Ryan Grimm <grimm@linux.vnet.ibm.com>
Acked-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
arch/powerpc/include/asm/pnv-pci.h | 2 +-
arch/powerpc/platforms/powernv/pci-ioda.c | 6 +++---
drivers/misc/cxl/pci.c | 2 +-
3 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/include/asm/pnv-pci.h b/arch/powerpc/include/asm/pnv-pci.h
index f09a22fa1bd7..bfa8f8ac51fa 100644
--- a/arch/powerpc/include/asm/pnv-pci.h
+++ b/arch/powerpc/include/asm/pnv-pci.h
@@ -19,7 +19,7 @@ int pnv_cxl_ioda_msi_setup(struct pci_dev *dev, unsigned int hwirq,
int pnv_cxl_alloc_hwirqs(struct pci_dev *dev, int num);
void pnv_cxl_release_hwirqs(struct pci_dev *dev, int hwirq, int num);
int pnv_cxl_get_irq_count(struct pci_dev *dev);
-struct device_node *pnv_pci_to_phb_node(struct pci_dev *dev);
+struct device_node *pnv_pci_get_phb_node(struct pci_dev *dev);
#ifdef CONFIG_CXL_BASE
int pnv_cxl_alloc_hwirq_ranges(struct cxl_irq_ranges *irqs,
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index fac88ed8a915..6a9a255d8058 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -1460,13 +1460,13 @@ static void set_msi_irq_chip(struct pnv_phb *phb, unsigned int virq)
#ifdef CONFIG_CXL_BASE
-struct device_node *pnv_pci_to_phb_node(struct pci_dev *dev)
+struct device_node *pnv_pci_get_phb_node(struct pci_dev *dev)
{
struct pci_controller *hose = pci_bus_to_host(dev->bus);
- return hose->dn;
+ return of_node_get(hose->dn);
}
-EXPORT_SYMBOL(pnv_pci_to_phb_node);
+EXPORT_SYMBOL(pnv_pci_get_phb_node);
int pnv_phb_to_cxl(struct pci_dev *dev)
{
diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index 184550baa8b9..eee4fd606dc1 100644
--- a/drivers/misc/cxl/pci.c
+++ b/drivers/misc/cxl/pci.c
@@ -316,7 +316,7 @@ static int init_implementation_adapter_regs(struct cxl *adapter, struct pci_dev
u64 psl_dsnctl;
u64 chipid;
- if (!(np = pnv_pci_to_phb_node(dev)))
+ if (!(np = pnv_pci_get_phb_node(dev)))
return -ENODEV;
while (np && !(prop = of_get_property(np, "ibm,chip-id", NULL)))
--
2.1.0
next prev parent reply other threads:[~2015-02-23 4:21 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-23 4:21 [PATCH 1/3] cxl: Use image state defaults for reloading FPGA Michael Ellerman
2015-02-23 4:21 ` Michael Ellerman [this message]
2015-02-23 4:21 ` [PATCH 3/3] cxl: Add missing return statement after handling AFU errror Michael Ellerman
2015-02-25 0:32 ` [PATCH 1/3] cxl: Use image state defaults for reloading FPGA Greg KH
2015-02-25 4:40 ` Ian Munsie
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