| Message ID | 20170301082540.23995-1-yinghai@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Wed, Mar 1, 2017 at 12:25 AM, Yinghai Lu <yinghai@kernel.org> wrote: > > ~ # echo 1 > /sys/bus/pci/devices/0000\:0b\:00.0/remove > ... > BUG: unable to handle kernel NULL pointer dereference at 0000000000000080 > IP: pcie_config_aspm_link+0x5d/0x2b0 > Call Trace: > pcie_aspm_exit_link_state+0x75/0x130 > pci_stop_bus_device+0xa4/0xb0 > pci_stop_and_remove_bus_device_locked+0x1a/0x30 > remove_store+0x50/0x70 > dev_attr_store+0x18/0x30 > sysfs_kf_write+0x44/0x60 > kernfs_fop_write+0x10e/0x190 > __vfs_write+0x28/0x110 > ? rcu_read_lock_sched_held+0x5d/0x80 > ? rcu_sync_lockdep_assert+0x2c/0x60 > ? __sb_start_write+0x173/0x1a0 > ? vfs_write+0xb3/0x180 > vfs_write+0xc4/0x180 > SyS_write+0x49/0xa0 > do_syscall_64+0xa6/0x1c0 > entry_SYSCALL64_slow_path+0x25/0x25 > ---[ end trace bd187ee0267df5d9 ]--- > > set downstream even with blacklist path. Thanks for fixing this. > > > Signed-off-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Rajat Jain <rajatja@google.com> > > --- > drivers/pci/pcie/aspm.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > Index: linux-2.6/drivers/pci/pcie/aspm.c > =================================================================== > --- linux-2.6.orig/drivers/pci/pcie/aspm.c > +++ linux-2.6/drivers/pci/pcie/aspm.c > @@ -478,7 +478,7 @@ static void aspm_calc_l1ss_info(struct p > > static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist) > { > - struct pci_dev *child, *parent = link->pdev; > + struct pci_dev *child = link->downstream, *parent = link->pdev; > struct pci_bus *linkbus = parent->subordinate; > struct aspm_register_info upreg, dwreg; > > @@ -491,9 +491,7 @@ static void pcie_aspm_cap_init(struct pc > > /* Get upstream/downstream components' register state */ > pcie_get_aspm_reg(parent, &upreg); > - child = pci_function_0(linkbus); > pcie_get_aspm_reg(child, &dwreg); > - link->downstream = child; > > /* > * If ASPM not supported, don't mess with the clocks and link, > @@ -800,6 +798,7 @@ static struct pcie_link_state *alloc_pci > INIT_LIST_HEAD(&link->children); > INIT_LIST_HEAD(&link->link); > link->pdev = pdev; > + link->downstream = pci_function_0(pdev->subordinate); > > /* > * Root Ports and PCI/PCI-X to PCIe Bridges are roots of PCIe
On Wed, Mar 01, 2017 at 12:25:40AM -0800, Yinghai Lu wrote: > ~ # echo 1 > /sys/bus/pci/devices/0000\:0b\:00.0/remove > ... > BUG: unable to handle kernel NULL pointer dereference at 0000000000000080 > IP: pcie_config_aspm_link+0x5d/0x2b0 > Call Trace: > pcie_aspm_exit_link_state+0x75/0x130 > pci_stop_bus_device+0xa4/0xb0 > pci_stop_and_remove_bus_device_locked+0x1a/0x30 > remove_store+0x50/0x70 > dev_attr_store+0x18/0x30 > sysfs_kf_write+0x44/0x60 > kernfs_fop_write+0x10e/0x190 > __vfs_write+0x28/0x110 > ? rcu_read_lock_sched_held+0x5d/0x80 > ? rcu_sync_lockdep_assert+0x2c/0x60 > ? __sb_start_write+0x173/0x1a0 > ? vfs_write+0xb3/0x180 > vfs_write+0xc4/0x180 > SyS_write+0x49/0xa0 > do_syscall_64+0xa6/0x1c0 > entry_SYSCALL64_slow_path+0x25/0x25 > ---[ end trace bd187ee0267df5d9 ]--- > > set downstream even with blacklist path. > > Signed-off-by: Yinghai Lu <yinghai@kernel.org> Applied with Rajat's ack to for-linus for v4.11, thanks! I added a stable tag, since I think this bug has been there a long time and it causes a NULL pointer dereference. > --- > drivers/pci/pcie/aspm.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > Index: linux-2.6/drivers/pci/pcie/aspm.c > =================================================================== > --- linux-2.6.orig/drivers/pci/pcie/aspm.c > +++ linux-2.6/drivers/pci/pcie/aspm.c > @@ -478,7 +478,7 @@ static void aspm_calc_l1ss_info(struct p > > static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist) > { > - struct pci_dev *child, *parent = link->pdev; > + struct pci_dev *child = link->downstream, *parent = link->pdev; > struct pci_bus *linkbus = parent->subordinate; > struct aspm_register_info upreg, dwreg; > > @@ -491,9 +491,7 @@ static void pcie_aspm_cap_init(struct pc > > /* Get upstream/downstream components' register state */ > pcie_get_aspm_reg(parent, &upreg); > - child = pci_function_0(linkbus); > pcie_get_aspm_reg(child, &dwreg); > - link->downstream = child; > > /* > * If ASPM not supported, don't mess with the clocks and link, > @@ -800,6 +798,7 @@ static struct pcie_link_state *alloc_pci > INIT_LIST_HEAD(&link->children); > INIT_LIST_HEAD(&link->link); > link->pdev = pdev; > + link->downstream = pci_function_0(pdev->subordinate); > > /* > * Root Ports and PCI/PCI-X to PCIe Bridges are roots of PCIe
Index: linux-2.6/drivers/pci/pcie/aspm.c =================================================================== --- linux-2.6.orig/drivers/pci/pcie/aspm.c +++ linux-2.6/drivers/pci/pcie/aspm.c @@ -478,7 +478,7 @@ static void aspm_calc_l1ss_info(struct p static void pcie_aspm_cap_init(struct pcie_link_state *link, int blacklist) { - struct pci_dev *child, *parent = link->pdev; + struct pci_dev *child = link->downstream, *parent = link->pdev; struct pci_bus *linkbus = parent->subordinate; struct aspm_register_info upreg, dwreg; @@ -491,9 +491,7 @@ static void pcie_aspm_cap_init(struct pc /* Get upstream/downstream components' register state */ pcie_get_aspm_reg(parent, &upreg); - child = pci_function_0(linkbus); pcie_get_aspm_reg(child, &dwreg); - link->downstream = child; /* * If ASPM not supported, don't mess with the clocks and link, @@ -800,6 +798,7 @@ static struct pcie_link_state *alloc_pci INIT_LIST_HEAD(&link->children); INIT_LIST_HEAD(&link->link); link->pdev = pdev; + link->downstream = pci_function_0(pdev->subordinate); /* * Root Ports and PCI/PCI-X to PCIe Bridges are roots of PCIe
~ # echo 1 > /sys/bus/pci/devices/0000\:0b\:00.0/remove ... BUG: unable to handle kernel NULL pointer dereference at 0000000000000080 IP: pcie_config_aspm_link+0x5d/0x2b0 Call Trace: pcie_aspm_exit_link_state+0x75/0x130 pci_stop_bus_device+0xa4/0xb0 pci_stop_and_remove_bus_device_locked+0x1a/0x30 remove_store+0x50/0x70 dev_attr_store+0x18/0x30 sysfs_kf_write+0x44/0x60 kernfs_fop_write+0x10e/0x190 __vfs_write+0x28/0x110 ? rcu_read_lock_sched_held+0x5d/0x80 ? rcu_sync_lockdep_assert+0x2c/0x60 ? __sb_start_write+0x173/0x1a0 ? vfs_write+0xb3/0x180 vfs_write+0xc4/0x180 SyS_write+0x49/0xa0 do_syscall_64+0xa6/0x1c0 entry_SYSCALL64_slow_path+0x25/0x25 ---[ end trace bd187ee0267df5d9 ]--- set downstream even with blacklist path. Signed-off-by: Yinghai Lu <yinghai@kernel.org> --- drivers/pci/pcie/aspm.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)