| Message ID | 1397112695-3945-1-git-send-email-qiudayu@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Thu, 2014-04-10 at 02:51 -0400, Mike Qiu wrote: > Unable to handle kernel paging request for data at address 0x00000000 > Faulting instruction address: 0xc000000000041d78 > Oops: Kernel access of bad area, sig: 11 [#1] > ... > NIP [c000000000041d78] .sys_pciconfig_iobase+0x68/0x1f0 > LR [c000000000041e0c] .sys_pciconfig_iobase+0xfc/0x1f0 > Call Trace: > [c0000003b4787db0] [c000000000041e0c] .sys_pciconfig_iobase+0xfc/0x1f0 (unreliable) > [c0000003b4787e30] [c000000000009ed8] syscall_exit+0x0/0x98 > > This bug was introduced by commit 3bc955987fb377f3c95bc29deb498e96819b8451 > The root cause was the 'bus' has been set to null while try to access > bus->next. Good catch. Out of curiosity, what is using that syscall nowadays ? It's been long buggy in all sort of ways and is pretty much deprecated... Cheers, Ben. > Signed-off-by: Mike Qiu <qiudayu@linux.vnet.ibm.com> > --- > arch/powerpc/kernel/pci_64.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c > index 2a47790..7b6c1ae 100644 > --- a/arch/powerpc/kernel/pci_64.c > +++ b/arch/powerpc/kernel/pci_64.c > @@ -209,6 +209,7 @@ long sys_pciconfig_iobase(long which, unsigned long in_bus, > { > struct pci_controller* hose; > struct pci_bus *bus = NULL; > + struct pci_bus *tmp_bus = NULL; > struct device_node *hose_node; > > /* Argh ! Please forgive me for that hack, but that's the > @@ -229,10 +230,12 @@ long sys_pciconfig_iobase(long which, unsigned long in_bus, > * used on pre-domains setup. We return the first match > */ > > - list_for_each_entry(bus, &pci_root_buses, node) { > - if (in_bus >= bus->number && in_bus <= bus->busn_res.end) > + list_for_each_entry(tmp_bus, &pci_root_buses, node) { > + if (in_bus >= tmp_bus->number && > + in_bus <= tmp_bus->busn_res.end) { > + bus = tmp_bus; > break; > - bus = NULL; > + } > } > if (bus == NULL || bus->dev.of_node == NULL) > return -ENODEV;
On 04/10/2014 03:54 PM, Benjamin Herrenschmidt wrote: > On Thu, 2014-04-10 at 02:51 -0400, Mike Qiu wrote: >> Unable to handle kernel paging request for data at address 0x00000000 >> Faulting instruction address: 0xc000000000041d78 >> Oops: Kernel access of bad area, sig: 11 [#1] >> ... >> NIP [c000000000041d78] .sys_pciconfig_iobase+0x68/0x1f0 >> LR [c000000000041e0c] .sys_pciconfig_iobase+0xfc/0x1f0 >> Call Trace: >> [c0000003b4787db0] [c000000000041e0c] .sys_pciconfig_iobase+0xfc/0x1f0 (unreliable) >> [c0000003b4787e30] [c000000000009ed8] syscall_exit+0x0/0x98 >> >> This bug was introduced by commit 3bc955987fb377f3c95bc29deb498e96819b8451 >> The root cause was the 'bus' has been set to null while try to access >> bus->next. > Good catch. Out of curiosity, what is using that syscall nowadays ? It's > been long buggy in all sort of ways and is pretty much deprecated... > I just boot my Power7 machine with newest mainline kernel, it happens and block the system. I really do not know which software use this syscall, need to do some research on it. Thanks Mike > Cheers, > Ben. > >> Signed-off-by: Mike Qiu <qiudayu@linux.vnet.ibm.com> >> --- >> arch/powerpc/kernel/pci_64.c | 9 ++++++--- >> 1 file changed, 6 insertions(+), 3 deletions(-) >> >> diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c >> index 2a47790..7b6c1ae 100644 >> --- a/arch/powerpc/kernel/pci_64.c >> +++ b/arch/powerpc/kernel/pci_64.c >> @@ -209,6 +209,7 @@ long sys_pciconfig_iobase(long which, unsigned long in_bus, >> { >> struct pci_controller* hose; >> struct pci_bus *bus = NULL; >> + struct pci_bus *tmp_bus = NULL; >> struct device_node *hose_node; >> >> /* Argh ! Please forgive me for that hack, but that's the >> @@ -229,10 +230,12 @@ long sys_pciconfig_iobase(long which, unsigned long in_bus, >> * used on pre-domains setup. We return the first match >> */ >> >> - list_for_each_entry(bus, &pci_root_buses, node) { >> - if (in_bus >= bus->number && in_bus <= bus->busn_res.end) >> + list_for_each_entry(tmp_bus, &pci_root_buses, node) { >> + if (in_bus >= tmp_bus->number && >> + in_bus <= tmp_bus->busn_res.end) { >> + bus = tmp_bus; >> break; >> - bus = NULL; >> + } >> } >> if (bus == NULL || bus->dev.of_node == NULL) >> return -ENODEV; > > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/linuxppc-dev
On Thu, Apr 10, 2014 at 12:51 AM, Mike Qiu <qiudayu@linux.vnet.ibm.com> wrote: > Unable to handle kernel paging request for data at address 0x00000000 > Faulting instruction address: 0xc000000000041d78 > Oops: Kernel access of bad area, sig: 11 [#1] > ... > NIP [c000000000041d78] .sys_pciconfig_iobase+0x68/0x1f0 > LR [c000000000041e0c] .sys_pciconfig_iobase+0xfc/0x1f0 > Call Trace: > [c0000003b4787db0] [c000000000041e0c] .sys_pciconfig_iobase+0xfc/0x1f0 (unreliable) > [c0000003b4787e30] [c000000000009ed8] syscall_exit+0x0/0x98 > > This bug was introduced by commit 3bc955987fb377f3c95bc29deb498e96819b8451 > The root cause was the 'bus' has been set to null while try to access > bus->next. > > Signed-off-by: Mike Qiu <qiudayu@linux.vnet.ibm.com> > --- > arch/powerpc/kernel/pci_64.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c > index 2a47790..7b6c1ae 100644 > --- a/arch/powerpc/kernel/pci_64.c > +++ b/arch/powerpc/kernel/pci_64.c > @@ -209,6 +209,7 @@ long sys_pciconfig_iobase(long which, unsigned long in_bus, > { > struct pci_controller* hose; > struct pci_bus *bus = NULL; > + struct pci_bus *tmp_bus = NULL; > struct device_node *hose_node; > > /* Argh ! Please forgive me for that hack, but that's the > @@ -229,10 +230,12 @@ long sys_pciconfig_iobase(long which, unsigned long in_bus, > * used on pre-domains setup. We return the first match > */ > > - list_for_each_entry(bus, &pci_root_buses, node) { > - if (in_bus >= bus->number && in_bus <= bus->busn_res.end) > + list_for_each_entry(tmp_bus, &pci_root_buses, node) { > + if (in_bus >= tmp_bus->number && > + in_bus <= tmp_bus->busn_res.end) { > + bus = tmp_bus; > break; > - bus = NULL; > + } Good fix, thanks. Sorry we didn't catch it before you tripped over it. Your code is much cleaner than the previous "clear out 'bus' if we didn't match" style. Nit: I don't think you need to initialize tmp_bus to NULL. Ben, I'll pick this up for v3.15 since the original change (3bc955987fb3) went through my tree, unless you want to handle it. Bjorn > } > if (bus == NULL || bus->dev.of_node == NULL) > return -ENODEV; > -- > 1.8.0.1 >
On Thu, 2014-04-10 at 09:27 -0600, Bjorn Helgaas wrote: > Ben, I'll pick this up for v3.15 since the original change > (3bc955987fb3) went through my tree, unless you want to handle it. Nah, go for it, I'm about to go on vacation for a week :-) Thanks ! Cheers, Ben.
diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c index 2a47790..7b6c1ae 100644 --- a/arch/powerpc/kernel/pci_64.c +++ b/arch/powerpc/kernel/pci_64.c @@ -209,6 +209,7 @@ long sys_pciconfig_iobase(long which, unsigned long in_bus, { struct pci_controller* hose; struct pci_bus *bus = NULL; + struct pci_bus *tmp_bus = NULL; struct device_node *hose_node; /* Argh ! Please forgive me for that hack, but that's the @@ -229,10 +230,12 @@ long sys_pciconfig_iobase(long which, unsigned long in_bus, * used on pre-domains setup. We return the first match */ - list_for_each_entry(bus, &pci_root_buses, node) { - if (in_bus >= bus->number && in_bus <= bus->busn_res.end) + list_for_each_entry(tmp_bus, &pci_root_buses, node) { + if (in_bus >= tmp_bus->number && + in_bus <= tmp_bus->busn_res.end) { + bus = tmp_bus; break; - bus = NULL; + } } if (bus == NULL || bus->dev.of_node == NULL) return -ENODEV;
Unable to handle kernel paging request for data at address 0x00000000 Faulting instruction address: 0xc000000000041d78 Oops: Kernel access of bad area, sig: 11 [#1] ... NIP [c000000000041d78] .sys_pciconfig_iobase+0x68/0x1f0 LR [c000000000041e0c] .sys_pciconfig_iobase+0xfc/0x1f0 Call Trace: [c0000003b4787db0] [c000000000041e0c] .sys_pciconfig_iobase+0xfc/0x1f0 (unreliable) [c0000003b4787e30] [c000000000009ed8] syscall_exit+0x0/0x98 This bug was introduced by commit 3bc955987fb377f3c95bc29deb498e96819b8451 The root cause was the 'bus' has been set to null while try to access bus->next. Signed-off-by: Mike Qiu <qiudayu@linux.vnet.ibm.com> --- arch/powerpc/kernel/pci_64.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)