linux-stable.git/arch/powerpc, branch v3.13.2 Linux kernel stable tree powerpc: Make sure "cache" directory is removed when offlining cpu 2014-02-06T19:34:12+00:00 Paul Mackerras paulus@samba.org 2014-01-18T10:14:47+00:00 8698e6867596eaaa98535f0e4ee801a076633928 commit 91b973f90c1220d71923e7efe1e61f5329806380 upstream. The code in remove_cache_dir() is supposed to remove the "cache" subdirectory from the sysfs directory for a CPU when that CPU is being offlined. It tries to do this by calling kobject_put() on the kobject for the subdirectory. However, the subdirectory only gets removed once the last reference goes away, and the reference being put here may well not be the last reference. That means that the "cache" subdirectory may still exist when the offlining operation has finished. If the same CPU subsequently gets onlined, the code tries to add a new "cache" subdirectory. If the old subdirectory has not yet been removed, we get a WARN_ON in the sysfs code, with stack trace, and an error message printed on the console. Further, we ultimately end up with an online cpu with no "cache" subdirectory. This fixes it by doing an explicit kobject_del() at the point where we want the subdirectory to go away. kobject_del() removes the sysfs directory even though the object still exists in memory. The object will get freed at some point in the future. A subsequent onlining operation can create a new sysfs directory, even if the old object still exists in memory, without causing any problems. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 91b973f90c1220d71923e7efe1e61f5329806380 upstream.

The code in remove_cache_dir() is supposed to remove the "cache"
subdirectory from the sysfs directory for a CPU when that CPU is
being offlined.  It tries to do this by calling kobject_put() on
the kobject for the subdirectory.  However, the subdirectory only
gets removed once the last reference goes away, and the reference
being put here may well not be the last reference.  That means
that the "cache" subdirectory may still exist when the offlining
operation has finished.  If the same CPU subsequently gets onlined,
the code tries to add a new "cache" subdirectory.  If the old
subdirectory has not yet been removed, we get a WARN_ON in the
sysfs code, with stack trace, and an error message printed on the
console.  Further, we ultimately end up with an online cpu with no
"cache" subdirectory.

This fixes it by doing an explicit kobject_del() at the point where
we want the subdirectory to go away.  kobject_del() removes the sysfs
directory even though the object still exists in memory.  The object
will get freed at some point in the future.  A subsequent onlining
operation can create a new sysfs directory, even if the old object
still exists in memory, without causing any problems.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
powerpc: Fix the setup of CPU-to-Node mappings during CPU online 2014-02-06T19:34:11+00:00 Srivatsa S. Bhat srivatsa.bhat@linux.vnet.ibm.com 2013-12-30T11:35:34+00:00 5326f5fc83fecf025bf211f429373d7bed0f7582 commit d4edc5b6c480a0917e61d93d55531d7efa6230be upstream. On POWER platforms, the hypervisor can notify the guest kernel about dynamic changes in the cpu-numa associativity (VPHN topology update). Hence the cpu-to-node mappings that we got from the firmware during boot, may no longer be valid after such updates. This is handled using the arch_update_cpu_topology() hook in the scheduler, and the sched-domains are rebuilt according to the new mappings. But unfortunately, at the moment, CPU hotplug ignores these updated mappings and instead queries the firmware for the cpu-to-numa relationships and uses them during CPU online. So the kernel can end up assigning wrong NUMA nodes to CPUs during subsequent CPU hotplug online operations (after booting). Further, a particularly problematic scenario can result from this bug: On POWER platforms, the SMT mode can be switched between 1, 2, 4 (and even 8) threads per core. The switch to Single-Threaded (ST) mode is performed by offlining all except the first CPU thread in each core. Switching back to SMT mode involves onlining those other threads back, in each core. Now consider this scenario: 1. During boot, the kernel gets the cpu-to-node mappings from the firmware and assigns the CPUs to NUMA nodes appropriately, during CPU online. 2. Later on, the hypervisor updates the cpu-to-node mappings dynamically and communicates this update to the kernel. The kernel in turn updates its cpu-to-node associations and rebuilds its sched domains. Everything is fine so far. 3. Now, the user switches the machine from SMT to ST mode (say, by running ppc64_cpu --smt=1). This involves offlining all except 1 thread in each core. 4. The user then tries to switch back from ST to SMT mode (say, by running ppc64_cpu --smt=4), and this involves onlining those threads back. Since CPU hotplug ignores the new mappings, it queries the firmware and tries to associate the newly onlined sibling threads to the old NUMA nodes. This results in sibling threads within the same core getting associated with different NUMA nodes, which is incorrect. The scheduler's build-sched-domains code gets thoroughly confused with this and enters an infinite loop and causes soft-lockups, as explained in detail in commit 3be7db6ab (powerpc: VPHN topology change updates all siblings). So to fix this, use the numa_cpu_lookup_table to remember the updated cpu-to-node mappings, and use them during CPU hotplug online operations. Further, we also need to ensure that all threads in a core are assigned to a common NUMA node, irrespective of whether all those threads were online during the topology update. To achieve this, we take care not to use cpu_sibling_mask() since it is not hotplug invariant. Instead, we use cpu_first_sibling_thread() and set up the mappings manually using the 'threads_per_core' value for that particular platform. This helps us ensure that we don't hit this bug with any combination of CPU hotplug and SMT mode switching. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d4edc5b6c480a0917e61d93d55531d7efa6230be upstream.

On POWER platforms, the hypervisor can notify the guest kernel about dynamic
changes in the cpu-numa associativity (VPHN topology update). Hence the
cpu-to-node mappings that we got from the firmware during boot, may no longer
be valid after such updates. This is handled using the arch_update_cpu_topology()
hook in the scheduler, and the sched-domains are rebuilt according to the new
mappings.

But unfortunately, at the moment, CPU hotplug ignores these updated mappings
and instead queries the firmware for the cpu-to-numa relationships and uses
them during CPU online. So the kernel can end up assigning wrong NUMA nodes
to CPUs during subsequent CPU hotplug online operations (after booting).

Further, a particularly problematic scenario can result from this bug:
On POWER platforms, the SMT mode can be switched between 1, 2, 4 (and even 8)
threads per core. The switch to Single-Threaded (ST) mode is performed by
offlining all except the first CPU thread in each core. Switching back to
SMT mode involves onlining those other threads back, in each core.

Now consider this scenario:

1. During boot, the kernel gets the cpu-to-node mappings from the firmware
   and assigns the CPUs to NUMA nodes appropriately, during CPU online.

2. Later on, the hypervisor updates the cpu-to-node mappings dynamically and
   communicates this update to the kernel. The kernel in turn updates its
   cpu-to-node associations and rebuilds its sched domains. Everything is
   fine so far.

3. Now, the user switches the machine from SMT to ST mode (say, by running
   ppc64_cpu --smt=1). This involves offlining all except 1 thread in each
   core.

4. The user then tries to switch back from ST to SMT mode (say, by running
   ppc64_cpu --smt=4), and this involves onlining those threads back. Since
   CPU hotplug ignores the new mappings, it queries the firmware and tries to
   associate the newly onlined sibling threads to the old NUMA nodes. This
   results in sibling threads within the same core getting associated with
   different NUMA nodes, which is incorrect.

   The scheduler's build-sched-domains code gets thoroughly confused with this
   and enters an infinite loop and causes soft-lockups, as explained in detail
   in commit 3be7db6ab (powerpc: VPHN topology change updates all siblings).

So to fix this, use the numa_cpu_lookup_table to remember the updated
cpu-to-node mappings, and use them during CPU hotplug online operations.
Further, we also need to ensure that all threads in a core are assigned to a
common NUMA node, irrespective of whether all those threads were online during
the topology update. To achieve this, we take care not to use cpu_sibling_mask()
since it is not hotplug invariant. Instead, we use cpu_first_sibling_thread()
and set up the mappings manually using the 'threads_per_core' value for that
particular platform. This helps us ensure that we don't hit this bug with any
combination of CPU hotplug and SMT mode switching.

Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
KVM: PPC: e500: Fix bad address type in deliver_tlb_misss() 2014-02-06T19:34:10+00:00 Mihai Caraman mihai.caraman@freescale.com 2014-01-09T15:01:05+00:00 946c119beade4f44113c09974410af82e92fcc3c commit 70713fe315ed14cd1bb07d1a7f33e973d136ae3d upstream. Use gva_t instead of unsigned int for eaddr in deliver_tlb_miss(). Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 70713fe315ed14cd1bb07d1a7f33e973d136ae3d upstream.

Use gva_t instead of unsigned int for eaddr in deliver_tlb_miss().

Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
KVM: PPC: Book3S HV: use xics_wake_cpu only when defined 2014-02-06T19:34:09+00:00 Andreas Schwab schwab@linux-m68k.org 2013-12-30T14:36:56+00:00 a03e895e05a2ee3939f559e2644f762d04b3972a commit 48eaef0518a565d3852e301c860e1af6a6db5a84 upstream. Signed-off-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 48eaef0518a565d3852e301c860e1af6a6db5a84 upstream.

Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-01-18T06:19:28+00:00 Linus Torvalds torvalds@linux-foundation.org 2014-01-18T06:19:28+00:00 7d0d46da750a252371cb747b48ddda27d1047881 Pull networking fixes from David Miller: 1) The value choosen for the new SO_MAX_PACING_RATE socket option on parisc was very poorly choosen, let's fix it while we still can. From Eric Dumazet. 2) Our generic reciprocal divide was found to handle some edge cases incorrectly, part of this is encoded into the BPF as deep as the JIT engines themselves. Just use a real divide throughout for now. From Eric Dumazet. 3) Because the initial lookup is lockless, the TCP metrics engine can end up creating two entries for the same lookup key. Fix this by doing a second lookup under the lock before we actually create the new entry. From Christoph Paasch. 4) Fix scatter-gather list init in usbnet driver, from Bjørn Mork. 5) Fix unintended 32-bit truncation in cxgb4 driver's bit shifting. From Dan Carpenter. 6) Netlink socket dumping uses the wrong socket state for timewait sockets. Fix from Neal Cardwell. 7) Fix netlink memory leak in ieee802154_add_iface(), from Christian Engelmayer. 8) Multicast forwarding in ipv4 can overflow the per-rule reference counts, causing all multicast traffic to cease. Fix from Hannes Frederic Sowa. 9) via-rhine needs to stop all TX queues when it resets the device, from Richard Weinberger. 10) Fix RDS per-cpu accesses broken by the this_cpu_* conversions. From Gerald Schaefer. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: s390/bpf,jit: fix 32 bit divisions, use unsigned divide instructions parisc: fix SO_MAX_PACING_RATE typo ipv6: simplify detection of first operational link-local address on interface tcp: metrics: Avoid duplicate entries with the same destination-IP net: rds: fix per-cpu helper usage e1000e: Fix compilation warning when !CONFIG_PM_SLEEP bpf: do not use reciprocal divide be2net: add dma_mapping_error() check for dma_map_page() bnx2x: Don't release PCI bars on shutdown net,via-rhine: Fix tx_timeout handling batman-adv: fix batman-adv header overhead calculation qlge: Fix vlan netdev features. net: avoid reference counter overflows on fib_rules in multicast forwarding dm9601: add USB IDs for new dm96xx variants MAINTAINERS: add virtio-dev ML for virtio ieee802154: Fix memory leak in ieee802154_add_iface() net: usbnet: fix SG initialisation inet_diag: fix inet_diag_dump_icsk() to use correct state for timewait sockets cxgb4: silence shift wrapping static checker warning 
Pull networking fixes from David Miller:

 1) The value choosen for the new SO_MAX_PACING_RATE socket option on
    parisc was very poorly choosen, let's fix it while we still can.
    From Eric Dumazet.

 2) Our generic reciprocal divide was found to handle some edge cases
    incorrectly, part of this is encoded into the BPF as deep as the JIT
    engines themselves.  Just use a real divide throughout for now.
    From Eric Dumazet.

 3) Because the initial lookup is lockless, the TCP metrics engine can
    end up creating two entries for the same lookup key.  Fix this by
    doing a second lookup under the lock before we actually create the
    new entry.  From Christoph Paasch.

 4) Fix scatter-gather list init in usbnet driver, from Bjørn Mork.

 5) Fix unintended 32-bit truncation in cxgb4 driver's bit shifting.
    From Dan Carpenter.

 6) Netlink socket dumping uses the wrong socket state for timewait
    sockets.  Fix from Neal Cardwell.

 7) Fix netlink memory leak in ieee802154_add_iface(), from Christian
    Engelmayer.

 8) Multicast forwarding in ipv4 can overflow the per-rule reference
    counts, causing all multicast traffic to cease.  Fix from Hannes
    Frederic Sowa.

 9) via-rhine needs to stop all TX queues when it resets the device,
    from Richard Weinberger.

10) Fix RDS per-cpu accesses broken by the this_cpu_* conversions.  From
    Gerald Schaefer.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  s390/bpf,jit: fix 32 bit divisions, use unsigned divide instructions
  parisc: fix SO_MAX_PACING_RATE typo
  ipv6: simplify detection of first operational link-local address on interface
  tcp: metrics: Avoid duplicate entries with the same destination-IP
  net: rds: fix per-cpu helper usage
  e1000e: Fix compilation warning when !CONFIG_PM_SLEEP
  bpf: do not use reciprocal divide
  be2net: add dma_mapping_error() check for dma_map_page()
  bnx2x: Don't release PCI bars on shutdown
  net,via-rhine: Fix tx_timeout handling
  batman-adv: fix batman-adv header overhead calculation
  qlge: Fix vlan netdev features.
  net: avoid reference counter overflows on fib_rules in multicast forwarding
  dm9601: add USB IDs for new dm96xx variants
  MAINTAINERS: add virtio-dev ML for virtio
  ieee802154: Fix memory leak in ieee802154_add_iface()
  net: usbnet: fix SG initialisation
  inet_diag: fix inet_diag_dump_icsk() to use correct state for timewait sockets
  cxgb4: silence shift wrapping static checker warning
bpf: do not use reciprocal divide 2014-01-16T01:02:08+00:00 Eric Dumazet edumazet@google.com 2014-01-15T14:50:07+00:00 aee636c4809fa54848ff07a899b326eb1f9987a2 At first Jakub Zawadzki noticed that some divisions by reciprocal_divide were not correct. (off by one in some cases) http://www.wireshark.org/~darkjames/reciprocal-buggy.c He could also show this with BPF: http://www.wireshark.org/~darkjames/set-and-dump-filter-k-bug.c The reciprocal divide in linux kernel is not generic enough, lets remove its use in BPF, as it is not worth the pain with current cpus. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Jakub Zawadzki <darkjames-ws@darkjames.pl> Cc: Mircea Gherzan <mgherzan@gmail.com> Cc: Daniel Borkmann <dxchgb@gmail.com> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: Matt Evans <matt@ozlabs.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: David S. Miller <davem@davemloft.net> 
At first Jakub Zawadzki noticed that some divisions by reciprocal_divide
were not correct. (off by one in some cases)
http://www.wireshark.org/~darkjames/reciprocal-buggy.c

He could also show this with BPF:
http://www.wireshark.org/~darkjames/set-and-dump-filter-k-bug.c

The reciprocal divide in linux kernel is not generic enough,
lets remove its use in BPF, as it is not worth the pain with
current cpus.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jakub Zawadzki <darkjames-ws@darkjames.pl>
Cc: Mircea Gherzan <mgherzan@gmail.com>
Cc: Daniel Borkmann <dxchgb@gmail.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Matt Evans <matt@ozlabs.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2014-01-13T03:59:05+00:00 Linus Torvalds torvalds@linux-foundation.org 2014-01-13T03:59:05+00:00 a6da83f98267bc8ee4e34aa899169991eb0ceb93 Pull powerpc fix from Ben Herrenschmidt: "Here's one regression fix for 3.13 that I would appreciate if you could still pull in. It was an "interesting" one to debug, basically it's an old bug that got somewhat "exposed" by new code breaking the boot on PA Semi boards (yes, it does appear that some people are still using these!)" * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: powerpc: Check return value of instance-to-package OF call 
Pull powerpc fix from Ben Herrenschmidt:
 "Here's one regression fix for 3.13 that I would appreciate if you
  could still pull in.  It was an "interesting" one to debug, basically
  it's an old bug that got somewhat "exposed" by new code breaking the
  boot on PA Semi boards (yes, it does appear that some people are still
  using these!)"

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc: Check return value of instance-to-package OF call
powerpc: Check return value of instance-to-package OF call 2014-01-12T22:49:17+00:00 Benjamin Herrenschmidt benh@kernel.crashing.org 2014-01-12T22:49:17+00:00 10348f5976830e5d8f74e8abb04a9a057a5e8478 On PA-Semi firmware, the instance-to-package callback doesn't seem to be implemented. We didn't check for error, however, thus subsequently passed the -1 value returned into stdout_node to thins like prom_getprop etc... Thus caused the firmware to load values around 0 (physical) internally as node structures. It somewhat "worked" as long as we had a NULL in the right place (address 8) at the beginning of the kernel, we didn't "see" the bug. But commit 5c0484e25ec03243d4c2f2d4416d4a13efc77f6a "powerpc: Endian safe trampoline" changed the kernel entry point causing that old bug to now cause a crash early during boot. This fixes booting on PA-Semi board by properly checking the return value from instance-to-package. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Olof Johansson <olof@lixom.net> --- 
On PA-Semi firmware, the instance-to-package callback doesn't seem
to be implemented. We didn't check for error, however, thus
subsequently passed the -1 value returned into stdout_node to
thins like prom_getprop etc...

Thus caused the firmware to load values around 0 (physical) internally
as node structures. It somewhat "worked" as long as we had a NULL in the
right place (address 8) at the beginning of the kernel, we didn't "see"
the bug. But commit 5c0484e25ec03243d4c2f2d4416d4a13efc77f6a
"powerpc: Endian safe trampoline" changed the kernel entry point causing
that old bug to now cause a crash early during boot.

This fixes booting on PA-Semi board by properly checking the return
value from instance-to-package.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Olof Johansson <olof@lixom.net>
---
Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2013-12-30T18:22:57+00:00 Linus Torvalds torvalds@linux-foundation.org 2013-12-30T18:22:57+00:00 6e4c61968beb641e8372733e4a0c0cdee720e675 Pull powerpc fixes from Ben Herrenschmidt: "A bit more endian problems found during testing of 3.13 and a few other simple fixes and regressions fixes" * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: powerpc: Fix alignment of secondary cpu spin vars powerpc: Align p_end powernv/eeh: Add buffer for P7IOC hub error data powernv/eeh: Fix possible buffer overrun in ioda_eeh_phb_diag() powerpc: Make 64-bit non-VMX __copy_tofrom_user bi-endian powerpc: Make unaligned accesses endian-safe for powerpc powerpc: Fix bad stack check in exception entry powerpc/512x: dts: disable MPC5125 usb module powerpc/512x: dts: remove misplaced IRQ spec from 'soc' node (5125) 
Pull powerpc fixes from Ben Herrenschmidt:
 "A bit more endian problems found during testing of 3.13 and a few
  other simple fixes and regressions fixes"

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc: Fix alignment of secondary cpu spin vars
  powerpc: Align p_end
  powernv/eeh: Add buffer for P7IOC hub error data
  powernv/eeh: Fix possible buffer overrun in ioda_eeh_phb_diag()
  powerpc: Make 64-bit non-VMX __copy_tofrom_user bi-endian
  powerpc: Make unaligned accesses endian-safe for powerpc
  powerpc: Fix bad stack check in exception entry
  powerpc/512x: dts: disable MPC5125 usb module
  powerpc/512x: dts: remove misplaced IRQ spec from 'soc' node (5125)
Merge remote-tracking branch 'agust/merge' into merge 2013-12-30T03:48:27+00:00 Benjamin Herrenschmidt benh@kernel.crashing.org 2013-12-30T03:48:27+00:00 f991db1cf1bdca43675b5d2df0af991719727029 Anatolij writes: Please pull two DTS fixes for MPC5125 tower board. Without them the v3.13-rcX kernels do not boot. 
Anatolij writes:

Please pull two DTS fixes for MPC5125 tower board. Without
them the v3.13-rcX kernels do not boot.