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  1. 23 9月, 2016 2 次提交
  3. 21 7月, 2016 1 次提交
  5. 16 6月, 2016 1 次提交
  7. 11 5月, 2016 2 次提交
  9. 28 10月, 2015 1 次提交
  11. 18 2月, 2015 1 次提交
  13. 29 12月, 2014 1 次提交
    • H
      powerpc/kdump: Ignore failure in enabling big endian exception during crash · c1caae3d
      由 Hari Bathini 提交于 
      In LE kernel, we currently have a hack for kexec that resets the exception
endian before starting a new kernel as the kernel that is loaded could be a
big endian or a little endian kernel. In kdump case, resetting exception
endian fails when one or more cpus is disabled. But we can ignore the failure
and still go ahead, as in most cases crashkernel will be of same endianess
as primary kernel and reseting endianess is not even needed in those cases.
This patch adds a new inline function to say if this is kdump path. This
function is used at places where such a check is needed.
Signed-off-by: NHari Bathini <hbathini@linux.vnet.ibm.com>
[mpe: Rename to kdump_in_progress(), use bool, and edit comment]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
      c1caae3d
  15. 28 5月, 2014 1 次提交
    • S
      powerpc, kexec: Fix "Processor X is stuck" issue during kexec from ST mode · 011e4b02
      由 Srivatsa S. Bhat 提交于 
      If we try to perform a kexec when the machine is in ST (Single-Threaded) mode
(ppc64_cpu --smt=off), the kexec operation doesn't succeed properly, and we
get the following messages during boot:

[    0.089866] POWER8 performance monitor hardware support registered
[    0.089985] power8-pmu: PMAO restore workaround active.
[    5.095419] Processor 1 is stuck.
[   10.097933] Processor 2 is stuck.
[   15.100480] Processor 3 is stuck.
[   20.102982] Processor 4 is stuck.
[   25.105489] Processor 5 is stuck.
[   30.108005] Processor 6 is stuck.
[   35.110518] Processor 7 is stuck.
[   40.113369] Processor 9 is stuck.
[   45.115879] Processor 10 is stuck.
[   50.118389] Processor 11 is stuck.
[   55.120904] Processor 12 is stuck.
[   60.123425] Processor 13 is stuck.
[   65.125970] Processor 14 is stuck.
[   70.128495] Processor 15 is stuck.
[   75.131316] Processor 17 is stuck.

Note that only the sibling threads are stuck, while the primary threads (0, 8,
16 etc) boot just fine. Looking closer at the previous step of kexec, we observe
that kexec tries to wakeup (bring online) the sibling threads of all the cores,
before performing kexec:

[ 9464.131231] Starting new kernel
[ 9464.148507] kexec: Waking offline cpu 1.
[ 9464.148552] kexec: Waking offline cpu 2.
[ 9464.148600] kexec: Waking offline cpu 3.
[ 9464.148636] kexec: Waking offline cpu 4.
[ 9464.148671] kexec: Waking offline cpu 5.
[ 9464.148708] kexec: Waking offline cpu 6.
[ 9464.148743] kexec: Waking offline cpu 7.
[ 9464.148779] kexec: Waking offline cpu 9.
[ 9464.148815] kexec: Waking offline cpu 10.
[ 9464.148851] kexec: Waking offline cpu 11.
[ 9464.148887] kexec: Waking offline cpu 12.
[ 9464.148922] kexec: Waking offline cpu 13.
[ 9464.148958] kexec: Waking offline cpu 14.
[ 9464.148994] kexec: Waking offline cpu 15.
[ 9464.149030] kexec: Waking offline cpu 17.

Instrumenting this piece of code revealed that the cpu_up() operation actually
fails with -EBUSY. Thus, only the primary threads of all the cores are online
during kexec, and hence this is a sure-shot receipe for disaster, as explained
in commit e8e5c215 (powerpc/kexec: Fix orphaned offline CPUs across kexec),
as well as in the comment above wake_offline_cpus().

It turns out that cpu_up() was returning -EBUSY because the variable
'cpu_hotplug_disabled' was set to 1; and this disabling of CPU hotplug was done
by migrate_to_reboot_cpu() inside kernel_kexec().

Now, migrate_to_reboot_cpu() was originally written with the assumption that
any further code will not need to perform CPU hotplug, since we are anyway in
the reboot path. However, kexec is clearly not such a case, since we depend on
onlining CPUs, atleast on powerpc.

So re-enable cpu-hotplug after returning from migrate_to_reboot_cpu() in the
kexec path, to fix this regression in kexec on powerpc.

Also, wrap the cpu_up() in powerpc kexec code within a WARN_ON(), so that we
can catch such issues more easily in the future.

Fixes: c97102ba (kexec: migrate to reboot cpu)
Cc: stable@vger.kernel.org
Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      011e4b02
  17. 11 2月, 2014 1 次提交
  19. 30 10月, 2013 1 次提交
  21. 14 5月, 2013 1 次提交
    • A
      powerpc/kexec: Fix kexec when using VMX optimised memcpy · 79c66ce8
      由 Anton Blanchard 提交于 
      commit b3f271e8 (powerpc: POWER7 optimised memcpy using VMX and
enhanced prefetch) uses VMX when it is safe to do so (ie not in
interrupt). It also looks at the task struct to decide if we have to
save the current tasks' VMX state.

kexec calls memcpy() at a point where the task struct may have been
overwritten by the new kexec segments. If it has been overwritten
then when memcpy -> enable_altivec looks up current->thread.regs->msr
we get a cryptic oops or lockup.

I also notice we aren't initialising thread_info->cpu, which means
smp_processor_id is broken. Fix that too.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Cc: <stable@vger.kernel.org> # 3.6+
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      79c66ce8
  23. 24 2月, 2013 1 次提交
  25. 15 11月, 2012 1 次提交
  27. 13 1月, 2012 2 次提交
  29. 20 9月, 2011 1 次提交
  31. 31 7月, 2010 3 次提交
  33. 22 6月, 2010 1 次提交
    • K
      powerpc, hw_breakpoints: Implement hw_breakpoints for 64-bit server processors · 5aae8a53
      由 K.Prasad 提交于 
      Implement perf-events based hw-breakpoint interfaces for PowerPC
64-bit server (Book III S) processors.  This allows access to a
given location to be used as an event that can be counted or
profiled by the perf_events subsystem.

This is done using the DABR (data breakpoint register), which can
also be used for process debugging via ptrace.  When perf_event
hw_breakpoint support is configured in, the perf_event subsystem
manages the DABR and arbitrates access to it, and ptrace then
creates a perf_event when it is requested to set a data breakpoint.

[Adopted suggestions from Paul Mackerras <paulus@samba.org> to
- emulate_step() all system-wide breakpoints and single-step only the
  per-task breakpoints
- perform arch-specific cleanup before unregistration through
  arch_unregister_hw_breakpoint()
]
Signed-off-by: NK.Prasad <prasad@linux.vnet.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      5aae8a53
  35. 15 6月, 2010 1 次提交
  37. 21 5月, 2010 1 次提交
    • M
      powerpc/kexec: Fix race in kexec shutdown · 1fc711f7
      由 Michael Neuling 提交于 
      In kexec_prepare_cpus, the primary CPU IPIs the secondary CPUs to
kexec_smp_down().  kexec_smp_down() calls kexec_smp_wait() which sets
the hw_cpu_id() to -1.  The primary does this while leaving IRQs on
which means the primary can take a timer interrupt which can lead to
the IPIing one of the secondary CPUs (say, for a scheduler re-balance)
but since the secondary CPU now has a hw_cpu_id = -1, we IPI CPU
-1... Kaboom!

We are hitting this case regularly on POWER7 machines.

There is also a second race, where the primary will tear down the MMU
mappings before knowing the secondaries have entered real mode.

Also, the secondaries are clearing out any pending IPIs before
guaranteeing that no more will be received.

This changes kexec_prepare_cpus() so that we turn off IRQs in the
primary CPU much earlier.  It adds a paca flag to say that the
secondaries have entered the kexec_smp_down() IPI and turned off IRQs,
rather than overloading hw_cpu_id with -1.  This new paca flag is
again used to in indicate when the secondaries has entered real mode.

It also ensures that all CPUs have their IRQs off before we clear out
any pending IPI requests (in kexec_cpu_down()) to ensure there are no
trailing IPIs left unacknowledged.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      1fc711f7
  39. 21 9月, 2009 1 次提交
  41. 23 12月, 2008 2 次提交
  43. 31 10月, 2008 1 次提交
    • M
      powerpc: Kexec exit should not use magic numbers · 1767c8f3
      由 Milton Miller 提交于 
      Commit 54622f10 ("powerpc: Support for
relocatable kdump kernel") added a magic flag value in a register to
tell purgatory that it should be a panic kernel.  This part is wrong
and is reverted by this commit.

The kernel gets a list of memory blocks and a entry point from user space.
Its job is to copy the blocks into place and then branch to the designated
entry point (after turning "off" the mmu).

The user space tool inserts a trampoline, called purgatory, that runs
before the user supplied code.   Its job is to establish the entry
environment for the new kernel or other application based on the contents
of memory.  The purgatory code is compiled and embedded in the tool,
where it is later patched using the elf symbol table using elf symbols.

Since the tool knows it is creating a purgatory that will run after a
kernel crash, it should just patch purgatory (or the kernel directly)
if something needs to happen.
Signed-off-by: NMilton Miller <miltonm@bga.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      1767c8f3
  45. 22 10月, 2008 1 次提交
    • M
      powerpc: Support for relocatable kdump kernel · 54622f10
      由 Mohan Kumar M 提交于 
      This adds relocatable kernel support for kdump. With this one can
use the same regular kernel to capture the kdump. A signature (0xfeed1234)
is passed in r6 from panic code to the next kernel through kexec_sequence
and purgatory code. The signature is used to differentiate between
kdump kernel and non-kdump kernels.

The purgatory code compares the signature and sets the __kdump_flag in
head_64.S.  During the boot up, kernel code checks __kdump_flag and if it
is set, the kernel will behave as relocatable kdump kernel. This kernel
will boot at the address where it was loaded by kexec-tools ie. at the
address reserved through crashkernel boot parameter.

CONFIG_CRASH_DUMP depends on CONFIG_RELOCATABLE option to build kdump
kernel as relocatable. So the same kernel can be used as production and
kdump kernel.

This patch incorporates the changes suggested by Paul Mackerras to avoid
GOT use and to avoid two copies of the code.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
Signed-off-by: NMohan Kumar M <mohan@in.ibm.com>
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      54622f10
  47. 21 10月, 2008 1 次提交
    • M
      powerpc: Find and destroy possible stale kernel added properties · ed7b2144
      由 Milton Miller 提交于 
      64 bit powerpc requires the kexec user space tools avoid overwriting
the static kernel image and translation hash table when choosing
where to put memory image data because it copies the data into place
using the kernels virtual memory system.  Kexec userspace determines
these and other areas blocked by reading properties the kernel adds,
but does not filter these properties when creating the device tree
for the next kernel.

When the second kernel tries to add its values for these properties,
the export via /proc/device-tree is hidden by the pre-existing but
stale values from the flat tree.  Kexec userspace reads the old
property, allocates the new kernel at the old kernel's end, and
gets rejected by the overlap check.

Search and remove these stale properties before adding the new values.
Signed-off-by: NMilton Miller <miltonm@bga.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      ed7b2144
  49. 03 7月, 2008 1 次提交
  51. 14 5月, 2008 1 次提交
    • M
      [POWERPC] Fix sparse warnings in arch/powerpc/kernel · 1c21a293
      由 Michael Ellerman 提交于 
      Make a few things static in lparcfg.c
Make init and exit routines static in rtas_flash.c
Make things static in rtas_pci.c
Make some functions static in rtas.c
Make fops static in rtas-proc.c
Remove unneeded extern for do_gtod in smp.c
Make clocksource_init() static in time.c
Make last_tick_len and ticklen_to_xs static in time.c
Move the declaration of the pvr per-cpu into smp.h
Make kexec_smp_down() and kexec_stack static in machine_kexec_64.c
Don't return void in arch_teardown_msi_irqs() in msi.c
Move declaration of GregorianDay()into asm/time.h
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      1c21a293
  53. 13 4月, 2007 2 次提交
  55. 17 8月, 2006 2 次提交
  57. 31 7月, 2006 1 次提交
  59. 28 6月, 2006 1 次提交
  61. 19 5月, 2006 2 次提交