commit f96972f2dc "kernel/sys.c: call disable_nonboot_cpus() in
kernel_restart()"
added a call to disable_nonboot_cpus() on kernel_restart(), which tries
to shutdown all the CPUs except the first one. The issue with the PA
Semi, is that it does not support CPU hotplug.
When the call is made to __cpu_down(), it calls the notifiers
CPU_DOWN_PREPARE, and then tries to take the CPU down.
One of the notifiers to the CPU hotplug code, is the cpufreq. The
DOWN_PREPARE will call __cpufreq_remove_dev() which calls
cpufreq_driver->exit. The PA Semi exit handler unmaps regions of I/O
that is used by an interrupt that goes off constantly
(system_reset_common, but it goes off during normal system operations
too). I'm not sure exactly what this interrupt does.
Running a simple function trace, you can see it goes off quite a bit:
# tracer: function
#
# TASK-PID CPU# TIMESTAMP FUNCTION
# | | | | |
<idle>-0 [001] 1558.859363: .pasemi_system_reset_exception <-.system_reset_exception
<idle>-0 [000] 1558.860112: .pasemi_system_reset_exception <-.system_reset_exception
<idle>-0 [000] 1558.861109: .pasemi_system_reset_exception <-.system_reset_exception
<idle>-0 [001] 1558.861361: .pasemi_system_reset_exception <-.system_reset_exception
<idle>-0 [000] 1558.861437: .pasemi_system_reset_exception <-.system_reset_exception
When the region is unmapped, the system crashes with:
Disabling non-boot CPUs ...
Error taking CPU1 down: -38
Unable to handle kernel paging request for data at address 0xd0000800903a0100
Faulting instruction address: 0xc000000000055fcc
Oops: Kernel access of bad area, sig: 11 [#1]
PREEMPT SMP NR_CPUS=64 NUMA PA Semi PWRficient
Modules linked in: shpchp
NIP: c000000000055fcc LR: c000000000055fb4 CTR: c0000000000df1fc
REGS: c0000000012175d0 TRAP: 0300 Not tainted (3.8.0-rc4-test-dirty)
MSR: 9000000000009032 <SF,HV,EE,ME,IR,DR,RI> CR: 24000088 XER: 00000000
SOFTE: 0
DAR: d0000800903a0100, DSISR: 42000000
TASK = c0000000010e9008[0] 'swapper/0' THREAD: c000000001214000 CPU: 0
GPR00: d0000800903a0000 c000000001217850 c0000000012167e0 0000000000000000
GPR04: 0000000000000000 0000000000000724 0000000000000724 0000000000000000
GPR08: 0000000000000000 0000000000000000 0000000000000001 0000000000a70000
GPR12: 0000000024000080 c00000000fff0000 ffffffffffffffff 000000003ffffae0
GPR16: ffffffffffffffff 0000000000a21198 0000000000000060 0000000000000000
GPR20: 00000000008fdd35 0000000000a21258 000000003ffffaf0 0000000000000417
GPR24: 0000000000a226d0 c000000000000000 0000000000000000 0000000000000000
GPR28: c00000000138b358 0000000000000000 c000000001144818 d0000800903a0100
NIP [c000000000055fcc] .set_astate+0x5c/0xa4
LR [c000000000055fb4] .set_astate+0x44/0xa4
Call Trace:
[c000000001217850] [c000000000055fb4] .set_astate+0x44/0xa4 (unreliable)
[c0000000012178f0] [c00000000005647c] .restore_astate+0x2c/0x34
[c000000001217980] [c000000000054668] .pasemi_system_reset_exception+0x6c/0x88
[c000000001217a00] [c000000000019ef0] .system_reset_exception+0x48/0x84
[c000000001217a80] [c000000000001e40] system_reset_common+0x140/0x180
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Pull driver core __dev* removal patches - take 3 - from Greg Kroah-Hartman: "Here are the remaining __dev* removal patches against the 3.8-rc2 tree. All of these patches were previously sent to the subsystem maintainers, most of them were picked up and pushed to you, but there were a number that fell through the cracks, and new drivers were added during the merge window, so this series cleans up the rest of the instances of these markings. Third time's the charm... Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>" Fixed up trivial conflict with the pinctrl pull in pinctrl-sirf.c. * tag 'driver-core-3.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (54 commits) misc: remove __dev* attributes. include: remove __dev* attributes. Documentation: remove __dev* attributes. Drivers: misc: remove __dev* attributes. Drivers: block: remove __dev* attributes. Drivers: bcma: remove __dev* attributes. Drivers: char: remove __dev* attributes. Drivers: clocksource: remove __dev* attributes. Drivers: ssb: remove __dev* attributes. Drivers: dma: remove __dev* attributes. Drivers: gpu: remove __dev* attributes. Drivers: infinband: remove __dev* attributes. Drivers: memory: remove __dev* attributes. Drivers: mmc: remove __dev* attributes. Drivers: iommu: remove __dev* attributes. Drivers: power: remove __dev* attributes. Drivers: message: remove __dev* attributes. Drivers: macintosh: remove __dev* attributes. Drivers: mfd: remove __dev* attributes. pstore: remove __dev* attributes. ...
CONFIG_HOTPLUG is going away as an option. As a result, the __dev* markings need to be removed. This change removes the use of __devinit, __devexit_p, __devinitdata, __devinitconst, and __devexit from these drivers. Based on patches originally written by Bill Pemberton, but redone by me in order to handle some of the coding style issues better, by hand. Cc: Bill Pemberton <wfp5p@virginia.edu> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The missing NULL terminator can cause a panic on PPC405 boards during boot: Linux/PowerPC load: console=ttyS0,115200 root=/dev/mtdblock1 rootfstype=squashfs,jffs2 noinitrd init=/etc/preinit Finalizing device tree... flat tree at 0x6a5160 bootconsole [udbg0] enabled Page fault in user mode with in_atomic() = 1 mm = (null) NIP = c0275f50 MSR = fffffffe Oops: Weird page fault, sig: 11 [#1] PowerPC 40x Platform Modules linked in: NIP: c0275f50 LR: c0275f60 CTR: c0280000 REGS: c0275eb0 TRAP: 636f7265 Not tainted (3.7.1) MSR: fffffffe <VEC,VSX,EE,PR,FP,ME,SE,BE,IR,DR,PMM,RI> CR: c06a6190 XER: 00000001 TASK = c02662a8[0] 'swapper' THREAD: c0274000 GPR00: c0275ec0 c000c658 c027c4bf 00000000 c0275ee0 c000a0ec c020a1a8 c020a1f0 GPR08: c020f631 c020f404 c025f078 c025f080 c0275f10 Call Trace: ---[ end trace 31fd0ba7d8756001 ]--- Kernel panic - not syncing: Attempted to kill the idle task! The panic happens since commit 9597abe00c1bab2aedce6b49866bf6d1e81c9eed (sections: fix section conflicts in arch/powerpc), however the root cause of this is that the NULL terminator were not added in commit a4f740cf33f7f6c164bbde3c0cdbcc77b0c4997c (of/flattree: Add of_flat_dt_match() helper function). Cc: Grant Likely <grant.likely@secretlab.ca> Cc: <stable@vger.kernel.org> Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Where we can pass in LOOKUP_DIRECTORY or LOOKUP_REVAL. Any other flags passed in here are currently ignored. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull powerpc update from Benjamin Herrenschmidt: "The main highlight is probably some base POWER8 support. There's more to come such as transactional memory support but that will wait for the next one. Overall it's pretty quiet, or rather I've been pretty poor at picking things up from patchwork and reviewing them this time around and Kumar no better on the FSL side it seems..." * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (73 commits) powerpc+of: Rename and fix OF reconfig notifier error inject module powerpc: mpc5200: Add a3m071 board support powerpc/512x: don't compile any platform DIU code if the DIU is not enabled powerpc/mpc52xx: use module_platform_driver macro powerpc+of: Export of_reconfig_notifier_[register,unregister] powerpc/dma/raidengine: add raidengine device powerpc/iommu/fsl: Add PAMU bypass enable register to ccsr_guts struct powerpc/mpc85xx: Change spin table to cached memory powerpc/fsl-pci: Add PCI controller ATMU PM support powerpc/86xx: fsl_pcibios_fixup_bus requires CONFIG_PCI drivers/virt: the Freescale hypervisor driver doesn't need to check MSR[GS] powerpc/85xx: p1022ds: Use NULL instead of 0 for pointers powerpc: Disable relocation on exceptions when kexecing powerpc: Enable relocation on during exceptions at boot powerpc: Move get_longbusy_msecs into hvcall.h and remove duplicate function powerpc: Add wrappers to enable/disable relocation on exceptions powerpc: Add set_mode hcall powerpc: Setup relocation on exceptions for bare metal systems powerpc: Move initial mfspr LPCR out of __init_LPCR powerpc: Add relocation on exception vector handlers ...
Pull user namespace changes from Eric Biederman:
"While small this set of changes is very significant with respect to
containers in general and user namespaces in particular. The user
space interface is now complete.
This set of changes adds support for unprivileged users to create user
namespaces and as a user namespace root to create other namespaces.
The tyranny of supporting suid root preventing unprivileged users from
using cool new kernel features is broken.
This set of changes completes the work on setns, adding support for
the pid, user, mount namespaces.
This set of changes includes a bunch of basic pid namespace
cleanups/simplifications. Of particular significance is the rework of
the pid namespace cleanup so it no longer requires sending out
tendrils into all kinds of unexpected cleanup paths for operation. At
least one case of broken error handling is fixed by this cleanup.
The files under /proc/<pid>/ns/ have been converted from regular files
to magic symlinks which prevents incorrect caching by the VFS,
ensuring the files always refer to the namespace the process is
currently using and ensuring that the ptrace_mayaccess permission
checks are always applied.
The files under /proc/<pid>/ns/ have been given stable inode numbers
so it is now possible to see if different processes share the same
namespaces.
Through the David Miller's net tree are changes to relax many of the
permission checks in the networking stack to allowing the user
namespace root to usefully use the networking stack. Similar changes
for the mount namespace and the pid namespace are coming through my
tree.
Two small changes to add user namespace support were commited here adn
in David Miller's -net tree so that I could complete the work on the
/proc/<pid>/ns/ files in this tree.
Work remains to make it safe to build user namespaces and 9p, afs,
ceph, cifs, coda, gfs2, ncpfs, nfs, nfsd, ocfs2, and xfs so the
Kconfig guard remains in place preventing that user namespaces from
being built when any of those filesystems are enabled.
Future design work remains to allow root users outside of the initial
user namespace to mount more than just /proc and /sys."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (38 commits)
proc: Usable inode numbers for the namespace file descriptors.
proc: Fix the namespace inode permission checks.
proc: Generalize proc inode allocation
userns: Allow unprivilged mounts of proc and sysfs
userns: For /proc/self/{uid,gid}_map derive the lower userns from the struct file
procfs: Print task uids and gids in the userns that opened the proc file
userns: Implement unshare of the user namespace
userns: Implent proc namespace operations
userns: Kill task_user_ns
userns: Make create_new_namespaces take a user_ns parameter
userns: Allow unprivileged use of setns.
userns: Allow unprivileged users to create new namespaces
userns: Allow setting a userns mapping to your current uid.
userns: Allow chown and setgid preservation
userns: Allow unprivileged users to create user namespaces.
userns: Ignore suid and sgid on binaries if the uid or gid can not be mapped
userns: fix return value on mntns_install() failure
vfs: Allow unprivileged manipulation of the mount namespace.
vfs: Only support slave subtrees across different user namespaces
vfs: Add a user namespace reference from struct mnt_namespace
...
Brings some 52xx updates. Also manually merged tools/perf/perf.h. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Pull KVM updates from Marcelo Tosatti: "Considerable KVM/PPC work, x86 kvmclock vsyscall support, IA32_TSC_ADJUST MSR emulation, amongst others." Fix up trivial conflict in kernel/sched/core.c due to cross-cpu migration notifier added next to rq migration call-back. * tag 'kvm-3.8-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (156 commits) KVM: emulator: fix real mode segment checks in address linearization VMX: remove unneeded enable_unrestricted_guest check KVM: VMX: fix DPL during entry to protected mode x86/kexec: crash_vmclear_local_vmcss needs __rcu kvm: Fix irqfd resampler list walk KVM: VMX: provide the vmclear function and a bitmap to support VMCLEAR in kdump x86/kexec: VMCLEAR VMCSs loaded on all cpus if necessary KVM: MMU: optimize for set_spte KVM: PPC: booke: Get/set guest EPCR register using ONE_REG interface KVM: PPC: bookehv: Add EPCR support in mtspr/mfspr emulation KVM: PPC: bookehv: Add guest computation mode for irq delivery KVM: PPC: Make EPCR a valid field for booke64 and bookehv KVM: PPC: booke: Extend MAS2 EPN mask for 64-bit KVM: PPC: e500: Mask MAS2 EPN high 32-bits in 32/64 tlbwe emulation KVM: PPC: Mask ea's high 32-bits in 32/64 instr emulation KVM: PPC: e500: Add emulation helper for getting instruction ea KVM: PPC: bookehv64: Add support for interrupt handling KVM: PPC: bookehv: Remove GET_VCPU macro from exception handler KVM: PPC: booke: Fix get_tb() compile error on 64-bit KVM: PPC: e500: Silence bogus GCC warning in tlb code ...
Pull trivial branch from Jiri Kosina: "Usual stuff -- comment/printk typo fixes, documentation updates, dead code elimination." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits) HOWTO: fix double words typo x86 mtrr: fix comment typo in mtrr_bp_init propagate name change to comments in kernel source doc: Update the name of profiling based on sysfs treewide: Fix typos in various drivers treewide: Fix typos in various Kconfig wireless: mwifiex: Fix typo in wireless/mwifiex driver messages: i2o: Fix typo in messages/i2o scripts/kernel-doc: check that non-void fcts describe their return value Kernel-doc: Convention: Use a "Return" section to describe return values radeon: Fix typo and copy/paste error in comments doc: Remove unnecessary declarations from Documentation/accounting/getdelays.c various: Fix spelling of "asynchronous" in comments. Fix misspellings of "whether" in comments. eisa: Fix spelling of "asynchronous". various: Fix spelling of "registered" in comments. doc: fix quite a few typos within Documentation target: iscsi: fix comment typos in target/iscsi drivers treewide: fix typo of "suport" in various comments and Kconfig treewide: fix typo of "suppport" in various comments ...