linux.git/arch, branch v3.15

Revert "x86/smpboot: Initialize secondary CPU only if master CPU will wait for it"

2014-06-08T17:09:49+00:00

This reverts commit 3e1a878b7ccdb31da6d9d2b855c72ad87afeba3f.

It came in very late, and already has one reported failure: Sitsofe
reports that the current tree fails to boot on his EeePC, and bisected
it down to this.  Rather than waste time trying to figure out what's
wrong, just revert it.

Reported-by: Sitsofe Wheeler 
Cc: Igor Mammedov 
Cc: Toshi Kani 
Cc: Thomas Gleixner 
Acked-by: Ingo Molnar 
Signed-off-by: Linus Torvalds

x86/boot: EFI_MIXED should not prohibit loading above 4G

2014-06-07T16:31:00+00:00

commit 7d453eee36ae ("x86/efi: Wire up CONFIG_EFI_MIXED") introduced a
regression for the functionality to load kernels above 4G. The relevant
(incorrect) reasoning behind this change can be seen in the commit
message,

  "The xloadflags field in the bzImage header is also updated to reflect
  that the kernel supports both entry points by setting both of
  XLF_EFI_HANDOVER_32 and XLF_EFI_HANDOVER_64 when CONFIG_EFI_MIXED=y.
  XLF_CAN_BE_LOADED_ABOVE_4G is disabled so that the kernel text is
  guaranteed to be addressable with 32-bits."

This is obviously bogus since 32-bit EFI loaders will never place the
kernel above the 4G mark. So this restriction is entirely unnecessary.

But things are worse than that - since we want to encourage people to
always compile with CONFIG_EFI_MIXED=y so that their kernels work out of
the box for both 32-bit and 64-bit firmware, commit 7d453eee36ae
effectively disables XLF_CAN_BE_LOADED_ABOVE_4G completely.

Remove the overzealous and superfluous restriction and restore the
XLF_CAN_BE_LOADED_ABOVE_4G functionality.

Cc: "H. Peter Anvin" 
Cc: Dave Young 
Cc: Vivek Goyal 
Signed-off-by: Matt Fleming 
Link: http://lkml.kernel.org/r/1402140380-15377-1-git-send-email-matt@console-pimps.org
Signed-off-by: H. Peter Anvin

Merge tag 'efi-urgent' into x86/urgent

2014-06-05T20:09:44+00:00

 * Fix earlyprintk=efi,keep support by switching to an ioremap() mapping
   of the framebuffer when early_ioremap() is no longer available and
   dropping __init from functions that may be invoked after
   free_initmem() - Dave Young

 * We shouldn't be exporting the EFI runtime map in sysfs if not using
   the new 1:1 EFI mapping code since in that case the mappings are not
   static across a kexec reboot - Dave Young

Signed-off-by: H. Peter Anvin

x86/smpboot: Initialize secondary CPU only if master CPU will wait for it

2014-06-05T14:33:08+00:00

Hang is observed on virtual machines during CPU hotplug,
especially in big guests with many CPUs. (It reproducible
more often if host is over-committed).

It happens because master CPU gives up waiting on
secondary CPU and allows it to run wild. As result
AP causes locking or crashing system. For example
as described here:

   https://lkml.org/lkml/2014/3/6/257

If master CPU have sent STARTUP IPI successfully,
and AP signalled to master CPU that it's ready
to start initialization, make master CPU wait
indefinitely till AP is onlined.
To ensure that AP won't ever run wild, make it
wait at early startup till master CPU confirms its
intention to wait for AP. If AP doesn't respond in 10
seconds, the master CPU will timeout and cancel
AP onlining.

Signed-off-by: Igor Mammedov 
Acked-by: Toshi Kani 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1401975765-22328-4-git-send-email-imammedo@redhat.com
Signed-off-by: Ingo Molnar

x86/smpboot: Log error on secondary CPU wakeup failure at ERR level

2014-06-05T14:33:07+00:00

If system is running without debug level logging,
it will not log error if do_boot_cpu() failed to
wakeup AP. It may lead to silent AP bringup
failures at boot time.
Change message level to KERN_ERR to make error
visible to user as it's done on other architectures.

Signed-off-by: Igor Mammedov 
Acked-by: Toshi Kani 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1401975765-22328-3-git-send-email-imammedo@redhat.com
Signed-off-by: Ingo Molnar

x86: Fix list/memory corruption on CPU hotplug

2014-06-05T14:33:07+00:00

currently if AP wake up is failed, master CPU marks AP as not
present in do_boot_cpu() by calling set_cpu_present(cpu, false).
That leads to following list corruption on the next physical CPU
hotplug:

[  418.107336] WARNING: CPU: 1 PID: 45 at lib/list_debug.c:33 __list_add+0xbe/0xd0()
[  418.115268] list_add corruption. prev->next should be next (ffff88003dc57600), but was ffff88003e20c3a0. (prev=ffff88003e20c3a0).
[  418.123693] Modules linked in: nf_conntrack_netbios_ns nf_conntrack_broadcast ipt_MASQUERADE ip6t_REJECT ipt_REJECT cfg80211 xt_conntrack rfkill ee
[  418.138979] CPU: 1 PID: 45 Comm: kworker/u10:1 Not tainted 3.14.0-rc6+ #387
[  418.149989] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2007
[  418.165750] Workqueue: kacpi_hotplug acpi_hotplug_work_fn
[  418.166433]  0000000000000021 ffff880038ca7988 ffffffff8159b22d 0000000000000021
[  418.176460]  ffff880038ca79d8 ffff880038ca79c8 ffffffff8106942c ffff880038ca79e8
[  418.177453]  ffff88003e20c3a0 ffff88003dc57600 ffff88003e20c3a0 00000000ffffffea
[  418.178445] Call Trace:
[  418.185811]  [] dump_stack+0x49/0x5c
[  418.186440]  [] warn_slowpath_common+0x8c/0xc0
[  418.187192]  [] warn_slowpath_fmt+0x46/0x50
[  418.191231]  [] ? acpi_ns_get_node+0xb7/0xc7
[  418.193889]  [] __list_add+0xbe/0xd0
[  418.196649]  [] kobject_add_internal+0x79/0x200
[  418.208610]  [] kobject_add_varg+0x38/0x60
[  418.213831]  [] kobject_add+0x44/0x70
[  418.229961]  [] device_add+0xd0/0x550
[  418.234991]  [] ? pm_runtime_init+0xe5/0xf0
[  418.250226]  [] device_register+0x1e/0x30
[  418.255296]  [] register_cpu+0xe3/0x130
[  418.266539]  [] arch_register_cpu+0x65/0x150
[  418.285845]  [] acpi_processor_hotadd_init+0x5a/0x9b
...
Which is caused by the fact that generic_processor_info() allocates
logical CPU id by calling:

 cpu = cpumask_next_zero(-1, cpu_present_mask);

which returns id of previously failed to wake up CPU, since its
bit is cleared by do_boot_cpu() and as result register_cpu()
tries to register another CPU with the same id as already
present but failed to be onlined CPU.

Taking in account that AP will not do anything if master CPU
failed to wake it up, there is no reason to mark that AP as not
present and break next cpu hotplug attempts. As a side effect of
not marking AP as not present, user would be allowed to online
it again later.

Also fix memory corruption in acpi_unmap_lsapic()

if during CPU hotplug master CPU failed to wake up AP
it set percpu x86_cpu_to_apicid to BAD_APICID=0xFFFF for AP.

However following attempt to unplug that CPU will lead to
out of bound write access to __apicid_to_node[] which is
32768 items long on x86_64 kernel.

So with above fix of cpu_present_mask make sure that a present
CPU has a valid APIC ID by not setting x86_cpu_to_apicid
to BAD_APICID in do_boot_cpu() on failure and allow
acpi_processor_remove()->acpi_unmap_lsapic() cleanly remove CPU.

Signed-off-by: Igor Mammedov 
Acked-by: Toshi Kani 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1401975765-22328-2-git-send-email-imammedo@redhat.com
Signed-off-by: Ingo Molnar

x86: irq: Get correct available vectors for cpu disable

2014-06-04T12:18:34+00:00

check_irq_vectors_for_cpu_disable() can overestimate the number of
available interrupt vectors, so the check for cpu down succeeds, but
the actual cpu removal fails.

It iterates from FIRST_EXTERNAL_VECTOR to NR_VECTORS, which is wrong
because the systems vectors are not taken into account.

Limit the search to first_system_vector instead of NR_VECTORS.

The second indicator for vector availability the used_vectors bitmap
is not taken into account at all. So system vectors,
e.g. IA32_SYSCALL_VECTOR (0x80) and IRQ_MOVE_CLEANUP_VECTOR (0x20),
are accounted as available.

Add a check for the used_vectors bitmap and do not account vectors
which are marked there.

[ tglx: Simplified code. Rewrote changelog and code comments. ]

Signed-off-by: Yinghai Lu 
Acked-by: Prarit Bhargava 
Cc: Seiji Aguchi 
Cc: Andi Kleen 
Cc: K. Y. Srinivasan 
Cc: Steven Rostedt (Red Hat) 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Cc: "Elliott, Robert (Server Storage)" 
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/1400160305-17774-2-git-send-email-prarit@redhat.com
Signed-off-by: Thomas Gleixner

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2014-06-02T23:57:23+00:00

Pull x86 fix from Peter Anvin:
 "A single quite small patch that managed to get overlooked earlier, to
  prevent a user space triggerable oops on systems without HPET"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, vdso: Fix an OOPS accessing the HPET mapping w/o an HPET

x86/efi: Do not export efi runtime map in case old map

2014-06-02T11:21:59+00:00

For ioremapped efi memory aka old_map the virt addresses are not persistant
across kexec reboot. kexec-tools will read the runtime maps from sysfs then
pass them to 2nd kernel and assuming kexec efi boot is ok. This will cause
kexec boot failure.

To address this issue do not export runtime maps in case efi old_map so
userspace can use no efi boot instead.

Signed-off-by: Dave Young 
Acked-by: Borislav Petkov 
Acked-by: Vivek Goyal 
Signed-off-by: Matt Fleming

Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

2014-06-02T01:30:07+00:00

Pull powerpc fix from Ben Herrenschmidt:
 "Here's just one trivial patch to wire up sys_renameat2 which I seem to
  have completely missed so far.

  (My test build scripts fwd me warnings but miss the ones generated for
  missing syscalls)"

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc: Wire renameat2() syscall