Zhenzhong Duan 4ea9b9aca9 xen: mask x2APIC feature in PV ...

On x2apic enabled pvm, doing sysrq+l, got NULL pointer dereference as below.

    SysRq : Show backtrace of all active CPUs
    BUG: unable to handle kernel NULL pointer dereference at           (null)
    IP: [<ffffffff8125e3cb>] memcpy+0xb/0x120
    Call Trace:
     [<ffffffff81039633>] ? __x2apic_send_IPI_mask+0x73/0x160
     [<ffffffff8103973e>] x2apic_send_IPI_all+0x1e/0x20
     [<ffffffff8103498c>] arch_trigger_all_cpu_backtrace+0x6c/0xb0
     [<ffffffff81501be4>] ? _raw_spin_lock_irqsave+0x34/0x50
     [<ffffffff8131654e>] sysrq_handle_showallcpus+0xe/0x10
     [<ffffffff8131616d>] __handle_sysrq+0x7d/0x140
     [<ffffffff81316230>] ? __handle_sysrq+0x140/0x140
     [<ffffffff81316287>] write_sysrq_trigger+0x57/0x60
     [<ffffffff811ca996>] proc_reg_write+0x86/0xc0
     [<ffffffff8116dd8e>] vfs_write+0xce/0x190
     [<ffffffff8116e3e5>] sys_write+0x55/0x90
     [<ffffffff8150a242>] system_call_fastpath+0x16/0x1b

That's because apic points to apic_x2apic_cluster or apic_x2apic_phys
but the basic element like cpumask isn't initialized.

Mask x2APIC feature in pvm to avoid overwrite of apic pointer,
update commit message per Konrad's suggestion.

Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Tested-by: Tamon Shiose <tamon.shiose@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

2013-05-08 08:38:11 -04:00

..

boot

x86: Fix rebuild with EFI_STUB enabled

2013-04-05 13:59:23 -07:00

configs

x86: Default to ARCH=x86 to avoid overriding CONFIG_64BIT

2012-12-20 14:37:18 -08:00

crypto

Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6

2013-02-25 15:56:15 -08:00

ia32

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal

2013-03-02 08:34:06 -08:00

include

x86: remove the x32 syscall bitmask from syscall_get_nr()

2013-04-02 14:38:09 -07:00

kernel

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

2013-03-24 10:10:34 -07:00

kvm

KVM: Allow cross page reads and writes from cached translations.

2013-04-07 13:05:35 +03:00

lguest

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

2013-02-21 18:06:55 -08:00

lib

x86-64: Fix the failure case in copy_user_handle_tail()

2013-03-18 11:32:03 -07:00

math-emu

x86: Rename trap_no to trap_nr in thread_struct

2012-03-13 06:24:09 +01:00

mm

x86: Do not try to sync identity map for non-mapped pages

2013-03-07 13:23:28 -08:00

net

x86: bpf_jit_comp: add pkt_type support

2013-01-30 22:38:34 -05:00

oprofile

oprofile, x86: Fix wrapping bug in op_x86_get_ctrl()

2012-10-15 14:38:24 +02:00

pci

xen: drop tracking of IRQ vector

2013-04-16 15:05:45 -04:00

platform

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

2013-02-27 16:17:42 -08:00

power

perf,x86: fix kernel crash with PEBS/BTS after suspend/resume

2013-03-15 09:26:35 -07:00

realmode

Merge remote-tracking branch 'origin/x86/mm' into x86/mm2

2013-02-01 02:28:36 -08:00

syscalls

fix compat truncate/ftruncate

2013-02-25 09:24:55 -05:00

tools

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

2013-02-05 07:57:09 +11:00

um

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal

2013-02-23 18:50:11 -08:00

vdso

timers/x86/hpet: Use HPET_COUNTER to specify the hpet counter in vread_hpet()

2013-02-15 12:13:18 +01:00

video

x86: Use vga_default_device() when determining whether an fb is primary

2012-04-24 09:50:17 +01:00

xen

xen: mask x2APIC feature in PV

2013-05-08 08:38:11 -04:00

.gitignore

…

Kbuild

x86, realmode: realmode.bin infrastructure

2012-05-08 11:41:48 -07:00

Kconfig

Select VIRT_TO_BUS directly where needed

2013-03-12 11:16:40 -07:00

Kconfig.cpu

x86, 386 removal: Document Nx586 as a 386 and thus unsupported

2012-11-29 13:28:39 -08:00

Kconfig.debug

x86/tlb: add tlb_flushall_shift knob into debugfs

2012-06-27 19:29:10 -07:00

Makefile

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

2013-02-19 19:12:03 -08:00

Makefile_32.cpu

x86, 386 removal: Remove CONFIG_M386 from Kconfig

2012-11-29 13:23:01 -08:00

Makefile.um

um: fix linker script generation

2012-04-09 13:59:00 -04:00