Ross Lagerwall 707e59ba49 xen/qspinlock: Don't kick CPU if IRQ is not initialized ... The following commit: 1fb3a8b2cf ("xen/spinlock: Fix locking path engaging too soon under PVHVM.") ... moved the initalization of the kicker interrupt until after native_cpu_up() is called. However, when using qspinlocks, a CPU may try to kick another CPU that is spinning (because it has not yet initialized its kicker interrupt), resulting in the following crash during boot: kernel BUG at /build/linux-Ay7j_C/linux-4.4.0/drivers/xen/events/events_base.c:1210! invalid opcode: 0000 [#1] SMP ... RIP: 0010:[<ffffffff814c97c9>] [<ffffffff814c97c9>] xen_send_IPI_one+0x59/0x60 ... Call Trace: [<ffffffff8102be9e>] xen_qlock_kick+0xe/0x10 [<ffffffff810cabc2>] __pv_queued_spin_unlock+0xb2/0xf0 [<ffffffff810ca6d1>] ? __raw_callee_save___pv_queued_spin_unlock+0x11/0x20 [<ffffffff81052936>] ? check_tsc_warp+0x76/0x150 [<ffffffff81052aa6>] check_tsc_sync_source+0x96/0x160 [<ffffffff81051e28>] native_cpu_up+0x3d8/0x9f0 [<ffffffff8102b315>] xen_hvm_cpu_up+0x35/0x80 [<ffffffff8108198c>] _cpu_up+0x13c/0x180 [<ffffffff81081a4a>] cpu_up+0x7a/0xa0 [<ffffffff81f80dfc>] smp_init+0x7f/0x81 [<ffffffff81f5a121>] kernel_init_freeable+0xef/0x212 [<ffffffff81817f30>] ? rest_init+0x80/0x80 [<ffffffff81817f3e>] kernel_init+0xe/0xe0 [<ffffffff8182488f>] ret_from_fork+0x3f/0x70 [<ffffffff81817f30>] ? rest_init+0x80/0x80 To fix this, only send the kick if the target CPU's interrupt has been initialized. This check isn't racy, because the target is waiting for the spinlock, so it won't have initialized the interrupt in the meantime. Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Juergen Gross <jgross@suse.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Cc: xen-devel@lists.xenproject.org Signed-off-by: Ingo Molnar <mingo@kernel.org>		2016-04-23 13:40:02 +02:00
..
apic.c	xen/apic: Provide Xen-specific version of cpu_present_to_apicid APIC op	2016-03-25 11:42:53 -04:00
debugfs.c
debugfs.h
efi.c
enlighten.c	Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2016-03-24 09:47:32 -07:00
grant-table.c
irq.c
Kconfig
Makefile
mmu.c	x86: Fix misspellings in comments	2016-02-24 08:44:58 +01:00
mmu.h
multicalls.c
multicalls.h
p2m.c
pci-swiotlb-xen.c
platform-pci-unplug.c
pmu.c	perf/x86: Move perf_event.h to its new home	2016-02-17 10:11:36 +01:00
pmu.h
setup.c
smp.c	xen/x86: Call cpu_startup_entry(CPUHP_AP_ONLINE_IDLE) from xen_play_dead()	2016-03-29 09:34:10 -04:00
smp.h
spinlock.c	xen/qspinlock: Don't kick CPU if IRQ is not initialized	2016-04-23 13:40:02 +02:00
suspend.c	xen: features and fixes for 4.5-rc0	2016-01-12 13:05:36 -08:00
time.c
trace.c
vdso.h
vga.c
xen-asm_32.S
xen-asm_64.S	x86/asm/xen: Set ELF function type for xen_adjust_exception_frame()	2016-02-24 08:35:41 +01:00
xen-asm.h
xen-asm.S	x86/asm/xen: Create stack frames in xen-asm.S	2016-02-24 08:35:42 +01:00
xen-head.S	Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2016-03-24 09:47:32 -07:00
xen-ops.h