linux/arch
Yisheng Xie 26984c3bc2 arm64/numa: fix pcpu_cpu_distance() to get correct CPU proximity
The pcpu_build_alloc_info() function group CPUs according to their
proximity, by call callback function @cpu_distance_fn from different
ARCHs.

For arm64 the callback of @cpu_distance_fn is
    pcpu_cpu_distance(from, to)
        -> node_distance(from, to)
The @from and @to for function node_distance() should be nid.

However, pcpu_cpu_distance() in arch/arm64/mm/numa.c just past the
cpu id for @from and @to, and didn't convert to numa node id.

For this incorrect cpu proximity get from ARCH, it may cause each CPU
in one group and make group_cnt out of bound:

	setup_per_cpu_areas()
		pcpu_embed_first_chunk()
			pcpu_build_alloc_info()
in pcpu_build_alloc_info, since cpu_distance_fn will return
REMOTE_DISTANCE if we pass cpu ids (0,1,2...), so
cpu_distance_fn(cpu, tcpu) > LOCAL_DISTANCE will wrongly be ture.

This may results in triggering the BUG_ON(unit != nr_units) later:

[    0.000000] kernel BUG at mm/percpu.c:1916!
[    0.000000] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.9.0-rc1-00003-g14155ca-dirty #26
[    0.000000] Hardware name: Hisilicon Hi1616 Evaluation Board (DT)
[    0.000000] task: ffff000008d6e900 task.stack: ffff000008d60000
[    0.000000] PC is at pcpu_embed_first_chunk+0x420/0x704
[    0.000000] LR is at pcpu_embed_first_chunk+0x3bc/0x704
[    0.000000] pc : [<ffff000008c754f4>] lr : [<ffff000008c75490>] pstate: 800000c5
[    0.000000] sp : ffff000008d63eb0
[    0.000000] x29: ffff000008d63eb0 [    0.000000] x28: 0000000000000000
[    0.000000] x27: 0000000000000040 [    0.000000] x26: ffff8413fbfcef00
[    0.000000] x25: 0000000000000042 [    0.000000] x24: 0000000000000042
[    0.000000] x23: 0000000000001000 [    0.000000] x22: 0000000000000046
[    0.000000] x21: 0000000000000001 [    0.000000] x20: ffff000008cb3bc8
[    0.000000] x19: ffff8413fbfcf570 [    0.000000] x18: 0000000000000000
[    0.000000] x17: ffff000008e49ae0 [    0.000000] x16: 0000000000000003
[    0.000000] x15: 000000000000001e [    0.000000] x14: 0000000000000004
[    0.000000] x13: 0000000000000000 [    0.000000] x12: 000000000000006f
[    0.000000] x11: 00000413fbffff00 [    0.000000] x10: 0000000000000004
[    0.000000] x9 : 0000000000000000 [    0.000000] x8 : 0000000000000001
[    0.000000] x7 : ffff8413fbfcf63c [    0.000000] x6 : ffff000008d65d28
[    0.000000] x5 : ffff000008d65e50 [    0.000000] x4 : 0000000000000000
[    0.000000] x3 : ffff000008cb3cc8 [    0.000000] x2 : 0000000000000040
[    0.000000] x1 : 0000000000000040 [    0.000000] x0 : 0000000000000000
[...]
[    0.000000] Call trace:
[    0.000000] Exception stack(0xffff000008d63ce0 to 0xffff000008d63e10)
[    0.000000] 3ce0: ffff8413fbfcf570 0001000000000000 ffff000008d63eb0 ffff000008c754f4
[    0.000000] 3d00: ffff000008d63d50 ffff0000081af210 00000413fbfff010 0000000000001000
[    0.000000] 3d20: ffff000008d63d50 ffff0000081af220 00000413fbfff010 0000000000001000
[    0.000000] 3d40: 00000413fbfcef00 0000000000000004 ffff000008d63db0 ffff0000081af390
[    0.000000] 3d60: 00000413fbfcef00 0000000000001000 0000000000000000 0000000000001000
[    0.000000] 3d80: 0000000000000000 0000000000000040 0000000000000040 ffff000008cb3cc8
[    0.000000] 3da0: 0000000000000000 ffff000008d65e50 ffff000008d65d28 ffff8413fbfcf63c
[    0.000000] 3dc0: 0000000000000001 0000000000000000 0000000000000004 00000413fbffff00
[    0.000000] 3de0: 000000000000006f 0000000000000000 0000000000000004 000000000000001e
[    0.000000] 3e00: 0000000000000003 ffff000008e49ae0
[    0.000000] [<ffff000008c754f4>] pcpu_embed_first_chunk+0x420/0x704
[    0.000000] [<ffff000008c6658c>] setup_per_cpu_areas+0x38/0xc8
[    0.000000] [<ffff000008c608d8>] start_kernel+0x10c/0x390
[    0.000000] [<ffff000008c601d8>] __primary_switched+0x5c/0x64
[    0.000000] Code: b8018660 17ffffd7 6b16037f 54000080 (d4210000)
[    0.000000] ---[ end trace 0000000000000000 ]---
[    0.000000] Kernel panic - not syncing: Attempted to kill the idle task!

Fix by getting cpu's node id with early_cpu_to_node() then pass it
to node_distance() as the original intention.

Fixes: 7af3a0a992 ("arm64/numa: support HAVE_SETUP_PER_CPU_AREA")
Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-10-26 18:21:51 +01:00
..
alpha Merge branch 'gup_flag-cleanups' 2016-10-19 08:39:47 -07:00
arc Merge branch 'work.uaccess' into for-linus 2016-10-14 20:42:44 -04:00
arm arm/arm64: KVM: Map the BSS at HYP 2016-10-21 17:26:24 +01:00
arm64 arm64/numa: fix pcpu_cpu_distance() to get correct CPU proximity 2016-10-26 18:21:51 +01:00
avr32 Merge branch 'akpm' (patches from Andrew) 2016-10-07 21:38:00 -07:00
blackfin Merge branch 'gup_flag-cleanups' 2016-10-19 08:39:47 -07:00
c6x nmi_backtrace: generate one-line reports for idle cpus 2016-10-07 18:46:30 -07:00
cris mm: replace access_process_vm() write parameter with gup_flags 2016-10-19 08:31:25 -07:00
frv Merge branch 'work.uaccess2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-11 23:38:39 -07:00
h8300 nmi_backtrace: generate one-line reports for idle cpus 2016-10-07 18:46:30 -07:00
hexagon nmi_backtrace: generate one-line reports for idle cpus 2016-10-07 18:46:30 -07:00
ia64 Merge branch 'gup_flag-cleanups' 2016-10-19 08:39:47 -07:00
m32r mm: replace access_process_vm() write parameter with gup_flags 2016-10-19 08:31:25 -07:00
m68k Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2016-10-14 14:26:58 -07:00
metag Metag architecture fixes for v4.9-rc1 2016-10-14 11:11:39 -07:00
microblaze Merge branch 'work.uaccess2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-11 23:38:39 -07:00
mips KVM fixes for v4.9-rc2 2016-10-21 19:09:29 -07:00
mn10300 Merge branch 'work.uaccess2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-11 23:38:39 -07:00
nios2 nios2 update for v4.9-rc1 2016-10-10 11:31:19 -07:00
openrisc Merge branch 'work.uaccess2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-11 23:38:39 -07:00
parisc Merge branch 'parisc-4.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2016-10-11 23:59:07 -07:00
powerpc powerpc fixes for 4.9 #3 2016-10-21 19:13:00 -07:00
s390 KVM fixes for v4.9-rc2 2016-10-21 19:09:29 -07:00
score Merge branch 'gup_flag-cleanups' 2016-10-19 08:39:47 -07:00
sh Minor changes to improve J2 support and match Kconfig expectations of 2016-10-19 11:21:06 -07:00
sparc Merge branch 'gup_flag-cleanups' 2016-10-19 08:39:47 -07:00
tile tile: use simpler API for random address requests 2016-10-11 15:06:32 -07:00
um nmi_backtrace: generate one-line reports for idle cpus 2016-10-07 18:46:30 -07:00
unicore32 unicore32: use simpler API for random address requests 2016-10-11 15:06:32 -07:00
x86 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-10-22 09:58:49 -07:00
xtensa Merge branch 'work.uaccess2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-11 23:38:39 -07:00
.gitignore
Kconfig This adds a new gcc plugin named "latent_entropy". It is designed to 2016-10-15 10:03:15 -07:00