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| author | Yang Shi <yang.shi@linaro.org> | 2016-05-20 16:59:08 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-05-20 17:58:30 -0700 |
| commit | b8f1a75d61d8405a753380c6fb17ba84a5603cd4 (patch) | |
| tree | c16275eaf6318764d233c877424f7fd60ad63116 /init | |
| parent | dfef2ef4027b1304149a65dc33794eab65e8a3bf (diff) | |
| download | lwn-b8f1a75d61d8405a753380c6fb17ba84a5603cd4.tar.gz lwn-b8f1a75d61d8405a753380c6fb17ba84a5603cd4.zip | |
mm: call page_ext_init() after all struct pages are initialized
When DEFERRED_STRUCT_PAGE_INIT is enabled, just a subset of memmap at
boot are initialized, then the rest are initialized in parallel by
starting one-off "pgdatinitX" kernel thread for each node X.
If page_ext_init is called before it, some pages will not have valid
extension, this may lead the below kernel oops when booting up kernel:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff8118d982>] free_pcppages_bulk+0x2d2/0x8d0
PGD 0
Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
Modules linked in:
CPU: 11 PID: 106 Comm: pgdatinit1 Not tainted 4.6.0-rc5-next-20160427 #26
Hardware name: Intel Corporation S5520HC/S5520HC, BIOS S5500.86B.01.10.0025.030220091519 03/02/2009
task: ffff88017c080040 ti: ffff88017c084000 task.ti: ffff88017c084000
RIP: 0010:[<ffffffff8118d982>] [<ffffffff8118d982>] free_pcppages_bulk+0x2d2/0x8d0
RSP: 0000:ffff88017c087c48 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000980 RSI: 0000000000000080 RDI: 0000000000660401
RBP: ffff88017c087cd0 R08: 0000000000000401 R09: 0000000000000009
R10: ffff88017c080040 R11: 000000000000000a R12: 0000000000000400
R13: ffffea0019810000 R14: ffffea0019810040 R15: ffff88066cfe6080
FS: 0000000000000000(0000) GS:ffff88066cd40000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000002406000 CR4: 00000000000006e0
Call Trace:
free_hot_cold_page+0x192/0x1d0
__free_pages+0x5c/0x90
__free_pages_boot_core+0x11a/0x14e
deferred_free_range+0x50/0x62
deferred_init_memmap+0x220/0x3c3
kthread+0xf8/0x110
ret_from_fork+0x22/0x40
Code: 49 89 d4 48 c1 e0 06 49 01 c5 e9 de fe ff ff 4c 89 f7 44 89 4d b8 4c 89 45 c0 44 89 5d c8 48 89 4d d0 e8 62 c7 07 00 48 8b 4d d0 <48> 8b 00 44 8b 5d c8 4c 8b 45 c0 44 8b 4d b8 a8 02 0f 84 05 ff
RIP [<ffffffff8118d982>] free_pcppages_bulk+0x2d2/0x8d0
RSP <ffff88017c087c48>
CR2: 0000000000000000
Move page_ext_init() after page_alloc_init_late() to make sure page extension
is setup for all pages.
Link: http://lkml.kernel.org/r/1463696006-31360-1-git-send-email-yang.shi@linaro.org
Signed-off-by: Yang Shi <yang.shi@linaro.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'init')
| -rw-r--r-- | init/main.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/init/main.c b/init/main.c index b3c6e363ae18..2075fafaad59 100644 --- a/init/main.c +++ b/init/main.c @@ -606,7 +606,6 @@ asmlinkage __visible void __init start_kernel(void) initrd_start = 0; } #endif - page_ext_init(); debug_objects_mem_init(); kmemleak_init(); setup_per_cpu_pageset(); @@ -1004,6 +1003,8 @@ static noinline void __init kernel_init_freeable(void) sched_init_smp(); page_alloc_init_late(); + /* Initialize page ext after all struct pages are initializaed */ + page_ext_init(); do_basic_setup(); |