[PATCH 0/2 x86] fix some page faults in nmi if kmemcheck is enabled

Li Zhong
2012-02-20T06:01:21Z

If CONFIG_KMEMCHECK is enabled, there might be page faults in nmi if the
pages are marked as not present by kmemcheck, like following:

[ 4.535803] WARNING: at arch/x86/mm/kmemcheck/kmemcheck.c:634 kmemcheck_fault+0xb9/0xd0()
[ 4.633429] Hardware name: System x3650 M3 -[7945AC1]-
[ 4.694710] Modules linked in:
[ 4.731105] Pid: 1, comm: swapper/0 Not tainted 3.3.0-rc3 #15
[ 4.799654] Call Trace:
[ 4.828751] <NMI> [<ffffffff81042eca>] warn_slowpath_common+0x7a/0xb0
[ 4.907713] [<ffffffff81042f15>] warn_slowpath_null+0x15/0x20
[ 4.977301] [<ffffffff8103ce89>] kmemcheck_fault+0xb9/0xd0
[ 5.043778] [<ffffffff81551ba6>] do_page_fault+0x406/0x550
[ 5.110252] [<ffffffff8154e235>] page_fault+0x25/0x30
[ 5.171535] [<ffffffff8154f005>] ? nmi_handle.clone.1+0x75/0xc0
[ 5.243202] [<ffffffff8154efcf>] ? nmi_handle.clone.1+0x3f/0xc0
[ 5.314867] [<ffffffff8154ef90>] ? __die+0xf0/0xf0
[ 5.373038] [<ffffffff8154f15f>] do_nmi+0x10f/0x360
[ 5.432243] [<ffffffff8154e5cd>] restart_nmi+0x1a/0x1e
[ 5.494565] [<ffffffff8154e210>] ? general_protection+0x30/0x30
[ 5.566234] [<ffffffff8154e210>] ? general_protection+0x30/0x30
[ 5.637898] [<ffffffff8154e210>] ? general_protection+0x30/0x30
[ 5.709566] <<EOE>> [<ffffffff8126d814>] ? rb_insert_color+0xa4/0x150
[ 5.788526] [<ffffffff8119d17b>] sysfs_link_sibling+0x8b/0x110
[ 5.859155] [<ffffffff8119dff1>] __sysfs_add_one+0xc1/0x100
[ 5.926666] [<ffffffff8119e056>] sysfs_add_one+0x26/0xd0
[ 5.991065] [<ffffffff8119cdf4>] sysfs_add_file_mode+0xc4/0x100
[ 6.062731] [<ffffffff8119fc41>] internal_create_group+0xc1/0x1a0
[ 6.136473] [<ffffffff8119fd4e>] sysfs_create_group+0xe/0x10
[ 6.205026] [<ffffffff81351c1a>] dpm_sysfs_add+0x2a/0xd0
[ 6.269425] [<ffffffff81349bf5>] device_add+0x5e5/0x730
[ 6.332783] [<ffffffff81349d59>] device_register+0x19/0x20
[ 6.399260] [<ffffffff8135b6b8>] add_memory_section+0x158/0x1e0
[ 6.470927] [<ffffffff81ca757e>] memory_dev_init+0x75/0x108
[ 6.538439] [<ffffffff81ca73a9>] driver_init+0x31/0x33
[ 6.600762] [<ffffffff81c72c68>] kernel_init+0xcc/0x169
[ 6.664121] [<ffffffff81555e64>] kernel_thread_helper+0x4/0x10
[ 6.734749] [<ffffffff81c72b9c>] ? start_kernel+0x3ab/0x3ab
[ 6.802261] [<ffffffff81555e60>] ? gs_change+0x13/0x13
[ 6.864585] ---[ end trace a7919e7f17c0a725 ]---

These two patches tries to fix some of the problems by avoiding using the
non-present pages.