Question

我修改了Linux内核，以便修改特定进程的某些内存页面。总之，我写的函数在该进程中接收进程ID和地址，然后他们用另一个虚拟页面替换该特定地址的页面。最后，其中一个函数在被替换的原始页面上调用__free_page()。

问题是我在尝试重用原始页面时从Linux内核中收到此错误。那么，它抱怨的那面旗帜是什么？以及如何摆脱这个错误？这是syslog中的相关行。

感谢。

Nov 14 19:15:23 localhost kernel: [ 1466.949451] BUG: Bad page state in process mytestapp  pfn:7d309
Nov 14 19:15:23 localhost kernel: [ 1466.949452] page:ffffea0001f4c240 count:-1 mapcount:0 mapping:          (null) index:0x7fd632179
Nov 14 19:15:23 localhost kernel: [ 1466.949453] page flags: 0x100000000000000()
Nov 14 19:15:23 localhost kernel: [ 1466.949453] Modules linked in: test_module(O) acpiphp bnep rfcomm bluetooth binfmt_misc joydev hid_generic usbhid hid snd_ens1371 gameport snd_ac97_codec ac97_bus snd_pcm ghash_clmulni_intel snd_seq_midi snd_rawmidi snd_seq_midi_event ppdev snd_seq aesni_intel ablk_helper cryptd aes_x86_64 snd_timer snd_seq_device psmouse microcode snd vmw_balloon acpi_memhotplug parport_pc soundcore snd_page_alloc vmwgfx ttm mac_hid drm i2c_piix4 serio_raw shpchp lp parport e1000 mptspi mptscsih mptbase floppy vmw_pvscsi vmxnet3
Nov 14 19:15:23 localhost kernel: [ 1466.949484] Pid: 15064, comm: mytestapp Tainted: G    B      O 3.6.11-elasticos-0.01 #31
Nov 14 19:15:23 localhost kernel: [ 1466.949485] Call Trace:
Nov 14 19:15:23 localhost kernel: [ 1466.949487]  [<ffffffff8111941f>] bad_page+0xbf/0x110
Nov 14 19:15:23 localhost kernel: [ 1466.949505]  [<ffffffff8111aac9>] get_page_from_freelist+0x6f9/0x810
Nov 14 19:15:23 localhost kernel: [ 1466.949508]  [<ffffffff8111a702>] ? get_page_from_freelist+0x332/0x810
Nov 14 19:15:23 localhost kernel: [ 1466.949509]  [<ffffffff8111b06e>] __alloc_pages_nodemask+0x48e/0x9b0
Nov 14 19:15:23 localhost kernel: [ 1466.949512]  [<ffffffff8111f03a>] ? pagevec_lru_move_fn+0xea/0x110
Nov 14 19:15:23 localhost kernel: [ 1466.949514]  [<ffffffff81154ec3>] alloc_pages_vma+0xb3/0x190
Nov 14 19:15:23 localhost kernel: [ 1466.949515]  [<ffffffff811397cc>] handle_pte_fault+0x56c/0xb00
Nov 14 19:15:23 localhost kernel: [ 1466.949517]  [<ffffffff810473f7>] ? pte_alloc_one+0x37/0x50
Nov 14 19:15:23 localhost kernel: [ 1466.949527]  [<ffffffff8113afd9>] handle_mm_fault+0x259/0x340
Nov 14 19:15:23 localhost kernel: [ 1466.949538]  [<ffffffff8107c218>] ? up_read+0x18/0x30
Nov 14 19:15:23 localhost kernel: [ 1466.949540]  [<ffffffff816213d2>] do_page_fault+0x152/0x520
Nov 14 19:15:23 localhost kernel: [ 1466.949541]  [<ffffffff8108c36d>] ? set_next_entity+0x9d/0xb0
Nov 14 19:15:23 localhost kernel: [ 1466.949543]  [<ffffffff810135ca>] ? __switch_to+0x17a/0x410
Nov 14 19:15:23 localhost kernel: [ 1466.949545]  [<ffffffff8161de65>] page_fault+0x25/0x30

Answer 1

此宏检查是否取消设置了适当的页面标志。正如我在你的情况下看到的那样，PG_LOCKED标志设置有问题。这意味着您释放了锁定的页面。请参阅unlock_page来处理此问题或（可能）使用free_page

在更换进程中的物理页面时触发BUG断言

1 个答案: