Using trinity I often trigger under a user mode linux image with host kernel 3.8.4
and guest kernel linux-v3.9-rc3-244-g9217cbb the following :
(The UML guest is a 32bit stable Gentoo Linux)
2013-03-22T18:03:01.232+01:00 trinity kernel: BUG: Bad page map in process trinity-child6 pte:002f9045 pmd:29e421e1
2013-03-22T18:03:01.232+01:00 trinity kernel: page:0920df20 count:1 mapcount:-1 mapping: (null) index:0x0
2013-03-22T18:03:01.232+01:00 trinity kernel: page flags: 0x400(reserved)
2013-03-22T18:03:01.232+01:00 trinity kernel: addr:00100000 vm_flags:00060055 anon_vma: (null) mapping: (null) index:100
2013-03-22T18:03:01.232+01:00 trinity kernel: vma->vm_ops->fault: special_mapping_fault+0x0/0x80
2013-03-22T18:03:01.232+01:00 trinity kernel: 31e87d1c: [<0833b8b8>] dump_stack+0x22/0x24
2013-03-22T18:03:01.232+01:00 trinity kernel: 31e87d34: [<0833cc71>] print_bad_pte+0x17b/0x197
2013-03-22T18:03:01.232+01:00 trinity kernel: 31e87d78: [<080e1138>] unmap_single_vma+0x268/0x430
2013-03-22T18:03:01.232+01:00 trinity kernel: 31e87dd8: [<080e1837>] unmap_vmas+0x37/0x50
2013-03-22T18:03:01.232+01:00 trinity kernel: 31e87df4: [<080e4970>] unmap_region+0x80/0xe0
2013-03-22T18:03:01.233+01:00 trinity kernel: 31e87e30: [<080e6661>] do_munmap+0x231/0x2a0
2013-03-22T18:03:01.233+01:00 trinity kernel: 31e87e68: [<080e8ae8>] sys_mremap+0x248/0x480
2013-03-22T18:03:01.233+01:00 trinity kernel: 31e87eac: [<08062a82>] handle_syscall+0x82/0xb0
2013-03-22T18:03:01.233+01:00 trinity kernel: 31e87ef4: [<08074dfd>] userspace+0x46d/0x590
2013-03-22T18:03:01.233+01:00 trinity kernel: 31e87fec: [<0805f7bc>] fork_handler+0x6c/0x70
2013-03-22T18:03:01.233+01:00 trinity kernel: 31e87ffc: [<00000000>] 0x0
2013-03-22T18:03:01.233+01:00 trinity kernel: 2013-03-22T18:03:01.233+01:00 trinity kernel: Disabling lock debugging due to kernel taint
2013-03-22T18:03:01.233+01:00 trinity kernel: BUG: Bad page state in process trinity-child6 pfn:002f9
2013-03-22T18:03:01.233+01:00 trinity kernel: page:0920df20 count:0 mapcount:-1 mapping: (null) index:0x0
2013-03-22T18:03:01.235+01:00 trinity kernel: page flags: 0x400(reserved)
2013-03-22T18:03:01.235+01:00 trinity kernel: 31e87cd4: [<0833b8b8>] dump_stack+0x22/0x24
2013-03-22T18:03:01.235+01:00 trinity kernel: 31e87cec: [<080cd755>] bad_page+0xb5/0xe0
2013-03-22T18:03:01.235+01:00 trinity kernel: 31e87d08: [<080cd7f3>] free_pages_prepare+0x73/0xb0
2013-03-22T18:03:01.235+01:00 trinity kernel: 31e87d24: [<080cec1d>] free_hot_cold_page+0x1d/0x100
2013-03-22T18:03:01.235+01:00 trinity kernel: 31e87d4c: [<080d15ae>] __put_single_page+0x1e/0x30
2013-03-22T18:03:01.235+01:00 trinity kernel: 31e87d60: [<080d16d7>] put_page+0x27/0x30
2013-03-22T18:03:01.235+01:00 trinity kernel: 31e87d68: [<080ee6ec>] free_page_and_swap_cache+0x3c/0x50
2013-03-22T18:03:01.235+01:00 trinity kernel: 31e87d78: [<080e1155>] unmap_single_vma+0x285/0x430
2013-03-22T18:03:01.235+01:00 trinity kernel: 31e87dd8: [<080e1837>] unmap_vmas+0x37/0x50
2013-03-22T18:03:01.236+01:00 trinity kernel: 31e87df4: [<080e4970>] unmap_region+0x80/0xe0
2013-03-22T18:03:01.236+01:00 trinity kernel: 31e87e30: [<080e6661>] do_munmap+0x231/0x2a0
2013-03-22T18:03:01.236+01:00 trinity kernel: 31e87e68: [<080e8ae8>] sys_mremap+0x248/0x480
2013-03-22T18:03:01.236+01:00 trinity kernel: 31e87eac: [<08062a82>] handle_syscall+0x82/0xb0
2013-03-22T18:03:01.236+01:00 trinity kernel: 31e87ef4: [<08074dfd>] userspace+0x46d/0x590
2013-03-22T18:03:01.236+01:00 trinity kernel: 31e87fec: [<0805f7bc>] fork_handler+0x6c/0x70
2013-03-22T18:03:01.236+01:00 trinity kernel: 31e87ffc: [<00000000>] 0x0
2013-03-22T18:03:01.236+01:00 trinity kernel: 2013-03-22T18:03:01.236+01:00 trinity kernel: BUG: Bad page map in process trinity-child6 pte:29e38045 pmd:29e421e1
2013-03-22T18:03:01.236+01:00 trinity kernel: page:09744700 count:1 mapcount:-1 mapping: (null) index:0x0
2013-03-22T18:03:01.237+01:00 trinity kernel: page flags: 0x0()
2013-03-22T18:03:01.237+01:00 trinity kernel: addr:00101000 vm_flags:00060055 anon_vma: (null) mapping: (null) index:101
2013-03-22T18:03:01.237+01:00 trinity kernel: vma->vm_ops->fault: special_mapping_fault+0x0/0x80
2013-03-22T18:03:01.237+01:00 trinity kernel: 31e87d1c: [<0833b8b8>] dump_stack+0x22/0x24
2013-03-22T18:03:01.237+01:00 trinity kernel: 31e87d34: [<0833cc71>] print_bad_pte+0x17b/0x197
2013-03-22T18:03:01.237+01:00 trinity kernel: 31e87d78: [<080e1138>] unmap_single_vma+0x268/0x430
2013-03-22T18:03:01.237+01:00 trinity kernel: 31e87dd8: [<080e1837>] unmap_vmas+0x37/0x50
2013-03-22T18:03:01.237+01:00 trinity kernel: 31e87df4: [<080e4970>] unmap_region+0x80/0xe0
2013-03-22T18:03:01.237+01:00 trinity kernel: 31e87e30: [<080e6661>] do_munmap+0x231/0x2a0
2013-03-22T18:03:01.237+01:00 trinity kernel: 31e87e68: [<080e8ae8>] sys_mremap+0x248/0x480
2013-03-22T18:03:01.238+01:00 trinity kernel: 31e87eac: [<08062a82>] handle_syscall+0x82/0xb0
2013-03-22T18:03:01.238+01:00 trinity kernel: 31e87ef4: [<08074dfd>] userspace+0x46d/0x590
2013-03-22T18:03:01.238+01:00 trinity kernel: 31e87fec: [<0805f7bc>] fork_handler+0x6c/0x70
2013-03-22T18:03:01.238+01:00 trinity kernel: 31e87ffc: [<00000000>] 0x0
2013-03-22T18:03:01.238+01:00 trinity kernel: 2013-03-22T18:03:01.238+01:00 trinity kernel: BUG: Bad page state in process trinity-child6 pfn:29e38
2013-03-22T18:03:01.238+01:00 trinity kernel: page:09744700 count:0 mapcount:-1 mapping: (null) index:0x0
2013-03-22T18:03:01.238+01:00 trinity kernel: page flags: 0x0()
2013-03-22T18:03:01.238+01:00 trinity kernel: 31e87cd4: [<0833b8b8>] dump_stack+0x22/0x24
2013-03-22T18:03:01.238+01:00 trinity kernel: 31e87cec: [<080cd755>] bad_page+0xb5/0xe0
2013-03-22T18:03:01.239+01:00 trinity kernel: 31e87d08: [<080cd7f3>] free_pages_prepare+0x73/0xb0
2013-03-22T18:03:01.239+01:00 trinity kernel: 31e87d24: [<080cec1d>] free_hot_cold_page+0x1d/0x100
2013-03-22T18:03:01.239+01:00 trinity kernel: 31e87d4c: [<080d15ae>] __put_single_page+0x1e/0x30
2013-03-22T18:03:01.239+01:00 trinity kernel: 31e87d60: [<080d16d7>] put_page+0x27/0x30
2013-03-22T18:03:01.239+01:00 trinity kernel: 31e87d68: [<080ee6ec>] free_page_and_swap_cache+0x3c/0x50
2013-03-22T18:03:01.239+01:00 trinity kernel: 31e87d78: [<080e1155>] unmap_single_vma+0x285/0x430
2013-03-22T18:03:01.239+01:00 trinity kernel: 31e87dd8: [<080e1837>] unmap_vmas+0x37/0x50
2013-03-22T18:03:01.239+01:00 trinity kernel: 31e87df4: [<080e4970>] unmap_region+0x80/0xe0
2013-03-22T18:03:01.239+01:00 trinity kernel: 31e87e30: [<080e6661>] do_munmap+0x231/0x2a0
2013-03-22T18:03:01.239+01:00 trinity kernel: 31e87e68: [<080e8ae8>] sys_mremap+0x248/0x480
2013-03-22T18:03:01.240+01:00 trinity kernel: 31e87eac: [<08062a82>] handle_syscall+0x82/0xb0
2013-03-22T18:03:01.240+01:00 trinity kernel: 31e87ef4: [<08074dfd>] userspace+0x46d/0x590
2013-03-22T18:03:01.240+01:00 trinity kernel: 31e87fec: [<0805f7bc>] fork_handler+0x6c/0x70
2013-03-22T18:03:01.240+01:00 trinity kernel: 31e87ffc: [<00000000>] 0x0
2013-03-22T18:03:01.240+01:00 trinity kernel: 2013-03-22T18:03:01.240+01:00 trinity kernel: Stub registers -
2013-03-22T18:03:01.240+01:00 trinity kernel: 0 - 100000
2013-03-22T18:03:01.240+01:00 trinity kernel: 1 - 300000
2013-03-22T18:03:01.240+01:00 trinity kernel: 2 - 0
2013-03-22T18:03:01.240+01:00 trinity kernel: 3 - 0
2013-03-22T18:03:01.243+01:00 trinity kernel: 4 - 0
2013-03-22T18:03:01.243+01:00 trinity kernel: 5 - 0
2013-03-22T18:03:01.243+01:00 trinity kernel: 6 - 0
2013-03-22T18:03:01.243+01:00 trinity kernel: 7 - 7b
2013-03-22T18:03:01.243+01:00 trinity kernel: 8 - 7b
2013-03-22T18:03:01.243+01:00 trinity kernel: 9 - 0
2013-03-22T18:03:01.243+01:00 trinity kernel: 10 - 33
2013-03-22T18:03:01.243+01:00 trinity kernel: 11 - ffffffff
2013-03-22T18:03:01.243+01:00 trinity kernel: 12 - 1000c3
2013-03-22T18:03:01.243+01:00 trinity kernel: 13 - 73
2013-03-22T18:03:01.244+01:00 trinity kernel: 14 - 10206
2013-03-22T18:03:01.244+01:00 trinity kernel: 15 - 101028
2013-03-22T18:03:01.244+01:00 trinity kernel: 16 - 7b
2013-03-22T18:03:01.244+01:00 trinity kernel: wait_stub_done : failed to wait for SIGTRAP, pid = 3143, n = 3143, errno = 0, status = 0xb7f
--
MfG/Sincerely
Toralf Förster
pgp finger print: 7B1A 07F4 EC82 0F90 D4C2 8936 872A E508 7DB6 9DA3
On Fri, 22 Mar 2013 18:28:36 +0100 Toralf F__rster <[email protected]> wrote:
> Using trinity I often trigger under a user mode linux image with host kernel 3.8.4
> and guest kernel linux-v3.9-rc3-244-g9217cbb the following :
> (The UML guest is a 32bit stable Gentoo Linux)
I assume 3.8 is OK?
>
> 2013-03-22T18:03:01.232+01:00 trinity kernel: BUG: Bad page map in process trinity-child6 pte:002f9045 pmd:29e421e1
> 2013-03-22T18:03:01.232+01:00 trinity kernel: page:0920df20 count:1 mapcount:-1 mapping: (null) index:0x0
mapcount=-1.
> 2013-03-22T18:03:01.232+01:00 trinity kernel: page flags: 0x400(reserved)
> 2013-03-22T18:03:01.232+01:00 trinity kernel: addr:00100000 vm_flags:00060055 anon_vma: (null) mapping: (null) index:100
> 2013-03-22T18:03:01.232+01:00 trinity kernel: vma->vm_ops->fault: special_mapping_fault+0x0/0x80
> 2013-03-22T18:03:01.232+01:00 trinity kernel: 31e87d1c: [<0833b8b8>] dump_stack+0x22/0x24
> 2013-03-22T18:03:01.232+01:00 trinity kernel: 31e87d34: [<0833cc71>] print_bad_pte+0x17b/0x197
> 2013-03-22T18:03:01.232+01:00 trinity kernel: 31e87d78: [<080e1138>] unmap_single_vma+0x268/0x430
> 2013-03-22T18:03:01.232+01:00 trinity kernel: 31e87dd8: [<080e1837>] unmap_vmas+0x37/0x50
> 2013-03-22T18:03:01.232+01:00 trinity kernel: 31e87df4: [<080e4970>] unmap_region+0x80/0xe0
> 2013-03-22T18:03:01.233+01:00 trinity kernel: 31e87e30: [<080e6661>] do_munmap+0x231/0x2a0
> 2013-03-22T18:03:01.233+01:00 trinity kernel: 31e87e68: [<080e8ae8>] sys_mremap+0x248/0x480
> 2013-03-22T18:03:01.233+01:00 trinity kernel: 31e87eac: [<08062a82>] handle_syscall+0x82/0xb0
> 2013-03-22T18:03:01.233+01:00 trinity kernel: 31e87ef4: [<08074dfd>] userspace+0x46d/0x590
> 2013-03-22T18:03:01.233+01:00 trinity kernel: 31e87fec: [<0805f7bc>] fork_handler+0x6c/0x70
> 2013-03-22T18:03:01.233+01:00 trinity kernel: 31e87ffc: [<00000000>] 0x0
> 2013-03-22T18:03:01.233+01:00 trinity kernel: 2013-03-22T18:03:01.233+01:00 trinity kernel: Disabling lock debugging due to kernel taint
> 2013-03-22T18:03:01.233+01:00 trinity kernel: BUG: Bad page state in process trinity-child6 pfn:002f9
> 2013-03-22T18:03:01.233+01:00 trinity kernel: page:0920df20 count:0 mapcount:-1 mapping: (null) index:0x0
> 2013-03-22T18:03:01.235+01:00 trinity kernel: page flags: 0x400(reserved)
> 2013-03-22T18:03:01.235+01:00 trinity kernel: 31e87cd4: [<0833b8b8>] dump_stack+0x22/0x24
> 2013-03-22T18:03:01.235+01:00 trinity kernel: 31e87cec: [<080cd755>] bad_page+0xb5/0xe0
> 2013-03-22T18:03:01.235+01:00 trinity kernel: 31e87d08: [<080cd7f3>] free_pages_prepare+0x73/0xb0
> 2013-03-22T18:03:01.235+01:00 trinity kernel: 31e87d24: [<080cec1d>] free_hot_cold_page+0x1d/0x100
> 2013-03-22T18:03:01.235+01:00 trinity kernel: 31e87d4c: [<080d15ae>] __put_single_page+0x1e/0x30
> 2013-03-22T18:03:01.235+01:00 trinity kernel: 31e87d60: [<080d16d7>] put_page+0x27/0x30
> 2013-03-22T18:03:01.235+01:00 trinity kernel: 31e87d68: [<080ee6ec>] free_page_and_swap_cache+0x3c/0x50
> 2013-03-22T18:03:01.235+01:00 trinity kernel: 31e87d78: [<080e1155>] unmap_single_vma+0x285/0x430
> 2013-03-22T18:03:01.235+01:00 trinity kernel: 31e87dd8: [<080e1837>] unmap_vmas+0x37/0x50
> 2013-03-22T18:03:01.236+01:00 trinity kernel: 31e87df4: [<080e4970>] unmap_region+0x80/0xe0
> 2013-03-22T18:03:01.236+01:00 trinity kernel: 31e87e30: [<080e6661>] do_munmap+0x231/0x2a0
> 2013-03-22T18:03:01.236+01:00 trinity kernel: 31e87e68: [<080e8ae8>] sys_mremap+0x248/0x480
> 2013-03-22T18:03:01.236+01:00 trinity kernel: 31e87eac: [<08062a82>] handle_syscall+0x82/0xb0
> 2013-03-22T18:03:01.236+01:00 trinity kernel: 31e87ef4: [<08074dfd>] userspace+0x46d/0x590
> 2013-03-22T18:03:01.236+01:00 trinity kernel: 31e87fec: [<0805f7bc>] fork_handler+0x6c/0x70
> 2013-03-22T18:03:01.236+01:00 trinity kernel: 31e87ffc: [<00000000>] 0x0
> 2013-03-22T18:03:01.236+01:00 trinity kernel: 2013-03-22T18:03:01.236+01:00 trinity kernel: BUG: Bad page map in process trinity-child6 pte:29e38045 pmd:29e421e1
> 2013-03-22T18:03:01.236+01:00 trinity kernel: page:09744700 count:1 mapcount:-1 mapping: (null) index:0x0
> 2013-03-22T18:03:01.237+01:00 trinity kernel: page flags: 0x0()
> 2013-03-22T18:03:01.237+01:00 trinity kernel: addr:00101000 vm_flags:00060055 anon_vma: (null) mapping: (null) index:101
> 2013-03-22T18:03:01.237+01:00 trinity kernel: vma->vm_ops->fault: special_mapping_fault+0x0/0x80
> 2013-03-22T18:03:01.237+01:00 trinity kernel: 31e87d1c: [<0833b8b8>] dump_stack+0x22/0x24
> 2013-03-22T18:03:01.237+01:00 trinity kernel: 31e87d34: [<0833cc71>] print_bad_pte+0x17b/0x197
> 2013-03-22T18:03:01.237+01:00 trinity kernel: 31e87d78: [<080e1138>] unmap_single_vma+0x268/0x430
> 2013-03-22T18:03:01.237+01:00 trinity kernel: 31e87dd8: [<080e1837>] unmap_vmas+0x37/0x50
> 2013-03-22T18:03:01.237+01:00 trinity kernel: 31e87df4: [<080e4970>] unmap_region+0x80/0xe0
> 2013-03-22T18:03:01.237+01:00 trinity kernel: 31e87e30: [<080e6661>] do_munmap+0x231/0x2a0
> 2013-03-22T18:03:01.237+01:00 trinity kernel: 31e87e68: [<080e8ae8>] sys_mremap+0x248/0x480
> 2013-03-22T18:03:01.238+01:00 trinity kernel: 31e87eac: [<08062a82>] handle_syscall+0x82/0xb0
> 2013-03-22T18:03:01.238+01:00 trinity kernel: 31e87ef4: [<08074dfd>] userspace+0x46d/0x590
> 2013-03-22T18:03:01.238+01:00 trinity kernel: 31e87fec: [<0805f7bc>] fork_handler+0x6c/0x70
> 2013-03-22T18:03:01.238+01:00 trinity kernel: 31e87ffc: [<00000000>] 0x0
> 2013-03-22T18:03:01.238+01:00 trinity kernel: 2013-03-22T18:03:01.238+01:00 trinity kernel: BUG: Bad page state in process trinity-child6 pfn:29e38
> 2013-03-22T18:03:01.238+01:00 trinity kernel: page:09744700 count:0 mapcount:-1 mapping: (null) index:0x0
> 2013-03-22T18:03:01.238+01:00 trinity kernel: page flags: 0x0()
> 2013-03-22T18:03:01.238+01:00 trinity kernel: 31e87cd4: [<0833b8b8>] dump_stack+0x22/0x24
> 2013-03-22T18:03:01.238+01:00 trinity kernel: 31e87cec: [<080cd755>] bad_page+0xb5/0xe0
> 2013-03-22T18:03:01.239+01:00 trinity kernel: 31e87d08: [<080cd7f3>] free_pages_prepare+0x73/0xb0
> 2013-03-22T18:03:01.239+01:00 trinity kernel: 31e87d24: [<080cec1d>] free_hot_cold_page+0x1d/0x100
> 2013-03-22T18:03:01.239+01:00 trinity kernel: 31e87d4c: [<080d15ae>] __put_single_page+0x1e/0x30
> 2013-03-22T18:03:01.239+01:00 trinity kernel: 31e87d60: [<080d16d7>] put_page+0x27/0x30
> 2013-03-22T18:03:01.239+01:00 trinity kernel: 31e87d68: [<080ee6ec>] free_page_and_swap_cache+0x3c/0x50
> 2013-03-22T18:03:01.239+01:00 trinity kernel: 31e87d78: [<080e1155>] unmap_single_vma+0x285/0x430
> 2013-03-22T18:03:01.239+01:00 trinity kernel: 31e87dd8: [<080e1837>] unmap_vmas+0x37/0x50
> 2013-03-22T18:03:01.239+01:00 trinity kernel: 31e87df4: [<080e4970>] unmap_region+0x80/0xe0
> 2013-03-22T18:03:01.239+01:00 trinity kernel: 31e87e30: [<080e6661>] do_munmap+0x231/0x2a0
> 2013-03-22T18:03:01.239+01:00 trinity kernel: 31e87e68: [<080e8ae8>] sys_mremap+0x248/0x480
> 2013-03-22T18:03:01.240+01:00 trinity kernel: 31e87eac: [<08062a82>] handle_syscall+0x82/0xb0
> 2013-03-22T18:03:01.240+01:00 trinity kernel: 31e87ef4: [<08074dfd>] userspace+0x46d/0x590
> 2013-03-22T18:03:01.240+01:00 trinity kernel: 31e87fec: [<0805f7bc>] fork_handler+0x6c/0x70
> 2013-03-22T18:03:01.240+01:00 trinity kernel: 31e87ffc: [<00000000>] 0x0
> 2013-03-22T18:03:01.240+01:00 trinity kernel: 2013-03-22T18:03:01.240+01:00 trinity kernel: Stub registers -
> 2013-03-22T18:03:01.240+01:00 trinity kernel: 0 - 100000
> 2013-03-22T18:03:01.240+01:00 trinity kernel: 1 - 300000
> 2013-03-22T18:03:01.240+01:00 trinity kernel: 2 - 0
> 2013-03-22T18:03:01.240+01:00 trinity kernel: 3 - 0
> 2013-03-22T18:03:01.243+01:00 trinity kernel: 4 - 0
> 2013-03-22T18:03:01.243+01:00 trinity kernel: 5 - 0
> 2013-03-22T18:03:01.243+01:00 trinity kernel: 6 - 0
> 2013-03-22T18:03:01.243+01:00 trinity kernel: 7 - 7b
> 2013-03-22T18:03:01.243+01:00 trinity kernel: 8 - 7b
> 2013-03-22T18:03:01.243+01:00 trinity kernel: 9 - 0
> 2013-03-22T18:03:01.243+01:00 trinity kernel: 10 - 33
> 2013-03-22T18:03:01.243+01:00 trinity kernel: 11 - ffffffff
> 2013-03-22T18:03:01.243+01:00 trinity kernel: 12 - 1000c3
> 2013-03-22T18:03:01.243+01:00 trinity kernel: 13 - 73
> 2013-03-22T18:03:01.244+01:00 trinity kernel: 14 - 10206
> 2013-03-22T18:03:01.244+01:00 trinity kernel: 15 - 101028
> 2013-03-22T18:03:01.244+01:00 trinity kernel: 16 - 7b
> 2013-03-22T18:03:01.244+01:00 trinity kernel: wait_stub_done : failed to wait for SIGTRAP, pid = 3143, n = 3143, errno = 0, status = 0xb7f
>
>
> --
> MfG/Sincerely
> Toralf F__rster
> pgp finger print: 7B1A 07F4 EC82 0F90 D4C2 8936 872A E508 7DB6 9DA3
>
On 03/25/2013 11:53 PM, Andrew Morton wrote:
> On Fri, 22 Mar 2013 18:28:36 +0100 Toralf F__rster <[email protected]> wrote:
>
>> > Using trinity I often trigger under a user mode linux image with host kernel 3.8.4
>> > and guest kernel linux-v3.9-rc3-244-g9217cbb the following :
>> > (The UML guest is a 32bit stable Gentoo Linux)
> I assume 3.8 is OK?
>
With UML kernel 3.7.10 (host kernel still 3.8.4) I can trigger this
issue too.
Just to clarify it - here the bug appears in the UML kernel - the host
kernel is ok (I can of course crash a host kernel too by trinity'ing an
UML guest, but that's another thread - see [1])
FWIW he trinity command is just a test of 1 syscall:
$> trinity --children 1 --victims /mnt/nfs/n22/victims -c mremap
[1] https://lkml.org/lkml/2013/3/24/174
--
MfG/Sincerely
Toralf Förster
pgp finger print: 7B1A 07F4 EC82 0F90 D4C2 8936 872A E508 7DB6 9DA3
On Tue, 26 Mar 2013, Toralf Foerster wrote:
> On 03/25/2013 11:53 PM, Andrew Morton wrote:
> > On Fri, 22 Mar 2013 18:28:36 +0100 Toralf Foerster <[email protected]> wrote:
> >
> >> > Using trinity I often trigger under a user mode linux image with host kernel 3.8.4
> >> > and guest kernel linux-v3.9-rc3-244-g9217cbb the following :
> >> > (The UML guest is a 32bit stable Gentoo Linux)
> > I assume 3.8 is OK?
> >
> With UML kernel 3.7.10 (host kernel still 3.8.4) I can trigger this
> issue too.
> Just to clarify it - here the bug appears in the UML kernel - the host
> kernel is ok (I can of course crash a host kernel too by trinity'ing an
> UML guest, but that's another thread - see [1])
>
>
> FWIW he trinity command is just a test of 1 syscall:
>
> $> trinity --children 1 --victims /mnt/nfs/n22/victims -c mremap
>
>
>
> [1] https://lkml.org/lkml/2013/3/24/174
I should think it's been like this for five years, or even more: maybe
you are the first person to try unmapping user address 0x100000 on UML;
though it's odd that you find it using mremap than the more common munmap.
uml_setup_stubs() sets up the special vma with install_special_mapping(),
but instead of then faulting in the two pages concerned, it has preset
the ptes with init_stub_pte(), which did not increment page mapcount.
munmap() that area (or set up another mapping in that place), and
zap_pte_range() will decrement page mapcount negative, hence the
"Bad page" errors. Whereas UML uses an arch_exit_mmap() hook to
clear the ptes at exit time, to avoid encountering such errors.
I think that adding VM_PFNMAP to those install_special_mapping() flags
would be enough to fix it (and avoid the need for the arch_exit_mmap(),
and let vm_insert_pfn() do the work of init_stub_pte()); but I'm not
certain that would be the approved way, and I may have missed problems
doing it like this (which would disallow get_user_pages(), e.g. ptrace,
on that area: which might or might not be a good thing, I don't know).
I'm saying this just by examination, I've not tried any of it at all.
Over to Richard.
Hugh
On Wed, Mar 27, 2013 at 12:03 AM, Hugh Dickins <[email protected]> wrote:
> On Tue, 26 Mar 2013, Toralf Foerster wrote:
>> On 03/25/2013 11:53 PM, Andrew Morton wrote:
>> > On Fri, 22 Mar 2013 18:28:36 +0100 Toralf Foerster <[email protected]> wrote:
>> >
>> >> > Using trinity I often trigger under a user mode linux image with host kernel 3.8.4
>> >> > and guest kernel linux-v3.9-rc3-244-g9217cbb the following :
>> >> > (The UML guest is a 32bit stable Gentoo Linux)
>> > I assume 3.8 is OK?
>> >
>> With UML kernel 3.7.10 (host kernel still 3.8.4) I can trigger this
>> issue too.
>> Just to clarify it - here the bug appears in the UML kernel - the host
>> kernel is ok (I can of course crash a host kernel too by trinity'ing an
>> UML guest, but that's another thread - see [1])
>>
>>
>> FWIW he trinity command is just a test of 1 syscall:
>>
>> $> trinity --children 1 --victims /mnt/nfs/n22/victims -c mremap
>>
>>
>>
>> [1] https://lkml.org/lkml/2013/3/24/174
>
> I should think it's been like this for five years, or even more: maybe
> you are the first person to try unmapping user address 0x100000 on UML;
> though it's odd that you find it using mremap than the more common munmap.
Sounds sane.
I fear trinity will find more "you are the first person to try"-bugs in UML.
I'll look at it.
> uml_setup_stubs() sets up the special vma with install_special_mapping(),
> but instead of then faulting in the two pages concerned, it has preset
> the ptes with init_stub_pte(), which did not increment page mapcount.
>
> munmap() that area (or set up another mapping in that place), and
> zap_pte_range() will decrement page mapcount negative, hence the
> "Bad page" errors. Whereas UML uses an arch_exit_mmap() hook to
> clear the ptes at exit time, to avoid encountering such errors.
>
> I think that adding VM_PFNMAP to those install_special_mapping() flags
> would be enough to fix it (and avoid the need for the arch_exit_mmap(),
> and let vm_insert_pfn() do the work of init_stub_pte()); but I'm not
> certain that would be the approved way, and I may have missed problems
> doing it like this (which would disallow get_user_pages(), e.g. ptrace,
> on that area: which might or might not be a good thing, I don't know).
>
> I'm saying this just by examination, I've not tried any of it at all.
> Over to Richard.
:-)
--
Thanks,
//richard