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  1. 20 7月, 2012 8 次提交
  3. 15 6月, 2012 1 次提交
    • S
      xen: mark local pages as FOREIGN in the m2p_override · b9e0d95c
      由 Stefano Stabellini 提交于 
      When the frontend and the backend reside on the same domain, even if we
add pages to the m2p_override, these pages will never be returned by
mfn_to_pfn because the check "get_phys_to_machine(pfn) != mfn" will
always fail, so the pfn of the frontend will be returned instead
(resulting in a deadlock because the frontend pages are already locked).

INFO: task qemu-system-i38:1085 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
qemu-system-i38 D ffff8800cfc137c0     0  1085      1 0x00000000
 ffff8800c47ed898 0000000000000282 ffff8800be4596b0 00000000000137c0
 ffff8800c47edfd8 ffff8800c47ec010 00000000000137c0 00000000000137c0
 ffff8800c47edfd8 00000000000137c0 ffffffff82213020 ffff8800be4596b0
Call Trace:
 [<ffffffff81101ee0>] ? __lock_page+0x70/0x70
 [<ffffffff81a0fdd9>] schedule+0x29/0x70
 [<ffffffff81a0fe80>] io_schedule+0x60/0x80
 [<ffffffff81101eee>] sleep_on_page+0xe/0x20
 [<ffffffff81a0e1ca>] __wait_on_bit_lock+0x5a/0xc0
 [<ffffffff81101ed7>] __lock_page+0x67/0x70
 [<ffffffff8106f750>] ? autoremove_wake_function+0x40/0x40
 [<ffffffff811867e6>] ? bio_add_page+0x36/0x40
 [<ffffffff8110b692>] set_page_dirty_lock+0x52/0x60
 [<ffffffff81186021>] bio_set_pages_dirty+0x51/0x70
 [<ffffffff8118c6b4>] do_blockdev_direct_IO+0xb24/0xeb0
 [<ffffffff811e71a0>] ? ext3_get_blocks_handle+0xe00/0xe00
 [<ffffffff8118ca95>] __blockdev_direct_IO+0x55/0x60
 [<ffffffff811e71a0>] ? ext3_get_blocks_handle+0xe00/0xe00
 [<ffffffff811e91c8>] ext3_direct_IO+0xf8/0x390
 [<ffffffff811e71a0>] ? ext3_get_blocks_handle+0xe00/0xe00
 [<ffffffff81004b60>] ? xen_mc_flush+0xb0/0x1b0
 [<ffffffff81104027>] generic_file_aio_read+0x737/0x780
 [<ffffffff813bedeb>] ? gnttab_map_refs+0x15b/0x1e0
 [<ffffffff811038f0>] ? find_get_pages+0x150/0x150
 [<ffffffff8119736c>] aio_rw_vect_retry+0x7c/0x1d0
 [<ffffffff811972f0>] ? lookup_ioctx+0x90/0x90
 [<ffffffff81198856>] aio_run_iocb+0x66/0x1a0
 [<ffffffff811998b8>] do_io_submit+0x708/0xb90
 [<ffffffff81199d50>] sys_io_submit+0x10/0x20
 [<ffffffff81a18d69>] system_call_fastpath+0x16/0x1b

The explanation is in the comment within the code:

We need to do this because the pages shared by the frontend
(xen-blkfront) can be already locked (lock_page, called by
do_read_cache_page); when the userspace backend tries to use them
with direct_IO, mfn_to_pfn returns the pfn of the frontend, so
do_blockdev_direct_IO is going to try to lock the same pages
again resulting in a deadlock.

A simplified call graph looks like this:

pygrub                          QEMU
-----------------------------------------------
do_read_cache_page              io_submit
  |                              |
lock_page                       ext3_direct_IO
                                 |
                                bio_add_page
                                 |
                                lock_page

Internally the xen-blkback uses m2p_add_override to swizzle (temporarily)
a 'struct page' to have a different MFN (so that it can point to another
guest). It also can easily find out whether another pfn corresponding
to the mfn exists in the m2p, and can set the FOREIGN bit
in the p2m, making sure that mfn_to_pfn returns the pfn of the backend.

This allows the backend to perform direct_IO on these pages, but as a
side effect prevents the frontend from using get_user_pages_fast on
them while they are being shared with the backend.
Signed-off-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      b9e0d95c
  5. 14 6月, 2012 1 次提交
  7. 13 6月, 2012 2 次提交
    • S
      perf/x86: Fix broken LBR fixup code · 25f42985
      由 Stephane Eranian 提交于 
      I noticed that the LBR fixups were not working anymore
on programs where they used to. I tracked this down to
a recent change to copy_from_user_nmi():

 db0dc75d ("perf/x86: Check user address explicitly in copy_from_user_nmi()")

This commit added a call to __range_not_ok() to the
copy_from_user_nmi() routine. The problem is that the logic
of the test must be reversed. __range_not_ok() returns 0 if the
range is VALID. We want to return early from copy_from_user_nmi()
if the range is NOT valid.
Signed-off-by: NStephane Eranian <eranian@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NArun Sharma <asharma@fb.com>
Link: http://lkml.kernel.org/r/20120611134426.GA7542@quadSigned-off-by: NIngo Molnar <mingo@kernel.org>
      25f42985
    • B
      x86/smp: Fix topology checks on AMD MCM CPUs · 161270fc
      由 Borislav Petkov 提交于 
      The warning below triggers on AMD MCM packages because physical package
IDs on the cores of a _physical_ socket are the same. I.e., this field
says which CPUs belong to the same physical package.

However, the same two CPUs belong to two different internal, i.e.
"logical" nodes in the same physical socket which is reflected in the
CPU-to-node map on x86 with NUMA.

Which makes this check wrong on the above topologies so circumvent it.

[    0.444413] Booting Node   0, Processors  #1 #2 #3 #4 #5 Ok.
[    0.461388] ------------[ cut here ]------------
[    0.465997] WARNING: at arch/x86/kernel/smpboot.c:310 topology_sane.clone.1+0x6e/0x81()
[    0.473960] Hardware name: Dinar
[    0.477170] sched: CPU #6's mc-sibling CPU #0 is not on the same node! [node: 1 != 0]. Ignoring dependency.
[    0.486860] Booting Node   1, Processors  #6
[    0.491104] Modules linked in:
[    0.494141] Pid: 0, comm: swapper/6 Not tainted 3.4.0+ #1
[    0.499510] Call Trace:
[    0.501946]  [<ffffffff8144bf92>] ? topology_sane.clone.1+0x6e/0x81
[    0.508185]  [<ffffffff8102f1fc>] warn_slowpath_common+0x85/0x9d
[    0.514163]  [<ffffffff8102f2b7>] warn_slowpath_fmt+0x46/0x48
[    0.519881]  [<ffffffff8144bf92>] topology_sane.clone.1+0x6e/0x81
[    0.525943]  [<ffffffff8144c234>] set_cpu_sibling_map+0x251/0x371
[    0.532004]  [<ffffffff8144c4ee>] start_secondary+0x19a/0x218
[    0.537729] ---[ end trace 4eaa2a86a8e2da22 ]---
[    0.628197]  #7 #8 #9 #10 #11 Ok.
[    0.807108] Booting Node   3, Processors  #12 #13 #14 #15 #16 #17 Ok.
[    0.897587] Booting Node   2, Processors  #18 #19 #20 #21 #22 #23 Ok.
[    0.917443] Brought up 24 CPUs

We ran a topology sanity check test we have here on it and
it all looks ok... hopefully :).
Signed-off-by: NBorislav Petkov <borislav.petkov@amd.com>
Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20120529135442.GE29157@aftab.osrc.amd.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      161270fc
  9. 12 6月, 2012 1 次提交
  11. 11 6月, 2012 1 次提交
  13. 10 6月, 2012 1 次提交
  15. 08 6月, 2012 4 次提交
  17. 06 6月, 2012 17 次提交
  19. 02 6月, 2012 4 次提交
    • H
      x86, x32, ptrace: Remove PTRACE_ARCH_PRCTL for x32 · bad1a753
      由 H.J. Lu 提交于 
      When I added x32 ptrace to 3.4 kernel, I also include PTRACE_ARCH_PRCTL
support for x32 GDB  For ARCH_GET_FS/GS, it takes a pointer to int64.  But
at user level, ARCH_GET_FS/GS takes a pointer to int32.  So I have to add
x32 ptrace to glibc to handle it with a temporary int64 passed to kernel and
copy it back to GDB as int32.  Roland suggested that PTRACE_ARCH_PRCTL
is obsolete and x32 GDB should use fs_base and gs_base fields of
user_regs_struct instead.

Accordingly, remove PTRACE_ARCH_PRCTL completely from the x32 code to
avoid possible memory overrun when pointer to int32 is passed to
kernel.

Link: http://lkml.kernel.org/r/CAMe9rOpDzHfS7NH7m1vmD9QRw8SSj4Sc%2BaNOgcWm_WJME2eRsQ@mail.gmail.comSigned-off-by: NH. Peter Anvin <hpa@zytor.com>
Cc: <stable@vger.kernel.org> v3.4
      bad1a753
    • A
      x86: get rid of calling do_notify_resume() when returning to kernel mode · 44fbbb3d
      由 Al Viro 提交于 
      If we end up calling do_notify_resume() with !user_mode(refs), it
does nothing (do_signal() explicitly bails out and we can't get there
with TIF_NOTIFY_RESUME in such situations).  Then we jump to
resume_userspace_sig, which rechecks the same thing and bails out
to resume_kernel, thus breaking the loop.

It's easier and cheaper to check *before* calling do_notify_resume()
and bail out to resume_kernel immediately.  And kill the check in
do_signal()...

Note that on amd64 we can't get there with !user_mode() at all - asm
glue takes care of that.
Acked-and-reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      44fbbb3d
    • A
      new helper: signal_delivered() · efee984c
      由 Al Viro 提交于 
      Does block_sigmask() + tracehook_signal_handler();  called when
sigframe has been successfully built.  All architectures converted
to it; block_sigmask() itself is gone now (merged into this one).

I'm still not too happy with the signature, but that's a separate
story (IMO we need a structure that would contain signal number +
siginfo + k_sigaction, so that get_signal_to_deliver() would fill one,
signal_delivered(), handle_signal() and probably setup...frame() -
take one).
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      efee984c
    • A
      most of set_current_blocked() callers want SIGKILL/SIGSTOP removed from set · 77097ae5
      由 Al Viro 提交于 
      Only 3 out of 63 do not.  Renamed the current variant to __set_current_blocked(),
added set_current_blocked() that will exclude unblockable signals, switched
open-coded instances to it.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      77097ae5