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  1. 08 Sep, 2008 32 commits
  3. 20 Aug, 2008 8 commits
    • Greg Kroah-Hartman's avatar
      Linux 2.6.26.3 · c373e9c5
      Greg Kroah-Hartman authored
      c373e9c5
    • Suresh Siddha's avatar
      crypto: padlock - fix VIA PadLock instruction usage with irq_ts_save/restore() · faf996d6
      Suresh Siddha authored 
      crypto: padlock - fix VIA PadLock instruction usage with irq_ts_save/restore()

[ Upstream commit: e4914012 ]

Wolfgang Walter reported this oops on his via C3 using padlock for
AES-encryption:

##################################################################

BUG: unable to handle kernel NULL pointer dereference at 000001f0
IP: [<c01028c5>] __switch_to+0x30/0x117
*pde = 00000000
Oops: 0002 [#1] PREEMPT
Modules linked in:

Pid: 2071, comm: sleep Not tainted (2.6.26 #11)
EIP: 0060:[<c01028c5>] EFLAGS: 00010002 CPU: 0
EIP is at __switch_to+0x30/0x117
EAX: 00000000 EBX: c0493300 ECX: dc48dd00 EDX: c0493300
ESI: dc48dd00 EDI: c0493530 EBP: c04cff8c ESP: c04cff7c
DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068
Process sleep (pid: 2071, ti=c04ce000 task=dc48dd00 task.ti=d2fe6000)
Stack: dc48df30 c0493300 00000000 00000000 d2fe7f44 c03b5b43 c04cffc8 00000046
   c0131856 0000005a dc472d3c c0493300 c0493470 d983ae00 00002696 00000000
   c0239f54 00000000 c04c4000 c04cffd8 c01025fe c04f3740 00049800 c04cffe0
Call Trace:
[<c03b5b43>] ? schedule+0x285/0x2ff
[<c0131856>] ? pm_qos_requirement+0x3c/0x53
[<c0239f54>] ? acpi_processor_idle+0x0/0x434
[<c01025fe>] ? cpu_idle+0x73/0x7f
[<c03a4dcd>] ? rest_init+0x61/0x63
=======================

Wolfgang also found out that adding kernel_fpu_begin() and kernel_fpu_end()
around the padlock instructions fix the oops.

Suresh wrote:

These padlock instructions though don't use/touch SSE registers, but it behaves
similar to other SSE instructions. For example, it might cause DNA faults
when cr0.ts is set. While this is a spurious DNA trap, it might cause
oops with the recent fpu code changes.

This is the code sequence  that is probably causing this problem:

a) new app is getting exec'd and it is somewhere in between
start_thread() and flush_old_exec() in the load_xyz_binary()

b) At pont "a", task's fpu state (like TS_USEDFPU, used_math() etc) is
cleared.

c) Now we get an interrupt/softirq which starts using these encrypt/decrypt
routines in the network stack. This generates a math fault (as
cr0.ts is '1') which sets TS_USEDFPU and restores the math that is
in the task's xstate.

d) Return to exec code path, which does start_thread() which does
free_thread_xstate() and sets xstate pointer to NULL while
the TS_USEDFPU is still set.

e) At the next context switch from the new exec'd task to another task,
we have a scenarios where TS_USEDFPU is set but xstate pointer is null.
This can cause an oops during unlazy_fpu() in __switch_to()

Now:

1) This should happen with or with out pre-emption. Viro also encountered
similar problem with out CONFIG_PREEMPT.

2) kernel_fpu_begin() and kernel_fpu_end() will fix this problem, because
kernel_fpu_begin() will manually do a clts() and won't run in to the
situation of setting TS_USEDFPU in step "c" above.

3) This was working before the fpu changes, because its a spurious
math fault  which doesn't corrupt any fpu/sse registers and the task's
math state was always in an allocated state.

With out the recent lazy fpu allocation changes, while we don't see oops,
there is a possible race still present in older kernels(for example,
while kernel is using kernel_fpu_begin() in some optimized clear/copy
page and an interrupt/softirq happens which uses these padlock
instructions generating DNA fault).

This is the failing scenario that existed even before the lazy fpu allocation
changes:

0. CPU's TS flag is set

1. kernel using FPU in some optimized copy  routine and while doing
kernel_fpu_begin() takes an interrupt just before doing clts()

2. Takes an interrupt and ipsec uses padlock instruction. And we
take a DNA fault as TS flag is still set.

3. We handle the DNA fault and set TS_USEDFPU and clear cr0.ts

4. We complete the padlock routine

5. Go back to step-1, which resumes clts() in kernel_fpu_begin(), finishes
the optimized copy routine and does kernel_fpu_end(). At this point,
we have cr0.ts again set to '1' but the task's TS_USEFPU is stilll
set and not cleared.

6. Now kernel resumes its user operation. And at the next context
switch, kernel sees it has do a FP save as TS_USEDFPU is still set
and then will do a unlazy_fpu() in __switch_to(). unlazy_fpu()
will take a DNA fault, as cr0.ts is '1' and now, because we are
in __switch_to(), math_state_restore() will get confused and will
restore the next task's FP state and will save it in prev tasks's FP state.
Remember, in __switch_to() we are already on the stack of the next task
but take a DNA fault for the prev task.

This causes the fpu leakage.

Fix the padlock instruction usage by calling them inside the
context of new routines irq_ts_save/restore(), which clear/restore cr0.ts
manually in the interrupt context. This will not generate spurious DNA
in the  context of the interrupt which will fix the oops encountered and
the possible FPU leakage issue.
Reported-and-bisected-by: default avatarWolfgang Walter <wolfgang.walter@stwm.de>
Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      faf996d6
    • Dean Hildebrand's avatar
      PCI: Limit VPD length for Broadcom 5708S · f8e6fcea
      Dean Hildebrand authored 
      commit 35405f25 upstream

BCM5706S wont work correctly unless VPD length truncated to 128
Signed-off-by: default avatarDean Hildebrand <dhildeb@us.ibm.com>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      f8e6fcea
    • Jeff Layton's avatar
      CIFS: properly account for new user= field in SPNEGO upcall string allocation · bd69c736
      Jeff Layton authored 
      commit 66b8bd3c upstream

[CIFS] properly account for new user= field in SPNEGO upcall string allocation

...it doesn't look like it's being accounted for at the moment. Also
try to reorganize the calculation to make it a little more evident
what each piece means.

This should probably go to the stable series as well...
Signed-off-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      bd69c736
    • Alan Stern's avatar
      usb-storage: automatically recognize bad residues · 978e8c75
      Alan Stern authored 
      commit 59f4ff2e upstream

This patch (as1119b) will help to reduce the clutter of usb-storage's
unusual_devs file by automatically detecting some devices that need
the IGNORE_RESIDUE flag.  The idea is that devices should never return
a non-zero residue for an INQUIRY or a READ CAPACITY command unless
they failed to transfer all the requested data.  So if one of these
commands transfers a standard amount of data but there is a positive
residue, we know that the residue is bogus and we can set the flag.

This fixes the problems reported in Bugzilla #11125.
Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Tested-by: default avatarMatthew Frost <artusemrys@sbcglobal.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      978e8c75
    • Alan Stern's avatar
      usb-storage: revert DMA-alignment change for Wireless USB · b0d87b93
      Alan Stern authored 
      commit f756cbd4 upstream.

This patch (as1110) reverts an earlier patch meant to help with
Wireless USB host controllers.  These controllers can have bulk
maxpacket values larger than 512, which puts unusual constraints on
the sizes of scatter-gather list elements.  However it turns out that
the block layer does not provide the support we need to enforce these
constraints; merely changing the DMA alignment mask doesn't help.
Hence there's no reason to keep the original patch.  The Wireless USB
problem will have to be solved a different way.

In addition, there is a reason to get rid of the earlier patch.  By
dereferencing a pointer stored in the ep_in array of struct
usb_device, the current code risks an invalid memory access when it
runs concurrently with device removal.  The members of that array are
cleared before the driver's disconnect method is called, so it should
not try to use them.
Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      b0d87b93
    • Andrew Vasquez's avatar
      qla2xxx: Set an rport's dev_loss_tmo value in a consistent manner. · ac2ef120
      Andrew Vasquez authored 
      [ Upstream commit 85821c90 ]

As there's no point in adding a fixed-fudge value (originally 5
seconds), honor the user settings only.  We also remove the
driver's dead-callback get_rport_dev_loss_tmo function
(qla2x00_get_rport_loss_tmo()).
Signed-off-by: default avatarAndrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      ac2ef120
    • Seokmann Ju's avatar
      qla2xxx: Add dev_loss_tmo_callbk/terminate_rport_io callback support. · 34b8cfcf
      Seokmann Ju authored 
      [ Upstream commit 5f3a9a20 ]
Signed-off-by: default avatarSeokmann Ju <seokmann.ju@qlogic.com>
Signed-off-by: default avatarAndrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      34b8cfcf