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  1. 11 Aug, 2017 9 commits
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Save/restore host values of debug registers · 94f743e4
      Paul Mackerras authored 
      commit 7ceaa6dc upstream.

At present, HV KVM on POWER8 and POWER9 machines loses any instruction
or data breakpoint set in the host whenever a guest is run.
Instruction breakpoints are currently only used by xmon, but ptrace
and the perf_event subsystem can set data breakpoints as well as xmon.

To fix this, we save the host values of the debug registers (CIABR,
DAWR and DAWRX) before entering the guest and restore them on exit.
To provide space to save them in the stack frame, we expand the stack
frame allocated by kvmppc_hv_entry() from 112 to 144 bytes.

[paulus@ozlabs.org - Adjusted stack offsets since we aren't saving
 POWER9-specific registers.]

Fixes: b005255e ("KVM: PPC: Book3S HV: Context-switch new POWER8 SPRs", 2014-01-08)
Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      94f743e4
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Reload HTM registers explicitly · 1c3ab876
      Paul Mackerras authored 
      Commit 46a704f8 ("KVM: PPC: Book3S HV: Preserve userspace HTM
state properly", 2017-06-15) added code which assumes that the kernel
is able to handle a TM (transactional memory) unavailable interrupt
from userspace by reloading the TM-related registers and enabling TM
for the process.  That ability was added in the 4.9 kernel; earlier
kernel versions simply panic on getting the TM unavailable interrupt.

Since commit 46a704f8 has been backported to the 3.18 stable tree
as commit 0b423dab, 3.18.59 and subsequent versions are vulnerable
to a userspace-triggerable panic.

This patch fixes the problem by explicitly reloading the TM-related
registers before returning to userspace, rather than disabling TM
for the process.

Commit 46a704f8 also failed to enable TM for the kernel, leading
to a TM unavailable interrupt in the kernel, causing an oops.  This
fixes that problem too, by enabling TM before accessing the TM
registers.  That problem is fixed upstream by the patch "KVM: PPC:
Book3S HV: Enable TM before accessing TM registers".

Fixes: 0b423dab ("KVM: PPC: Book3S HV: Preserve userspace HTM state properly")
Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1c3ab876
    • Paul Mackerras's avatar
      KVM: PPC: Book3S HV: Restore critical SPRs to host values on guest exit · 901aae4f
      Paul Mackerras authored 
      commit 4c3bb4cc upstream.

This restores several special-purpose registers (SPRs) to sane values
on guest exit that were missed before.

TAR and VRSAVE are readable and writable by userspace, and we need to
save and restore them to prevent the guest from potentially affecting
userspace execution (not that TAR or VRSAVE are used by any known
program that run uses the KVM_RUN ioctl).  We save/restore these
in kvmppc_vcpu_run_hv() rather than on every guest entry/exit.

FSCR affects userspace execution in that it can prohibit access to
certain facilities by userspace.  We restore it to the normal value
for the task on exit from the KVM_RUN ioctl.

IAMR is normally 0, and is restored to 0 on guest exit.  However,
with a radix host on POWER9, it is set to a value that prevents the
kernel from executing user-accessible memory.  On POWER9, we save
IAMR on guest entry and restore it on guest exit to the saved value
rather than 0.  On POWER8 we continue to set it to 0 on guest exit.

PSPB is normally 0.  We restore it to 0 on guest exit to prevent
userspace taking advantage of the guest having set it non-zero
(which would allow userspace to set its SMT priority to high).

UAMOR is normally 0.  We restore it to 0 on guest exit to prevent
the AMR from being used as a covert channel between userspace
processes, since the AMR is not context-switched at present.

[paulus@ozlabs.org - removed IAMR bits that are only needed on POWER9;
 adjusted FSCR save/restore for lack of fscr field in thread_struct.]

Fixes: b005255e ("KVM: PPC: Book3S HV: Context-switch new POWER8 SPRs", 2014-01-08)
Cc: stable@vger.kernel.org # v3.14+
Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      901aae4f
    • Sinclair Yeh's avatar
      drm/vmwgfx: Fix gcc-7.1.1 warning · 7f1957f2
      Sinclair Yeh authored 
      commit fcfffdd8 upstream.

The current code does not look correct, and the reason for it is
probably lost.  Since this now generates a compiler warning,
fix it to what makes sense.
Reported-by: default avatarArnd Bergmann <arnd@arndb.de>
Reported-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarSinclair Yeh <syeh@vmware.com>
Reviewed-by: default avatarBrian Paul <brianp@vmware.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7f1957f2
    • Ofer Heifetz's avatar
      md/raid5: add thread_group worker async_tx_issue_pending_all · c81489cc
      Ofer Heifetz authored 
      commit 7e96d559 upstream.

Since thread_group worker and raid5d kthread are not in sync, if
worker writes stripe before raid5d then requests will be waiting
for issue_pendig.

Issue observed when building raid5 with ext4, in some build runs
jbd2 would get hung and requests were waiting in the HW engine
waiting to be issued.

Fix this by adding a call to async_tx_issue_pending_all in the
raid5_do_work.
Signed-off-by: default avatarOfer Heifetz <oferh@marvell.com>
Signed-off-by: default avatarShaohua Li <shli@fb.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c81489cc
    • Laurent Vivier's avatar
      powerpc/pseries: Fix of_node_put() underflow during reconfig remove · 716c82ac
      Laurent Vivier authored 
      commit 4fd1bd44 upstream.

As for commit 68baf692 ("powerpc/pseries: Fix of_node_put()
underflow during DLPAR remove"), the call to of_node_put() must be
removed from pSeries_reconfig_remove_node().

dlpar_detach_node() and pSeries_reconfig_remove_node() both call
of_detach_node(), and thus the node should not be released in both
cases.

Fixes: 0829f6d1 ("of: device_node kobject lifecycle fixes")
Signed-off-by: default avatarLaurent Vivier <lvivier@redhat.com>
Reviewed-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      716c82ac
    • Eric Dumazet's avatar
      net: reduce skb_warn_bad_offload() noise · d85f4de8
      Eric Dumazet authored 
      commit b2504a5d upstream.

Dmitry reported warnings occurring in __skb_gso_segment() [1]

All SKB_GSO_DODGY producers can allow user space to feed
packets that trigger the current check.

We could prevent them from doing so, rejecting packets, but
this might add regressions to existing programs.

It turns out our SKB_GSO_DODGY handlers properly set up checksum
information that is needed anyway when packets needs to be segmented.

By checking again skb_needs_check() after skb_mac_gso_segment(),
we should remove these pesky warnings, at a very minor cost.

With help from Willem de Bruijn

[1]
WARNING: CPU: 1 PID: 6768 at net/core/dev.c:2439 skb_warn_bad_offload+0x2af/0x390 net/core/dev.c:2434
lo: caps=(0x000000a2803b7c69, 0x0000000000000000) len=138 data_len=0 gso_size=15883 gso_type=4 ip_summed=0
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 6768 Comm: syz-executor1 Not tainted 4.9.0 #5
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801c063ecd8 ffffffff82346bdf ffffffff00000001 1ffff100380c7d2e
 ffffed00380c7d26 0000000041b58ab3 ffffffff84b37e38 ffffffff823468f1
 ffffffff84820740 ffffffff84f289c0 dffffc0000000000 ffff8801c063ee20
Call Trace:
 [<ffffffff82346bdf>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff82346bdf>] dump_stack+0x2ee/0x3ef lib/dump_stack.c:51
 [<ffffffff81827e34>] panic+0x1fb/0x412 kernel/panic.c:179
 [<ffffffff8141f704>] __warn+0x1c4/0x1e0 kernel/panic.c:542
 [<ffffffff8141f7e5>] warn_slowpath_fmt+0xc5/0x100 kernel/panic.c:565
 [<ffffffff8356cbaf>] skb_warn_bad_offload+0x2af/0x390 net/core/dev.c:2434
 [<ffffffff83585cd2>] __skb_gso_segment+0x482/0x780 net/core/dev.c:2706
 [<ffffffff83586f19>] skb_gso_segment include/linux/netdevice.h:3985 [inline]
 [<ffffffff83586f19>] validate_xmit_skb+0x5c9/0xc20 net/core/dev.c:2969
 [<ffffffff835892bb>] __dev_queue_xmit+0xe6b/0x1e70 net/core/dev.c:3383
 [<ffffffff8358a2d7>] dev_queue_xmit+0x17/0x20 net/core/dev.c:3424
 [<ffffffff83ad161d>] packet_snd net/packet/af_packet.c:2930 [inline]
 [<ffffffff83ad161d>] packet_sendmsg+0x32ed/0x4d30 net/packet/af_packet.c:2955
 [<ffffffff834f0aaa>] sock_sendmsg_nosec net/socket.c:621 [inline]
 [<ffffffff834f0aaa>] sock_sendmsg+0xca/0x110 net/socket.c:631
 [<ffffffff834f329a>] ___sys_sendmsg+0x8fa/0x9f0 net/socket.c:1954
 [<ffffffff834f5e58>] __sys_sendmsg+0x138/0x300 net/socket.c:1988
 [<ffffffff834f604d>] SYSC_sendmsg net/socket.c:1999 [inline]
 [<ffffffff834f604d>] SyS_sendmsg+0x2d/0x50 net/socket.c:1995
 [<ffffffff84371941>] entry_SYSCALL_64_fastpath+0x1f/0xc2
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reported-by: default avatarDmitry Vyukov  <dvyukov@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Cc: Mark Salyzyn <salyzyn@android.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      d85f4de8
    • Joel Fernandes's avatar
      pstore: Make spinlock per zone instead of global · 2d0abb7b
      Joel Fernandes authored 
      commit 10970449 upstream.

Currently pstore has a global spinlock for all zones. Since the zones
are independent and modify different areas of memory, there's no need
to have a global lock, so we should use a per-zone lock as introduced
here. Also, when ramoops's ftrace use-case has a FTRACE_PER_CPU flag
introduced later, which splits the ftrace memory area into a single zone
per CPU, it will eliminate the need for locking. In preparation for this,
make the locking optional.
Signed-off-by: default avatarJoel Fernandes <joelaf@google.com>
[kees: updated commit message]
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Cc: Leo Yan <leo.yan@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      2d0abb7b
    • Yuejie Shi's avatar
      af_key: Add lock to key dump · c64a196b
      Yuejie Shi authored 
      commit 89e357d8 upstream.

A dump may come in the middle of another dump, modifying its dump
structure members. This race condition will result in NULL pointer
dereference in kernel. So add a lock to prevent that race.

Fixes: 83321d6b ("[AF_KEY]: Dump SA/SP entries non-atomically")
Signed-off-by: default avatarYuejie Shi <syjcnss@gmail.com>
Signed-off-by: default avatarSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: default avatarMark Salyzyn <salyzyn@android.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c64a196b
  3. 27 Jul, 2017 31 commits
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