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  1. 23 Feb, 2017 6 commits
    • Paul Mackerras's avatar
      powerpc/64: Disable use of radix under a hypervisor · 920b60aa
      Paul Mackerras authored 
      commit 3f91a89d upstream.

Currently, if the kernel is running on a POWER9 processor under a
hypervisor, it may try to use the radix MMU even though it doesn't have
the necessary code to do so (it doesn't negotiate use of radix, and it
doesn't do the H_REGISTER_PROC_TBL hcall).  If the hypervisor supports
both radix and HPT, then it will set up the guest to use HPT (since the
guest doesn't request radix in the CAS call), but if the radix feature
bit is set in the ibm,pa-features property (which is valid, since
ibm,pa-features is defined to represent the capabilities of the
processor) the guest will try to use radix, resulting in a crash when
it turns the MMU on.

This makes the minimal fix for the current code, which is to disable
radix unless we are running in hypervisor mode.

Fixes: 2bfd65e4 ("powerpc/mm/radix: Add radix callbacks for early init routines")
Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      920b60aa
    • Anssi Hannula's avatar
      mmc: core: fix multi-bit bus width without high-speed mode · ef746a30
      Anssi Hannula authored 
      commit 3d4ef329 upstream.

Commit 577fb131 ("mmc: rework selection of bus speed mode")
refactored bus width selection code to mmc_select_bus_width().

However, it also altered the behavior to not call the selection code in
non-high-speed modes anymore.

This causes 1-bit mode to always be used when the high-speed mode is not
enabled, even though 4-bit and 8-bit bus are valid bus widths in the
backwards-compatibility (legacy) mode as well (see e.g. 5.3.2 Bus Speed
Modes in JEDEC 84-B50). This results in a significant regression in
transfer speeds.

Fix the code to allow 4-bit and 8-bit widths even without high-speed
mode, as before.

Tested with a Zynq-7000 PicoZed 7020 board.

Fixes: 577fb131 ("mmc: rework selection of bus speed mode")
Signed-off-by: default avatarAnssi Hannula <anssi.hannula@bitwise.fi>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      ef746a30
    • Miklos Szeredi's avatar
      fuse: fix uninitialized flags in pipe_buffer · 80a04776
      Miklos Szeredi authored 
      commit 84588a93 upstream.
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
Fixes: d82718e3 ("fuse_dev_splice_read(): switch to add_to_pipe()")
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      80a04776
    • Sahitya Tummala's avatar
      fuse: fix use after free issue in fuse_dev_do_read() · 7283448f
      Sahitya Tummala authored 
      commit 6ba4d272 upstream.

There is a potential race between fuse_dev_do_write()
and request_wait_answer() contexts as shown below:

TASK 1:
__fuse_request_send():
  |--spin_lock(&fiq->waitq.lock);
  |--queue_request();
  |--spin_unlock(&fiq->waitq.lock);
  |--request_wait_answer():
       |--if (test_bit(FR_SENT, &req->flags))
       <gets pre-empted after it is validated true>
                                   TASK 2:
                                   fuse_dev_do_write():
                                     |--clears bit FR_SENT,
                                     |--request_end():
                                        |--sets bit FR_FINISHED
                                        |--spin_lock(&fiq->waitq.lock);
                                        |--list_del_init(&req->intr_entry);
                                        |--spin_unlock(&fiq->waitq.lock);
                                        |--fuse_put_request();
       |--queue_interrupt();
       <request gets queued to interrupts list>
            |--wake_up_locked(&fiq->waitq);
       |--wait_event_freezable();
       <as FR_FINISHED is set, it returns and then
       the caller frees this request>

Now, the next fuse_dev_do_read(), see interrupts list is not empty
and then calls fuse_read_interrupt() which tries to access the request
which is already free'd and gets the below crash:

[11432.401266] Unable to handle kernel paging request at virtual address
6b6b6b6b6b6b6b6b
...
[11432.418518] Kernel BUG at ffffff80083720e0
[11432.456168] PC is at __list_del_entry+0x6c/0xc4
[11432.463573] LR is at fuse_dev_do_read+0x1ac/0x474
...
[11432.679999] [<ffffff80083720e0>] __list_del_entry+0x6c/0xc4
[11432.687794] [<ffffff80082c65e0>] fuse_dev_do_read+0x1ac/0x474
[11432.693180] [<ffffff80082c6b14>] fuse_dev_read+0x6c/0x78
[11432.699082] [<ffffff80081d5638>] __vfs_read+0xc0/0xe8
[11432.704459] [<ffffff80081d5efc>] vfs_read+0x90/0x108
[11432.709406] [<ffffff80081d67f0>] SyS_read+0x58/0x94

As FR_FINISHED bit is set before deleting the intr_entry with input
queue lock in request completion path, do the testing of this flag and
queueing atomically with the same lock in queue_interrupt().
Signed-off-by: default avatarSahitya Tummala <stummala@codeaurora.org>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
Fixes: fd22d62e ("fuse: no fc->lock for iqueue parts")
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7283448f
    • Mauro Carvalho Chehab's avatar
      siano: make it work again with CONFIG_VMAP_STACK · 6cf921be
      Mauro Carvalho Chehab authored 
      commit f9c85ee6 upstream.

Reported as a Kaffeine bug:
	https://bugs.kde.org/show_bug.cgi?id=375811

The USB control messages require DMA to work. We cannot pass
a stack-allocated buffer, as it is not warranted that the
stack would be into a DMA enabled area.

On Kernel 4.9, the default is to not accept DMA on stack anymore
on x86 architecture. On other architectures, this has been a
requirement since Kernel 2.2. So, after this patch, this driver
should likely work fine on all archs.

Tested with USB ID 2040:5510: Hauppauge Windham
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6cf921be
    • Miklos Szeredi's avatar
      vfs: fix uninitialized flags in splice_to_pipe() · 166a2464
      Miklos Szeredi authored 
      commit 5a81e6a1 upstream.

Flags (PIPE_BUF_FLAG_PACKET, PIPE_BUF_FLAG_GIFT) could remain on the
unused part of the pipe ring buffer.  Previously splice_to_pipe() left
the flags value alone, which could result in incorrect behavior.

Uninitialized flags appears to have been there from the introduction of
the splice syscall.
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      166a2464
  3. 18 Feb, 2017 34 commits
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