Skip to content

L
linux
Switch branch/tag
  1. 13 Jun, 2018 3 commits
    • Linus Torvalds's avatar
      mmap: introduce sane default mmap limits · bd2f9ce5
      Linus Torvalds authored 
      commit be83bbf8 upstream.

The internal VM "mmap()" interfaces are based on the mmap target doing
everything using page indexes rather than byte offsets, because
traditionally (ie 32-bit) we had the situation that the byte offset
didn't fit in a register.  So while the mmap virtual address was limited
by the word size of the architecture, the backing store was not.

So we're basically passing "pgoff" around as a page index, in order to
be able to describe backing store locations that are much bigger than
the word size (think files larger than 4GB etc).

But while this all makes a ton of sense conceptually, we've been dogged
by various drivers that don't really understand this, and internally
work with byte offsets, and then try to work with the page index by
turning it into a byte offset with "pgoff << PAGE_SHIFT".

Which obviously can overflow.

Adding the size of the mapping to it to get the byte offset of the end
of the backing store just exacerbates the problem, and if you then use
this overflow-prone value to check various limits of your device driver
mmap capability, you're just setting yourself up for problems.

The correct thing for drivers to do is to do their limit math in page
indices, the way the interface is designed.  Because the generic mmap
code _does_ test that the index doesn't overflow, since that's what the
mmap code really cares about.

HOWEVER.

Finding and fixing various random drivers is a sisyphean task, so let's
just see if we can just make the core mmap() code do the limiting for
us.  Realistically, the only "big" backing stores we need to care about
are regular files and block devices, both of which are known to do this
properly, and which have nice well-defined limits for how much data they
can access.

So let's special-case just those two known cases, and then limit other
random mmap users to a backing store that still fits in "unsigned long".
Realistically, that's not much of a limit at all on 64-bit, and on
32-bit architectures the only worry might be the GPU drivers, which can
have big physical address spaces.

To make it possible for drivers like that to say that they are 64-bit
clean, this patch does repurpose the "FMODE_UNSIGNED_OFFSET" bit in the
file flags to allow drivers to mark their file descriptors as safe in
the full 64-bit mmap address space.

[ The timing for doing this is less than optimal, and this should really
  go in a merge window. But realistically, this needs wide testing more
  than it needs anything else, and being main-line is the only way to do
  that.

  So the earlier the better, even if it's outside the proper development
  cycle        - Linus ]

Cc: Kees Cook <keescook@chromium.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Dave Airlie <airlied@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      bd2f9ce5
    • Chris Chiu's avatar
      tpm: self test failure should not cause suspend to fail · 459e0c3b
      Chris Chiu authored 
      commit 0803d7be upstream.

The Acer Acer Veriton X4110G has a TPM device detected as:
  tpm_tis 00:0b: 1.2 TPM (device-id 0xFE, rev-id 71)

After the first S3 suspend, the following error appears during resume:
  tpm tpm0: A TPM error(38) occurred continue selftest

Any following S3 suspend attempts will now fail with this error:
  tpm tpm0: Error (38) sending savestate before suspend
  PM: Device 00:0b failed to suspend: error 38

Error 38 is TPM_ERR_INVALID_POSTINIT which means the TPM is
not in the correct state. This indicates that the platform BIOS
is not sending the usual TPM_Startup command during S3 resume.
>From this point onwards, all TPM commands will fail.

The same issue was previously reported on Foxconn 6150BK8MC and
Sony Vaio TX3.

The platform behaviour seems broken here, but we should not break
suspend/resume because of this.

When the unexpected TPM state is encountered, set a flag to skip the
affected TPM_SaveState command on later suspends.

Cc: stable@vger.kernel.org
Signed-off-by: default avatarChris Chiu <chiu@endlessm.com>
Signed-off-by: default avatarDaniel Drake <drake@endlessm.com>
Link: http://lkml.kernel.org/r/CAB4CAwfSCvj1cudi+MWaB5g2Z67d9DwY1o475YOZD64ma23UiQ@mail.gmail.com
Link: https://lkml.org/lkml/2011/3/28/192
Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=591031Reviewed-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      459e0c3b
    • Enric Balletbo i Serra's avatar
      tpm: do not suspend/resume if power stays on · c7d58182
      Enric Balletbo i Serra authored 
      commit b5d0ebc9 upstream.

The suspend/resume behavior of the TPM can be controlled by setting
"powered-while-suspended" in the DTS. This is useful for the cases
when hardware does not power-off the TPM.
Signed-off-by: default avatarSonny Rao <sonnyrao@chromium.org>
Signed-off-by: default avatarEnric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: default avatarJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: default avatarJames Morris <james.l.morris@oracle.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c7d58182
  3. 06 Jun, 2018 36 commits
  5. 30 May, 2018 1 commit
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7