Commit Graph

576655 Commits

Author SHA1 Message Date
Mark Brown
bad0ae3f3c spi: Fixes for v4.5
A few driver specific fixes for the Rockchip and i.MX SPI controllers,
 especially for the i.MX they're annoying bugs if you run into them.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJW4POVAAoJECTWi3JdVIfQMRYH/R3bNmMQHZB+qBm6vVL28Pdo
 OXNejqStZLJfvdP6+xNXKijomMmvL/Xd+Jf2XMhDcEH8FZDVyemp9WIfQg8LMsy8
 uSYxfNIitL7T4xfPkKF8J0z3E81lc6EDGtv9M/7XWYJM1FrfMibQB3lUv1OK6+Gd
 z3Q6lpTblh6o6sqN0m2g23uSv3FGhoSdTNMhLeT3Wo5L3SfGFupO35Um5pbX8nHZ
 ZKmVNu1wmnWvf879NsaRs8W7btP/l/lcaz+aKB0HlJfzjUjyojsgSZu+EYTBXEDF
 ZOe3YZnodXhnFjyHLAcI09aXeDbtLlx4QHGv36OL8ObWHX9M8UYG9pQUuh5/Ujc=
 =gJMG
 -----END PGP SIGNATURE-----

Merge tag 'spi-fix-v4.5-rc7' into spi-linus

spi: Fixes for v4.5

A few driver specific fixes for the Rockchip and i.MX SPI controllers,
especially for the i.MX they're annoying bugs if you run into them.

# gpg: Signature made Thu 10 Mar 2016 11:09:57 ICT using RSA key ID 5D5487D0
# gpg: key CD7BEEBC: no public key for trusted key - skipped
# gpg: key CD7BEEBC marked as ultimately trusted
# gpg: key AF88CD16: no public key for trusted key - skipped
# gpg: key AF88CD16 marked as ultimately trusted
# gpg: key 16005C11: no public key for trusted key - skipped
# gpg: key 16005C11 marked as ultimately trusted
# gpg: key 5621E907: no public key for trusted key - skipped
# gpg: key 5621E907 marked as ultimately trusted
# gpg: key 5C6153AD: no public key for trusted key - skipped
# gpg: key 5C6153AD marked as ultimately trusted
# gpg: Good signature from "Mark Brown <broonie@sirena.org.uk>"
# gpg:                 aka "Mark Brown <broonie@debian.org>"
# gpg:                 aka "Mark Brown <broonie@kernel.org>"
# gpg:                 aka "Mark Brown <broonie@tardis.ed.ac.uk>"
# gpg:                 aka "Mark Brown <broonie@linaro.org>"
# gpg:                 aka "Mark Brown <Mark.Brown@linaro.org>"
2016-03-11 14:28:07 +07:00
Javier Martinez Canillas
10f11a2238 spi: Add gfp parameter to kernel-doc to fix build warning
The spi_split_transfers_maxsize() gfp parameter is missing in the
function kernel-doc so building gives the following warning:

.//drivers/spi/spi.c:2359: warning: No description found for parameter 'gfp'

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-03-11 14:23:01 +07:00
Javier Martinez Canillas
c76d9ae415 spi: Fix htmldocs build error due struct spi_replaced_transfers
The kernel-doc has to be just before the structure definition but the one
for struct spi_replaced_transfers was before a structure declaration and
that confuses kernel-doc which complains with the following build error:

.//include/linux/spi/spi.h:933: error: Cannot parse struct or union!

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-03-11 14:23:01 +07:00
Thomas Gleixner
2a58c527bb cpu/hotplug: Fix smpboot thread ordering
Commit 931ef16330 moved the smpboot thread park/unpark invocation to the
state machine. The move of the unpark invocation was premature as it depends
on work in progress patches.

As a result cpu down can fail, because rcu synchronization in takedown_cpu()
eventually requires a functional softirq thread. I never encountered the
problem in testing, but 0day testing managed to provide a reliable reproducer.

Remove the smpboot_threads_park() call from the state machine for now and put
it back into the original place after the rcu synchronization.

I'm embarrassed as I knew about the dependency and still managed to get it
wrong. Hotplug induced brain melt seems to be the only sensible explanation
for that.

Fixes: 931ef16330 "cpu/hotplug: Unpark smpboot threads from the state machine"
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
2016-03-10 21:21:59 +01:00
Andi Kleen
206cab651d perf stat: Add --metric-only support for -A
Add metric only support for -A too. This requires a new print function
that prints the metrics in the right order.

v2: Fix manpage
v3: Simplify nrcpus computation

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/1457049458-28956-7-git-send-email-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-03-10 16:50:47 -03:00
Andi Kleen
54b5091606 perf stat: Implement --metric-only mode
Add a new mode to only print metrics. Sometimes we don't care about the
raw values, just want the computed metrics. This allows more compact
printing, so with -I each sample is only a single line.  This also
allows easier plotting and processing with other tools.

The main target is with using --topdown, but it also works with -T and
standard perf stat. A few metrics are not supported.

To avoiding having to hardcode all the metrics in the code it uses a two
pass approach: first compute dummy metrics and only print the headers in
the print_metric callback. Then use the callback to print the actual
values.

There are some additional changes in the stat printout code to handle
all metrics being on a single line.

One issue is that the column code doesn't know in advance what events
are not supported by the CPU, and it would be hard to find out as this
could change based on dynamic conditions. That causes empty columns in
some cases.

The output can be fairly wide, often you may need more than 80 columns.

Example:

% perf stat -a -I 1000 --metric-only
     1.001452803 frontend cycles idle insn per cycle       stalled cycles per insn branch-misses of all branches
     1.001452803  158.91%               0.66                2.39                    2.92%
     2.002192321  180.63%               0.76                2.08                    2.96%
     3.003088282  150.59%               0.62                2.57                    2.84%
     4.004369835  196.20%               0.98                1.62                    3.79%
     5.005227314  231.98%               0.84                1.90                    4.71%

v2: Lots of updates.
v3: Use slightly narrower columns
v4: Add comment

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/1457049458-28956-6-git-send-email-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-03-10 16:49:40 -03:00
Andi Kleen
6b45f7b2a3 perf stat: Document CSV format in manpage
With all the recently added fields in the perf stat CSV output we should
finally document them in the man page. Do this here.

v2: Fix fields in documentation (Jiri)
v3: fix order of fields again (Jiri)
v4: Change order again.
v5: Document more fields (Jiri)
v6: Move time stamp first
v7: More fixes (Jiri)

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/1457049458-28956-5-git-send-email-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-03-10 16:49:06 -03:00
Namhyung Kim
599a2f38a9 perf hists browser: Check sort keys before hot key actions
The context menu in TUI hists browser checks corresponding sort keys
when creating the menu item.  But hotkey actions lacks these checks so
it can filter using incorrect info.

For example, default sort key of 'perf top' doesn't contain 'comm' or
'pid' sort key so each hist entry's thread info is not reliable.  Thus
it should prohibit using thread filter on 't' key.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1457533253-21419-3-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-03-10 16:48:02 -03:00
Namhyung Kim
6962ccb37b perf hists browser: Allow thread filtering for comm sort key
The commit 2eafd410e6 ("perf hists browser: Only 'Zoom into thread'
only when sort order has 'pid'") disabled thread filtering in hist
browser for the default sort key.  However the he->thread is still valid
even if 'pid' sort key is not given.  Only thing it should not use is
the pid (or tid) of the thread.  So allow to filter by thread when
'comm' sort key is given and show pid only if 'pid' sort key is given.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1457536490-24084-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-03-10 16:47:37 -03:00
Namhyung Kim
078b8d4a40 perf tools: Add sort__has_comm variable
The sort__has_comm variable is to check whether the comm sort key is
given.  This is necessary to support thread filtering in the TUI hists
browser later.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1457533253-21419-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-03-10 16:47:19 -03:00
Namhyung Kim
f7fb538afe perf tools: Recalc total periods using top-level entries in hierarchy
When hierarchy mode is enabled, each entry in a hierarchy level shares
the period.  IOW an upper level entry's period is the sum of lower level
entries.  Thus perf uses only one of them to calculate the total period
of hists.  It was lowest-level (leaf) entries but it has a problem when
it comes to filters.

If a filter is applied, entries in the same level will be filtered or
not.  But upper level entries still have period of their sum including
filtered one.  So total sum of upper level entries will not be same as
sum of lower level entries.

This resulted in entries having more than 100% of overhead and it can be
produced using perf top with filter(s).

Reported-and-Tested-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1457531222-18130-8-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-03-10 16:46:13 -03:00
Namhyung Kim
86e3ee5224 perf tools: Remove nr_sort_keys field
The nr_sort_keys field is to carry the number of sort entries in a
hpp_list or hists to determine the depth of indentation of a hist entry.
As it's only used in hierarchy mode and now we have used nr_hpp_node for
this reason, there's no need to keep it anymore.  Let's get rid of it.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1457531222-18130-7-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-03-10 16:46:08 -03:00
Namhyung Kim
325a62834e perf hists browser: Cleanup hist_browser__fprintf_hierarchy_entry()
The hist_browser__fprintf_hierarchy_entry() if to dump current output
into a file so it needs to be sync-ed with the corresponding function
hist_browser__show_hierarchy_entry().  So use hists->nr_hpp_node to
indent width and use first fmt_node to print overhead columns instead of
checking whether it's a sort entry (or dynamic entry).

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1457531222-18130-6-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-03-10 16:46:04 -03:00
Namhyung Kim
a515d8ff70 perf tools: Remove hist_entry->fmt field
It's not used anymore and the output format is accessed by the hpp_list
pointer instead when hierarchy is enabled.  Let's get rid of it.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1457531222-18130-5-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-03-10 16:45:59 -03:00
Namhyung Kim
aec13a7ec7 perf tools: Fix command line filters in hierarchy mode
When a command-line filter is applied in hierarchy mode, output is
broken especially when filtering on lower level.  The higher level
entries doesn't show up so it's hard to see the results.

Also it needs to handle multi sort keys in a single hierarchy level.

Before:

  $ perf report --hierarchy -s 'cpu,{dso,comm}' --comms swapper --stdio
  ...
  #    Overhead  CPU / Shared Object+Command
  # ...........  ...........................
  #
         13.79%     [kernel.vmlinux]  swapper
      31.71%     000
         13.80%     [kernel.vmlinux]  swapper
          0.43%     [e1000e]          swapper
         11.89%     [kernel.vmlinux]  swapper
          9.18%     [kernel.vmlinux]  swapper

After:

  #    Overhead  CPU / Shared Object+Command
  # ...........  ...............................
  #
      33.09%     003
         13.79%     [kernel.vmlinux]  swapper
      31.71%     000
         13.80%     [kernel.vmlinux]  swapper
          0.43%     [e1000e]          swapper
      21.90%     002
         11.89%     [kernel.vmlinux]  swapper
      13.30%     001
          9.18%     [kernel.vmlinux]  swapper

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1457531222-18130-4-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-03-10 16:45:48 -03:00
Namhyung Kim
4945cf2aa1 perf tools: Add more sort entry check functions
Those functions are for checkinf if a given perf_hpp_fmt is a
filter-related sort entry.  With hierarchy mode, it needs to check
filters on the hist entries with its own hpp format list.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1457531222-18130-3-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-03-10 16:45:44 -03:00
Namhyung Kim
f4954cfb1c perf tools: Fix hist_entry__filter() for hierarchy
When hierarchy mode is enabled each output format is in a separate hpp
list.  So when applying a filter it should check all formats in the
list.  Currently it only checks a single ->fmt field which was not set
properly.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1457531222-18130-2-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-03-10 16:45:36 -03:00
Jiri Olsa
e12b202f8f perf jitdump: Build only on supported archs
Build jitdump only on architectures defined in util/genelf.h file, to avoid
breaking the build on such arches.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Davidlohr Bueso <dbueso@suse.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Mel Gorman <mgorman@suse.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20160310164113.GA11357@krava.redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-03-10 16:33:19 -03:00
Steven Rostedt
9eb42dee2b tools lib traceevent: Add '~' operation within arg_num_eval()
When evaluating values for print flags, if the value included a '~'
operator, the parsing would fail. This broke kmalloc's parsing of:

__print_flags(REC->gfp_flags, "|", {(unsigned
long)((((((( gfp_t)(0x400000u|0x2000000u)) | (( gfp_t)0x40u) |
(( gfp_t)0x80u) | (( gfp_t)0x20000u)) | (( gfp_t)0x02u)) |
(( gfp_t)0x08u)) | (( gfp_t)0x4000u) | (( gfp_t)0x10000u) |
(( gfp_t)0x1000u) | (( gfp_t)0x200u)) & ~(( gfp_t)0x2000000u))
                                        ^
                                        |
                                      here

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: David Ahern <dsahern@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20160226181328.22f47129@gandalf.local.home
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-03-10 16:27:41 -03:00
Boris BREZILLON
9df4f913eb MAINTAINERS: add a maintainer for the NAND subsystem
Add myself as the maintainer of the NAND subsystem.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Richard Weinberger <richard@nod.at>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
2016-03-10 10:48:04 -08:00
Linus Torvalds
f2c1242194 A few simple fixes for ARM, x86, PPC and generic code. The x86 MMU fix
is a bit larger because the surrounding code needed a cleanup, but
 nothing worrisome.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.22 (GNU/Linux)
 
 iQEcBAABAgAGBQJW4UwZAAoJEL/70l94x66DG3YH/0PfUr4sW0jnWRVXmYlPVka4
 sNFYrdtYnx08PwXu2sWMm1F+OBXlF/t0ZSJXJ9OBF8WdKIu8TU4yBOINRAvGO/oE
 slrivjktLTKgicTtIXP5BpRR14ohwHIGcuiIlppxvnhmQz1/rMtig7fvhZxYI545
 lJyIbyquNR86tiVdUSG9/T9+ulXXXCvOspYv8jPXZx7VKBXKTvp5P5qavSqciRb+
 O9RqY+GDCR/5vrw+MV0J7H9ZydeEJeD02LcWguTGMATTm0RCrhydvSbou42UcKfY
 osWii0kwt2LhcM/sTOz+cWnLJ6gwU9T+ZtJTTbLvYWXWDLP/+icp9ACMkwNciNo=
 =/y4V
 -----END PGP SIGNATURE-----

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fixes from Paolo Bonzini:
 "A few simple fixes for ARM, x86, PPC and generic code.

  The x86 MMU fix is a bit larger because the surrounding code needed a
  cleanup, but nothing worrisome"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: MMU: fix reserved bit check for ept=0/CR0.WP=0/CR4.SMEP=1/EFER.NX=0
  KVM: MMU: fix ept=0/pte.u=1/pte.w=0/CR0.WP=0/CR4.SMEP=1/EFER.NX=0 combo
  kvm: cap halt polling at exactly halt_poll_ns
  KVM: s390: correct fprs on SIGP (STOP AND) STORE STATUS
  KVM: VMX: disable PEBS before a guest entry
  KVM: PPC: Book3S HV: Sanitize special-purpose register values on guest exit
2016-03-10 10:42:15 -08:00
Linus Torvalds
c32c2cb272 arm64 fixes:
- Temporarily disable huge pages built using contiguous ptes
 - Ensure vmemmap region is sufficiently aligned for sparsemem sections
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABCgAGBQJW4FSYAAoJELescNyEwWM0cp4H/0+9iMTqb3KowIW1vQPNnOG2
 BG/RVsGlCPAwBu0V4FdcY7eK4fQ9J+/UCmVd5/SrlpjNpblinxRPihbIzs4bToqa
 It02wNk7ISPm0oYtyGrRu1TpC5AvMykcluZkU/CUk0sjZlBAi8WSaJiqftFuZSGH
 lhyhARO4KscbAUUhwDDYNKuWmLbmyOpt9RM2fziNQdjSp+8czCoCR9G+JXiPQFsJ
 ORU10BqBDCyFpp8/NhM55qA76FJo6RCBUWx/6L1oJJxjvahkmPba/hhnfI7+Xj1u
 3FKAntJ6wVZeKqRsIkOlECoU/mrgjlTByTFN+o3KhOky8ZYBHoveIQWtsqNMFd4=
 =7d1o
 -----END PGP SIGNATURE-----

Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Will Deacon:
 "I thought we were done for 4.5, but then the 64k-page chaps came
  crawling out of the woodwork.  *sigh*

  The vmemmap fix I sent for -rc7 caused a regression with 64k pages and
  sparsemem and at some point during the release cycle the new hugetlb
  code using contiguous ptes started failing the libhugetlbfs tests with
  64k pages enabled.

  So here are a couple of patches that fix the vmemmap alignment and
  disable the new hugetlb page sizes whilst a proper fix is being
  developed:

   - Temporarily disable huge pages built using contiguous ptes

   - Ensure vmemmap region is sufficiently aligned for sparsemem
     sections"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: hugetlb: partial revert of 66b3923a1a
  arm64: account for sparsemem section alignment when choosing vmemmap offset
2016-03-10 10:39:04 -08:00
Linus Torvalds
2da33f9f96 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 fixes from Martin Schwidefsky:
 "Three bug fixes:
   - The fix for the page table corruption (CVE-2016-2143)
   - The diagnose statistics introduced a regression for the dasd diag
     driver
   - Boot crash on systems without the set-program-parameters facility"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/mm: four page table levels vs. fork
  s390/cpumf: Fix lpp detection
  s390/dasd: fix diag 0x250 inline assembly
2016-03-10 10:36:07 -08:00
Mauro Carvalho Chehab
b2cd27448b [media] media-device: map new functions into old types for legacy API
The legacy media controller userspace API exposes entity types that
carry both type and function information. The new API replaces the type
with a function. It preserves backward compatibility by defining legacy
functions for the existing types and using them in drivers.

This works fine, as long as newer entity functions won't be added.

Unfortunately, some tools, like media-ctl with --print-dot argument
rely on the now legacy MEDIA_ENT_T_V4L2_SUBDEV and MEDIA_ENT_T_DEVNODE
numeric ranges to identify what entities will be shown.

Also, if the entity doesn't match those ranges, it will ignore the
major/minor information on devnodes, and won't be getting the devnode
name via udev or sysfs.

As we're now adding devices outside the old range, the legacy ioctl
needs to map the new entity functions into a type at the old range,
or otherwise we'll have a regression.

Detected on all released media-ctl versions (e. g. versions <= 1.10).

Fix this by deriving the type from the function to emulate the legacy
API if the function isn't in the legacy functions range.

Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2016-03-10 15:10:59 -03:00
Jianyu Zhan
10ee73865e x86/entry/traps: Show unhandled signal for i386 in do_trap()
Commit abd4f7505b ("x86: i386-show-unhandled-signals-v3") did turn on
the showing-unhandled-signal behaviour for i386 for some exception handlers,
but for no reason do_trap() is left out (my naive guess is because turning it on
for do_trap() would be too noisy since do_trap() is shared by several exceptions).

And since the same commit make "show_unhandled_signals" a debug tunable(in
/proc/sys/debug/exception-trace), and x86 by default turning it on.

So it would be strange for i386 users who turing it on manually and expect
seeing the unhandled signal output in log, but nothing.

This patch turns it on for i386 in do_trap() as well.

Signed-off-by: Jianyu Zhan <nasa4836@gmail.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bp@suse.de
Cc: dave.hansen@linux.intel.com
Cc: heukelum@fastmail.fm
Cc: jbeulich@novell.com
Cc: jdike@addtoit.com
Cc: joe@perches.com
Cc: luto@kernel.org
Link: http://lkml.kernel.org/r/1457612398-4568-1-git-send-email-nasa4836@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10 18:37:25 +01:00
Luck, Tony
eb1af3b71f EDAC/sb_edac: Fix computation of channel address
Large memory Haswell-EX systems with multiple DIMMs per channel were
sometimes reporting the wrong DIMM.

Found three problems:

 1) Debug printouts for socket and channel interleave were not interpreting
    the register fields correctly. The socket interleave field is a 2^X
    value (0=1, 1=2, 2=4, 3=8). The channel interleave is X+1 (0=1, 1=2,
    2=3. 3=4).

 2) Actual use of the socket interleave value didn't interpret as 2^X

 3) Conversion of address to channel address was complicated, and wrong.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Aristeu Rozanski <arozansk@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-edac@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10 18:31:55 +01:00
Vladimir Zapolskiy
edf8fcdc6b irqchip/mxs: Fix error check of of_io_request_and_map()
The of_io_request_and_map() returns a valid pointer in iomem region or
ERR_PTR(), check for NULL always fails and may cause a NULL pointer
dereference on error path.

Fixes: 25e34b4431 ("irqchip/mxs: Prepare driver for hardware with different offsets")
Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Oleksij Rempel <linux@rempel-privat.de>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1457486500-10237-1-git-send-email-vz@mleia.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-03-10 16:03:30 +01:00
Vladimir Zapolskiy
cfe199afef irqchip/sunxi-nmi: Fix error check of of_io_request_and_map()
The of_io_request_and_map() returns a valid pointer in iomem region or
ERR_PTR(), check for NULL always fails and may cause a NULL pointer
dereference on error path.

Fixes: 0e841b04c8 ("irqchip/sunxi-nmi: Switch to of_io_request_and_map() from of_iomap()")
Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1457486489-10189-1-git-send-email-vz@mleia.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-03-10 16:03:30 +01:00
Quan Nguyen
52b2a05fa7 genirq: Export IRQ functions for module use
Export irq_chip_*_parent(), irq_domain_create_hierarchy(),
irq_domain_set_hwirq_and_chip(), irq_domain_reset_irq_data(),
irq_domain_alloc/free_irqs_parent()

So gpio drivers can be built as modules. First user: gpio-xgene-sb

Signed-off-by: Quan Nguyen <qnguyen@apm.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Phong Vo <pvo@apm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: patches@apm.com
Cc: Loc Ho <lho@apm.com>
Cc: Keyur Chudgar <kchudgar@apm.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Link: https://lists.01.org/pipermail/kbuild-all/2016-February/017914.html
Link: http://lkml.kernel.org/r/1457017012-10628-1-git-send-email-qnguyen@apm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-03-10 16:00:35 +01:00
Ludovic Desroches
25c5e9626c dmaengine: at_xdmac: fix residue computation
When computing the residue we need two pieces of information: the current
descriptor and the remaining data of the current descriptor. To get
that information, we need to read consecutively two registers but we
can't do it in an atomic way. For that reason, we have to check manually
that current descriptor has not changed.

Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Suggested-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Reported-by: David Engraf <david.engraf@sysgo.com>
Tested-by: David Engraf <david.engraf@sysgo.com>
Fixes: e1f7c9eee7 ("dmaengine: at_xdmac: creation of the atmel
eXtended DMA Controller driver")
Cc: stable@vger.kernel.org #4.1 and later
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2016-03-10 16:32:36 +05:30
Borislav Petkov
84477336ec x86/delay: Avoid preemptible context checks in delay_mwaitx()
We do use this_cpu_ptr(&cpu_tss) as a cacheline-aligned, seldomly
accessed per-cpu var as the MONITORX target in delay_mwaitx(). However,
when called in preemptible context, this_cpu_ptr -> smp_processor_id() ->
debug_smp_processor_id() fires:

  BUG: using smp_processor_id() in preemptible [00000000] code: udevd/312
  caller is delay_mwaitx+0x40/0xa0

But we don't care about that check - we only need cpu_tss as a MONITORX
target and it doesn't really matter which CPU's var we're touching as
we're going idle anyway. Fix that.

Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: spg_linux_kernel@amd.com
Link: http://lkml.kernel.org/r/20160309205622.GG6564@pd.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10 11:27:12 +01:00
Paolo Bonzini
5f0b819995 KVM: MMU: fix reserved bit check for ept=0/CR0.WP=0/CR4.SMEP=1/EFER.NX=0
KVM has special logic to handle pages with pte.u=1 and pte.w=0 when
CR0.WP=1.  These pages' SPTEs flip continuously between two states:
U=1/W=0 (user and supervisor reads allowed, supervisor writes not allowed)
and U=0/W=1 (supervisor reads and writes allowed, user writes not allowed).

When SMEP is in effect, however, U=0 will enable kernel execution of
this page.  To avoid this, KVM also sets NX=1 in the shadow PTE together
with U=0, making the two states U=1/W=0/NX=gpte.NX and U=0/W=1/NX=1.
When guest EFER has the NX bit cleared, the reserved bit check thinks
that the latter state is invalid; teach it that the smep_andnot_wp case
will also use the NX bit of SPTEs.

Cc: stable@vger.kernel.org
Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.inel.com>
Fixes: c258b62b26
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-10 11:26:10 +01:00
Paolo Bonzini
844a5fe219 KVM: MMU: fix ept=0/pte.u=1/pte.w=0/CR0.WP=0/CR4.SMEP=1/EFER.NX=0 combo
Yes, all of these are needed. :) This is admittedly a bit odd, but
kvm-unit-tests access.flat tests this if you run it with "-cpu host"
and of course ept=0.

KVM runs the guest with CR0.WP=1, so it must handle supervisor writes
specially when pte.u=1/pte.w=0/CR0.WP=0.  Such writes cause a fault
when U=1 and W=0 in the SPTE, but they must succeed because CR0.WP=0.
When KVM gets the fault, it sets U=0 and W=1 in the shadow PTE and
restarts execution.  This will still cause a user write to fault, while
supervisor writes will succeed.  User reads will fault spuriously now,
and KVM will then flip U and W again in the SPTE (U=1, W=0).  User reads
will be enabled and supervisor writes disabled, going back to the
originary situation where supervisor writes fault spuriously.

When SMEP is in effect, however, U=0 will enable kernel execution of
this page.  To avoid this, KVM also sets NX=1 in the shadow PTE together
with U=0.  If the guest has not enabled NX, the result is a continuous
stream of page faults due to the NX bit being reserved.

The fix is to force EFER.NX=1 even if the CPU is taking care of the EFER
switch.  (All machines with SMEP have the CPU_LOAD_IA32_EFER vm-entry
control, so they do not use user-return notifiers for EFER---if they did,
EFER.NX would be forced to the same value as the host).

There is another bug in the reserved bit check, which I've split to a
separate patch for easier application to stable kernels.

Cc: stable@vger.kernel.org
Cc: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Fixes: f6577a5fa1
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-10 11:26:07 +01:00
Andy Lutomirski
9999c8c01f x86/entry: Call enter_from_user_mode() with IRQs off
Now that slow-path syscalls always enter C before enabling
interrupts, it's straightforward to call enter_from_user_mode() before
enabling interrupts rather than doing it as part of entry tracing.

With this change, we should finally be able to retire exception_enter().

This will also enable optimizations based on knowing that we never
change context tracking state with interrupts on.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/bc376ecf87921a495e874ff98139b1ca2f5c5dd7.1457558566.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10 10:53:26 +01:00
Andy Lutomirski
a798f09111 x86/entry/32: Change INT80 to be an interrupt gate
We want all of the syscall entries to run with interrupts off so that
we can efficiently run context tracking before enabling interrupts.

This will regress int $0x80 performance on 32-bit kernels by a
couple of cycles.  This shouldn't matter much -- int $0x80 is not a
fast path.

This effectively reverts:

  657c1eea00 ("x86/entry/32: Fix entry_INT80_32() to expect interrupts to be on")

... and fixes the same issue differently.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/59b4f90c9ebfccd8c937305dbbbca680bc74b905.1457558566.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10 10:53:26 +01:00
Davidlohr Bueso
38460a2178 locking/csd_lock: Use smp_cond_acquire() in csd_lock_wait()
We can micro-optimize this call and mildly relax the
barrier requirements by relying on ctrl + rmb, keeping
the acquire semantics. In addition, this is pretty much
the now standard for busy-waiting under such restraints.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave@stgolabs.net
Link: http://lkml.kernel.org/r/1457574936-19065-3-git-send-email-dbueso@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10 10:28:35 +01:00
Davidlohr Bueso
90d1098478 locking/csd_lock: Explicitly inline csd_lock*() helpers
While the compiler tends to already to it for us (except for
csd_unlock), make it explicit. These helpers mainly deal with
the ->flags, are short-lived  and can be called, for example,
from smp_call_function_many().

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave@stgolabs.net
Link: http://lkml.kernel.org/r/1457574936-19065-2-git-send-email-dbueso@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10 10:28:35 +01:00
Ingo Molnar
6cbe9e4a22 Merge branch 'linus' into locking/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10 10:28:27 +01:00
Yu-cheng Yu
a65050c6f1 x86/fpu: Revert ("x86/fpu: Disable AVX when eagerfpu is off")
Leonid Shatz noticed that the SDM interpretation of the following
recent commit:

  394db20ca2 ("x86/fpu: Disable AVX when eagerfpu is off")

... is incorrect and that the original behavior of the FPU code was correct.

Because AVX is not stated in CR0 TS bit description, it was mistakenly
believed to be not supported for lazy context switch. This turns out
to be false:

  Intel Software Developer's Manual Vol. 3A, Sec. 2.5 Control Registers:

   'TS Task Switched bit (bit 3 of CR0) -- Allows the saving of the x87 FPU/
    MMX/SSE/SSE2/SSE3/SSSE3/SSE4 context on a task switch to be delayed until
    an x87 FPU/MMX/SSE/SSE2/SSE3/SSSE3/SSE4 instruction is actually executed
    by the new task.'

  Intel Software Developer's Manual Vol. 2A, Sec. 2.4 Instruction Exception
  Specification:

   'AVX instructions refer to exceptions by classes that include #NM
    "Device Not Available" exception for lazy context switch.'

So revert the commit.

Reported-by: Leonid Shatz <leonid.shatz@ravellosystems.com>
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi V. Shankar <ravi.v.shankar@intel.com>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1457569734-3785-1-git-send-email-yu-cheng.yu@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10 10:15:58 +01:00
Andy Lutomirski
fda57b2267 x86/entry: Improve system call entry comments
Ingo suggested that the comments should explain when the various
entries are used.  This adds these explanations and improves other
parts of the comments.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/9524ecef7a295347294300045d08354d6a57c6e7.1457578375.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10 09:48:15 +01:00
Andy Lutomirski
392a62549f x86/entry: Remove TIF_SINGLESTEP entry work
Now that SYSENTER with TF set puts X86_EFLAGS_TF directly into
regs->flags, we don't need a TIF_SINGLESTEP fixup in the syscall
entry code.  Remove it.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/2d15f24da52dafc9d2f0b8d76f55544f4779c517.1457578375.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10 09:48:14 +01:00
Andy Lutomirski
2a41aa4feb x86/entry/32: Add and check a stack canary for the SYSENTER stack
The first instruction of the SYSENTER entry runs on its own tiny
stack.  That stack can be used if a #DB or NMI is delivered before
the SYSENTER prologue switches to a real stack.

We have code in place to prevent us from overflowing the tiny stack.
For added paranoia, add a canary to the stack and check it in
do_debug() -- that way, if something goes wrong with the #DB logic,
we'll eventually notice.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/6ff9a806f39098b166dc2c41c1db744df5272f29.1457578375.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10 09:48:14 +01:00
Andy Lutomirski
7536656f08 x86/entry/32: Simplify and fix up the SYSENTER stack #DB/NMI fixup
Right after SYSENTER, we can get a #DB or NMI.  On x86_32, there's no IST,
so the exception handler is invoked on the temporary SYSENTER stack.

Because the SYSENTER stack is very small, we have a fixup to switch
off the stack quickly when this happens.  The old fixup had several issues:

 1. It checked the interrupt frame's CS and EIP.  This wasn't
    obviously correct on Xen or if vm86 mode was in use [1].

 2. In the NMI handler, it did some frightening digging into the
    stack frame.  I'm not convinced this digging was correct.

 3. The fixup didn't switch stacks and then switch back.  Instead, it
    synthesized a brand new stack frame that would redirect the IRET
    back to the SYSENTER code.  That frame was highly questionable.
    For one thing, if NMI nested inside #DB, we would effectively
    abort the #DB prologue, which was probably safe but was
    frightening.  For another, the code used PUSHFL to write the
    FLAGS portion of the frame, which was simply bogus -- by the time
    PUSHFL was called, at least TF, NT, VM, and all of the arithmetic
    flags were clobbered.

Simplify this considerably.  Instead of looking at the saved frame
to see where we came from, check the hardware ESP register against
the SYSENTER stack directly.  Malicious user code cannot spoof the
kernel ESP register, and by moving the check after SAVE_ALL, we can
use normal PER_CPU accesses to find all the relevant addresses.

With this patch applied, the improved syscall_nt_32 test finally
passes on 32-bit kernels.

[1] It isn't obviously correct, but it is nonetheless safe from vm86
    shenanigans as far as I can tell.  A user can't point EIP at
    entry_SYSENTER_32 while in vm86 mode because entry_SYSENTER_32,
    like all kernel addresses, is greater than 0xffff and would thus
    violate the CS segment limit.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/b2cdbc037031c07ecf2c40a96069318aec0e7971.1457578375.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10 09:48:14 +01:00
Andy Lutomirski
6dcc94149d x86/entry: Only allocate space for tss_struct::SYSENTER_stack if needed
The SYSENTER stack is only used on 32-bit kernels.  Remove it on 64-bit kernels.

( We may end up using it down the road on 64-bit kernels. If so,
  we'll re-enable it for CONFIG_IA32_EMULATION. )

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/9dbd18429f9ff61a76b6eda97a9ea20510b9f6ba.1457578375.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10 09:48:14 +01:00
Andy Lutomirski
f2b375756c x86/entry: Vastly simplify SYSENTER TF (single-step) handling
Due to a blatant design error, SYSENTER doesn't clear TF (single-step).

As a result, if a user does SYSENTER with TF set, we will single-step
through the kernel until something clears TF.  There is absolutely
nothing we can do to prevent this short of turning off SYSENTER [1].

Simplify the handling considerably with two changes:

  1. We already sanitize EFLAGS in SYSENTER to clear NT and AC.  We can
     add TF to that list of flags to sanitize with no overhead whatsoever.

  2. Teach do_debug() to ignore single-step traps in the SYSENTER prologue.

That's all we need to do.

Don't get too excited -- our handling is still buggy on 32-bit
kernels.  There's nothing wrong with the SYSENTER code itself, but
the #DB prologue has a clever fixup for traps on the very first
instruction of entry_SYSENTER_32, and the fixup doesn't work quite
correctly.  The next two patches will fix that.

[1] We could probably prevent it by forcing BTF on at all times and
    making sure we clear TF before any branches in the SYSENTER
    code.  Needless to say, this is a bad idea.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/a30d2ea06fe4b621fe6a9ef911b02c0f38feb6f2.1457578375.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10 09:48:13 +01:00
Andy Lutomirski
8bb5643686 x86/entry/traps: Clear DR6 early in do_debug() and improve the comment
Leaving any bits set in DR6 on return from a debug exception is
asking for trouble.  Prevent it by writing zero right away and
clarify the comment.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/3857676e1be8fb27db4b89bbb1e2052b7f435ff4.1457578375.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10 09:48:13 +01:00
Andy Lutomirski
81edd9f69a x86/entry/traps: Clear TIF_BLOCKSTEP on all debug exceptions
The SDM says that debug exceptions clear BTF, and we need to keep
TIF_BLOCKSTEP in sync with BTF.  Clear it unconditionally and improve
the comment.

I suspect that the fact that kmemcheck could cause TIF_BLOCKSTEP not
to be cleared was just an oversight.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/fa86e55d196e6dde5b38839595bde2a292c52fdc.1457578375.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10 09:48:13 +01:00
Andy Lutomirski
c2c9b52fab x86/entry/32: Restore FLAGS on SYSEXIT
We weren't restoring FLAGS at all on SYSEXIT.  Apparently no one cared.

With this patch applied, native kernels should always honor
task_pt_regs()->flags, which opens the door for some sys_iopl()
cleanups.  I'll do those as a separate series, though, since getting
it right will involve tweaking some paravirt ops.

( The short version is that, before this patch, sys_iopl(), invoked via
  SYSENTER, wasn't guaranteed to ever transfer the updated
  regs->flags, so sys_iopl() had to change the hardware flags register
  as well. )

Reported-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/3f98b207472dc9784838eb5ca2b89dcc845ce269.1457578375.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10 09:48:12 +01:00
Andy Lutomirski
67f590e8d4 x86/entry/32: Filter NT and speed up AC filtering in SYSENTER
This makes the 32-bit code work just like the 64-bit code.  It should
speed up syscalls on 32-bit kernels on Skylake by something like 20
cycles (by analogy to the 64-bit compat case).

It also cleans up NT just like we do for the 64-bit case.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/07daef3d44bd1ed62a2c866e143e8df64edb40ee.1457578375.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10 09:48:12 +01:00
Andy Lutomirski
e786041153 x86/entry/compat: In SYSENTER, sink AC clearing below the existing FLAGS test
CLAC is slow, and the SYSENTER code already has an unlikely path
that runs if unusual flags are set.  Drop the CLAC and instead rely
on the unlikely path to clear AC.

This seems to save ~24 cycles on my Skylake laptop.  (Hey, Intel,
make this faster please!)

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/90d6db2189f9add83bc7bddd75a0c19ebbd676b2.1457578375.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-10 09:48:12 +01:00