delta/linux.git/include/linux/kernel.h, branch proc-cmdline

taint: add taint for randstruct

2018-04-11T17:28:35+00:00

Since the randstruct plugin can intentionally produce extremely unusual
kernel structure layouts (even performance pathological ones), some
maintainers want to be able to trivially determine if an Oops is coming
from a randstruct-built kernel, so as to keep their sanity when
debugging.  This adds the new flag and initializes taint_mask
immediately when built with randstruct.

Link: http://lkml.kernel.org/r/1519084390-43867-4-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook 
Reviewed-by: Andrew Morton 
Cc: Al Viro 
Cc: Alexey Dobriyan 
Cc: Jonathan Corbet 
Cc: Randy Dunlap 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

taint: convert to indexed initialization

2018-04-11T17:28:34+00:00

This converts to using indexed initializers instead of comments, adds a
comment on why the taint flags can't be an enum, and make sure that no
one forgets to update the taint_flags when adding new bits.

Link: http://lkml.kernel.org/r/1519084390-43867-2-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook 
Reviewed-by: Andrew Morton 
Cc: Al Viro 
Cc: Alexey Dobriyan 
Cc: Jonathan Corbet 
Cc: Randy Dunlap 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

proc: add seq_put_decimal_ull_width to speed up /proc/pid/smaps

2018-04-11T17:28:33+00:00

seq_put_decimal_ull_w(m, str, val, width) prints a decimal number with a
specified minimal field width.

It is equivalent of seq_printf(m, "%s%*d", str, width, val), but it
works much faster.

== test_smaps.py
  num = 0
  with open("/proc/1/smaps") as f:
          for x in xrange(10000):
                  data = f.read()
                  f.seek(0, 0)
==

== Before patch ==
  $ time python test_smaps.py
  real    0m4.593s
  user    0m0.398s
  sys     0m4.158s

== After patch ==
  $ time python test_smaps.py
  real    0m3.828s
  user    0m0.413s
  sys     0m3.408s

$ perf -g record python test_smaps.py
== Before patch ==
-   79.01%     3.36%  python   [kernel.kallsyms]    [k] show_smap.isra.33
   - 75.65% show_smap.isra.33
      + 48.85% seq_printf
      + 15.75% __walk_page_range
      + 9.70% show_map_vma.isra.23
        0.61% seq_puts

== After patch ==
-   75.51%     4.62%  python   [kernel.kallsyms]    [k] show_smap.isra.33
   - 70.88% show_smap.isra.33
      + 24.82% seq_put_decimal_ull_w
      + 19.78% __walk_page_range
      + 12.74% seq_printf
      + 11.08% show_map_vma.isra.23
      + 1.68% seq_puts

[akpm@linux-foundation.org: fix drivers/of/unittest.c build]
Link: http://lkml.kernel.org/r/20180212074931.7227-1-avagin@openvz.org
Signed-off-by: Andrei Vagin 
Cc: Alexey Dobriyan 
Cc: KAMEZAWA Hiroyuki 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Fix subtle macro variable shadowing in min_not_zero()

2018-04-09T17:34:07+00:00

Commit 3c8ba0d61d04 ("kernel.h: Retain constant expression output for
max()/min()") rewrote our min/max macros to be very clever, but in the
meantime resurrected a variable name shadow issue that we had had
previously fixed in commit 589a9785ee3a ("min/max: remove sparse
warnings when they're nested").

That commit talks about the sparse warnings that this shadowing causes,
which we ignored as just a minor annoyance.  But it turns out that the
sparse warning is the least of our problems.  We actually have a real
bug due to the shadowing through the interaction with "min_not_zero()",
which ends up doing

   min(__x, __y)

internally, and then the new declaration of "__x" and "__y" as new
variables in __cmp_once() results in a complete mess of an expression,
and "min_not_zero()" doesn't work at all.

For some odd reason, this only ever caused (reported) problems on s390,
even though it is a generic issue and most of the (obviously successful)
testing of the problematic commit had happened on other architectures.

Quoting Sebastian Ott:
 "What happened is that the bio build by the partition detection code
  was attempted to be split by the block layer because the block queue
  had a max_sector setting of 0. blk_queue_max_hw_sectors uses
  min_not_zero."

So re-introduce the use of __UNIQUE_ID() to make sure that the min/max
macros do not have these kinds of clashes.

[ That said, __UNIQUE_ID() itself has several issues that make it less
  than wonderful.

  In particular, the "uniqueness" has a fallback on the line number,
  which means that it's not actually unique in more complex cases if you
  don't build with gcc or clang (which have working unique counters that
  aren't tied to line numbers).

  That historical broken fallback also means that we have that pointless
  "prefix" argument that doesn't actually make much sense _except_ for
  the known-broken case. Oh well. ]

Fixes: 3c8ba0d61d04 ("kernel.h: Retain constant expression output for max()/min()")
Reported-and-tested-by: Sebastian Ott 
Cc: Kees Cook 
Cc: Ingo Molnar 
Cc: Miguel Ojeda 
Signed-off-by: Linus Torvalds

kernel.h: Retain constant expression output for max()/min()

2018-04-05T21:17:16+00:00

In the effort to remove all VLAs from the kernel[1], it is desirable to
build with -Wvla.  However, this warning is overly pessimistic, in that
it is only happy with stack array sizes that are declared as constant
expressions, and not constant values.  One case of this is the
evaluation of the max() macro which, due to its construction, ends up
converting constant expression arguments into a constant value result.

All attempts to rewrite this macro with __builtin_constant_p() failed
with older compilers (e.g.  gcc 4.4)[2].  However, Martin Uecker,
constructed[3] a mind-shattering solution that works everywhere.
Cthulhu fhtagn!

This patch updates the min()/max() macros to evaluate to a constant
expression when called on constant expression arguments.  This removes
several false-positive stack VLA warnings from an x86 allmodconfig build
when -Wvla is added:

  $ diff -u before.txt after.txt | grep ^-
  -drivers/input/touchscreen/cyttsp4_core.c:871:2: warning: ISO C90 forbids variable length array ‘ids’ [-Wvla]
  -fs/btrfs/tree-checker.c:344:4: warning: ISO C90 forbids variable length array ‘namebuf’ [-Wvla]
  -lib/vsprintf.c:747:2: warning: ISO C90 forbids variable length array ‘sym’ [-Wvla]
  -net/ipv4/proc.c:403:2: warning: ISO C90 forbids variable length array ‘buff’ [-Wvla]
  -net/ipv6/proc.c:198:2: warning: ISO C90 forbids variable length array ‘buff’ [-Wvla]
  -net/ipv6/proc.c:218:2: warning: ISO C90 forbids variable length array ‘buff64’ [-Wvla]

This also updates two cases where different enums were being compared
and explicitly casts them to int (which matches the old side-effect of
the single-evaluation code): one in tpm/tpm_tis_core.h, and one in
drm/drm_color_mgmt.c.

 [1] https://lkml.org/lkml/2018/3/7/621
 [2] https://lkml.org/lkml/2018/3/10/170
 [3] https://lkml.org/lkml/2018/3/20/845

Co-Developed-by: Linus Torvalds 
Co-Developed-by: Martin Uecker 
Signed-off-by: Kees Cook 
Acked-by: Ingo Molnar 
Acked-by: Miguel Ojeda 
Signed-off-by: Linus Torvalds

Merge tag 'staging-4.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

2018-04-05T01:56:27+00:00

Pull staging/IIO updates from Greg KH:
 "Here is the big set of Staging/IIO driver patches for 4.17-rc1.

  It is a lot, over 500 changes, but not huge by previous kernel release
  standards. We deleted more lines than we added again (27k added vs.
  91k remvoed), thanks to finally being able to delete the IRDA drivers
  and networking code.

  We also deleted the ccree crypto driver, but that's coming back in
  through the crypto tree to you, in a much cleaned-up form.

  Added this round is at lot of "mt7621" device support, which is for an
  embedded device that Neil Brown cares about, and of course a handful
  of new IIO drivers as well.

  And finally, the fsl-mc core code moved out of the staging tree to the
  "real" part of the kernel, which is nice to see happen as well.

  Full details are in the shortlog, which has all of the tiny cleanup
  patches described.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'staging-4.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (579 commits)
  staging: rtl8723bs: Remove yield call, replace with cond_resched()
  staging: rtl8723bs: Replace yield() call with cond_resched()
  staging: rtl8723bs: Remove unecessary newlines from 'odm.h'.
  staging: rtl8723bs: Rework 'struct _ODM_Phy_Status_Info_' coding style.
  staging: rtl8723bs: Rework 'struct _ODM_Per_Pkt_Info_' coding style.
  staging: rtl8723bs: Replace NULL pointer comparison with '!'.
  staging: rtl8723bs: Factor out rtl8723bs_recv_tasklet() sections.
  staging: rtl8723bs: Fix function signature that goes over 80 characters.
  staging: rtl8723bs: Fix lines too long in update_recvframe_attrib().
  staging: rtl8723bs: Remove unnecessary blank lines in 'rtl8723bs_recv.c'.
  staging: rtl8723bs: Change camel case to snake case in 'rtl8723bs_recv.c'.
  staging: rtl8723bs: Add missing braces in else statement.
  staging: rtl8723bs: Add spaces around ternary operators.
  staging: rtl8723bs: Fix lines with trailing open parentheses.
  staging: rtl8723bs: Remove unnecessary length #define's.
  staging: rtl8723bs: Fix IEEE80211 authentication algorithm constants.
  staging: rtl8723bs: Fix alignment in rtw_wx_set_auth().
  staging: rtl8723bs: Remove braces from single statement conditionals.
  staging: rtl8723bs: Remove unecessary braces from switch statement.
  staging: rtl8723bs: Fix newlines in rtw_wx_set_auth().
  ...

macro: introduce COUNT_ARGS() macro

2018-03-28T20:55:19+00:00

move COUNT_ARGS() macro from apparmor to generic header and extend it
to count till twelve.

COUNT() was an alternative name for this logic, but it's used for
different purpose in many other places.

Similarly for CONCATENATE() macro.

Suggested-by: Linus Torvalds 
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Daniel Borkmann

Merge 4.16-rc6 into staging-next

2018-03-19T05:47:01+00:00

We want the staging fixes in here as well to handle merge/test issues.

Signed-off-by: Greg Kroah-Hartman

extable: Make init_kernel_text() global

2018-02-21T15:54:06+00:00

Convert init_kernel_text() to a global function and use it in a few
places instead of manually comparing _sinittext and _einittext.

Note that kallsyms.h has a very similar function called
is_kernel_inittext(), but its end check is inclusive.  I'm not sure
whether that's intentional behavior, so I didn't touch it.

Suggested-by: Jason Baron 
Signed-off-by: Josh Poimboeuf 
Acked-by: Peter Zijlstra 
Acked-by: Steven Rostedt (VMware) 
Cc: Borislav Petkov 
Cc: Linus Torvalds 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/4335d02be8d45ca7d265d2f174251d0b7ee6c5fd.1519051220.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar

lib: Add strongly typed 64bit int_sqrt

2018-02-04T10:17:21+00:00

There is no option to perform 64bit integer sqrt on 32bit platform.
Added stronger typed int_sqrt64 enables the 64bit calculations to
be performed on 32bit platforms. Using same algorithm as int_sqrt()
with strong typing provides enough precision also on 32bit platforms,
but it sacrifices some performance. In case values are smaller than
ULONG_MAX the standard int_sqrt is used for calculation to maximize the
performance due to more native calculations.

Signed-off-by: Crt Mori 
Acked-by: Joe Perches 
Signed-off-by: Jonathan Cameron