linux-toradex.git/lib/Makefile, branch v4.8-rc6

mm/usercopy: get rid of CONFIG_DEBUG_STRICT_USER_COPY_CHECKS

2016-08-30T17:10:21+00:00

There are three usercopy warnings which are currently being silenced for
gcc 4.6 and newer:

1) "copy_from_user() buffer size is too small" compile warning/error

   This is a static warning which happens when object size and copy size
   are both const, and copy size > object size.  I didn't see any false
   positives for this one.  So the function warning attribute seems to
   be working fine here.

   Note this scenario is always a bug and so I think it should be
   changed to *always* be an error, regardless of
   CONFIG_DEBUG_STRICT_USER_COPY_CHECKS.

2) "copy_from_user() buffer size is not provably correct" compile warning

   This is another static warning which happens when I enable
   __compiletime_object_size() for new compilers (and
   CONFIG_DEBUG_STRICT_USER_COPY_CHECKS).  It happens when object size
   is const, but copy size is *not*.  In this case there's no way to
   compare the two at build time, so it gives the warning.  (Note the
   warning is a byproduct of the fact that gcc has no way of knowing
   whether the overflow function will be called, so the call isn't dead
   code and the warning attribute is activated.)

   So this warning seems to only indicate "this is an unusual pattern,
   maybe you should check it out" rather than "this is a bug".

   I get 102(!) of these warnings with allyesconfig and the
   __compiletime_object_size() gcc check removed.  I don't know if there
   are any real bugs hiding in there, but from looking at a small
   sample, I didn't see any.  According to Kees, it does sometimes find
   real bugs.  But the false positive rate seems high.

3) "Buffer overflow detected" runtime warning

   This is a runtime warning where object size is const, and copy size >
   object size.

All three warnings (both static and runtime) were completely disabled
for gcc 4.6 with the following commit:

  2fb0815c9ee6 ("gcc4: disable __compiletime_object_size for GCC 4.6+")

That commit mistakenly assumed that the false positives were caused by a
gcc bug in __compiletime_object_size().  But in fact,
__compiletime_object_size() seems to be working fine.  The false
positives were instead triggered by #2 above.  (Though I don't have an
explanation for why the warnings supposedly only started showing up in
gcc 4.6.)

So remove warning #2 to get rid of all the false positives, and re-enable
warnings #1 and #3 by reverting the above commit.

Furthermore, since #1 is a real bug which is detected at compile time,
upgrade it to always be an error.

Having done all that, CONFIG_DEBUG_STRICT_USER_COPY_CHECKS is no longer
needed.

Signed-off-by: Josh Poimboeuf 
Cc: Kees Cook 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H . Peter Anvin" 
Cc: Andy Lutomirski 
Cc: Steven Rostedt 
Cc: Brian Gerst 
Cc: Peter Zijlstra 
Cc: Frederic Weisbecker 
Cc: Byungchul Park 
Cc: Nilay Vaish 
Signed-off-by: Linus Torvalds

Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random

2016-07-27T22:11:55+00:00

Pull random driver updates from Ted Ts'o:
 "A number of improvements for the /dev/random driver; the most
  important is the use of a ChaCha20-based CRNG for /dev/urandom, which
  is faster, more efficient, and easier to make scalable for
  silly/abusive userspace programs that want to read from /dev/urandom
  in a tight loop on NUMA systems.

  This set of patches also improves entropy gathering on VM's running on
  Microsoft Azure, and will take advantage of a hw random number
  generator (if present) to initialize the /dev/urandom pool"

(It turns out that the random tree hadn't been in linux-next this time
around, because it had been dropped earlier as being too quiet.  Oh
well).

* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
  random: strengthen input validation for RNDADDTOENTCNT
  random: add backtracking protection to the CRNG
  random: make /dev/urandom scalable for silly userspace programs
  random: replace non-blocking pool with a Chacha20-based CRNG
  random: properly align get_random_int_hash
  random: add interrupt callback to VMBus IRQ handler
  random: print a warning for the first ten uninitialized random users
  random: initialize the non-blocking pool via add_hwgenerator_randomness()

random: replace non-blocking pool with a Chacha20-based CRNG

2016-07-03T04:57:23+00:00

The CRNG is faster, and we don't pretend to track entropy usage in the
CRNG any more.

Signed-off-by: Theodore Ts'o

x86/hweight: Get rid of the special calling convention

2016-06-08T13:01:02+00:00

People complained about ARCH_HWEIGHT_CFLAGS and how it throws a wrench
into kcov, lto, etc, experimentations.

Add asm versions for __sw_hweight{32,64}() and do explicit saving and
restoring of clobbered registers. This gets rid of the special calling
convention. We get to call those functions on !X86_FEATURE_POPCNT CPUs.

We still need to hardcode POPCNT and register operands as some old gas
versions which we support, do not know about POPCNT.

Btw, remove redundant REX prefix from 32-bit POPCNT because alternatives
can do padding now.

Suggested-by: H. Peter Anvin 
Signed-off-by: Borislav Petkov 
Acked-by: Peter Zijlstra (Intel) 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1464605787-20603-1-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar

lib/uuid: add a test module

2016-05-30T22:26:57+00:00

It appears that somehow I missed a test of the latest UUID rework which
landed in the kernel.  Present a small test module to avoid such cases
in the future.

Signed-off-by: Andy Shevchenko 
Signed-off-by: Linus Torvalds

Merge branch 'hash' of git://ftp.sciencehorizons.net/linux

2016-05-28T23:15:25+00:00

Pull string hash improvements from George Spelvin:
 "This series does several related things:

   - Makes the dcache hash (fs/namei.c) useful for general kernel use.

     (Thanks to Bruce for noticing the zero-length corner case)

   - Converts the string hashes in  to use the
     above.

   - Avoids 64-bit multiplies in hash_64() on 32-bit platforms.  Two
     32-bit multiplies will do well enough.

   - Rids the world of the bad hash multipliers in hash_32.

     This finishes the job started in commit 689de1d6ca95 ("Minimal
     fix-up of bad hashing behavior of hash_64()")

     The vast majority of Linux architectures have hardware support for
     32x32-bit multiply and so derive no benefit from "simplified"
     multipliers.

     The few processors that do not (68000, h8/300 and some models of
     Microblaze) have arch-specific implementations added.  Those
     patches are last in the series.

   - Overhauls the dcache hash mixing.

     The patch in commit 0fed3ac866ea ("namei: Improve hash mixing if
     CONFIG_DCACHE_WORD_ACCESS") was an off-the-cuff suggestion.
     Replaced with a much more careful design that's simultaneously
     faster and better.  (My own invention, as there was noting suitable
     in the literature I could find.  Comments welcome!)

   - Modify the hash_name() loop to skip the initial HASH_MIX().  This
     would let us salt the hash if we ever wanted to.

   - Sort out partial_name_hash().

     The hash function is declared as using a long state, even though
     it's truncated to 32 bits at the end and the extra internal state
     contributes nothing to the result.  And some callers do odd things:

      - fs/hfs/string.c only allocates 32 bits of state
      - fs/hfsplus/unicode.c uses it to hash 16-bit unicode symbols not bytes

   - Modify bytemask_from_count to handle inputs of 1..sizeof(long)
     rather than 0..sizeof(long)-1.  This would simplify users other
     than full_name_hash"

  Special thanks to Bruce Fields for testing and finding bugs in v1.  (I
  learned some humbling lessons about "obviously correct" code.)

  On the arch-specific front, the m68k assembly has been tested in a
  standalone test harness, I've been in contact with the Microblaze
  maintainers who mostly don't care, as the hardware multiplier is never
  omitted in real-world applications, and I haven't heard anything from
  the H8/300 world"

* 'hash' of git://ftp.sciencehorizons.net/linux:
  h8300: Add 
  microblaze: Add 
  m68k: Add 
  : Add support for architecture-specific functions
  fs/namei.c: Improve dcache hash function
  Eliminate bad hash multipliers from hash_32() and  hash_64()
  Change hash_64() return value to 32 bits
  : Define hash_str() in terms of hashlen_string()
  fs/namei.c: Add hashlen_string() function
  Pull out string hash to

: Add support for architecture-specific functions

2016-05-28T19:48:31+00:00

This is just the infrastructure; there are no users yet.

This is modelled on CONFIG_ARCH_RANDOM; a CONFIG_ symbol declares
the existence of .

That file may define its own versions of various functions, and define
HAVE_* symbols (no CONFIG_ prefix!) to suppress the generic ones.

Included is a self-test (in lib/test_hash.c) that verifies the basics.
It is NOT in general required that the arch-specific functions compute
the same thing as the generic, but if a HAVE_* symbol is defined with
the value 1, then equality is tested.

Signed-off-by: George Spelvin 
Cc: Geert Uytterhoeven 
Cc: Greg Ungerer 
Cc: Andreas Schwab 
Cc: Philippe De Muyter 
Cc: linux-m68k@lists.linux-m68k.org
Cc: Alistair Francis 
Cc: Michal Simek 
Cc: Yoshinori Sato 
Cc: uclinux-h8-devel@lists.sourceforge.jp

include/linux/nodemask.h: create next_node_in() helper

2016-05-20T02:12:14+00:00

Lots of code does

	node = next_node(node, XXX);
	if (node == MAX_NUMNODES)
		node = first_node(XXX);

so create next_node_in() to do this and use it in various places.

[mhocko@suse.com: use next_node_in() helper]
Acked-by: Vlastimil Babka 
Acked-by: Michal Hocko 
Signed-off-by: Michal Hocko 
Cc: Xishi Qiu 
Cc: Joonsoo Kim 
Cc: David Rientjes 
Cc: Naoya Horiguchi 
Cc: Laura Abbott 
Cc: Hui Zhu 
Cc: Wang Xiaoqiang 
Cc: Johannes Weiner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

2016-05-18T23:38:59+00:00

Pull SCSI updates from James Bottomley:
 "First round of SCSI updates for the 4.6+ merge window.

  This batch includes the usual quota of driver updates (bnx2fc, mp3sas,
  hpsa, ncr5380, lpfc, hisi_sas, snic, aacraid, megaraid_sas).  There's
  also a multiqueue update for scsi_debug, assorted bug fixes and a few
  other minor updates (refactor of scsi_sg_pools into generic code, alua
  and VPD updates, and struct timeval conversions)"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (138 commits)
  mpt3sas: Used "synchronize_irq()"API to synchronize timed-out IO & TMs
  mpt3sas: Set maximum transfer length per IO to 4MB for VDs
  mpt3sas: Updating mpt3sas driver version to 13.100.00.00
  mpt3sas: Fix initial Reference tag field for 4K PI drives.
  mpt3sas: Handle active cable exception event
  mpt3sas: Update MPI header to 2.00.42
  Revert "lpfc: Delete unnecessary checks before the function call mempool_destroy"
  eata_pio: missing break statement
  hpsa: Fix type ZBC conditional checks
  scsi_lib: Decode T10 vendor IDs
  scsi_dh_alua: do not fail for unknown VPD identification
  scsi_debug: use locally assigned naa
  scsi_debug: uuid for lu name
  scsi_debug: vpd and mode page work
  scsi_debug: add multiple queue support
  bfa: fix bfa_fcb_itnim_alloc() error handling
  megaraid_sas: Downgrade two success messages to info
  cxlflash: Fix to resolve dead-lock during EEH recovery
  scsi_debug: rework resp_report_luns
  scsi_debug: use pdt constants
  ...

lib: scatterlist: move SG pool code from SCSI driver to lib/sg_pool.c

2016-04-15T20:53:14+00:00

Now it's ready to move the mempool based SG chained allocator code from
SCSI driver to lib/sg_pool.c, which will be compiled only based on a Kconfig
symbol CONFIG_SG_POOL.

SCSI selects CONFIG_SG_POOL.

Reviewed-by: Christoph Hellwig 
Signed-off-by: Ming Lin 
Reviewed-by: Sagi Grimberg 
Signed-off-by: Martin K. Petersen