Now BUILD_BUG_ON() can handle optimizable constants, we don't need
MAYBE_BUILD_BUG_ON any more.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

It turns out that even zero-sized struct members (int foo[0];) will affect
the struct layout, causing us in particular to lose 4 bytes in struct
sock.

This patch fixes the regression in CONFIG_KMEMCHECK=n case.

Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

gcc permitting variable length arrays makes the current construct used for
BUILD_BUG_ON() useless, as that doesn't produce any diagnostic if the
controlling expression isn't really constant.  Instead, this patch makes
it so that a bit field gets used here.  Consequently, those uses where the
condition isn't really constant now also need fixing.

Note that in the gfp.h, kmemcheck.h, and virtio_config.h cases
MAYBE_BUILD_BUG_ON() really just serves documentation purposes - even if
the expression is compile time constant (__builtin_constant_p() yields
true), the array is still deemed of variable length by gcc, and hence the
whole expression doesn't have the intended effect.

[akpm@linux-foundation.org: make arch/sparc/include/asm/vio.h compile]
[akpm@linux-foundation.org: more nonsensical assertions in tpm.c..]
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Rajiv Andrade <srajiv@linux.vnet.ibm.com>
Cc: Mimi Zohar <zohar@us.ibm.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

of the form

include/net/inet_sock.h:208: warning: ISO C90 forbids mixed declarations and code

Cc: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/vegard/kmemcheck:
  kmemcheck: add missing braces to do-while in kmemcheck_annotate_bitfield
  kmemcheck: update documentation
  kmemcheck: depend on HAVE_ARCH_KMEMCHECK
  kmemcheck: remove useless check
  kmemcheck: remove duplicated #include

Whether or not the sparse warning

	warning: do-while statement is not a compound statement

is justified or not in this case, it is annoying and trivial to fix.

[vegard.nossum@gmail.com: title and cleanup]
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>

Ingo Molnar reported the following kmemcheck warning when running both
kmemleak and kmemcheck enabled:

  PM: Adding info for No Bus:vcsa7
  WARNING: kmemcheck: Caught 32-bit read from uninitialized memory
  (f6f6e1a4)
  d873f9f600000000c42ae4c1005c87f70000000070665f666978656400000000
   i i i i u u u u i i i i i i i i i i i i i i i i i i i i i u u u
           ^

  Pid: 3091, comm: kmemleak Not tainted (2.6.31-rc7-tip #1303) P4DC6
  EIP: 0060:[<c110301f>] EFLAGS: 00010006 CPU: 0
  EIP is at scan_block+0x3f/0xe0
  EAX: f40bd700 EBX: f40bd780 ECX: f16b46c0 EDX: 00000001
  ESI: f6f6e1a4 EDI: 00000000 EBP: f10f3f4c ESP: c2605fcc
   DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
  CR0: 8005003b CR2: e89a4844 CR3: 30ff1000 CR4: 000006f0
  DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
  DR6: ffff4ff0 DR7: 00000400
   [<c110313c>] scan_object+0x7c/0xf0
   [<c1103389>] kmemleak_scan+0x1d9/0x400
   [<c1103a3c>] kmemleak_scan_thread+0x4c/0xb0
   [<c10819d4>] kthread+0x74/0x80
   [<c10257db>] kernel_thread_helper+0x7/0x3c
   [<ffffffff>] 0xffffffff
  kmemleak: 515 new suspected memory leaks (see
  /sys/kernel/debug/kmemleak)
  kmemleak: 42 new suspected memory leaks (see /sys/kernel/debug/kmemleak)

The problem here is that kmemleak will scan partially initialized
objects that makes kmemcheck complain. Fix that up by skipping
uninitialized memory regions when kmemcheck is enabled.

Reported-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>

Add the bitfield API which can be used to annotate bitfields in structs
and get rid of false positive reports.

According to Al Viro, the syntax we were using (putting #ifdef inside
macro arguments) was not valid C. He also suggested using begin/end
markers instead, which is what we do now.

[rebased for mainline inclusion]
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>

This adds support for tracking the initializedness of memory that
was allocated with the page allocator. Highmem requests are not
tracked.

Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>

[build fix for !CONFIG_KMEMCHECK]
Signed-off-by: Ingo Molnar <mingo@elte.hu>

[rebased for mainline inclusion]
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>

This patch hooks into the DMA API to prevent the reporting of the
false positives that would otherwise be reported when memory is
accessed that is also used directly by devices.

[rebased for mainline inclusion]
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>