linux-toradex.git/include/linux/compiler-gcc4.h, branch v4.0-rc1

kasan: enable instrumentation of global variables

2015-02-14T05:21:42+00:00

This feature let us to detect accesses out of bounds of global variables.
This will work as for globals in kernel image, so for globals in modules.
Currently this won't work for symbols in user-specified sections (e.g.
__init, __read_mostly, ...)

The idea of this is simple.  Compiler increases each global variable by
redzone size and add constructors invoking __asan_register_globals()
function.  Information about global variable (address, size, size with
redzone ...) passed to __asan_register_globals() so we could poison
variable's redzone.

This patch also forces module_alloc() to return 8*PAGE_SIZE aligned
address making shadow memory handling (
kasan_module_alloc()/kasan_module_free() ) more simple.  Such alignment
guarantees that each shadow page backing modules address space correspond
to only one module_alloc() allocation.

Signed-off-by: Andrey Ryabinin 
Cc: Dmitry Vyukov 
Cc: Konstantin Serebryany 
Cc: Dmitry Chernenkov 
Signed-off-by: Andrey Konovalov 
Cc: Yuri Gribov 
Cc: Konstantin Khlebnikov 
Cc: Sasha Levin 
Cc: Christoph Lameter 
Cc: Joonsoo Kim 
Cc: Dave Hansen 
Cc: Andi Kleen 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: "H. Peter Anvin" 
Cc: Christoph Lameter 
Cc: Pekka Enberg 
Cc: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

compiler/gcc4+: Remove inaccurate comment about 'asm goto' miscompiles

2014-10-28T10:03:40+00:00

The bug referenced by the comment in this commit was not
completely fixed in GCC 4.8.2, as I mentioned in a thread back
in February:

   https://lkml.org/lkml/2014/2/12/797

The conclusion at that time was to make the quirk unconditional
until the bug could be found and fixed in GCC. Unfortunately,
when I submitted the patch (commit a9f18034) I left a comment
in that claimed the bug was fixed in GCC 4.8.2+.

This comment is inaccurate, and should be removed.

Signed-off-by: Steven Noonan 
Signed-off-by: Ingo Molnar 
Cc: Jakub Jelinek 
Cc: Richard Henderson 
Cc: Linus Torvalds 
Cc: Steven Rostedt 
Link: http://lkml.kernel.org/r/1414274982-14040-1-git-send-email-steven@uplinklabs.net
Cc: Ingo Molnar

compiler/gcc4: Make quirk for asm_volatile_goto() unconditional

2014-02-13T11:34:05+00:00

I started noticing problems with KVM guest destruction on Linux
3.12+, where guest memory wasn't being cleaned up. I bisected it
down to the commit introducing the new 'asm goto'-based atomics,
and found this quirk was later applied to those.

Unfortunately, even with GCC 4.8.2 (which ostensibly fixed the
known 'asm goto' bug) I am still getting some kind of
miscompilation. If I enable the asm_volatile_goto quirk for my
compiler, KVM guests are destroyed correctly and the memory is
cleaned up.

So make the quirk unconditional for now, until bug is found
and fixed.

Suggested-by: Linus Torvalds 
Signed-off-by: Steven Noonan 
Cc: Peter Zijlstra 
Cc: Steven Rostedt 
Cc: Jakub Jelinek 
Cc: Richard Henderson 
Cc: Andrew Morton 
Cc: Oleg Nesterov 
Cc: 
Link: http://lkml.kernel.org/r/1392274867-15236-1-git-send-email-steven@uplinklabs.net
Link: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
Signed-off-by: Ingo Molnar

compiler/gcc4: Add quirk for 'asm goto' miscompilation bug

2013-10-11T05:39:14+00:00

Fengguang Wu, Oleg Nesterov and Peter Zijlstra tracked down
a kernel crash to a GCC bug: GCC miscompiles certain 'asm goto'
constructs, as outlined here:

  http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670

Implement a workaround suggested by Jakub Jelinek.

Reported-and-tested-by: Fengguang Wu 
Reported-by: Oleg Nesterov 
Reported-by: Peter Zijlstra 
Suggested-by: Jakub Jelinek 
Reviewed-by: Richard Henderson 
Cc: Linus Torvalds 
Cc: Andrew Morton 
Cc: 
Signed-off-by: Ingo Molnar

gcc4: disable __compiletime_object_size for GCC 4.6+

2013-04-30T01:28:13+00:00

__builtin_object_size is known to be broken on gcc 4.6+.
See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48880 for details.

This causes unnecssary build warnings and errors such as

  In function 'copy_from_user', inlined from 'sb16_copy_from_user'
	at sound/oss/sb_audio.c:878:22:
  arch/x86/include/asm/uaccess_32.h:211:26: error: call to 'copy_from_user_overflow'
	declared with attribute error: copy_from_user() buffer size is not provably correct
  make[3]: [sound/oss/sb_audio.o] Error 1 (ignored)

Disable it where broken.

Signed-off-by: Guenter Roeck 
Cc: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

compiler{,-gcc4}.h, bug.h: Remove duplicate macros

2013-02-22T01:22:15+00:00

__linktime_error() does the same thing as __compiletime_error() and is
only used in bug.h.  Since the macro defines a function attribute that
will cause a failure at compile-time (not link-time), it makes more sense
to keep __compiletime_error(), which is also neatly mated with
__compiletime_warning().

Signed-off-by: Daniel Santos 
Acked-by: David Rientjes 
Acked-by: Borislav Petkov 
Cc: Andi Kleen 
Cc: Joe Perches 
Cc: Josh Triplett 
Cc: Paul Gortmaker 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

compiler-gcc{3,4}.h: Use GCC_VERSION macro

2013-02-22T01:22:15+00:00

Using GCC_VERSION reduces complexity, is easier to read and is GCC's
recommended mechanism for doing version checks.  (Just don't ask me why
they didn't define it in the first place.) This also makes it easy to
merge compiler-gcc{,3,4}.h should somebody want to.

Signed-off-by: Daniel Santos 
Acked-by: David Rientjes 
Acked-by: Borislav Petkov 
Cc: Andi Kleen 
Cc: Joe Perches 
Cc: Josh Triplett 
Cc: Paul Gortmaker 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

compiler-gcc4.h: Reorder macros based upon gcc ver

2013-02-22T01:22:15+00:00

This helps to keep the file from getting confusing, removes one
duplicate version check and should encourage future editors to put new
macros where they belong.

Signed-off-by: Daniel Santos 
Acked-by: David Rientjes 
Acked-by: Borislav Petkov 
Cc: Andi Kleen 
Cc: Joe Perches 
Cc: Josh Triplett 
Cc: Paul Gortmaker 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

2012-12-19T15:55:08+00:00

Pull module update from Rusty Russell:
 "Nothing all that exciting; a new module-from-fd syscall for those who
  want to verify the source of the module (ChromeOS) and/or use standard
  IMA on it or other security hooks."

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  MODSIGN: Fix kbuild output when using default extra_certificates
  MODSIGN: Avoid using .incbin in C source
  modules: don't hand 0 to vmalloc.
  module: Remove a extra null character at the top of module->strtab.
  ASN.1: Use the ASN1_LONG_TAG and ASN1_INDEFINITE_LENGTH constants
  ASN.1: Define indefinite length marker constant
  moduleparam: use __UNIQUE_ID()
  __UNIQUE_ID()
  MODSIGN: Add modules_sign make target
  powerpc: add finit_module syscall.
  ima: support new kernel module syscall
  add finit_module syscall to asm-generic
  ARM: add finit_module syscall to ARM
  security: introduce kernel_module_from_file hook
  module: add flags arg to sys_finit_module()
  module: add syscall to load module from fd

__UNIQUE_ID()

2012-12-14T02:35:30+00:00

Jan Beulich points out __COUNTER__ (gcc 4.3 and above), so let's use
that to create unique ids.  This is better than __LINE__ which we use
today, so provide a wrapper.

Stanislaw Gruszka  reported that some module parameters
start with a digit, so we need to prepend when we for the unique id.

Signed-off-by: Rusty Russell 
Acked-by: Jan Beulich