[Bug middle-end/60281] New: Address Sanitizer triggers alignment fault in ARM machines

[Bug middle-end/60281] New: Address Sanitizer triggers alignment fault in ARM machines

[manjian2006 at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60281

            Bug ID: 60281
           Summary: Address Sanitizer triggers alignment fault in ARM
                    machines
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: manjian2006 at gmail dot com

Without aligning the asan stack base,this base will only 64-bit aligned in ARM
machines.
But asan require 256-bit aligned base because of this:
1.right shift take ASAN_SHADOW_SHIFT ,which is 3,bits are zeros
2.store multiple/load multiple instructions require the other 2 bits are zeros

that add up lowest 5 bits should be zeros.That means 32 bytes or 256 bits
aligned.

Here is the test case:

#include <time.h>

int foo()
{
    struct timespec timeNow1 ;
    clock_gettime( 0, &timeNow1);
    return static_cast<double>(timeNow1.tv_sec);
}

compiles command:
arm-linux-androideabi-g++ -march=armv7-a -mthumb   -Os -fsanitize=address  -S
1.cpp
which generates assembly as:
    push    {r4, r5, r6, r7, lr} @ save 5*4 = 20 bytes
    sub    sp, sp, #100         @ save 20 + 100 = 120 bytes 
        ...
    mov    r4, sp
        ...
    lsrs    r5, r4, #3           @ as -120 is 11111111111111111111111110001000
r5 is aligned to 1 bits
        ...
    stmia    r5, {r1, r2, r3}     @  trigger alignment fault

[Bug middle-end/60281] Address Sanitizer triggers alignment fault in ARM machines

[manjian2006 at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60281

--- Comment #1 from linzj <manjian2006 at gmail dot com> ---
I have summit a patch for this bug,and tested in my Nexus 4.It works fine.Check
gcc-patches at gcc dot gnu dot org for that.

[Bug middle-end/60281] Address Sanitizer triggers alignment fault in ARM machines

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60281

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Tue Apr 22 05:55:40 2014
New Revision: 209554

URL: http://gcc.gnu.org/viewcvs?rev=209554&root=gcc&view=rev
Log:
    PR middle-end/60281
    * asan.c (asan_emit_stack_protection): Force the base to align to
    appropriate bits if STRICT_ALIGNMENT.  Set shadow_mem align to
    appropriate bits if STRICT_ALIGNMENT.
    * cfgexpand.c (expand_stack_vars): Set base_align appropriately
    when asan is on.
    (expand_used_vars): Leave a space in the stack frame for alignment
    if STRICT_ALIGNMENT.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/asan.c
    trunk/gcc/cfgexpand.c

[Bug middle-end/60281] Address Sanitizer triggers alignment fault in ARM machines

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60281

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Author: jakub
Date: Tue Apr 22 13:15:24 2014
New Revision: 209625

URL: http://gcc.gnu.org/viewcvs?rev=209625&root=gcc&view=rev
Log:
    PR middle-end/60281
    * asan.c (asan_emit_stack_protection): Force the base to align to
    appropriate bits if STRICT_ALIGNMENT.  Set shadow_mem align to
    appropriate bits if STRICT_ALIGNMENT.
    * cfgexpand.c (expand_stack_vars): Set base_align appropriately
    when asan is on.
    (expand_used_vars): Leave a space in the stack frame for alignment
    if STRICT_ALIGNMENT.

Modified:
    branches/gcc-4_9-branch/gcc/ChangeLog
    branches/gcc-4_9-branch/gcc/asan.c
    branches/gcc-4_9-branch/gcc/cfgexpand.c

[Bug middle-end/60281] Address Sanitizer triggers alignment fault in ARM machines

[ramana at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60281

Ramana Radhakrishnan <ramana at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
                 CC|                            |ramana at gcc dot gnu.org
         Resolution|---                         |FIXED
   Target Milestone|---                         |4.9.1

--- Comment #4 from Ramana Radhakrishnan <ramana at gcc dot gnu.org> ---
>From code generated currently - looks fixed for 4.9.1 since GCC 4.9.0 was
actually released on 22nd April !

[Bug middle-end/60281] Address Sanitizer triggers alignment fault in ARM machines

[manjian2006 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60281

--- Comment #5 from linzj <manjian2006 at gmail dot com> ---
Sorry, but I have to wait for my GNU assignment.
(In reply to Ramana Radhakrishnan from comment #4)
> From code generated currently - looks fixed for 4.9.1 since GCC 4.9.0 was
> actually released on 22nd April !