[Bug middle-end/36043] gcc reads 8 bytes for a struct of size 6 which leads to sigsegv

[Bug middle-end/36043] gcc reads 8 bytes for a struct of size 6 which leads to sigsegv

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36043

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Target|x86_64-unknown-linux-gnu    |x86_64-unknown-linux-gnu,
                   |                            |i?86-*-*
          Component|target                      |middle-end
      Known to fail|                            |2.95.2

--- Comment #16 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-03-28 11:57:36 UTC ---
Also broken at least since GCC 2.95 on i?86 with

struct colour
{
  unsigned char red;
  unsigned char green;
  unsigned char blue;
};

void print_colour(struct colour col) __attribute__((regparm(3)));

void
foo(struct colour *c)
{
  print_colour(*c);
}

[Bug middle-end/36043] gcc reads 8 bytes for a struct of size 6 which leads to sigsegv

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36043

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Blocks|                            |37954

--- Comment #17 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-03-28 11:58:50 UTC ---
PR37954 looks like a dup for arm.

[Bug middle-end/36043] gcc reads 8 bytes for a struct of size 6 which leads to sigsegv

[bergner at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36043

Peter Bergner <bergner at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |vries at gcc dot gnu.org

--- Comment #18 from Peter Bergner <bergner at gcc dot gnu.org> 2012-02-02 15:07:34 UTC ---
*** Bug 50499 has been marked as a duplicate of this bug. ***

[Bug middle-end/36043] gcc reads 8 bytes for a struct of size 6 which leads to sigsegv

[bergner at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36043

Peter Bergner <bergner at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bergner at gcc dot gnu.org

--- Comment #19 from Peter Bergner <bergner at gcc dot gnu.org> 2012-02-02 15:46:09 UTC ---
>From PR50499, we have this similar test case that fails on powerpc64-linux:

struct S50 { char i[9]; };
extern void bar (struct S50);
void
foo (struct S50 *p)
{
  bar (*p);
}

Gives (using -m64 -O1):

        ...
    ld 3,0(3)
    ld 4,8(9)
    bl bar

[Bug middle-end/36043] gcc reads 8 bytes for a struct of size 6 which leads to sigsegv

[david at fries dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36043

David Fries <david at fries dot net> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |david at fries dot net

--- Comment #20 from David Fries <david at fries dot net> ---
I just ran into this and verified that it exists in gcc svn trunk
gcc (GCC) 4.9.0 20140221 (experimental)

[Bug middle-end/36043] gcc reads 8 bytes for a struct of size 6 which leads to sigsegv

[support@zzz-deskmobile.desk-mail.com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36043

--- Comment #21 from support@zzz-deskmobile.desk-mail.com ---
__________________________________
Type your response ABOVE THIS LINE to reply

------------------------------------------------------------------------------------------------------------
Customer: tromey at gcc dot gnu.org
Subject: [Bug middle-end/36043] gcc reads 8 bytes for a struct of size 6 which
leads to sigsegv
------------------------------------------------------------------------------------------------------------

Jamie Forrest | FEB 23, 2014 | 12:02AM UTC



------------------------------------------------------------------------------------------------------------

tromey | FEB 22, 2014 | 09:10PM UTC  | Original message 

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36043

David Fries <david at fries dot net> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |david at fries dot net

--- Comment #20 from David Fries <david at fries dot net> ---
I just ran into this and verified that it exists in gcc svn trunk
gcc (GCC) 4.9.0 20140221 (experimental)


------------------------------------------------------------------------------------------------------------
This message was sent to gcc-bugzilla@gcc.gnu.org in reference to Case #: 4164.
------------------------------------------------------------------------------------------------------------




[[0958b287b2c175eb67793a138c0536bfc6a0b07d-206330137]]

[Bug middle-end/36043] gcc reads 8 bytes for a struct of size 6 which leads to sigsegv

[arthur.j.odwyer at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36043

Arthur O'Dwyer <arthur.j.odwyer at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |arthur.j.odwyer at gmail dot com

--- Comment #22 from Arthur O'Dwyer <arthur.j.odwyer at gmail dot com> ---
Here's another segfaulting test case, for x86-64. This fails with GCC 4.6.2 and
GCC 4.8.1.
This GCC bug is really hard to work around, since it can strike anywhere
without warning. Is it possible that one of the patches above (e.g., Richard
Biener's comment #9) could be adopted into 4.8.x or 4.9.x?


#include <cstdio>
#include <stdint.h>
#include <sys/mman.h>

struct int24_t { uint8_t m_Internal[3]; };

void foo(int24_t a) { puts("2"); }

int main() {
    const int OS_PAGE_SIZE = 0x1000;
    const int COUNT = (OS_PAGE_SIZE) / sizeof(int24_t);
    printf("sizeof int24_t = %d\n", (int)sizeof(int24_t));

    void* arena1 = mmap(0, OS_PAGE_SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE |
MAP_ANONYMOUS, -1, 0);
    int24_t* ptr = (int24_t*)mmap(0, OS_PAGE_SIZE, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
    munmap(arena1, OS_PAGE_SIZE);

    puts("1");
    foo(ptr[COUNT-1]);
    puts("3");
}

[Bug middle-end/36043] gcc reads 8 bytes for a struct of size 6 which leads to sigsegv

[amodra at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=36043

Alan Modra <amodra at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
                 CC|                            |amodra at gmail dot com
           Assignee|unassigned at gcc dot gnu.org      |amodra at gmail dot com

[Bug middle-end/36043] gcc reads 8 bytes for a struct of size 6 which leads to sigsegv

[amodra at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=36043

--- Comment #24 from Alan Modra <amodra at gcc dot gnu.org> ---
Author: amodra
Date: Wed Apr 15 07:29:01 2015
New Revision: 222115

URL: https://gcc.gnu.org/viewcvs?rev=222115&root=gcc&view=rev
Log:
    PR target/65408
    PR target/58744
    PR middle-end/36043
    * calls.c (load_register_parameters): Don't load past end of
    mem unless suitably aligned.


Added:
    trunk/gcc/testsuite/gcc.dg/pr65408.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/calls.c
    trunk/gcc/testsuite/ChangeLog

[Bug middle-end/36043] gcc reads 8 bytes for a struct of size 6 which leads to sigsegv

[amodra at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=36043

--- Comment #25 from Alan Modra <amodra at gcc dot gnu.org> ---
Author: amodra
Date: Thu Apr 30 11:11:34 2015
New Revision: 222616

URL: https://gcc.gnu.org/viewcvs?rev=222616&root=gcc&view=rev
Log:
gcc/
        PR target/65408
        PR target/58744
        PR middle-end/36043
        * calls.c (load_register_parameters): Don't load past end of
        mem unless suitably aligned.
gcc/testsuite/
        * gcc.dg/pr65408.c: New.


Added:
    branches/gcc-5-branch/gcc/testsuite/gcc.dg/pr65408.c
Modified:
    branches/gcc-5-branch/gcc/ChangeLog
    branches/gcc-5-branch/gcc/calls.c
    branches/gcc-5-branch/gcc/testsuite/ChangeLog

[Bug middle-end/36043] gcc reads 8 bytes for a struct of size 6 which leads to sigsegv

[amodra at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=36043

Alan Modra <amodra at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED
   Target Milestone|---                         |5.2

--- Comment #26 from Alan Modra <amodra at gmail dot com> ---
Fixed for 5.2

[Bug middle-end/36043] gcc reads 8 bytes for a struct of size 6 which leads to sigsegv

[john.dallman at siemens dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=36043

--- Comment #27 from John Dallman <john.dallman at siemens dot com> ---
Thanks!