[Bug middle-end/23221] New: -fstack-protector does not protect tail call functions

["drepper at redhat dot com" <gcc-bugzilla at gcc dot gnu dot org>]

Compiling this little bit of code with -fstack-protector-all

extern int foo (int);
int bar (int a, int b)
{
  return foo (a + b);
}

produces on x86-64 the following object code:

   0:   01 f7                   add    %esi,%edi
   2:   64 48 8b 04 25 28 00    mov    %fs:0x28,%rax
   9:   00 00
   b:   48 89 44 24 f8          mov    %rax,0xfffffffffffffff8(%rsp)
  10:   31 c0                   xor    %eax,%eax
  12:   e9 00 00 00 00          jmpq   17 <bar+0x17>

The canary is set up but not tested.  Before the jump to the next function the
value must be checked.  This also applies to -fstack-protector (with appropriate
input) and to all architectures.

-- 
           Summary: -fstack-protector does not protect tail call functions
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: drepper at redhat dot com
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23221