)]}'
{
  "commit": "ecd744eec3aa8bbc949ec04ed3fbf7ecb2958a0e",
  "tree": "47c398a2e76b2354977df0d72ed91271ce85acf8",
  "parents": [
    "fd181c72a3c202a3986bcee7551c0838265aec2a"
  ],
  "author": {
    "name": "Chuck Ebbert",
    "email": "76306.1226@compuserve.com",
    "time": "Wed Nov 07 10:48:39 2007 -0500"
  },
  "committer": {
    "name": "Thomas Gleixner",
    "email": "tglx@apollo.(none)",
    "time": "Sat Nov 10 04:30:36 2007 +0100"
  },
  "message": "x86 - 32-bit ptrace emulation mishandles 6th arg\n\n[ jdike - Pushing Chuck\u0027s patch - see\nhttp://lkml.org/lkml/2005/9/16/261 for some history and a test\nprogram.  UML is also broken without this patch - its processes get\nSIGBUS from the corrupt 6th argument to mmap being interpretted as a\nfile offset ]\n\nWhen the 32-bit vDSO is used to make a system call, the %ebp register for\nthe 6th syscall arg has to be loaded from the user stack (where it\u0027s pushed\nby the vDSO user code).  The native i386 kernel always does this before\nstopping for syscall tracing, so %ebp can be seen and modified via ptrace\nto access the 6th syscall argument.  The x86-64 kernel fails to do this,\npresenting the stack address to ptrace instead.  This makes the %rbp value\nseen by 64-bit ptrace of a 32-bit process, and the %ebp value seen by a\n32-bit caller of ptrace, both differ from the native i386 behavior.\n\nThis patch fixes the problem by putting the word loaded from the user stack\ninto %rbp before calling syscall_trace_enter, and reloading the 6th syscall\nargument from there afterwards (so ptrace can change it).  This makes the\nbehavior match that of i386 kernels.\n\nOriginal-Patch-By: Roland McGrath \u003croland@redhat.com\u003e\n\nSigned-off-by: Chuck Ebbert \u003c76306.1226@compuserve.com\u003e\nSigned-off-by: Jeff Dike \u003cjdike@linux.intel.com\u003e\nSigned-off-by: Thomas Gleixner \u003ctglx@linutronix.de\u003e\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "18b23181090808b953f91568d6183345b8028fd1",
      "old_mode": 33188,
      "old_path": "arch/x86/ia32/ia32entry.S",
      "new_id": "df588f0f76e1c9c3d8027a3baced0089de612832",
      "new_mode": 33188,
      "new_path": "arch/x86/ia32/ia32entry.S"
    }
  ]
}