)]}'
{
  "commit": "f386c61fe1a1f36f0e434f1b577e6b112698caf7",
  "tree": "40578bc7a067fdb397c1d6dfcc165a433a7c4933",
  "parents": [
    "28df30e61b46a33d1f0bb60757747396886ef687"
  ],
  "author": {
    "name": "Peter Oberparleiter",
    "email": "oberpar@linux.vnet.ibm.com",
    "time": "Sun Jul 05 12:08:06 2009 -0700"
  },
  "committer": {
    "name": "Linus Torvalds",
    "email": "torvalds@linux-foundation.org",
    "time": "Mon Jul 06 13:57:03 2009 -0700"
  },
  "message": "gcov: exclude code operating in userspace from profiling\n\nFix for this issue on x86_64:\n\nrostedt@goodmis.org wrote:\n\u003e On bootup of the latest kernel my init segfaults. Debugging it,\n\u003e I found  that vread_tsc (a vsyscall) increments some strange\n\u003e kernel memory:\n\u003e\n\u003e 0000000000000000 \u003cvread_tsc\u003e:\n\u003e    0:   55                      push   %rbp\n\u003e    1:   48 ff 05 00 00 00 00    incq   0(%rip)\n\u003e                         # 8 \u003cvread_tsc+0x8\u003e\n\u003e                         4: R_X86_64_PC32        .bss+0x3c\n\u003e    8:   48 89 e5                mov    %rsp,%rbp\n\u003e    b:   66 66 90                xchg   %ax,%ax\n\u003e    e:   48 ff 05 00 00 00 00    incq   0(%rip)\n\u003e                         # 15 \u003cvread_tsc+0x15\u003e\n\u003e                         11: R_X86_64_PC32       .bss+0x44\n\u003e   15:   66 66 90                xchg   %ax,%ax\n\u003e   18:   48 ff 05 00 00 00 00    incq   0(%rip)\n\u003e                         # 1f \u003cvread_tsc+0x1f\u003e\n\u003e                         1b: R_X86_64_PC32       .bss+0x4c\n\u003e   1f:   0f 31                   rdtsc\n\u003e\n\u003e\n\u003e Those \"incq\" is very bad to happen in vsyscall memory, since\n\u003e userspace can not modify it. You need to make something prevent\n\u003e profiling of vsyscall  memory (like I do with ftrace).\n\nSigned-off-by: Peter Oberparleiter \u003coberpar@linux.vnet.ibm.com\u003e\nCc: Ingo Molnar \u003cmingo@elte.hu\u003e\nReported-by: Steven Rostedt \u003crostedt@goodmis.org\u003e\nTested-by: Steven Rostedt \u003crostedt@goodmis.org\u003e\nSigned-off-by: Andrew Morton \u003cakpm@linux-foundation.org\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@linux-foundation.org\u003e\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "6c327b852e23b528963dc4f23e59ffa13761463d",
      "old_mode": 33188,
      "old_path": "arch/x86/kernel/Makefile",
      "new_id": "430d5b24af7b210faf695f0c3619a1d66ae8acf5",
      "new_mode": 33188,
      "new_path": "arch/x86/kernel/Makefile"
    }
  ]
}