)]}'
{
  "commit": "8a0a9bd4db63bc45e3017bedeafbd88d0eb84d02",
  "tree": "2c961332be5d4c4e2c8c4a4a4f899afaebc44dd7",
  "parents": [
    "2c66fa7e6be6bdb88587ac13ac1de080d5be4f95"
  ],
  "author": {
    "name": "Linus Torvalds",
    "email": "torvalds@linux-foundation.org",
    "time": "Tue May 05 08:17:43 2009 -0700"
  },
  "committer": {
    "name": "Linus Torvalds",
    "email": "torvalds@linux-foundation.org",
    "time": "Thu May 07 11:59:06 2009 -0700"
  },
  "message": "random: make get_random_int() more random\n\nIt\u0027s a really simple patch that basically just open-codes the current\n\"secure_ip_id()\" call, but when open-coding it we now use a _static_\nhashing area, so that it gets updated every time.\n\nAnd to make sure somebody can\u0027t just start from the same original seed of\nall-zeroes, and then do the \"half_md4_transform()\" over and over until\nthey get the same sequence as the kernel has, each iteration also mixes in\nthe same old \"current-\u003epid + jiffies\" we used - so we should now have a\nregular strong pseudo-number generator, but we also have one that doesn\u0027t\nhave a single seed.\n\nNote: the \"pid + jiffies\" is just meant to be a tiny tiny bit of noise. It\nhas no real meaning. It could be anything. I just picked the previous\nseed, it\u0027s just that now we keep the state in between calls and that will\nfeed into the next result, and that should make all the difference.\n\nI made that hash be a per-cpu data just to avoid cache-line ping-pong:\nhaving multiple CPU\u0027s write to the same data would be fine for randomness,\nand add yet another layer of chaos to it, but since get_random_int() is\nsupposed to be a fast interface I did it that way instead. I considered\nusing \"__raw_get_cpu_var()\" to avoid any preemption overhead while still\ngetting the hash be _mostly_ ping-pong free, but in the end good taste won\nout.\n\nSigned-off-by: Ingo Molnar \u003cmingo@elte.hu\u003e\nSigned-off-by: Linus Torvalds \u003ctorvalds@linux-foundation.org\u003e\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "f824ef8a9273d7d46e63b113fa83ea03249f95e1",
      "old_mode": 33188,
      "old_path": "drivers/char/random.c",
      "new_id": "b2ced39d76b227a064d383f55aeca78ac2bf380a",
      "new_mode": 33188,
      "new_path": "drivers/char/random.c"
    }
  ]
}