diff options
| -rw-r--r-- | llvm/lib/Support/Unix/Process.inc | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/llvm/lib/Support/Unix/Process.inc b/llvm/lib/Support/Unix/Process.inc index df13bd22173..27083eeb072 100644 --- a/llvm/lib/Support/Unix/Process.inc +++ b/llvm/lib/Support/Unix/Process.inc @@ -430,13 +430,18 @@ const char *Process::ResetColor() { #if !defined(HAVE_DECL_ARC4RANDOM) || !HAVE_DECL_ARC4RANDOM static unsigned GetRandomNumberSeed() { // Attempt to get the initial seed from /dev/urandom, if possible. - if (FILE *RandomSource = ::fopen("/dev/urandom", "r")) { + int urandomFD = open("/dev/urandom", O_RDONLY); + + if (urandomFD != -1) { unsigned seed; - int count = ::fread((void *)&seed, sizeof(seed), 1, RandomSource); - ::fclose(RandomSource); + // Don't use a buffered read to avoid reading more data + // from /dev/urandom than we need. + int count = read(urandomFD, (void *)&seed, sizeof(seed)); + + close(urandomFD); // Return the seed if the read was successful. - if (count == 1) + if (count == sizeof(seed)) return seed; } |
