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-rw-r--r--contrib/llvm/lib/Support/Unix/Process.inc13
1 files changed, 9 insertions, 4 deletions
diff --git a/contrib/llvm/lib/Support/Unix/Process.inc b/contrib/llvm/lib/Support/Unix/Process.inc
index df13bd2..27083ee 100644
--- a/contrib/llvm/lib/Support/Unix/Process.inc
+++ b/contrib/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;
}
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