From 58cdc09af08e065c85b2f8834ee9848c010f5afe Mon Sep 17 00:00:00 2001

From: Yu Watanabe <watanabe.yu+github@gmail.com>

Date: Mon, 16 Dec 2019 19:47:48 +0900

Subject: [PATCH] random-util: call initialize_srand() after fork()

(cherry picked from commit a0f11d1d11a546f791855ec9c47c2ff830e6a5aa)

Related: #2005008

---

 src/basic/random-util.c | 14 +++++++++++++-

 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/basic/random-util.c b/src/basic/random-util.c

index 91481559db..801f6ad131 100644

--- a/src/basic/random-util.c

+++ b/src/basic/random-util.c

@@ -4,6 +4,7 @@

 #include <errno.h>

 #include <fcntl.h>

 #include <linux/random.h>

+#include <pthread.h>

 #include <stdbool.h>

 #include <stdint.h>

 #include <stdlib.h>

@@ -26,6 +27,8 @@

 #include "random-util.h"

 #include "time-util.h"

+static bool srand_called = false;

+

 int acquire_random_bytes(void *p, size_t n, bool high_quality_required) {

         static int have_syscall = -1;

@@ -81,8 +84,12 @@ int acquire_random_bytes(void *p, size_t n, bool high_quality_required) {

         return loop_read_exact(fd, (uint8_t*) p + already_done, n - already_done, true);

 }

+static void clear_srand_initialization(void) {

+        srand_called = false;

+}

+

 void initialize_srand(void) {

-        static bool srand_called = false;

+        static bool pthread_atfork_registered = false;

         unsigned x;

 #if HAVE_SYS_AUXV_H

         void *auxv;

@@ -109,6 +116,11 @@ void initialize_srand(void) {

         srand(x);

         srand_called = true;

+

+        if (!pthread_atfork_registered) {

+                (void) pthread_atfork(NULL, NULL, clear_srand_initialization);

+                pthread_atfork_registered = true;

+        }

 }

 /* INT_MAX gives us only 31 bits, so use 24 out of that. */