When the -seed option is given, call qemu_guest_random_seed_main,
putting the subsystem into deterministic mode. Pass derived seeds
to each cpu created during clone; which is a no-op unless the
subsystem is in deterministic mode.
Cc: Laurent Vivier <laur...@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com>
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
v5: Retain srand() until last user goes away.
---
linux-user/main.c | 30 +++++++++++++++++++-----------
linux-user/syscall.c | 3 +++
2 files changed, 22 insertions(+), 11 deletions(-)
diff --git a/linux-user/main.c b/linux-user/main.c
index 3d2230320b..7e704845c0 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -34,6 +34,7 @@
#include "tcg.h"
#include "qemu/timer.h"
#include "qemu/envlist.h"
+#include "qemu/guest-random.h"
#include "elf.h"
#include "trace/control.h"
#include "target_elf.h"
@@ -48,6 +49,7 @@ static int gdbstub_port;
static envlist_t *envlist;
static const char *cpu_model;
static const char *cpu_type;
+static const char *seed_optarg;
unsigned long mmap_min_addr;
unsigned long guest_base;
int have_guest_base;
@@ -290,15 +292,9 @@ static void handle_arg_pagesize(const char *arg)
}
}
-static void handle_arg_randseed(const char *arg)
+static void handle_arg_seed(const char *arg)
{
- unsigned long long seed;
-
- if (parse_uint_full(arg, &seed, 0) != 0 || seed > UINT_MAX) {
- fprintf(stderr, "Invalid seed number: %s\n", arg);
- exit(EXIT_FAILURE);
- }
- srand(seed);
+ seed_optarg = arg;
}
static void handle_arg_gdb(const char *arg)
@@ -433,7 +429,7 @@ static const struct qemu_argument arg_table[] = {
"", "run in singlestep mode"},
{"strace", "QEMU_STRACE", false, handle_arg_strace,
"", "log system calls"},
- {"seed", "QEMU_RAND_SEED", true, handle_arg_randseed,
+ {"seed", "QEMU_RAND_SEED", true, handle_arg_seed,
"", "Seed for pseudo-random number generator"},
{"trace", "QEMU_TRACE", true, handle_arg_trace,
"", "[[enable=]<pattern>][,events=<file>][,file=<file>]"},
@@ -689,8 +685,20 @@ int main(int argc, char **argv, char **envp)
do_strace = 1;
}
- if (getenv("QEMU_RAND_SEED")) {
- handle_arg_randseed(getenv("QEMU_RAND_SEED"));
+ if (seed_optarg == NULL) {
+ seed_optarg = getenv("QEMU_RAND_SEED");
+ }
+ if (seed_optarg != NULL) {
+ unsigned long long seed;
+
+ /* This will go away with the last user of rand(). */
+ if (parse_uint_full(seed_optarg, &seed, 0) != 0) {
+ fprintf(stderr, "Invalid seed number: %s\n", seed_optarg);
+ exit(EXIT_FAILURE);
+ }
+ srand(seed);
+
+ qemu_guest_random_seed_main(seed_optarg, &error_fatal);
}
target_environ = envlist_to_environ(envlist, NULL);
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 96cd4bf86d..ce377b2fc1 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -110,6 +110,7 @@
#include "uname.h"
#include "qemu.h"
+#include "qemu/guest-random.h"
#include "fd-trans.h"
#ifndef CLONE_IO
@@ -5441,6 +5442,7 @@ static void *clone_func(void *arg)
put_user_u32(info->tid, info->child_tidptr);
if (info->parent_tidptr)
put_user_u32(info->tid, info->parent_tidptr);
+ qemu_guest_random_seed_thread_part2(cpu->random_seed);
/* Enable signals. */
sigprocmask(SIG_SETMASK, &info->sigmask, NULL);
/* Signal to the parent that we're ready. */
@@ -5527,6 +5529,7 @@ static int do_fork(CPUArchState *env, unsigned int flags,
abi_ulong newsp,
initializing, so temporarily block all signals. */
sigfillset(&sigmask);
sigprocmask(SIG_BLOCK, &sigmask, &info.sigmask);
+ cpu->random_seed = qemu_guest_random_seed_thread_part1();
/* If this is our first additional thread, we need to ensure we
* generate code for parallel execution and flush old translations.
--
2.17.1
