[prev in list] [next in list] [prev in thread] [next in thread] 

List:       busybox-cvs
Subject:    [git commit] seedrng: code shrink
From:       Denys Vlasenko <vda.linux () googlemail ! com>
Date:       2022-04-30 13:38:44
Message-ID: 20220430133023.88C0784338 () busybox ! osuosl ! org
[Download RAW message or body]

commit: https://git.busybox.net/busybox/commit/?id=2cbfd01c150420199a9cb74f5de72d7279e6cd11
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master

Struct initializers do this double init:
># util-linux/seedrng.c:88:              struct pollfd random_fd = {
        movl    $0, 132(%esp)   #, random_fd
        movl    $0, 136(%esp)   #, random_fd
...
># util-linux/seedrng.c:88:              struct pollfd random_fd = {
        movl    %eax, 140(%esp) # _110, random_fd.fd
        movw    $1, 144(%esp)   #, random_fd.events

and close(random_fd.fd) needs to pull the item from the stack:
        pushl   132(%esp)       # random_fd.fd
        call    close   #

function                                             old     new   delta
seedrng_main                                        1076    1050     -26

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
---
 util-linux/seedrng.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/util-linux/seedrng.c b/util-linux/seedrng.c
index 5559ba77c..023ed8688 100644
--- a/util-linux/seedrng.c
+++ b/util-linux/seedrng.c
@@ -85,14 +85,14 @@ static bool read_new_seed(uint8_t *seed, size_t len)
 		return true;
 	}
 	if (ret < 0 && errno == ENOSYS) {
-		struct pollfd random_fd = {
-			.fd = xopen("/dev/random", O_RDONLY),
-			.events = POLLIN
-		};
+		int fd = xopen("/dev/random", O_RDONLY);
+		struct pollfd random_fd;
+		random_fd.fd = fd;
+		random_fd.events = POLLIN;
 		is_creditable = poll(&random_fd, 1, 0) == 1;
 //This is racy. is_creditable can be set to true here, but other process
 //can consume "good" random data from /dev/urandom before we do it below.
-		close(random_fd.fd);
+		close(fd);
 	} else {
 		if (getrandom(seed, len, GRND_INSECURE) == (ssize_t)len)
 			return false;
_______________________________________________
busybox-cvs mailing list
busybox-cvs@busybox.net
http://lists.busybox.net/mailman/listinfo/busybox-cvs
[prev in list] [next in list] [prev in thread] [next in thread]