seedrng: remove unnecessary zero-filling of local variables

function                                             old     new   delta
seedrng_main                                        1292    1273     -19

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 11 insertions, 8 deletions

diff --git a/util-linux/seedrng.c b/util-linux/seedrng.c
index c762e9ecd..dd082ea90 100644
--- a/util-linux/seedrng.c
+++ b/util-linux/seedrng.c
@@ -54,20 +54,23 @@
 #define CREDITABLE_SEED_NAME "seed.credit"
 #define NON_CREDITABLE_SEED_NAME "seed.no-credit"
 
-enum seedrng_lengths {
+enum {
         MIN_SEED_LEN = SHA256_OUTSIZE,
         MAX_SEED_LEN = 512
 };
 
 static size_t determine_optimal_seed_len(void)
 {
-        char poolsize_str[11] = { 0 };
-        unsigned long poolsize;
+        char poolsize_str[12];
+        unsigned poolsize;
+        int n;
 
-        if (open_read_close("/proc/sys/kernel/random/poolsize", poolsize_str, sizeof(poolsize_str) - 1) < 0) {
+        n = open_read_close("/proc/sys/kernel/random/poolsize", poolsize_str, sizeof(poolsize_str) - 1);
+        if (n < 0) {
                 bb_perror_msg("unable to determine pool size, assuming %u bits", MIN_SEED_LEN * 8);
                 return MIN_SEED_LEN;
         }
+        poolsize_str[n] = '\0';
         poolsize = (bb_strtoul(poolsize_str, NULL, 10) + 7) / 8;
         return MAX(MIN(poolsize, MAX_SEED_LEN), MIN_SEED_LEN);
 }
@@ -159,7 +162,7 @@ static int seed_from_file_if_exists(const char *filename, int dfd, bool credit,
 int seedrng_main(int argc, char *argv[]) MAIN_EXTERNALLY_VISIBLE;
 int seedrng_main(int argc UNUSED_PARAM, char *argv[])
 {
-        const char *seed_dir = DEFAULT_SEED_DIR, *creditable_seed, *non_creditable_seed;
+        const char *seed_dir, *creditable_seed, *non_creditable_seed;
         int fd, dfd, program_ret = 0;
         uint8_t new_seed[MAX_SEED_LEN];
         size_t new_seed_len;
@@ -178,10 +181,8 @@ int seedrng_main(int argc UNUSED_PARAM, char *argv[])
                 ;
 #endif
 
+        seed_dir = DEFAULT_SEED_DIR;
         skip_credit = getopt32long(argv, "d:n", longopts, &seed_dir) & OPT_n;
-        creditable_seed = concat_path_file(seed_dir, CREDITABLE_SEED_NAME);
-        non_creditable_seed = concat_path_file(seed_dir, NON_CREDITABLE_SEED_NAME);
-
         umask(0077);
         if (getuid())
                 bb_simple_error_msg_and_die(bb_msg_you_must_be_root);
@@ -200,6 +201,8 @@ int seedrng_main(int argc UNUSED_PARAM, char *argv[])
         clock_gettime(CLOCK_BOOTTIME, &timestamp);
         sha256_hash(&hash, &timestamp, sizeof(timestamp));
 
+        creditable_seed = concat_path_file(seed_dir, CREDITABLE_SEED_NAME);
+        non_creditable_seed = concat_path_file(seed_dir, NON_CREDITABLE_SEED_NAME);
         for (int i = 1; i < 3; ++i) {
                 if (seed_from_file_if_exists(i == 1 ? non_creditable_seed : creditable_seed,
                                              dfd, i == 1 ? false : !skip_credit, &hash) < 0)