From c79e274c7c6637eeaf631988b18dd68a30596778 Mon Sep 17 00:00:00 2001 From: Sughosh Ganu Date: Fri, 22 Jul 2022 21:32:07 +0530 Subject: [PATCH] cmd: rng: Use a statically allocated array for random bytes Use a statically allocated buffer on stack instead of using malloc for reading the random bytes. Using a local array is faster than allocating heap memory on every initiation of the command. Signed-off-by: Sughosh Ganu Reviewed-by: Ilias Apalodimas Reviewed-by: Simon Glass Signed-off-by: Ilias Apalodimas --- cmd/rng.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) diff --git a/cmd/rng.c b/cmd/rng.c index 2ddf275..81a2396 100644 --- a/cmd/rng.c +++ b/cmd/rng.c @@ -14,9 +14,9 @@ static int do_rng(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]) { size_t n; - struct udevice *dev; - void *buf; + u8 buf[64]; int devnum; + struct udevice *dev; int ret = CMD_RET_SUCCESS; switch (argc) { @@ -41,11 +41,10 @@ static int do_rng(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]) return CMD_RET_FAILURE; } - buf = malloc(n); - if (!buf) { - printf("Out of memory\n"); - return CMD_RET_FAILURE; - } + if (!n) + return 0; + + n = min(n, sizeof(buf)); if (dm_rng_read(dev, buf, n)) { printf("Reading RNG failed\n"); @@ -54,15 +53,13 @@ static int do_rng(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]) print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, buf, n); } - free(buf); - return ret; } #ifdef CONFIG_SYS_LONGHELP static char rng_help_text[] = "[dev [n]]\n" - " - print n random bytes read from dev\n"; + " - print n random bytes(max 64) read from dev\n"; #endif U_BOOT_CMD( -- 2.7.4