Re: [PATCH v7 5/7] cmd: rng: Use a statically allocated array for random bytes

Hi Sughosh,

This is missing the r-b tags from Simon and myself. Once I finish up the review, can you re-send the series with the missing tags?

Thanks /Ilias

On Wed, 20 Jul 2022 at 15:30, Sughosh Ganu sughosh.ganu@linaro.org wrote:

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 sughosh.ganu@linaro.org

Changes since V6: None

cmd/rng.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/cmd/rng.c b/cmd/rng.c index 2ddf27545f..81a23964b8 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(

2.34.1