Re: [PATCH v7 5/7] cmd: rng: Use a statically allocated array for random bytes
hi Ilias,
On Thu, 21 Jul 2022 at 13:36, Ilias Apalodimas
wrote:
>
> 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?
Sure, will add the r-b tags in the next version. Thanks.
-sughosh
>
> Thanks
> /Ilias
>
> On Wed, 20 Jul 2022 at 15:30, Sughosh Ganu 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
> > ---
> > 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
> >
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 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
> ---
> 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
>
[PATCH v7 5/7] 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
---
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
