use fdt_kaslrseed function to de-duplicate code

Use the fdt_kaslrseed function to deduplicate code doing the same thing.

Note that the kalsrseed command (CMD_KASLRSEED) is likely pointless now
but left in place in case boot scripts exist that rely on this command
existing and returning success. An informational message is printed to
alert users of this command that it is likely no longer needed.

Note that the Kernel's EFI STUB only relies on EFI_RNG_PROTOCOL for
randomization and completely ignores the kaslr-seed for its own
randomness needs (i.e the randomization of the physical placement of
the kernel). It gets weeded out from the DTB that gets handed over via
efi_install_fdt() as it would also mess up the measured boot DTB TPM
measurements as well.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Cc: Michal Simek <michal.simek@amd.com>
Cc: Andy Yan <andy.yan@rock-chips.com>
Cc: Akash Gajjar <gajjar04akash@gmail.com>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Simon Glass <sjg@chromium.org>
Cc: Patrick Delaunay <patrick.delaunay@foss.st.com>
Cc: Patrice Chotard <patrice.chotard@foss.st.com>
Cc: Devarsh Thakkar <devarsht@ti.com>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Tom Rini <trini@konsulko.com>
Cc: Chris Morgan <macromorgan@hotmail.com>
Acked-by: Michal Simek <michal.simek@amd.com>

1 files changed, 1 insertions, 33 deletions

diff --git a/boot/pxe_utils.c b/boot/pxe_utils.c
index 5c1c962..38ca9b8 100644
--- a/boot/pxe_utils.c
+++ b/boot/pxe_utils.c
@@ -324,10 +324,6 @@ static void label_boot_kaslrseed(void)
 #if CONFIG_IS_ENABLED(DM_RNG)
 	ulong fdt_addr;
 	struct fdt_header *working_fdt;
-	size_t n = 0x8;
-	struct udevice *dev;
-	u64 *buf;
-	int nodeoffset;
 	int err;
 
 	/* Get the main fdt and map it */
@@ -343,35 +339,7 @@ static void label_boot_kaslrseed(void)
 	if (err <= 0)
 		return;
 
-	if (uclass_get_device(UCLASS_RNG, 0, &dev) || !dev) {
-		printf("No RNG device\n");
-		return;
-	}
-
-	nodeoffset = fdt_find_or_add_subnode(working_fdt, 0, "chosen");
-	if (nodeoffset < 0) {
-		printf("Reading chosen node failed\n");
-		return;
-	}
-
-	buf = malloc(n);
-	if (!buf) {
-		printf("Out of memory\n");
-		return;
-	}
-
-	if (dm_rng_read(dev, buf, n)) {
-		printf("Reading RNG failed\n");
-		goto err;
-	}
-
-	err = fdt_setprop(working_fdt, nodeoffset, "kaslr-seed", buf, sizeof(buf));
-	if (err < 0) {
-		printf("Unable to set kaslr-seed on chosen node: %s\n", fdt_strerror(err));
-		goto err;
-	}
-err:
-	free(buf);
+	fdt_kaslrseed(working_fdt, true);
 #endif
 	return;
 }