Re: [PATCH v4 1/5] fdt: common API to populate kaslr seed
Hi Sean,
On Fri, 3 Nov 2023 at 12:39, wrote:
>
> From: Dhananjay Phadke
>
> fdt_fixup_kaslr_seed() will update given ofnode with random seed value.
> Source for random seed can be TPM or RNG driver in u-boot or sec
> firmware (ARM).
>
> Signed-off-by: Dhananjay Phadke
> Signed-off-by: Sean Edmond
> ---
> arch/arm/cpu/armv8/sec_firmware.c | 39 +++
> boot/fdt_support.c| 19 +++
> drivers/core/ofnode.c | 17 ++
> include/dm/ofnode.h | 12 ++
> include/fdt_support.h | 9 +++
> 5 files changed, 71 insertions(+), 25 deletions(-)
>
> diff --git a/arch/arm/cpu/armv8/sec_firmware.c
> b/arch/arm/cpu/armv8/sec_firmware.c
> index c0e8726346f..5f04cd8aecd 100644
> --- a/arch/arm/cpu/armv8/sec_firmware.c
> +++ b/arch/arm/cpu/armv8/sec_firmware.c
> @@ -411,46 +411,35 @@ int sec_firmware_init(const void *sec_firmware_img,
> /*
> * fdt_fix_kaslr - Add kalsr-seed node in Device tree
> * @fdt: Device tree
> - * @eret: 0 in case of error, 1 for success
> + * @eret: 0 for success
> */
> int fdt_fixup_kaslr(void *fdt)
> {
> - int nodeoffset;
> - int err, ret = 0;
> - u8 rand[8];
> + int ret = 0;
>
> #if defined(CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT)
> + u8 rand[8];
> + ofnode root;
> +
> /* Check if random seed generation is supported */
> if (sec_firmware_support_hwrng() == false) {
> printf("WARNING: SEC firmware not running, no kaslr-seed\n");
> - return 0;
> + return -EOPNOTSUPP;
> }
>
> - err = sec_firmware_get_random(rand, 8);
> - if (err < 0) {
> + ret = sec_firmware_get_random(rand, 8);
> + if (ret < 0) {
> printf("WARNING: No random number to set kaslr-seed\n");
> - return 0;
> + return ret;
> }
>
> - err = fdt_check_header(fdt);
> - if (err < 0) {
> - printf("fdt_chosen: %s\n", fdt_strerror(err));
> - return 0;
> + ret = root_ofnode_from_fdt(fdt, );
> + if (ret < 0) {
> + printf("WARNING: Unable to get root ofnode\n");
> + return ret;
> }
>
> - /* find or create "/chosen" node. */
> - nodeoffset = fdt_find_or_add_subnode(fdt, 0, "chosen");
> - if (nodeoffset < 0)
> - return 0;
> -
> - err = fdt_setprop(fdt, nodeoffset, "kaslr-seed", rand,
> - sizeof(rand));
> - if (err < 0) {
> - printf("WARNING: can't set kaslr-seed %s.\n",
> - fdt_strerror(err));
> - return 0;
> - }
> - ret = 1;
> + ret = fdt_fixup_kaslr_seed(root, rand, sizeof(rand));
> #endif
>
> return ret;
> diff --git a/boot/fdt_support.c b/boot/fdt_support.c
> index 5e49078f8c3..52be4375b46 100644
> --- a/boot/fdt_support.c
> +++ b/boot/fdt_support.c
> @@ -631,6 +631,25 @@ void fdt_fixup_ethernet(void *fdt)
> }
> }
>
> +int fdt_fixup_kaslr_seed(ofnode node, const u8 *seed, int len)
> +{
> + ofnode chosen;
> + int ret;
> +
> + /* find or create "/chosen" node. */
> + ret = ofnode_add_subnode(node, "chosen", );
> + if (ret && ret != -EEXIST)
> + return -ENOENT;
> +
> + ret = ofnode_write_prop(chosen, "kaslr-seed", seed, len, true);
> + if (ret) {
> + printf("WARNING: can't set kaslr-seed\n");
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> int fdt_record_loadable(void *blob, u32 index, const char *name,
> uintptr_t load_addr, u32 size, uintptr_t entry_point,
> const char *type, const char *os, const char *arch)
> diff --git a/drivers/core/ofnode.c b/drivers/core/ofnode.c
> index 29a42945102..55291f0202b 100644
> --- a/drivers/core/ofnode.c
> +++ b/drivers/core/ofnode.c
> @@ -966,6 +966,23 @@ ofnode oftree_path(oftree tree, const char *path)
> }
> }
>
> +int root_ofnode_from_fdt(void *fdt, ofnode *root_node)
> +{
> + oftree tree;
> + /* If OFNODE_MULTI_TREE is not set, and if fdt is not the control FDT,
> +* oftree_from_fdt() will return NULL
> +*/
> + tree = oftree_from_fdt(fdt);
> +
> + if (!oftree_valid(tree)) {
> + printf("Cannot create oftree\n");
> + return -EINVAL;
> + }
> + *root_node = oftree_root(tree);
> +
> + return 0;
> +}
> +
> const void *ofnode_read_chosen_prop(const char *propname, int *sizep)
> {
> ofnode chosen_node;
> diff --git a/include/dm/ofnode.h b/include/dm/ofnode.h
> index 19e97a90327..5759cac5b30 100644
> --- a/include/dm/ofnode.h
> +++ b/include/dm/ofnode.h
> @@ -936,6 +936,18 @@ ofnode oftree_path(oftree tree, const char *path);
> */
> ofnode oftree_root(oftree tree);
>
> +/**
> + *
[PATCH v4 1/5] fdt: common API to populate kaslr seed
From: Dhananjay Phadke
fdt_fixup_kaslr_seed() will update given ofnode with random seed value.
Source for random seed can be TPM or RNG driver in u-boot or sec
firmware (ARM).
Signed-off-by: Dhananjay Phadke
Signed-off-by: Sean Edmond
---
arch/arm/cpu/armv8/sec_firmware.c | 39 +++
boot/fdt_support.c| 19 +++
drivers/core/ofnode.c | 17 ++
include/dm/ofnode.h | 12 ++
include/fdt_support.h | 9 +++
5 files changed, 71 insertions(+), 25 deletions(-)
diff --git a/arch/arm/cpu/armv8/sec_firmware.c
b/arch/arm/cpu/armv8/sec_firmware.c
index c0e8726346f..5f04cd8aecd 100644
--- a/arch/arm/cpu/armv8/sec_firmware.c
+++ b/arch/arm/cpu/armv8/sec_firmware.c
@@ -411,46 +411,35 @@ int sec_firmware_init(const void *sec_firmware_img,
/*
* fdt_fix_kaslr - Add kalsr-seed node in Device tree
* @fdt: Device tree
- * @eret: 0 in case of error, 1 for success
+ * @eret: 0 for success
*/
int fdt_fixup_kaslr(void *fdt)
{
- int nodeoffset;
- int err, ret = 0;
- u8 rand[8];
+ int ret = 0;
#if defined(CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT)
+ u8 rand[8];
+ ofnode root;
+
/* Check if random seed generation is supported */
if (sec_firmware_support_hwrng() == false) {
printf("WARNING: SEC firmware not running, no kaslr-seed\n");
- return 0;
+ return -EOPNOTSUPP;
}
- err = sec_firmware_get_random(rand, 8);
- if (err < 0) {
+ ret = sec_firmware_get_random(rand, 8);
+ if (ret < 0) {
printf("WARNING: No random number to set kaslr-seed\n");
- return 0;
+ return ret;
}
- err = fdt_check_header(fdt);
- if (err < 0) {
- printf("fdt_chosen: %s\n", fdt_strerror(err));
- return 0;
+ ret = root_ofnode_from_fdt(fdt, );
+ if (ret < 0) {
+ printf("WARNING: Unable to get root ofnode\n");
+ return ret;
}
- /* find or create "/chosen" node. */
- nodeoffset = fdt_find_or_add_subnode(fdt, 0, "chosen");
- if (nodeoffset < 0)
- return 0;
-
- err = fdt_setprop(fdt, nodeoffset, "kaslr-seed", rand,
- sizeof(rand));
- if (err < 0) {
- printf("WARNING: can't set kaslr-seed %s.\n",
- fdt_strerror(err));
- return 0;
- }
- ret = 1;
+ ret = fdt_fixup_kaslr_seed(root, rand, sizeof(rand));
#endif
return ret;
diff --git a/boot/fdt_support.c b/boot/fdt_support.c
index 5e49078f8c3..52be4375b46 100644
--- a/boot/fdt_support.c
+++ b/boot/fdt_support.c
@@ -631,6 +631,25 @@ void fdt_fixup_ethernet(void *fdt)
}
}
+int fdt_fixup_kaslr_seed(ofnode node, const u8 *seed, int len)
+{
+ ofnode chosen;
+ int ret;
+
+ /* find or create "/chosen" node. */
+ ret = ofnode_add_subnode(node, "chosen", );
+ if (ret && ret != -EEXIST)
+ return -ENOENT;
+
+ ret = ofnode_write_prop(chosen, "kaslr-seed", seed, len, true);
+ if (ret) {
+ printf("WARNING: can't set kaslr-seed\n");
+ return ret;
+ }
+
+ return 0;
+}
+
int fdt_record_loadable(void *blob, u32 index, const char *name,
uintptr_t load_addr, u32 size, uintptr_t entry_point,
const char *type, const char *os, const char *arch)
diff --git a/drivers/core/ofnode.c b/drivers/core/ofnode.c
index 29a42945102..55291f0202b 100644
--- a/drivers/core/ofnode.c
+++ b/drivers/core/ofnode.c
@@ -966,6 +966,23 @@ ofnode oftree_path(oftree tree, const char *path)
}
}
+int root_ofnode_from_fdt(void *fdt, ofnode *root_node)
+{
+ oftree tree;
+ /* If OFNODE_MULTI_TREE is not set, and if fdt is not the control FDT,
+* oftree_from_fdt() will return NULL
+*/
+ tree = oftree_from_fdt(fdt);
+
+ if (!oftree_valid(tree)) {
+ printf("Cannot create oftree\n");
+ return -EINVAL;
+ }
+ *root_node = oftree_root(tree);
+
+ return 0;
+}
+
const void *ofnode_read_chosen_prop(const char *propname, int *sizep)
{
ofnode chosen_node;
diff --git a/include/dm/ofnode.h b/include/dm/ofnode.h
index 19e97a90327..5759cac5b30 100644
--- a/include/dm/ofnode.h
+++ b/include/dm/ofnode.h
@@ -936,6 +936,18 @@ ofnode oftree_path(oftree tree, const char *path);
*/
ofnode oftree_root(oftree tree);
+/**
+ * root_ofnode_from_fdt() - Gets the root ofnode given an FDT blob.
+ * Note, this will fail if OFNODE_MULTI_TREE
+ * is not set.
+ *
+ * @fdt: Device tree to use
+ * @root_node : Root ofnode
+ *
+ * Return: 0 if OK, -ve on error
+ */
+int root_ofnode_from_fdt(void *fdt, ofnode
