From: Dhananjay Phadke <dpha...@linux.microsoft.com> 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 <dpha...@linux.microsoft.com> Signed-off-by: Sean Edmond <senaedm...@microsoft.com> Signed-off-by: Sean Edmond <seanedm...@microsoft.com> --- Changes in v6: - root_ofnode_from_fdt()->ofnode_root_from_fdt() Changes in v5: - include dm/ofnode-decl.h instead of dm/ofnode.h Changes in v3: - Use event spy to do the FDT fixup Changes in v2: - fdt_fixup_kaslr_seed() uses the ofnode API - Add root_ofnode_from_fdt() to get the root node from an FDT and perform error checking on the oftree - add comments to exported functions 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..5f256939277 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 = ofnode_root_from_fdt(fdt, &root); + 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 b15d07765fe..49d14a949be 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", &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 f72ea416cf1..557a4a1b969 100644 --- a/drivers/core/ofnode.c +++ b/drivers/core/ofnode.c @@ -966,6 +966,23 @@ ofnode oftree_path(oftree tree, const char *path) } } +int ofnode_root_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 5795115c490..b3bb133df19 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); +/** + * ofnode_root_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 ofnode_root_from_fdt(void *fdt, ofnode *root_node); + /** * ofnode_read_chosen_prop() - get the value of a chosen property * diff --git a/include/fdt_support.h b/include/fdt_support.h index 2cd83668982..0624650dcee 100644 --- a/include/fdt_support.h +++ b/include/fdt_support.h @@ -11,6 +11,7 @@ !defined(USE_HOSTCC) #include <asm/u-boot.h> +#include <dm/ofnode_decl.h> #include <linux/libfdt.h> #include <abuf.h> @@ -121,6 +122,14 @@ static inline int fdt_fixup_memory_banks(void *blob, u64 start[], u64 size[], #endif void fdt_fixup_ethernet(void *fdt); + +/* + * fdt_fixup_kaslr_seed - Add kaslr-seed node in Device tree + * @node: ofnode + * @eret: 0 for success + */ +int fdt_fixup_kaslr_seed(ofnode node, const u8 *seed, int len); + int fdt_find_and_setprop(void *fdt, const char *node, const char *prop, const void *val, int len, int create); void fdt_fixup_qe_firmware(void *fdt); -- 2.42.0