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author | Zhang Ning <zhangn1985@qq.com> | 2022-02-01 08:33:37 +0800 |
---|---|---|
committer | Tom Rini <trini@konsulko.com> | 2022-02-11 09:00:47 -0500 |
commit | 0290146943af203c1a9e332e19ec76b414b0a771 (patch) | |
tree | 6375c4b40ec89df2c7039309955825ba788fec8d /boot | |
parent | 86752b2814091bd8df30bdbf38768924b60cccab (diff) | |
download | u-boot-0290146943af203c1a9e332e19ec76b414b0a771.zip u-boot-0290146943af203c1a9e332e19ec76b414b0a771.tar.gz u-boot-0290146943af203c1a9e332e19ec76b414b0a771.tar.bz2 |
cmd: pxe_utils: sysboot: add kaslr-seed generation support
this will add kaslrseed keyword to sysboot lable,
when it set, it will request to genarate random number
from hwrng as kaslr-seed.
with this patch exlinux.conf label looks like
label l0
menu testing
linux /boot/vmlinuz-5.15.16-arm
initrd /boot/initramfs-5.15.16-arm.img
fdtdir /boot/dtbs/5.15.16-arm/
kaslrseed
append root=UUID=92ae1e50-eeeb-4c5b-8939-7e1cd6cfb059 ro
Tested on Khadas VIM with kernel 5.16.0-rc5-arm64, Debian 11.
Signed-off-by: Zhang Ning <zhangn1985@qq.com>
Diffstat (limited to 'boot')
-rw-r--r-- | boot/pxe_utils.c | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/boot/pxe_utils.c b/boot/pxe_utils.c index bb231b1..0c24bec 100644 --- a/boot/pxe_utils.c +++ b/boot/pxe_utils.c @@ -20,6 +20,11 @@ #include <errno.h> #include <linux/list.h> +#ifdef CONFIG_DM_RNG +#include <dm.h> +#include <rng.h> +#endif + #include <splash.h> #include <asm/io.h> @@ -311,6 +316,67 @@ static int label_localboot(struct pxe_label *label) return run_command_list(localcmd, strlen(localcmd), 0); } +/* + * label_boot_kaslrseed generate kaslrseed from hw rng + */ + +static void label_boot_kaslrseed(void) +{ +#ifdef CONFIG_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 */ + fdt_addr = hextoul(env_get("fdt_addr_r"), NULL); + working_fdt = map_sysmem(fdt_addr, 0); + err = fdt_check_header(working_fdt); + if (err) + return; + + /* add extra size for holding kaslr-seed */ + /* err is new fdt size, 0 or negtive */ + err = fdt_shrink_to_minimum(working_fdt, 512); + 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); +#endif + return; +} + /** * label_boot_fdtoverlay() - Loads fdt overlays specified in 'fdtoverlays' * @@ -631,6 +697,9 @@ static int label_boot(struct pxe_context *ctx, struct pxe_label *label) } } + if (label->kaslrseed) + label_boot_kaslrseed(); + #ifdef CONFIG_OF_LIBFDT_OVERLAY if (label->fdtoverlays) label_boot_fdtoverlay(ctx, label); @@ -710,6 +779,7 @@ enum token_type { T_ONTIMEOUT, T_IPAPPEND, T_BACKGROUND, + T_KASLRSEED, T_INVALID }; @@ -741,6 +811,7 @@ static const struct token keywords[] = { {"ontimeout", T_ONTIMEOUT,}, {"ipappend", T_IPAPPEND,}, {"background", T_BACKGROUND,}, + {"kaslrseed", T_KASLRSEED,}, {NULL, T_INVALID} }; @@ -1194,6 +1265,10 @@ static int parse_label(char **c, struct pxe_menu *cfg) err = parse_integer(c, &label->ipappend); break; + case T_KASLRSEED: + label->kaslrseed = 1; + break; + case T_EOL: break; |