diff options
Diffstat (limited to 'arch/powerpc/platforms/pseries/plpks.c')
-rw-r--r-- | arch/powerpc/platforms/pseries/plpks.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/plpks.c b/arch/powerpc/platforms/pseries/plpks.c index 671a10acaebf..cdf09e5bd741 100644 --- a/arch/powerpc/platforms/pseries/plpks.c +++ b/arch/powerpc/platforms/pseries/plpks.c @@ -16,6 +16,9 @@ #include <linux/slab.h> #include <linux/string.h> #include <linux/types.h> +#include <linux/of_fdt.h> +#include <linux/libfdt.h> +#include <linux/memblock.h> #include <asm/hvcall.h> #include <asm/machdep.h> #include <asm/plpks.h> @@ -128,6 +131,12 @@ static int plpks_gen_password(void) u8 *password, consumer = PLPKS_OS_OWNER; int rc; + // If we booted from kexec, we could be reusing an existing password already + if (ospassword) { + pr_debug("Password of length %u already in use\n", ospasswordlength); + return 0; + } + // The password must not cross a page boundary, so we align to the next power of 2 password = kzalloc(roundup_pow_of_two(maxpwsize), GFP_KERNEL); if (!password) @@ -621,6 +630,58 @@ int plpks_read_bootloader_var(struct plpks_var *var) return plpks_read_var(PLPKS_BOOTLOADER_OWNER, var); } +int plpks_populate_fdt(void *fdt) +{ + int chosen_offset = fdt_path_offset(fdt, "/chosen"); + + if (chosen_offset < 0) { + pr_err("Can't find chosen node: %s\n", + fdt_strerror(chosen_offset)); + return chosen_offset; + } + + return fdt_setprop(fdt, chosen_offset, "ibm,plpks-pw", ospassword, ospasswordlength); +} + +// Once a password is registered with the hypervisor it cannot be cleared without +// rebooting the LPAR, so to keep using the PLPKS across kexec boots we need to +// recover the previous password from the FDT. +// +// There are a few challenges here. We don't want the password to be visible to +// users, so we need to clear it from the FDT. This has to be done in early boot. +// Clearing it from the FDT would make the FDT's checksum invalid, so we have to +// manually cause the checksum to be recalculated. +void __init plpks_early_init_devtree(void) +{ + void *fdt = initial_boot_params; + int chosen_node = fdt_path_offset(fdt, "/chosen"); + const u8 *password; + int len; + + if (chosen_node < 0) + return; + + password = fdt_getprop(fdt, chosen_node, "ibm,plpks-pw", &len); + if (len <= 0) { + pr_debug("Couldn't find ibm,plpks-pw node.\n"); + return; + } + + ospassword = memblock_alloc_raw(len, SMP_CACHE_BYTES); + if (!ospassword) { + pr_err("Error allocating memory for password.\n"); + goto out; + } + + memcpy(ospassword, password, len); + ospasswordlength = (u16)len; + +out: + fdt_nop_property(fdt, chosen_node, "ibm,plpks-pw"); + // Since we've cleared the password, we must update the FDT checksum + early_init_dt_verify(fdt); +} + static __init int pseries_plpks_init(void) { int rc; |