diff options
| -rw-r--r-- | arch/riscv/kernel/pi/Makefile | 3 | ||||
| -rw-r--r-- | arch/riscv/kernel/pi/archrandom_early.c | 30 | ||||
| -rw-r--r-- | arch/riscv/kernel/pi/fdt_early.c | 160 | ||||
| -rw-r--r-- | arch/riscv/kernel/pi/pi.h | 3 | ||||
| -rw-r--r-- | arch/riscv/mm/init.c | 5 |
5 files changed, 199 insertions, 2 deletions
diff --git a/arch/riscv/kernel/pi/Makefile b/arch/riscv/kernel/pi/Makefile index 1ef7584be0c3..d5bf1bc7de62 100644 --- a/arch/riscv/kernel/pi/Makefile +++ b/arch/riscv/kernel/pi/Makefile @@ -17,6 +17,7 @@ KBUILD_CFLAGS += -mcmodel=medany CFLAGS_cmdline_early.o += -D__NO_FORTIFY CFLAGS_lib-fdt_ro.o += -D__NO_FORTIFY +CFLAGS_fdt_early.o += -D__NO_FORTIFY $(obj)/%.pi.o: OBJCOPYFLAGS := --prefix-symbols=__pi_ \ --remove-section=.note.gnu.property \ @@ -33,5 +34,5 @@ $(obj)/string.o: $(srctree)/lib/string.c FORCE $(obj)/ctype.o: $(srctree)/lib/ctype.c FORCE $(call if_changed_rule,cc_o_c) -obj-y := cmdline_early.pi.o fdt_early.pi.o string.pi.o ctype.pi.o lib-fdt.pi.o lib-fdt_ro.pi.o +obj-y := cmdline_early.pi.o fdt_early.pi.o string.pi.o ctype.pi.o lib-fdt.pi.o lib-fdt_ro.pi.o archrandom_early.pi.o extra-y := $(patsubst %.pi.o,%.o,$(obj-y)) diff --git a/arch/riscv/kernel/pi/archrandom_early.c b/arch/riscv/kernel/pi/archrandom_early.c new file mode 100644 index 000000000000..3f05d3cf3b7b --- /dev/null +++ b/arch/riscv/kernel/pi/archrandom_early.c @@ -0,0 +1,30 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <asm/csr.h> +#include <linux/processor.h> + +#include "pi.h" + +/* + * To avoid rewriting code include asm/archrandom.h and create macros + * for the functions that won't be included. + */ +#undef riscv_has_extension_unlikely +#define riscv_has_extension_likely(...) false +#undef pr_err_once +#define pr_err_once(...) + +#include <asm/archrandom.h> + +u64 get_kaslr_seed_zkr(const uintptr_t dtb_pa) +{ + unsigned long seed = 0; + + if (!fdt_early_match_extension_isa((const void *)dtb_pa, "zkr")) + return 0; + + if (!csr_seed_long(&seed)) + return 0; + + return seed; +} diff --git a/arch/riscv/kernel/pi/fdt_early.c b/arch/riscv/kernel/pi/fdt_early.c index 40ee299702bf..9bdee2fafe47 100644 --- a/arch/riscv/kernel/pi/fdt_early.c +++ b/arch/riscv/kernel/pi/fdt_early.c @@ -2,6 +2,7 @@ #include <linux/types.h> #include <linux/init.h> #include <linux/libfdt.h> +#include <linux/ctype.h> #include "pi.h" @@ -23,3 +24,162 @@ u64 get_kaslr_seed(uintptr_t dtb_pa) *prop = 0; return ret; } + +/** + * fdt_device_is_available - check if a device is available for use + * + * @fdt: pointer to the device tree blob + * @node: offset of the node whose property to find + * + * Returns true if the status property is absent or set to "okay" or "ok", + * false otherwise + */ +static bool fdt_device_is_available(const void *fdt, int node) +{ + const char *status; + int statlen; + + status = fdt_getprop(fdt, node, "status", &statlen); + if (!status) + return true; + + if (statlen > 0) { + if (!strcmp(status, "okay") || !strcmp(status, "ok")) + return true; + } + + return false; +} + +/* Copy of fdt_nodename_eq_ */ +static int fdt_node_name_eq(const void *fdt, int offset, + const char *s) +{ + int olen; + int len = strlen(s); + const char *p = fdt_get_name(fdt, offset, &olen); + + if (!p || olen < len) + /* short match */ + return 0; + + if (memcmp(p, s, len) != 0) + return 0; + + if (p[len] == '\0') + return 1; + else if (!memchr(s, '@', len) && (p[len] == '@')) + return 1; + else + return 0; +} + +/** + * isa_string_contains - check if isa string contains an extension + * + * @isa_str: isa string to search + * @ext_name: the extension to search for + * + * Returns true if the extension is in the given isa string, + * false otherwise + */ +static bool isa_string_contains(const char *isa_str, const char *ext_name) +{ + size_t i, single_end, len = strlen(ext_name); + char ext_end; + + /* Error must contain rv32/64 */ + if (strlen(isa_str) < 4) + return false; + + if (len == 1) { + single_end = strcspn(isa_str, "sSxXzZ"); + /* Search for single chars between rv32/64 and multi-letter extensions */ + for (i = 4; i < single_end; i++) { + if (tolower(isa_str[i]) == ext_name[0]) + return true; + } + return false; + } + + /* Skip to start of multi-letter extensions */ + isa_str = strpbrk(isa_str, "sSxXzZ"); + while (isa_str) { + if (strncasecmp(isa_str, ext_name, len) == 0) { + ext_end = isa_str[len]; + /* Check if matches the whole extension. */ + if (ext_end == '\0' || ext_end == '_') + return true; + } + /* Multi-letter extensions must be split from other multi-letter + * extensions with an "_", the end of a multi-letter extension will + * either be the null character or the "_" at the start of the next + * multi-letter extension. + */ + isa_str = strchr(isa_str, '_'); + if (isa_str) + isa_str++; + } + + return false; +} + +/** + * early_cpu_isa_ext_available - check if cpu node has an extension + * + * @fdt: pointer to the device tree blob + * @node: offset of the cpu node + * @ext_name: the extension to search for + * + * Returns true if the cpu node has the extension, + * false otherwise + */ +static bool early_cpu_isa_ext_available(const void *fdt, int node, const char *ext_name) +{ + const void *prop; + int len; + + prop = fdt_getprop(fdt, node, "riscv,isa-extensions", &len); + if (prop && fdt_stringlist_contains(prop, len, ext_name)) + return true; + + prop = fdt_getprop(fdt, node, "riscv,isa", &len); + if (prop && isa_string_contains(prop, ext_name)) + return true; + + return false; +} + +/** + * fdt_early_match_extension_isa - check if all cpu nodes have an extension + * + * @fdt: pointer to the device tree blob + * @ext_name: the extension to search for + * + * Returns true if the all available the cpu nodes have the extension, + * false otherwise + */ +bool fdt_early_match_extension_isa(const void *fdt, const char *ext_name) +{ + int node, parent; + bool ret = false; + + parent = fdt_path_offset(fdt, "/cpus"); + if (parent < 0) + return false; + + fdt_for_each_subnode(node, fdt, parent) { + if (!fdt_node_name_eq(fdt, node, "cpu")) + continue; + + if (!fdt_device_is_available(fdt, node)) + continue; + + if (!early_cpu_isa_ext_available(fdt, node, ext_name)) + return false; + + ret = true; + } + + return ret; +} diff --git a/arch/riscv/kernel/pi/pi.h b/arch/riscv/kernel/pi/pi.h index 493c8cb7c0e6..21141d84fea6 100644 --- a/arch/riscv/kernel/pi/pi.h +++ b/arch/riscv/kernel/pi/pi.h @@ -11,7 +11,10 @@ */ u64 get_kaslr_seed(uintptr_t dtb_pa); +u64 get_kaslr_seed_zkr(const uintptr_t dtb_pa); bool set_nokaslr_from_cmdline(uintptr_t dtb_pa); u64 set_satp_mode_from_cmdline(uintptr_t dtb_pa); +bool fdt_early_match_extension_isa(const void *fdt, const char *ext_name); + #endif /* _RISCV_PI_H_ */ diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index e3218d65f21d..5551403a85ae 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -1042,6 +1042,7 @@ static void __init pt_ops_set_late(void) #ifdef CONFIG_RANDOMIZE_BASE extern bool __init __pi_set_nokaslr_from_cmdline(uintptr_t dtb_pa); extern u64 __init __pi_get_kaslr_seed(uintptr_t dtb_pa); +extern u64 __init __pi_get_kaslr_seed_zkr(const uintptr_t dtb_pa); static int __init print_nokaslr(char *p) { @@ -1062,10 +1063,12 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) #ifdef CONFIG_RANDOMIZE_BASE if (!__pi_set_nokaslr_from_cmdline(dtb_pa)) { - u64 kaslr_seed = __pi_get_kaslr_seed(dtb_pa); + u64 kaslr_seed = __pi_get_kaslr_seed_zkr(dtb_pa); u32 kernel_size = (uintptr_t)(&_end) - (uintptr_t)(&_start); u32 nr_pos; + if (kaslr_seed == 0) + kaslr_seed = __pi_get_kaslr_seed(dtb_pa); /* * Compute the number of positions available: we are limited * by the early page table that only has one PUD and we must |