mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
219 lines
4.4 KiB
219 lines
4.4 KiB
// SPDX-License-Identifier: GPL-2.0 |
|
/* |
|
* Early cpufeature override framework |
|
* |
|
* Copyright (C) 2020 Google LLC |
|
* Author: Marc Zyngier <[email protected]> |
|
*/ |
|
|
|
#include <linux/ctype.h> |
|
#include <linux/kernel.h> |
|
#include <linux/libfdt.h> |
|
|
|
#include <asm/cacheflush.h> |
|
#include <asm/cpufeature.h> |
|
#include <asm/setup.h> |
|
|
|
#define FTR_DESC_NAME_LEN 20 |
|
#define FTR_DESC_FIELD_LEN 10 |
|
#define FTR_ALIAS_NAME_LEN 30 |
|
#define FTR_ALIAS_OPTION_LEN 80 |
|
|
|
struct ftr_set_desc { |
|
char name[FTR_DESC_NAME_LEN]; |
|
struct arm64_ftr_override *override; |
|
struct { |
|
char name[FTR_DESC_FIELD_LEN]; |
|
u8 shift; |
|
} fields[]; |
|
}; |
|
|
|
static const struct ftr_set_desc mmfr1 __initconst = { |
|
.name = "id_aa64mmfr1", |
|
.override = &id_aa64mmfr1_override, |
|
.fields = { |
|
{ "vh", ID_AA64MMFR1_VHE_SHIFT }, |
|
{} |
|
}, |
|
}; |
|
|
|
static const struct ftr_set_desc pfr1 __initconst = { |
|
.name = "id_aa64pfr1", |
|
.override = &id_aa64pfr1_override, |
|
.fields = { |
|
{ "bt", ID_AA64PFR1_BT_SHIFT }, |
|
{} |
|
}, |
|
}; |
|
|
|
static const struct ftr_set_desc isar1 __initconst = { |
|
.name = "id_aa64isar1", |
|
.override = &id_aa64isar1_override, |
|
.fields = { |
|
{ "gpi", ID_AA64ISAR1_GPI_SHIFT }, |
|
{ "gpa", ID_AA64ISAR1_GPA_SHIFT }, |
|
{ "api", ID_AA64ISAR1_API_SHIFT }, |
|
{ "apa", ID_AA64ISAR1_APA_SHIFT }, |
|
{} |
|
}, |
|
}; |
|
|
|
extern struct arm64_ftr_override kaslr_feature_override; |
|
|
|
static const struct ftr_set_desc kaslr __initconst = { |
|
.name = "kaslr", |
|
#ifdef CONFIG_RANDOMIZE_BASE |
|
.override = &kaslr_feature_override, |
|
#endif |
|
.fields = { |
|
{ "disabled", 0 }, |
|
{} |
|
}, |
|
}; |
|
|
|
static const struct ftr_set_desc * const regs[] __initconst = { |
|
&mmfr1, |
|
&pfr1, |
|
&isar1, |
|
&kaslr, |
|
}; |
|
|
|
static const struct { |
|
char alias[FTR_ALIAS_NAME_LEN]; |
|
char feature[FTR_ALIAS_OPTION_LEN]; |
|
} aliases[] __initconst = { |
|
{ "kvm-arm.mode=nvhe", "id_aa64mmfr1.vh=0" }, |
|
{ "kvm-arm.mode=protected", "id_aa64mmfr1.vh=0" }, |
|
{ "arm64.nobti", "id_aa64pfr1.bt=0" }, |
|
{ "arm64.nopauth", |
|
"id_aa64isar1.gpi=0 id_aa64isar1.gpa=0 " |
|
"id_aa64isar1.api=0 id_aa64isar1.apa=0" }, |
|
{ "nokaslr", "kaslr.disabled=1" }, |
|
}; |
|
|
|
static int __init find_field(const char *cmdline, |
|
const struct ftr_set_desc *reg, int f, u64 *v) |
|
{ |
|
char opt[FTR_DESC_NAME_LEN + FTR_DESC_FIELD_LEN + 2]; |
|
int len; |
|
|
|
len = snprintf(opt, ARRAY_SIZE(opt), "%s.%s=", |
|
reg->name, reg->fields[f].name); |
|
|
|
if (!parameqn(cmdline, opt, len)) |
|
return -1; |
|
|
|
return kstrtou64(cmdline + len, 0, v); |
|
} |
|
|
|
static void __init match_options(const char *cmdline) |
|
{ |
|
int i; |
|
|
|
for (i = 0; i < ARRAY_SIZE(regs); i++) { |
|
int f; |
|
|
|
if (!regs[i]->override) |
|
continue; |
|
|
|
for (f = 0; strlen(regs[i]->fields[f].name); f++) { |
|
u64 shift = regs[i]->fields[f].shift; |
|
u64 mask = 0xfUL << shift; |
|
u64 v; |
|
|
|
if (find_field(cmdline, regs[i], f, &v)) |
|
continue; |
|
|
|
regs[i]->override->val &= ~mask; |
|
regs[i]->override->val |= (v << shift) & mask; |
|
regs[i]->override->mask |= mask; |
|
|
|
return; |
|
} |
|
} |
|
} |
|
|
|
static __init void __parse_cmdline(const char *cmdline, bool parse_aliases) |
|
{ |
|
do { |
|
char buf[256]; |
|
size_t len; |
|
int i; |
|
|
|
cmdline = skip_spaces(cmdline); |
|
|
|
for (len = 0; cmdline[len] && !isspace(cmdline[len]); len++); |
|
if (!len) |
|
return; |
|
|
|
len = min(len, ARRAY_SIZE(buf) - 1); |
|
strncpy(buf, cmdline, len); |
|
buf[len] = 0; |
|
|
|
if (strcmp(buf, "--") == 0) |
|
return; |
|
|
|
cmdline += len; |
|
|
|
match_options(buf); |
|
|
|
for (i = 0; parse_aliases && i < ARRAY_SIZE(aliases); i++) |
|
if (parameq(buf, aliases[i].alias)) |
|
__parse_cmdline(aliases[i].feature, false); |
|
} while (1); |
|
} |
|
|
|
static __init const u8 *get_bootargs_cmdline(void) |
|
{ |
|
const u8 *prop; |
|
void *fdt; |
|
int node; |
|
|
|
fdt = get_early_fdt_ptr(); |
|
if (!fdt) |
|
return NULL; |
|
|
|
node = fdt_path_offset(fdt, "/chosen"); |
|
if (node < 0) |
|
return NULL; |
|
|
|
prop = fdt_getprop(fdt, node, "bootargs", NULL); |
|
if (!prop) |
|
return NULL; |
|
|
|
return strlen(prop) ? prop : NULL; |
|
} |
|
|
|
static __init void parse_cmdline(void) |
|
{ |
|
const u8 *prop = get_bootargs_cmdline(); |
|
|
|
if (IS_ENABLED(CONFIG_CMDLINE_FORCE) || !prop) |
|
__parse_cmdline(CONFIG_CMDLINE, true); |
|
|
|
if (!IS_ENABLED(CONFIG_CMDLINE_FORCE) && prop) |
|
__parse_cmdline(prop, true); |
|
} |
|
|
|
/* Keep checkers quiet */ |
|
void init_feature_override(void); |
|
|
|
asmlinkage void __init init_feature_override(void) |
|
{ |
|
int i; |
|
|
|
for (i = 0; i < ARRAY_SIZE(regs); i++) { |
|
if (regs[i]->override) { |
|
regs[i]->override->val = 0; |
|
regs[i]->override->mask = 0; |
|
} |
|
} |
|
|
|
parse_cmdline(); |
|
|
|
for (i = 0; i < ARRAY_SIZE(regs); i++) { |
|
if (regs[i]->override) |
|
__flush_dcache_area(regs[i]->override, |
|
sizeof(*regs[i]->override)); |
|
} |
|
}
|
|
|