Disabling KASLR from the command line is implemented as a feature
override. Repaint it slightly so that it can further be used as
more generic infrastructure for SW override purposes.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20230609162200.2024064-4-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
#define MAX_CPU_FEATURES 128
#define cpu_feature(x) KERNEL_HWCAP_ ## x
+#define ARM64_SW_FEATURE_OVERRIDE_NOKASLR 0
+
#ifndef __ASSEMBLY__
#include <linux/bug.h>
extern struct arm64_ftr_override id_aa64isar1_override;
extern struct arm64_ftr_override id_aa64isar2_override;
+extern struct arm64_ftr_override arm64_sw_feature_override;
+
u32 get_kvm_ipa_limit(void);
void dump_cpu_features(void);
struct arm64_ftr_override __ro_after_init id_aa64isar1_override;
struct arm64_ftr_override __ro_after_init id_aa64isar2_override;
+struct arm64_ftr_override arm64_sw_feature_override;
+
static const struct __ftr_reg_entry {
u32 sys_id;
struct arm64_ftr_reg *reg;
},
};
-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
+static const struct ftr_set_desc sw_features __initconst = {
+ .name = "arm64_sw",
+ .override = &arm64_sw_feature_override,
.fields = {
- FIELD("disabled", 0, NULL),
+ FIELD("nokaslr", ARM64_SW_FEATURE_OVERRIDE_NOKASLR, NULL),
{}
},
};
&isar1,
&isar2,
&smfr0,
- &kaslr,
+ &sw_features,
};
static const struct {
"id_aa64isar1.api=0 id_aa64isar1.apa=0 "
"id_aa64isar2.gpa3=0 id_aa64isar2.apa3=0" },
{ "arm64.nomte", "id_aa64pfr1.mte=0" },
- { "nokaslr", "kaslr.disabled=1" },
+ { "nokaslr", "arm64_sw.nokaslr=1" },
};
static int __init parse_nokaslr(char *unused)
u64 __ro_after_init module_alloc_base;
u16 __initdata memstart_offset_seed;
-struct arm64_ftr_override kaslr_feature_override __initdata;
-
static int __init kaslr_init(void)
{
u64 module_range;
*/
module_alloc_base = (u64)_etext - MODULES_VSIZE;
- if (kaslr_feature_override.val & kaslr_feature_override.mask & 0xf) {
+ if (cpuid_feature_extract_unsigned_field(arm64_sw_feature_override.val &
+ arm64_sw_feature_override.mask,
+ ARM64_SW_FEATURE_OVERRIDE_NOKASLR)) {
pr_info("KASLR disabled on command line\n");
return 0;
}