Merge branch 'for-next/kernel-ptrauth' into for-next/core

* for-next/kernel-ptrauth:
  : Return address signing - in-kernel support
  arm64: Kconfig: verify binutils support for ARM64_PTR_AUTH
  lkdtm: arm64: test kernel pointer authentication
  arm64: compile the kernel with ptrauth return address signing
  kconfig: Add support for 'as-option'
  arm64: suspend: restore the kernel ptrauth keys
  arm64: __show_regs: strip PAC from lr in printk
  arm64: unwind: strip PAC from kernel addresses
  arm64: mask PAC bits of __builtin_return_address
  arm64: initialize ptrauth keys for kernel booting task
  arm64: initialize and switch ptrauth kernel keys
  arm64: enable ptrauth earlier
  arm64: cpufeature: handle conflicts based on capability
  arm64: cpufeature: Move cpu capability helpers inside C file
  arm64: ptrauth: Add bootup/runtime flags for __cpu_setup
  arm64: install user ptrauth keys at kernel exit time
  arm64: rename ptrauth key structures to be user-specific
  arm64: cpufeature: add pointer auth meta-capabilities
  arm64: cpufeature: Fix meta-capability cpufeature check

1 files changed, 71 insertions, 22 deletions

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 38ebad880f5c..9fac745aa7bb 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -116,6 +116,8 @@ cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused)
 
 static void cpu_enable_cnp(struct arm64_cpu_capabilities const *cap);
 
+static bool __system_matches_cap(unsigned int n);
+
 /*
  * NOTE: Any changes to the visibility of features should be kept in
  * sync with the documentation of the CPU feature register ABI.
@@ -1368,10 +1370,18 @@ static void cpu_clear_disr(const struct arm64_cpu_capabilities *__unused)
 #endif /* CONFIG_ARM64_RAS_EXTN */
 
 #ifdef CONFIG_ARM64_PTR_AUTH
-static void cpu_enable_address_auth(struct arm64_cpu_capabilities const *cap)
+static bool has_address_auth(const struct arm64_cpu_capabilities *entry,
+			     int __unused)
+{
+	return __system_matches_cap(ARM64_HAS_ADDRESS_AUTH_ARCH) ||
+	       __system_matches_cap(ARM64_HAS_ADDRESS_AUTH_IMP_DEF);
+}
+
+static bool has_generic_auth(const struct arm64_cpu_capabilities *entry,
+			     int __unused)
 {
-	sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_ENIA | SCTLR_ELx_ENIB |
-				       SCTLR_ELx_ENDA | SCTLR_ELx_ENDB);
+	return __system_matches_cap(ARM64_HAS_GENERIC_AUTH_ARCH) ||
+	       __system_matches_cap(ARM64_HAS_GENERIC_AUTH_IMP_DEF);
 }
 #endif /* CONFIG_ARM64_PTR_AUTH */
 
@@ -1399,6 +1409,25 @@ static bool can_use_gic_priorities(const struct arm64_cpu_capabilities *entry,
 }
 #endif
 
+/* Internal helper functions to match cpu capability type */
+static bool
+cpucap_late_cpu_optional(const struct arm64_cpu_capabilities *cap)
+{
+	return !!(cap->type & ARM64_CPUCAP_OPTIONAL_FOR_LATE_CPU);
+}
+
+static bool
+cpucap_late_cpu_permitted(const struct arm64_cpu_capabilities *cap)
+{
+	return !!(cap->type & ARM64_CPUCAP_PERMITTED_FOR_LATE_CPU);
+}
+
+static bool
+cpucap_panic_on_conflict(const struct arm64_cpu_capabilities *cap)
+{
+	return !!(cap->type & ARM64_CPUCAP_PANIC_ON_CONFLICT);
+}
+
 static const struct arm64_cpu_capabilities arm64_features[] = {
 	{
 		.desc = "GIC system register CPU interface",
@@ -1662,24 +1691,27 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
 	{
 		.desc = "Address authentication (architected algorithm)",
 		.capability = ARM64_HAS_ADDRESS_AUTH_ARCH,
-		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
+		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
 		.sign = FTR_UNSIGNED,
 		.field_pos = ID_AA64ISAR1_APA_SHIFT,
 		.min_field_value = ID_AA64ISAR1_APA_ARCHITECTED,
 		.matches = has_cpuid_feature,
-		.cpu_enable = cpu_enable_address_auth,
 	},
 	{
 		.desc = "Address authentication (IMP DEF algorithm)",
 		.capability = ARM64_HAS_ADDRESS_AUTH_IMP_DEF,
-		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
+		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
 		.sys_reg = SYS_ID_AA64ISAR1_EL1,
 		.sign = FTR_UNSIGNED,
 		.field_pos = ID_AA64ISAR1_API_SHIFT,
 		.min_field_value = ID_AA64ISAR1_API_IMP_DEF,
 		.matches = has_cpuid_feature,
-		.cpu_enable = cpu_enable_address_auth,
+	},
+	{
+		.capability = ARM64_HAS_ADDRESS_AUTH,
+		.type = ARM64_CPUCAP_BOOT_CPU_FEATURE,
+		.matches = has_address_auth,
 	},
 	{
 		.desc = "Generic authentication (architected algorithm)",
@@ -1701,6 +1733,11 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
 		.min_field_value = ID_AA64ISAR1_GPI_IMP_DEF,
 		.matches = has_cpuid_feature,
 	},
+	{
+		.capability = ARM64_HAS_GENERIC_AUTH,
+		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
+		.matches = has_generic_auth,
+	},
 #endif /* CONFIG_ARM64_PTR_AUTH */
 #ifdef CONFIG_ARM64_PSEUDO_NMI
 	{
@@ -2050,10 +2087,8 @@ static void __init enable_cpu_capabilities(u16 scope_mask)
  * Run through the list of capabilities to check for conflicts.
  * If the system has already detected a capability, take necessary
  * action on this CPU.
- *
- * Returns "false" on conflicts.
  */
-static bool verify_local_cpu_caps(u16 scope_mask)
+static void verify_local_cpu_caps(u16 scope_mask)
 {
 	int i;
 	bool cpu_has_cap, system_has_cap;
@@ -2098,10 +2133,12 @@ static bool verify_local_cpu_caps(u16 scope_mask)
 		pr_crit("CPU%d: Detected conflict for capability %d (%s), System: %d, CPU: %d\n",
 			smp_processor_id(), caps->capability,
 			caps->desc, system_has_cap, cpu_has_cap);
-		return false;
-	}
 
-	return true;
+		if (cpucap_panic_on_conflict(caps))
+			cpu_panic_kernel();
+		else
+			cpu_die_early();
+	}
 }
 
 /*
@@ -2111,12 +2148,8 @@ static bool verify_local_cpu_caps(u16 scope_mask)
 static void check_early_cpu_features(void)
 {
 	verify_cpu_asid_bits();
-	/*
-	 * Early features are used by the kernel already. If there
-	 * is a conflict, we cannot proceed further.
-	 */
-	if (!verify_local_cpu_caps(SCOPE_BOOT_CPU))
-		cpu_panic_kernel();
+
+	verify_local_cpu_caps(SCOPE_BOOT_CPU);
 }
 
 static void
@@ -2164,8 +2197,7 @@ static void verify_local_cpu_capabilities(void)
 	 * check_early_cpu_features(), as they need to be verified
 	 * on all secondary CPUs.
 	 */
-	if (!verify_local_cpu_caps(SCOPE_ALL & ~SCOPE_BOOT_CPU))
-		cpu_die_early();
+	verify_local_cpu_caps(SCOPE_ALL & ~SCOPE_BOOT_CPU);
 
 	verify_local_elf_hwcaps(arm64_elf_hwcaps);
 
@@ -2216,6 +2248,23 @@ bool this_cpu_has_cap(unsigned int n)
 	return false;
 }
 
+/*
+ * This helper function is used in a narrow window when,
+ * - The system wide safe registers are set with all the SMP CPUs and,
+ * - The SYSTEM_FEATURE cpu_hwcaps may not have been set.
+ * In all other cases cpus_have_{const_}cap() should be used.
+ */
+static bool __system_matches_cap(unsigned int n)
+{
+	if (n < ARM64_NCAPS) {
+		const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[n];
+
+		if (cap)
+			return cap->matches(cap, SCOPE_SYSTEM);
+	}
+	return false;
+}
+
 void cpu_set_feature(unsigned int num)
 {
 	WARN_ON(num >= MAX_CPU_FEATURES);
@@ -2288,7 +2337,7 @@ void __init setup_cpu_features(void)
 static bool __maybe_unused
 cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused)
 {
-	return (cpus_have_const_cap(ARM64_HAS_PAN) && !cpus_have_const_cap(ARM64_HAS_UAO));
+	return (__system_matches_cap(ARM64_HAS_PAN) && !__system_matches_cap(ARM64_HAS_UAO));
 }
 
 static void __maybe_unused cpu_enable_cnp(struct arm64_cpu_capabilities const *cap)