Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Will Deacon:

 - Fix kexec and hibernation when using 5-level page-table configuration

 - Remove references to non-existent SF8MM4 and SF8MM8 ID register
   fields, hooking up hwcaps for the FPRCVT, F8MM4 and F8MM8 fields
   instead

 - Drop unused .ARM.attributes ELF sections

 - Fix array indexing when probing CPU cache topology from firmware

 - Fix potential use-after-free in AMU initialisation code

 - Work around broken GTDT entries by tolerating excessively large timer
   arrays

 - Force use of Rust's "softfloat" target to avoid a threatening warning
   about the NEON target feature

 - Typo fix in GCS documentation and removal of duplicate Kconfig select

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: rust: clean Rust 1.85.0 warning using softfloat target
  arm64: Add missing registrations of hwcaps
  ACPI: GTDT: Relax sanity checking on Platform Timers array count
  arm64: amu: Delay allocating cpumask for AMU FIE support
  arm64: cacheinfo: Avoid out-of-bounds write to cacheinfo array
  arm64: Handle .ARM.attributes section in linker scripts
  arm64/hwcap: Remove stray references to SF8MMx
  arm64/gcs: Fix documentation for HWCAP
  arm64: Kconfig: Remove selecting replaced HAVE_FUNCTION_GRAPH_RETVAL
  arm64: Fix 5-level paging support in kexec/hibernate trampoline

Author: torvalds

Documentation/arch/arm64/gcs.rst

@@ -37,7 +37,7 @@ intended to be exhaustive.
   shadow stacks rather than GCS.
 
 * Support for GCS is reported to userspace via HWCAP_GCS in the aux vector
-  AT_HWCAP2 entry.
+  AT_HWCAP entry.
 
 * GCS is enabled per thread.  While there is support for disabling GCS
   at runtime this should be done with great care.

arch/arm64/Kconfig

@@ -225,7 +225,6 @@ config ARM64
 	select HAVE_FUNCTION_ERROR_INJECTION
 	select HAVE_FUNCTION_GRAPH_FREGS
 	select HAVE_FUNCTION_GRAPH_TRACER
-	select HAVE_FUNCTION_GRAPH_RETVAL
 	select HAVE_GCC_PLUGINS
 	select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && \
 		HW_PERF_EVENTS && HAVE_PERF_EVENTS_NMI

arch/arm64/Makefile

@@ -48,7 +48,11 @@ KBUILD_CFLAGS	+= $(CC_FLAGS_NO_FPU) \
 KBUILD_CFLAGS	+= $(call cc-disable-warning, psabi)
 KBUILD_AFLAGS	+= $(compat_vdso)
 
+ifeq ($(call test-ge, $(CONFIG_RUSTC_VERSION), 108500),y)
+KBUILD_RUSTFLAGS += --target=aarch64-unknown-none-softfloat
+else
 KBUILD_RUSTFLAGS += --target=aarch64-unknown-none -Ctarget-feature="-neon"
+endif
 
 KBUILD_CFLAGS	+= $(call cc-option,-mabi=lp64)
 KBUILD_AFLAGS	+= $(call cc-option,-mabi=lp64)

arch/arm64/kernel/cacheinfo.c

@@ -101,16 +101,18 @@ int populate_cache_leaves(unsigned int cpu)
 	unsigned int level, idx;
 	enum cache_type type;
 	struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
-	struct cacheinfo *this_leaf = this_cpu_ci->info_list;
+	struct cacheinfo *infos = this_cpu_ci->info_list;
 
 	for (idx = 0, level = 1; level <= this_cpu_ci->num_levels &&
-	     idx < this_cpu_ci->num_leaves; idx++, level++) {
+	     idx < this_cpu_ci->num_leaves; level++) {
 		type = get_cache_type(level);
 		if (type == CACHE_TYPE_SEPARATE) {
-			ci_leaf_init(this_leaf++, CACHE_TYPE_DATA, level);
-			ci_leaf_init(this_leaf++, CACHE_TYPE_INST, level);
+			if (idx + 1 >= this_cpu_ci->num_leaves)
+				break;
+			ci_leaf_init(&infos[idx++], CACHE_TYPE_DATA, level);
+			ci_leaf_init(&infos[idx++], CACHE_TYPE_INST, level);
 		} else {
-			ci_leaf_init(this_leaf++, type, level);
+			ci_leaf_init(&infos[idx++], type, level);
 		}
 	}
 	return 0;

arch/arm64/kernel/cpufeature.c

@@ -3091,6 +3091,7 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
 	HWCAP_CAP(ID_AA64ISAR0_EL1, TS, FLAGM, CAP_HWCAP, KERNEL_HWCAP_FLAGM),
 	HWCAP_CAP(ID_AA64ISAR0_EL1, TS, FLAGM2, CAP_HWCAP, KERNEL_HWCAP_FLAGM2),
 	HWCAP_CAP(ID_AA64ISAR0_EL1, RNDR, IMP, CAP_HWCAP, KERNEL_HWCAP_RNG),
+	HWCAP_CAP(ID_AA64ISAR3_EL1, FPRCVT, IMP, CAP_HWCAP, KERNEL_HWCAP_FPRCVT),
 	HWCAP_CAP(ID_AA64PFR0_EL1, FP, IMP, CAP_HWCAP, KERNEL_HWCAP_FP),
 	HWCAP_CAP(ID_AA64PFR0_EL1, FP, FP16, CAP_HWCAP, KERNEL_HWCAP_FPHP),
 	HWCAP_CAP(ID_AA64PFR0_EL1, AdvSIMD, IMP, CAP_HWCAP, KERNEL_HWCAP_ASIMD),
@@ -3180,8 +3181,6 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
 	HWCAP_CAP(ID_AA64SMFR0_EL1, SF8FMA, IMP, CAP_HWCAP, KERNEL_HWCAP_SME_SF8FMA),
 	HWCAP_CAP(ID_AA64SMFR0_EL1, SF8DP4, IMP, CAP_HWCAP, KERNEL_HWCAP_SME_SF8DP4),
 	HWCAP_CAP(ID_AA64SMFR0_EL1, SF8DP2, IMP, CAP_HWCAP, KERNEL_HWCAP_SME_SF8DP2),
-	HWCAP_CAP(ID_AA64SMFR0_EL1, SF8MM8, IMP, CAP_HWCAP, KERNEL_HWCAP_SME_SF8MM8),
-	HWCAP_CAP(ID_AA64SMFR0_EL1, SF8MM4, IMP, CAP_HWCAP, KERNEL_HWCAP_SME_SF8MM4),
 	HWCAP_CAP(ID_AA64SMFR0_EL1, SBitPerm, IMP, CAP_HWCAP, KERNEL_HWCAP_SME_SBITPERM),
 	HWCAP_CAP(ID_AA64SMFR0_EL1, AES, IMP, CAP_HWCAP, KERNEL_HWCAP_SME_AES),
 	HWCAP_CAP(ID_AA64SMFR0_EL1, SFEXPA, IMP, CAP_HWCAP, KERNEL_HWCAP_SME_SFEXPA),
@@ -3192,6 +3191,8 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
 	HWCAP_CAP(ID_AA64FPFR0_EL1, F8FMA, IMP, CAP_HWCAP, KERNEL_HWCAP_F8FMA),
 	HWCAP_CAP(ID_AA64FPFR0_EL1, F8DP4, IMP, CAP_HWCAP, KERNEL_HWCAP_F8DP4),
 	HWCAP_CAP(ID_AA64FPFR0_EL1, F8DP2, IMP, CAP_HWCAP, KERNEL_HWCAP_F8DP2),
+	HWCAP_CAP(ID_AA64FPFR0_EL1, F8MM8, IMP, CAP_HWCAP, KERNEL_HWCAP_F8MM8),
+	HWCAP_CAP(ID_AA64FPFR0_EL1, F8MM4, IMP, CAP_HWCAP, KERNEL_HWCAP_F8MM4),
 	HWCAP_CAP(ID_AA64FPFR0_EL1, F8E4M3, IMP, CAP_HWCAP, KERNEL_HWCAP_F8E4M3),
 	HWCAP_CAP(ID_AA64FPFR0_EL1, F8E5M2, IMP, CAP_HWCAP, KERNEL_HWCAP_F8E5M2),
 #ifdef CONFIG_ARM64_POE

arch/arm64/kernel/topology.c

@@ -194,12 +194,19 @@ static void amu_fie_setup(const struct cpumask *cpus)
 	int cpu;
 
 	/* We are already set since the last insmod of cpufreq driver */
-	if (unlikely(cpumask_subset(cpus, amu_fie_cpus)))
+	if (cpumask_available(amu_fie_cpus) &&
+	    unlikely(cpumask_subset(cpus, amu_fie_cpus)))
 		return;
 
-	for_each_cpu(cpu, cpus) {
+	for_each_cpu(cpu, cpus)
 		if (!freq_counters_valid(cpu))
 			return;
+
+	if (!cpumask_available(amu_fie_cpus) &&
+	    !zalloc_cpumask_var(&amu_fie_cpus, GFP_KERNEL)) {
+		WARN_ONCE(1, "Failed to allocate FIE cpumask for CPUs[%*pbl]\n",
+			  cpumask_pr_args(cpus));
+		return;
 	}
 
 	cpumask_or(amu_fie_cpus, amu_fie_cpus, cpus);
@@ -237,17 +244,8 @@ static struct notifier_block init_amu_fie_notifier = {
 
 static int __init init_amu_fie(void)
 {
-	int ret;
-
-	if (!zalloc_cpumask_var(&amu_fie_cpus, GFP_KERNEL))
-		return -ENOMEM;
-
-	ret = cpufreq_register_notifier(&init_amu_fie_notifier,
+	return cpufreq_register_notifier(&init_amu_fie_notifier,
 					CPUFREQ_POLICY_NOTIFIER);
-	if (ret)
-		free_cpumask_var(amu_fie_cpus);
-
-	return ret;
 }
 core_initcall(init_amu_fie);
 

arch/arm64/kernel/vdso/vdso.lds.S

@@ -41,6 +41,7 @@ SECTIONS
 	 */
 	/DISCARD/	: {
 		*(.note.GNU-stack .note.gnu.property)
+		*(.ARM.attributes)
 	}
 	.note		: { *(.note.*) }		:text	:note
 

arch/arm64/kernel/vmlinux.lds.S

@@ -162,6 +162,7 @@ SECTIONS
 	/DISCARD/ : {
 		*(.interp .dynamic)
 		*(.dynsym .dynstr .hash .gnu.hash)
+		*(.ARM.attributes)
 	}
 
 	. = KIMAGE_VADDR;

arch/arm64/mm/trans_pgd.c

@@ -162,6 +162,13 @@ static int copy_p4d(struct trans_pgd_info *info, pgd_t *dst_pgdp,
 	unsigned long next;
 	unsigned long addr = start;
 
+	if (pgd_none(READ_ONCE(*dst_pgdp))) {
+		dst_p4dp = trans_alloc(info);
+		if (!dst_p4dp)
+			return -ENOMEM;
+		pgd_populate(NULL, dst_pgdp, dst_p4dp);
+	}
+
 	dst_p4dp = p4d_offset(dst_pgdp, start);
 	src_p4dp = p4d_offset(src_pgdp, start);
 	do {

drivers/acpi/arm64/gtdt.c

@@ -163,7 +163,7 @@ int __init acpi_gtdt_init(struct acpi_table_header *table,
 {
 	void *platform_timer;
 	struct acpi_table_gtdt *gtdt;
-	int cnt = 0;
+	u32 cnt = 0;
 
 	gtdt = container_of(table, struct acpi_table_gtdt, header);
 	acpi_gtdt_desc.gtdt = gtdt;
@@ -188,13 +188,17 @@ int __init acpi_gtdt_init(struct acpi_table_header *table,
 		cnt++;
 
 	if (cnt != gtdt->platform_timer_count) {
+		cnt = min(cnt, gtdt->platform_timer_count);
+		pr_err(FW_BUG "limiting Platform Timer count to %d\n", cnt);
+	}
+
+	if (!cnt) {
 		acpi_gtdt_desc.platform_timer = NULL;
-		pr_err(FW_BUG "invalid timer data.\n");
-		return -EINVAL;
+		return 0;
 	}
 
 	if (platform_timer_count)
-		*platform_timer_count = gtdt->platform_timer_count;
+		*platform_timer_count = cnt;
 
 	return 0;
 }