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

Pull arm64 fixes from Will Deacon:

 - Preserve old 'tt_core' UAPI for Hisilicon L3C PMU driver

 - Ensure linear alias of kprobes instruction page is not writable

 - Fix kernel stack unwinding from BPF

 - Fix build warnings from the Fujitsu uncore PMU documentation

 - Fix hang with deferred 'struct page' initialisation and MTE

 - Consolidate KPTI page-table re-writing code

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: mte: Do not flag the zero page as PG_mte_tagged
  docs: perf: Fujitsu: Fix htmldocs build warnings and errors
  arm64: mm: Move KPTI helpers to mmu.c
  tracing: Fix the bug where bpf_get_stackid returns -EFAULT on the ARM64
  arm64: kprobes: call set_memory_rox() for kprobe page
  drivers/perf: hisi: Add tt_core_deprecated for compatibility

Author: torvalds

Documentation/admin-guide/perf/fujitsu_uncore_pmu.rst

@@ -15,15 +15,19 @@ The driver provides a description of its available events and configuration
 options in sysfs, see /sys/bus/event_sources/devices/mac_iod<iod>_mac<mac>_ch<ch>/
 and /sys/bus/event_sources/devices/pci_iod<iod>_pci<pci>/.
 This driver exports:
+
 - formats, used by perf user space and other tools to configure events
 - events, used by perf user space and other tools to create events
-  symbolically, e.g.:
+  symbolically, e.g.::
+
     perf stat -a -e mac_iod0_mac0_ch0/event=0x21/ ls
     perf stat -a -e pci_iod0_pci0/event=0x24/ ls
+
 - cpumask, used by perf user space and other tools to know on which CPUs
   to open the events
 
 This driver supports the following events for MAC:
+
 - cycles
   This event counts MAC cycles at MAC frequency.
 - read-count
@@ -77,6 +81,7 @@ Examples for use with perf::
   perf stat -e mac_iod0_mac0_ch0/ea-mac/ ls
 
 And, this driver supports the following events for PCI:
+
 - pci-port0-cycles
   This event counts PCI cycles at PCI frequency in port0.
 - pci-port0-read-count

Documentation/admin-guide/perf/hisi-pmu.rst

@@ -66,6 +66,10 @@ specified as a bitmap::
 
 This will only count the operations from core/thread 0 and 1 in this cluster.
 
+User should not use tt_core_deprecated to specify the core/thread filtering.
+This option is provided for backward compatiblility and only support 8bit
+which may not cover all the core/thread sharing L3C.
+
 2. Tracetag allow the user to chose to count only read, write or atomic
 operations via the tt_req parameeter in perf. The default value counts all
 operations. tt_req is 3bits, 3'b100 represents read operations, 3'b101

arch/arm64/include/asm/ftrace.h

@@ -153,6 +153,7 @@ ftrace_partial_regs(const struct ftrace_regs *fregs, struct pt_regs *regs)
 	regs->pc = afregs->pc;
 	regs->regs[29] = afregs->fp;
 	regs->regs[30] = afregs->lr;
+	regs->pstate = PSR_MODE_EL1h;
 	return regs;
 }
 

arch/arm64/include/asm/mmu.h

@@ -79,7 +79,6 @@ extern void create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys,
 extern void *fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot);
 extern void mark_linear_text_alias_ro(void);
 extern int split_kernel_leaf_mapping(unsigned long start, unsigned long end);
-extern void init_idmap_kpti_bbml2_flag(void);
 extern void linear_map_maybe_split_to_ptes(void);
 
 /*
@@ -107,5 +106,11 @@ static inline bool kaslr_requires_kpti(void)
 	return true;
 }
 
+#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
+void kpti_install_ng_mappings(void);
+#else
+static inline void kpti_install_ng_mappings(void) {}
+#endif
+
 #endif	/* !__ASSEMBLY__ */
 #endif

arch/arm64/kernel/cpufeature.c

@@ -1941,104 +1941,6 @@ static bool has_pmuv3(const struct arm64_cpu_capabilities *entry, int scope)
 }
 #endif
 
-#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
-#define KPTI_NG_TEMP_VA		(-(1UL << PMD_SHIFT))
-
-extern
-void create_kpti_ng_temp_pgd(pgd_t *pgdir, phys_addr_t phys, unsigned long virt,
-			     phys_addr_t size, pgprot_t prot,
-			     phys_addr_t (*pgtable_alloc)(enum pgtable_type), int flags);
-
-static phys_addr_t __initdata kpti_ng_temp_alloc;
-
-static phys_addr_t __init kpti_ng_pgd_alloc(enum pgtable_type type)
-{
-	kpti_ng_temp_alloc -= PAGE_SIZE;
-	return kpti_ng_temp_alloc;
-}
-
-static int __init __kpti_install_ng_mappings(void *__unused)
-{
-	typedef void (kpti_remap_fn)(int, int, phys_addr_t, unsigned long);
-	extern kpti_remap_fn idmap_kpti_install_ng_mappings;
-	kpti_remap_fn *remap_fn;
-
-	int cpu = smp_processor_id();
-	int levels = CONFIG_PGTABLE_LEVELS;
-	int order = order_base_2(levels);
-	u64 kpti_ng_temp_pgd_pa = 0;
-	pgd_t *kpti_ng_temp_pgd;
-	u64 alloc = 0;
-
-	if (levels == 5 && !pgtable_l5_enabled())
-		levels = 4;
-	else if (levels == 4 && !pgtable_l4_enabled())
-		levels = 3;
-
-	remap_fn = (void *)__pa_symbol(idmap_kpti_install_ng_mappings);
-
-	if (!cpu) {
-		alloc = __get_free_pages(GFP_ATOMIC | __GFP_ZERO, order);
-		kpti_ng_temp_pgd = (pgd_t *)(alloc + (levels - 1) * PAGE_SIZE);
-		kpti_ng_temp_alloc = kpti_ng_temp_pgd_pa = __pa(kpti_ng_temp_pgd);
-
-		//
-		// Create a minimal page table hierarchy that permits us to map
-		// the swapper page tables temporarily as we traverse them.
-		//
-		// The physical pages are laid out as follows:
-		//
-		// +--------+-/-------+-/------ +-/------ +-\\\--------+
-		// :  PTE[] : | PMD[] : | PUD[] : | P4D[] : ||| PGD[]  :
-		// +--------+-\-------+-\------ +-\------ +-///--------+
-		//      ^
-		// The first page is mapped into this hierarchy at a PMD_SHIFT
-		// aligned virtual address, so that we can manipulate the PTE
-		// level entries while the mapping is active. The first entry
-		// covers the PTE[] page itself, the remaining entries are free
-		// to be used as a ad-hoc fixmap.
-		//
-		create_kpti_ng_temp_pgd(kpti_ng_temp_pgd, __pa(alloc),
-					KPTI_NG_TEMP_VA, PAGE_SIZE, PAGE_KERNEL,
-					kpti_ng_pgd_alloc, 0);
-	}
-
-	cpu_install_idmap();
-	remap_fn(cpu, num_online_cpus(), kpti_ng_temp_pgd_pa, KPTI_NG_TEMP_VA);
-	cpu_uninstall_idmap();
-
-	if (!cpu) {
-		free_pages(alloc, order);
-		arm64_use_ng_mappings = true;
-	}
-
-	return 0;
-}
-
-static void __init kpti_install_ng_mappings(void)
-{
-	/* Check whether KPTI is going to be used */
-	if (!arm64_kernel_unmapped_at_el0())
-		return;
-
-	/*
-	 * We don't need to rewrite the page-tables if either we've done
-	 * it already or we have KASLR enabled and therefore have not
-	 * created any global mappings at all.
-	 */
-	if (arm64_use_ng_mappings)
-		return;
-
-	init_idmap_kpti_bbml2_flag();
-	stop_machine(__kpti_install_ng_mappings, NULL, cpu_online_mask);
-}
-
-#else
-static inline void kpti_install_ng_mappings(void)
-{
-}
-#endif	/* CONFIG_UNMAP_KERNEL_AT_EL0 */
-
 static void cpu_enable_kpti(struct arm64_cpu_capabilities const *cap)
 {
 	if (__this_cpu_read(this_cpu_vector) == vectors) {
@@ -2419,17 +2321,21 @@ static void bti_enable(const struct arm64_cpu_capabilities *__unused)
 #ifdef CONFIG_ARM64_MTE
 static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap)
 {
+	static bool cleared_zero_page = false;
+
 	sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_ATA | SCTLR_EL1_ATA0);
 
 	mte_cpu_setup();
 
 	/*
 	 * Clear the tags in the zero page. This needs to be done via the
-	 * linear map which has the Tagged attribute.
+	 * linear map which has the Tagged attribute. Since this page is
+	 * always mapped as pte_special(), set_pte_at() will not attempt to
+	 * clear the tags or set PG_mte_tagged.
 	 */
-	if (try_page_mte_tagging(ZERO_PAGE(0))) {
+	if (!cleared_zero_page) {
+		cleared_zero_page = true;
 		mte_clear_page_tags(lm_alias(empty_zero_page));
-		set_page_mte_tagged(ZERO_PAGE(0));
 	}
 
 	kasan_init_hw_tags_cpu();

arch/arm64/kernel/mte.c

@@ -478,7 +478,7 @@ static int __access_remote_tags(struct mm_struct *mm, unsigned long addr,
 		if (folio_test_hugetlb(folio))
 			WARN_ON_ONCE(!folio_test_hugetlb_mte_tagged(folio));
 		else
-			WARN_ON_ONCE(!page_mte_tagged(page));
+			WARN_ON_ONCE(!page_mte_tagged(page) && !is_zero_page(page));
 
 		/* limit access to the end of the page */
 		offset = offset_in_page(addr);

arch/arm64/kernel/probes/kprobes.c

@@ -10,6 +10,7 @@
 
 #define pr_fmt(fmt) "kprobes: " fmt
 
+#include <linux/execmem.h>
 #include <linux/extable.h>
 #include <linux/kasan.h>
 #include <linux/kernel.h>
@@ -41,6 +42,17 @@ DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
 static void __kprobes
 post_kprobe_handler(struct kprobe *, struct kprobe_ctlblk *, struct pt_regs *);
 
+void *alloc_insn_page(void)
+{
+	void *addr;
+
+	addr = execmem_alloc(EXECMEM_KPROBES, PAGE_SIZE);
+	if (!addr)
+		return NULL;
+	set_memory_rox((unsigned long)addr, 1);
+	return addr;
+}
+
 static void __kprobes arch_prepare_ss_slot(struct kprobe *p)
 {
 	kprobe_opcode_t *addr = p->ainsn.xol_insn;

arch/arm64/mm/mmu.c

@@ -470,14 +470,6 @@ static void __create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys,
 	mutex_unlock(&fixmap_lock);
 }
 
-#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
-extern __alias(__create_pgd_mapping_locked)
-void create_kpti_ng_temp_pgd(pgd_t *pgdir, phys_addr_t phys, unsigned long virt,
-			     phys_addr_t size, pgprot_t prot,
-			     phys_addr_t (*pgtable_alloc)(enum pgtable_type),
-			     int flags);
-#endif
-
 #define INVALID_PHYS_ADDR	(-1ULL)
 
 static phys_addr_t __pgd_pgtable_alloc(struct mm_struct *mm, gfp_t gfp,
@@ -823,7 +815,7 @@ static bool linear_map_requires_bbml2 __initdata;
 
 u32 idmap_kpti_bbml2_flag;
 
-void __init init_idmap_kpti_bbml2_flag(void)
+static void __init init_idmap_kpti_bbml2_flag(void)
 {
 	WRITE_ONCE(idmap_kpti_bbml2_flag, 1);
 	/* Must be visible to other CPUs before stop_machine() is called. */
@@ -1135,7 +1127,93 @@ static void __init declare_vma(struct vm_struct *vma,
 }
 
 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0
-static pgprot_t kernel_exec_prot(void)
+#define KPTI_NG_TEMP_VA		(-(1UL << PMD_SHIFT))
+
+static phys_addr_t kpti_ng_temp_alloc __initdata;
+
+static phys_addr_t __init kpti_ng_pgd_alloc(enum pgtable_type type)
+{
+	kpti_ng_temp_alloc -= PAGE_SIZE;
+	return kpti_ng_temp_alloc;
+}
+
+static int __init __kpti_install_ng_mappings(void *__unused)
+{
+	typedef void (kpti_remap_fn)(int, int, phys_addr_t, unsigned long);
+	extern kpti_remap_fn idmap_kpti_install_ng_mappings;
+	kpti_remap_fn *remap_fn;
+
+	int cpu = smp_processor_id();
+	int levels = CONFIG_PGTABLE_LEVELS;
+	int order = order_base_2(levels);
+	u64 kpti_ng_temp_pgd_pa = 0;
+	pgd_t *kpti_ng_temp_pgd;
+	u64 alloc = 0;
+
+	if (levels == 5 && !pgtable_l5_enabled())
+		levels = 4;
+	else if (levels == 4 && !pgtable_l4_enabled())
+		levels = 3;
+
+	remap_fn = (void *)__pa_symbol(idmap_kpti_install_ng_mappings);
+
+	if (!cpu) {
+		alloc = __get_free_pages(GFP_ATOMIC | __GFP_ZERO, order);
+		kpti_ng_temp_pgd = (pgd_t *)(alloc + (levels - 1) * PAGE_SIZE);
+		kpti_ng_temp_alloc = kpti_ng_temp_pgd_pa = __pa(kpti_ng_temp_pgd);
+
+		//
+		// Create a minimal page table hierarchy that permits us to map
+		// the swapper page tables temporarily as we traverse them.
+		//
+		// The physical pages are laid out as follows:
+		//
+		// +--------+-/-------+-/------ +-/------ +-\\\--------+
+		// :  PTE[] : | PMD[] : | PUD[] : | P4D[] : ||| PGD[]  :
+		// +--------+-\-------+-\------ +-\------ +-///--------+
+		//      ^
+		// The first page is mapped into this hierarchy at a PMD_SHIFT
+		// aligned virtual address, so that we can manipulate the PTE
+		// level entries while the mapping is active. The first entry
+		// covers the PTE[] page itself, the remaining entries are free
+		// to be used as a ad-hoc fixmap.
+		//
+		__create_pgd_mapping_locked(kpti_ng_temp_pgd, __pa(alloc),
+					    KPTI_NG_TEMP_VA, PAGE_SIZE, PAGE_KERNEL,
+					    kpti_ng_pgd_alloc, 0);
+	}
+
+	cpu_install_idmap();
+	remap_fn(cpu, num_online_cpus(), kpti_ng_temp_pgd_pa, KPTI_NG_TEMP_VA);
+	cpu_uninstall_idmap();
+
+	if (!cpu) {
+		free_pages(alloc, order);
+		arm64_use_ng_mappings = true;
+	}
+
+	return 0;
+}
+
+void __init kpti_install_ng_mappings(void)
+{
+	/* Check whether KPTI is going to be used */
+	if (!arm64_kernel_unmapped_at_el0())
+		return;
+
+	/*
+	 * We don't need to rewrite the page-tables if either we've done
+	 * it already or we have KASLR enabled and therefore have not
+	 * created any global mappings at all.
+	 */
+	if (arm64_use_ng_mappings)
+		return;
+
+	init_idmap_kpti_bbml2_flag();
+	stop_machine(__kpti_install_ng_mappings, NULL, cpu_online_mask);
+}
+
+static pgprot_t __init kernel_exec_prot(void)
 {
 	return rodata_enabled ? PAGE_KERNEL_ROX : PAGE_KERNEL_EXEC;
 }