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

Pull arm64 updates from Catalin Marinas:

 - MTE asynchronous support for KASan. Previously only synchronous
   (slower) mode was supported. Asynchronous is faster but does not
   allow precise identification of the illegal access.

 - Run kernel mode SIMD with softirqs disabled. This allows using NEON
   in softirq context for crypto performance improvements. The
   conditional yield support is modified to take softirqs into account
   and reduce the latency.

 - Preparatory patches for Apple M1: handle CPUs that only have the VHE
   mode available (host kernel running at EL2), add FIQ support.

 - arm64 perf updates: support for HiSilicon PA and SLLC PMU drivers,
   new functions for the HiSilicon HHA and L3C PMU, cleanups.

 - Re-introduce support for execute-only user permissions but only when
   the EPAN (Enhanced Privileged Access Never) architecture feature is
   available.

 - Disable fine-grained traps at boot and improve the documented boot
   requirements.

 - Support CONFIG_KASAN_VMALLOC on arm64 (only with KASAN_GENERIC).

 - Add hierarchical eXecute Never permissions for all page tables.

 - Add arm64 prctl(PR_PAC_{SET,GET}_ENABLED_KEYS) allowing user programs
   to control which PAC keys are enabled in a particular task.

 - arm64 kselftests for BTI and some improvements to the MTE tests.

 - Minor improvements to the compat vdso and sigpage.

 - Miscellaneous cleanups.

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (86 commits)
  arm64/sve: Add compile time checks for SVE hooks in generic functions
  arm64/kernel/probes: Use BUG_ON instead of if condition followed by BUG.
  arm64: pac: Optimize kernel entry/exit key installation code paths
  arm64: Introduce prctl(PR_PAC_{SET,GET}_ENABLED_KEYS)
  arm64: mte: make the per-task SCTLR_EL1 field usable elsewhere
  arm64/sve: Remove redundant system_supports_sve() tests
  arm64: fpsimd: run kernel mode NEON with softirqs disabled
  arm64: assembler: introduce wxN aliases for wN registers
  arm64: assembler: remove conditional NEON yield macros
  kasan, arm64: tests supports for HW_TAGS async mode
  arm64: mte: Report async tag faults before suspend
  arm64: mte: Enable async tag check fault
  arm64: mte: Conditionally compile mte_enable_kernel_*()
  arm64: mte: Enable TCO in functions that can read beyond buffer limits
  kasan: Add report for async mode
  arm64: mte: Drop arch_enable_tagging()
  kasan: Add KASAN mode kernel parameter
  arm64: mte: Add asynchronous mode support
  arm64: Get rid of CONFIG_ARM64_VHE
  arm64: Cope with CPUs stuck in VHE mode
  ...

4 files changed, 123 insertions, 11 deletions

diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c
index 2aad21fda156..4004388b4e4b 100644
--- a/mm/kasan/hw_tags.c
+++ b/mm/kasan/hw_tags.c
@@ -25,6 +25,12 @@ enum kasan_arg {
 	KASAN_ARG_ON,
 };
 
+enum kasan_arg_mode {
+	KASAN_ARG_MODE_DEFAULT,
+	KASAN_ARG_MODE_SYNC,
+	KASAN_ARG_MODE_ASYNC,
+};
+
 enum kasan_arg_stacktrace {
 	KASAN_ARG_STACKTRACE_DEFAULT,
 	KASAN_ARG_STACKTRACE_OFF,
@@ -38,6 +44,7 @@ enum kasan_arg_fault {
 };
 
 static enum kasan_arg kasan_arg __ro_after_init;
+static enum kasan_arg_mode kasan_arg_mode __ro_after_init;
 static enum kasan_arg_stacktrace kasan_arg_stacktrace __ro_after_init;
 static enum kasan_arg_fault kasan_arg_fault __ro_after_init;
 
@@ -45,6 +52,10 @@ static enum kasan_arg_fault kasan_arg_fault __ro_after_init;
 DEFINE_STATIC_KEY_FALSE(kasan_flag_enabled);
 EXPORT_SYMBOL(kasan_flag_enabled);
 
+/* Whether the asynchronous mode is enabled. */
+bool kasan_flag_async __ro_after_init;
+EXPORT_SYMBOL_GPL(kasan_flag_async);
+
 /* Whether to collect alloc/free stack traces. */
 DEFINE_STATIC_KEY_FALSE(kasan_flag_stacktrace);
 
@@ -68,6 +79,23 @@ static int __init early_kasan_flag(char *arg)
 }
 early_param("kasan", early_kasan_flag);
 
+/* kasan.mode=sync/async */
+static int __init early_kasan_mode(char *arg)
+{
+	if (!arg)
+		return -EINVAL;
+
+	if (!strcmp(arg, "sync"))
+		kasan_arg_mode = KASAN_ARG_MODE_SYNC;
+	else if (!strcmp(arg, "async"))
+		kasan_arg_mode = KASAN_ARG_MODE_ASYNC;
+	else
+		return -EINVAL;
+
+	return 0;
+}
+early_param("kasan.mode", early_kasan_mode);
+
 /* kasan.stacktrace=off/on */
 static int __init early_kasan_flag_stacktrace(char *arg)
 {
@@ -115,7 +143,15 @@ void kasan_init_hw_tags_cpu(void)
 		return;
 
 	hw_init_tags(KASAN_TAG_MAX);
-	hw_enable_tagging();
+
+	/*
+	 * Enable async mode only when explicitly requested through
+	 * the command line.
+	 */
+	if (kasan_arg_mode == KASAN_ARG_MODE_ASYNC)
+		hw_enable_tagging_async();
+	else
+		hw_enable_tagging_sync();
 }
 
 /* kasan_init_hw_tags() is called once on boot CPU. */
@@ -132,6 +168,22 @@ void __init kasan_init_hw_tags(void)
 	/* Enable KASAN. */
 	static_branch_enable(&kasan_flag_enabled);
 
+	switch (kasan_arg_mode) {
+	case KASAN_ARG_MODE_DEFAULT:
+		/*
+		 * Default to sync mode.
+		 * Do nothing, kasan_flag_async keeps its default value.
+		 */
+		break;
+	case KASAN_ARG_MODE_SYNC:
+		/* Do nothing, kasan_flag_async keeps its default value. */
+		break;
+	case KASAN_ARG_MODE_ASYNC:
+		/* Async mode enabled. */
+		kasan_flag_async = true;
+		break;
+	}
+
 	switch (kasan_arg_stacktrace) {
 	case KASAN_ARG_STACKTRACE_DEFAULT:
 		/* Default to enabling stack trace collection. */
@@ -194,10 +246,16 @@ void kasan_set_tagging_report_once(bool state)
 }
 EXPORT_SYMBOL_GPL(kasan_set_tagging_report_once);
 
-void kasan_enable_tagging(void)
+void kasan_enable_tagging_sync(void)
+{
+	hw_enable_tagging_sync();
+}
+EXPORT_SYMBOL_GPL(kasan_enable_tagging_sync);
+
+void kasan_force_async_fault(void)
 {
-	hw_enable_tagging();
+	hw_force_async_tag_fault();
 }
-EXPORT_SYMBOL_GPL(kasan_enable_tagging);
+EXPORT_SYMBOL_GPL(kasan_force_async_fault);
 
 #endif
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index 3436c6bf7c0c..c1581e8a9b8e 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -7,20 +7,37 @@
 #include <linux/stackdepot.h>
 
 #ifdef CONFIG_KASAN_HW_TAGS
+
 #include <linux/static_key.h>
+
 DECLARE_STATIC_KEY_FALSE(kasan_flag_stacktrace);
+extern bool kasan_flag_async __ro_after_init;
+
 static inline bool kasan_stack_collection_enabled(void)
 {
 	return static_branch_unlikely(&kasan_flag_stacktrace);
 }
+
+static inline bool kasan_async_mode_enabled(void)
+{
+	return kasan_flag_async;
+}
 #else
+
 static inline bool kasan_stack_collection_enabled(void)
 {
 	return true;
 }
+
+static inline bool kasan_async_mode_enabled(void)
+{
+	return false;
+}
+
 #endif
 
 extern bool kasan_flag_panic __ro_after_init;
+extern bool kasan_flag_async __ro_after_init;
 
 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
 #define KASAN_GRANULE_SIZE	(1UL << KASAN_SHADOW_SCALE_SHIFT)
@@ -275,8 +292,11 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
 
 #ifdef CONFIG_KASAN_HW_TAGS
 
-#ifndef arch_enable_tagging
-#define arch_enable_tagging()
+#ifndef arch_enable_tagging_sync
+#define arch_enable_tagging_sync()
+#endif
+#ifndef arch_enable_tagging_async
+#define arch_enable_tagging_async()
 #endif
 #ifndef arch_init_tags
 #define arch_init_tags(max_tag)
@@ -284,6 +304,9 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
 #ifndef arch_set_tagging_report_once
 #define arch_set_tagging_report_once(state)
 #endif
+#ifndef arch_force_async_tag_fault
+#define arch_force_async_tag_fault()
+#endif
 #ifndef arch_get_random_tag
 #define arch_get_random_tag()	(0xFF)
 #endif
@@ -294,16 +317,19 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
 #define arch_set_mem_tag_range(addr, size, tag) ((void *)(addr))
 #endif
 
-#define hw_enable_tagging()			arch_enable_tagging()
+#define hw_enable_tagging_sync()		arch_enable_tagging_sync()
+#define hw_enable_tagging_async()		arch_enable_tagging_async()
 #define hw_init_tags(max_tag)			arch_init_tags(max_tag)
 #define hw_set_tagging_report_once(state)	arch_set_tagging_report_once(state)
+#define hw_force_async_tag_fault()		arch_force_async_tag_fault()
 #define hw_get_random_tag()			arch_get_random_tag()
 #define hw_get_mem_tag(addr)			arch_get_mem_tag(addr)
 #define hw_set_mem_tag_range(addr, size, tag)	arch_set_mem_tag_range((addr), (size), (tag))
 
 #else /* CONFIG_KASAN_HW_TAGS */
 
-#define hw_enable_tagging()
+#define hw_enable_tagging_sync()
+#define hw_enable_tagging_async()
 #define hw_set_tagging_report_once(state)
 
 #endif /* CONFIG_KASAN_HW_TAGS */
@@ -311,12 +337,14 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
 #if defined(CONFIG_KASAN_HW_TAGS) && IS_ENABLED(CONFIG_KASAN_KUNIT_TEST)
 
 void kasan_set_tagging_report_once(bool state);
-void kasan_enable_tagging(void);
+void kasan_enable_tagging_sync(void);
+void kasan_force_async_fault(void);
 
 #else /* CONFIG_KASAN_HW_TAGS || CONFIG_KASAN_KUNIT_TEST */
 
 static inline void kasan_set_tagging_report_once(bool state) { }
-static inline void kasan_enable_tagging(void) { }
+static inline void kasan_enable_tagging_sync(void) { }
+static inline void kasan_force_async_fault(void) { }
 
 #endif /* CONFIG_KASAN_HW_TAGS || CONFIG_KASAN_KUNIT_TEST */
 
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 87b271206163..14bd51ea2348 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -87,7 +87,8 @@ static void start_report(unsigned long *flags)
 
 static void end_report(unsigned long *flags, unsigned long addr)
 {
-	trace_error_report_end(ERROR_DETECTOR_KASAN, addr);
+	if (!kasan_async_mode_enabled())
+		trace_error_report_end(ERROR_DETECTOR_KASAN, addr);
 	pr_err("==================================================================\n");
 	add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
 	spin_unlock_irqrestore(&report_lock, *flags);
@@ -360,6 +361,25 @@ void kasan_report_invalid_free(void *object, unsigned long ip)
 	end_report(&flags, (unsigned long)object);
 }
 
+#ifdef CONFIG_KASAN_HW_TAGS
+void kasan_report_async(void)
+{
+	unsigned long flags;
+
+#if IS_ENABLED(CONFIG_KUNIT)
+	if (current->kunit_test)
+		kasan_update_kunit_status(current->kunit_test);
+#endif /* IS_ENABLED(CONFIG_KUNIT) */
+
+	start_report(&flags);
+	pr_err("BUG: KASAN: invalid-access\n");
+	pr_err("Asynchronous mode enabled: no access details available\n");
+	pr_err("\n");
+	dump_stack();
+	end_report(&flags, 0);
+}
+#endif /* CONFIG_KASAN_HW_TAGS */
+
 static void __kasan_report(unsigned long addr, size_t size, bool is_write,
 				unsigned long ip)
 {
diff --git a/mm/mmap.c b/mm/mmap.c
index 3f287599a7a3..1d96a21acb2f 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -93,6 +93,12 @@ static void unmap_region(struct mm_struct *mm,
  * MAP_PRIVATE	r: (no) no	r: (yes) yes	r: (no) yes	r: (no) yes
  *		w: (no) no	w: (no) no	w: (copy) copy	w: (no) no
  *		x: (no) no	x: (no) yes	x: (no) yes	x: (yes) yes
+ *
+ * On arm64, PROT_EXEC has the following behaviour for both MAP_SHARED and
+ * MAP_PRIVATE (with Enhanced PAN supported):
+ *								r: (no) no
+ *								w: (no) no
+ *								x: (yes) yes
  */
 pgprot_t protection_map[16] __ro_after_init = {
 	__P000, __P001, __P010, __P011, __P100, __P101, __P110, __P111,