Merge branch 'for-next/mte' into for-next/core

Add userspace support for the Memory Tagging Extension introduced by
Armv8.5.

(Catalin Marinas and others)
* for-next/mte: (30 commits)
  arm64: mte: Fix typo in memory tagging ABI documentation
  arm64: mte: Add Memory Tagging Extension documentation
  arm64: mte: Kconfig entry
  arm64: mte: Save tags when hibernating
  arm64: mte: Enable swap of tagged pages
  mm: Add arch hooks for saving/restoring tags
  fs: Handle intra-page faults in copy_mount_options()
  arm64: mte: ptrace: Add NT_ARM_TAGGED_ADDR_CTRL regset
  arm64: mte: ptrace: Add PTRACE_{PEEK,POKE}MTETAGS support
  arm64: mte: Allow {set,get}_tagged_addr_ctrl() on non-current tasks
  arm64: mte: Restore the GCR_EL1 register after a suspend
  arm64: mte: Allow user control of the generated random tags via prctl()
  arm64: mte: Allow user control of the tag check mode via prctl()
  mm: Allow arm64 mmap(PROT_MTE) on RAM-based files
  arm64: mte: Validate the PROT_MTE request via arch_validate_flags()
  mm: Introduce arch_validate_flags()
  arm64: mte: Add PROT_MTE support to mmap() and mprotect()
  mm: Introduce arch_calc_vm_flag_bits()
  arm64: mte: Tags-aware aware memcmp_pages() implementation
  arm64: Avoid unnecessary clear_user_page() indirection
  ...

1 files changed, 118 insertions, 0 deletions

diff --git a/arch/arm64/kernel/hibernate.c b/arch/arm64/kernel/hibernate.c
index 3a1662392c95..42003774d261 100644
--- a/arch/arm64/kernel/hibernate.c
+++ b/arch/arm64/kernel/hibernate.c
@@ -30,6 +30,7 @@
 #include <asm/kexec.h>
 #include <asm/memory.h>
 #include <asm/mmu_context.h>
+#include <asm/mte.h>
 #include <asm/pgalloc.h>
 #include <asm/pgtable-hwdef.h>
 #include <asm/sections.h>
@@ -284,6 +285,117 @@ static int create_safe_exec_page(void *src_start, size_t length,
 
 #define dcache_clean_range(start, end)	__flush_dcache_area(start, (end - start))
 
+#ifdef CONFIG_ARM64_MTE
+
+static DEFINE_XARRAY(mte_pages);
+
+static int save_tags(struct page *page, unsigned long pfn)
+{
+	void *tag_storage, *ret;
+
+	tag_storage = mte_allocate_tag_storage();
+	if (!tag_storage)
+		return -ENOMEM;
+
+	mte_save_page_tags(page_address(page), tag_storage);
+
+	ret = xa_store(&mte_pages, pfn, tag_storage, GFP_KERNEL);
+	if (WARN(xa_is_err(ret), "Failed to store MTE tags")) {
+		mte_free_tag_storage(tag_storage);
+		return xa_err(ret);
+	} else if (WARN(ret, "swsusp: %s: Duplicate entry", __func__)) {
+		mte_free_tag_storage(ret);
+	}
+
+	return 0;
+}
+
+static void swsusp_mte_free_storage(void)
+{
+	XA_STATE(xa_state, &mte_pages, 0);
+	void *tags;
+
+	xa_lock(&mte_pages);
+	xas_for_each(&xa_state, tags, ULONG_MAX) {
+		mte_free_tag_storage(tags);
+	}
+	xa_unlock(&mte_pages);
+
+	xa_destroy(&mte_pages);
+}
+
+static int swsusp_mte_save_tags(void)
+{
+	struct zone *zone;
+	unsigned long pfn, max_zone_pfn;
+	int ret = 0;
+	int n = 0;
+
+	if (!system_supports_mte())
+		return 0;
+
+	for_each_populated_zone(zone) {
+		max_zone_pfn = zone_end_pfn(zone);
+		for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) {
+			struct page *page = pfn_to_online_page(pfn);
+
+			if (!page)
+				continue;
+
+			if (!test_bit(PG_mte_tagged, &page->flags))
+				continue;
+
+			ret = save_tags(page, pfn);
+			if (ret) {
+				swsusp_mte_free_storage();
+				goto out;
+			}
+
+			n++;
+		}
+	}
+	pr_info("Saved %d MTE pages\n", n);
+
+out:
+	return ret;
+}
+
+static void swsusp_mte_restore_tags(void)
+{
+	XA_STATE(xa_state, &mte_pages, 0);
+	int n = 0;
+	void *tags;
+
+	xa_lock(&mte_pages);
+	xas_for_each(&xa_state, tags, ULONG_MAX) {
+		unsigned long pfn = xa_state.xa_index;
+		struct page *page = pfn_to_online_page(pfn);
+
+		mte_restore_page_tags(page_address(page), tags);
+
+		mte_free_tag_storage(tags);
+		n++;
+	}
+	xa_unlock(&mte_pages);
+
+	pr_info("Restored %d MTE pages\n", n);
+
+	xa_destroy(&mte_pages);
+}
+
+#else	/* CONFIG_ARM64_MTE */
+
+static int swsusp_mte_save_tags(void)
+{
+	return 0;
+}
+
+static void swsusp_mte_restore_tags(void)
+{
+}
+
+#endif	/* CONFIG_ARM64_MTE */
+
 int swsusp_arch_suspend(void)
 {
 	int ret = 0;
@@ -301,6 +413,10 @@ int swsusp_arch_suspend(void)
 		/* make the crash dump kernel image visible/saveable */
 		crash_prepare_suspend();
 
+		ret = swsusp_mte_save_tags();
+		if (ret)
+			return ret;
+
 		sleep_cpu = smp_processor_id();
 		ret = swsusp_save();
 	} else {
@@ -314,6 +430,8 @@ int swsusp_arch_suspend(void)
 			dcache_clean_range(__hyp_text_start, __hyp_text_end);
 		}
 
+		swsusp_mte_restore_tags();
+
 		/* make the crash dump kernel image protected again */
 		crash_post_resume();