kasan-vmalloc-arm64-mark-vmalloc-mappings-as-pgprot_tagged.patch removed from -mm tree

The patch titled
Subject: kasan, vmalloc, arm64: mark vmalloc mappings as pgprot_tagged
has been removed from the -mm tree. Its filename was
kasan-vmalloc-arm64-mark-vmalloc-mappings-as-pgprot_tagged.patch

This patch was dropped because it was merged into mainline or a subsystem tree

------------------------------------------------------
From: Andrey Konovalov <[email protected]>
Subject: kasan, vmalloc, arm64: mark vmalloc mappings as pgprot_tagged

HW_TAGS KASAN relies on ARM Memory Tagging Extension (MTE). With MTE, a memory region must be mapped as MT_NORMAL_TAGGED to allow setting memory tags via MTE-specific instructions.

Add proper protection bits to vmalloc() allocations. These allocations are always backed by page_alloc pages, so the tags will actually be getting set on the corresponding physical memory.

---

 arch/arm64/include/asm/vmalloc.h |    6 ++++++
 include/linux/vmalloc.h          |    7 +++++++
 mm/vmalloc.c                     |    9 +++++++++
 3 files changed, 22 insertions(+)

@@ -25,4 +25,10 @@ static inline bool arch_vmap_pmd_support
 
 #endif
 
+#define arch_vmap_pgprot_tagged arch_vmap_pgprot_tagged
+static inline pgprot_t arch_vmap_pgprot_tagged(pgprot_t prot)
+{
+	return pgprot_tagged(prot);
+}
+
 #endif /* _ASM_ARM64_VMALLOC_H */

@@ -115,6 +115,13 @@ static inline int arch_vmap_pte_supporte
 }
 #endif
 
+#ifndef arch_vmap_pgprot_tagged
+static inline pgprot_t arch_vmap_pgprot_tagged(pgprot_t prot)
+{
+	return prot;
+}
+#endif
+
 /*
  *	Highlevel APIs for driver use
  */

@@ -3128,6 +3128,15 @@ again:
 		goto fail;
 	}
 
+	/*
+	 * Modify protection bits to allow tagging.
+	 * This must be done before mapping by __vmalloc_area_node().
+	 */
+	if (kasan_hw_tags_enabled() &&
+	    pgprot_val(prot) == pgprot_val(PAGE_KERNEL))
+		prot = arch_vmap_pgprot_tagged(prot);
+
+	/* Allocate physical pages and map them into vmalloc space. */
 	addr = __vmalloc_area_node(area, gfp_mask, prot, shift, node);
 	if (!addr)
 		goto fail;

_

Patches currently in -mm which might be from [email protected] are

stacktrace-add-interface-based-on-shadow-call-stack.patch arm64-scs-save-scs_sp-values-per-cpu-when-switching-stacks.patch arm64-implement-stack_trace_save_shadow.patch kasan-use-stack_trace_save_shadow.patch