From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 7 Apr 2024 20:49:45 +0200
Subject: Adding upstream version 6.1.76.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 arch/arm/include/asm/kfence.h | 53 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)
 create mode 100644 arch/arm/include/asm/kfence.h

(limited to 'arch/arm/include/asm/kfence.h')

diff --git a/arch/arm/include/asm/kfence.h b/arch/arm/include/asm/kfence.h
new file mode 100644
index 000000000..7980d0f22
--- /dev/null
+++ b/arch/arm/include/asm/kfence.h
@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __ASM_ARM_KFENCE_H
+#define __ASM_ARM_KFENCE_H
+
+#include <linux/kfence.h>
+
+#include <asm/pgalloc.h>
+#include <asm/set_memory.h>
+
+static inline int split_pmd_page(pmd_t *pmd, unsigned long addr)
+{
+	int i;
+	unsigned long pfn = PFN_DOWN(__pa(addr));
+	pte_t *pte = pte_alloc_one_kernel(&init_mm);
+
+	if (!pte)
+		return -ENOMEM;
+
+	for (i = 0; i < PTRS_PER_PTE; i++)
+		set_pte_ext(pte + i, pfn_pte(pfn + i, PAGE_KERNEL), 0);
+	pmd_populate_kernel(&init_mm, pmd, pte);
+
+	flush_tlb_kernel_range(addr, addr + PMD_SIZE);
+	return 0;
+}
+
+static inline bool arch_kfence_init_pool(void)
+{
+	unsigned long addr;
+	pmd_t *pmd;
+
+	for (addr = (unsigned long)__kfence_pool; is_kfence_address((void *)addr);
+	     addr += PAGE_SIZE) {
+		pmd = pmd_off_k(addr);
+
+		if (pmd_leaf(*pmd)) {
+			if (split_pmd_page(pmd, addr & PMD_MASK))
+				return false;
+		}
+	}
+
+	return true;
+}
+
+static inline bool kfence_protect_page(unsigned long addr, bool protect)
+{
+	set_memory_valid(addr, 1, !protect);
+
+	return true;
+}
+
+#endif /* __ASM_ARM_KFENCE_H */
-- 
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