From: AKASHI Takahiro <takahiro.akashi@linaro.org>
Date: Mon, 3 Apr 2017 02:24:33 +0000 (+0900)
Subject: arm64: mm: add set_memory_valid()
X-Git-Tag: release-20171130_firefly~4^2~100^2~1^2~2^2~9
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=8d8d32ab8f8bc41cdf00c2c44c50041cb93a3dc4;p=firefly-linux-kernel-4.4.55.git

arm64: mm: add set_memory_valid()

This function validates and invalidates PTE entries, and will be utilized
in kdump to protect loaded crash dump kernel image.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Conflicts:
	arch/arm64/mm/pageattr.c
due to missing commit 83863f25e4b8 ("arm64: Add support for
ARCH_SUPPORTS_DEBUG_PAGEALLOC")
---

diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h
index 22dda613f9c9..22aabdeacc24 100644
--- a/arch/arm64/include/asm/cacheflush.h
+++ b/arch/arm64/include/asm/cacheflush.h
@@ -155,5 +155,6 @@ int set_memory_ro(unsigned long addr, int numpages);
 int set_memory_rw(unsigned long addr, int numpages);
 int set_memory_x(unsigned long addr, int numpages);
 int set_memory_nx(unsigned long addr, int numpages);
+int set_memory_valid(unsigned long addr, unsigned long size, int enable);
 
 #endif
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index ca6d268e3313..f4e39dbdd36b 100644
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c
@@ -125,6 +125,19 @@ int set_memory_x(unsigned long addr, int numpages)
 }
 EXPORT_SYMBOL_GPL(set_memory_x);
 
+
+int set_memory_valid(unsigned long addr, int numpages, int enable)
+{
+	if (enable)
+		return __change_memory_common(addr, PAGE_SIZE * numpages,
+					__pgprot(PTE_VALID),
+					__pgprot(0));
+	else
+		return __change_memory_common(addr, PAGE_SIZE * numpages,
+					__pgprot(0),
+					__pgprot(PTE_VALID));
+}
+
 #ifdef CONFIG_DEBUG_PAGEALLOC
 void __kernel_map_pages(struct page *page, int numpages, int enable)
 {