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Message-Id: <1451301654-32019-2-git-send-email-ard.biesheuvel@linaro.org>
Date: Mon, 28 Dec 2015 12:20:45 +0100
From: Ard Biesheuvel <ard.biesheuvel@...aro.org>
To: linux-arm-kernel@...ts.infradead.org,
kernel-hardening@...ts.openwall.com,
will.deacon@....com,
catalin.marinas@....com,
mark.rutland@....com,
leif.lindholm@...aro.org,
keescook@...omium.org,
lkml@...r.kernel.org
Cc: stuart.yoder@...escale.com,
bhupesh.sharma@...escale.com,
Ard Biesheuvel <ard.biesheuvel@...aro.org>
Subject: [RFC PATCH 01/10] arm64: introduce KIMAGE_VADDR as the virtual base of the kernel region
This introduces the preprocessor symbol KIMAGE_VADDR which will serve as
the symbolic virtual base of the kernel region, i.e., the kernel's virtual
offset will be KIMAGE_VADDR + TEXT_OFFSET. For now, we define it as being
equal to PAGE_OFFSET, but in the future, it will be moved below it once
we move the kernel virtual mapping out of the linear mapping.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@...aro.org>
---
arch/arm64/include/asm/memory.h | 10 ++++++++--
arch/arm64/kernel/head.S | 2 +-
arch/arm64/kernel/vmlinux.lds.S | 4 ++--
3 files changed, 11 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index 853953cd1f08..bea9631b34a8 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -51,7 +51,8 @@
#define VA_BITS (CONFIG_ARM64_VA_BITS)
#define VA_START (UL(0xffffffffffffffff) << VA_BITS)
#define PAGE_OFFSET (UL(0xffffffffffffffff) << (VA_BITS - 1))
-#define MODULES_END (PAGE_OFFSET)
+#define KIMAGE_VADDR (PAGE_OFFSET)
+#define MODULES_END (KIMAGE_VADDR)
#define MODULES_VADDR (MODULES_END - SZ_64M)
#define PCI_IO_END (MODULES_VADDR - SZ_2M)
#define PCI_IO_START (PCI_IO_END - PCI_IO_SIZE)
@@ -75,8 +76,13 @@
* private definitions which should NOT be used outside memory.h
* files. Use virt_to_phys/phys_to_virt/__pa/__va instead.
*/
-#define __virt_to_phys(x) (((phys_addr_t)(x) - PAGE_OFFSET + PHYS_OFFSET))
+#define __virt_to_phys(x) ({ \
+ phys_addr_t __x = (phys_addr_t)(x); \
+ __x >= PAGE_OFFSET ? (__x - PAGE_OFFSET + PHYS_OFFSET) : \
+ (__x - KIMAGE_VADDR + PHYS_OFFSET); })
+
#define __phys_to_virt(x) ((unsigned long)((x) - PHYS_OFFSET + PAGE_OFFSET))
+#define __phys_to_kimg(x) ((unsigned long)((x) - PHYS_OFFSET + KIMAGE_VADDR))
/*
* Convert a page to/from a physical address
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 23cfc08fc8ba..6434c844a0e4 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -389,7 +389,7 @@ __create_page_tables:
* Map the kernel image (starting with PHYS_OFFSET).
*/
mov x0, x26 // swapper_pg_dir
- mov x5, #PAGE_OFFSET
+ ldr x5, =KIMAGE_VADDR
create_pgd_entry x0, x5, x3, x6
ldr x6, =KERNEL_END // __va(KERNEL_END)
mov x3, x24 // phys offset
diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index 7de6c39858a5..ced0dedcabcc 100644
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -88,7 +88,7 @@ SECTIONS
*(.discard.*)
}
- . = PAGE_OFFSET + TEXT_OFFSET;
+ . = KIMAGE_VADDR + TEXT_OFFSET;
.head.text : {
_text = .;
@@ -185,4 +185,4 @@ ASSERT(__idmap_text_end - (__idmap_text_start & ~(SZ_4K - 1)) <= SZ_4K,
/*
* If padding is applied before .head.text, virt<->phys conversions will fail.
*/
-ASSERT(_text == (PAGE_OFFSET + TEXT_OFFSET), "HEAD is misaligned")
+ASSERT(_text == (KIMAGE_VADDR + TEXT_OFFSET), "HEAD is misaligned")
--
2.5.0
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