From: Mark Rutland <mark.rutland@arm.com>
Date: Mon, 25 Jan 2016 11:45:11 +0000 (+0000)
Subject: BACKPORT: arm64: ensure _stext and _etext are page-aligned
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=9f31360553319ee4e8fc3a1c97ef4788c024d6de;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git

BACKPORT: arm64: ensure _stext and _etext are page-aligned

Currently we have separate ALIGN_DEBUG_RO{,_MIN} directives to align
_etext and __init_begin. While we ensure that __init_begin is
page-aligned, we do not provide the same guarantee for _etext. This is
not problematic currently as the alignment of __init_begin is sufficient
to prevent issues when we modify permissions.

Subsequent patches will assume page alignment of segments of the kernel
we wish to map with different permissions. To ensure this, move _etext
after the ALIGN_DEBUG_RO_MIN for the init section. This renders the
prior ALIGN_DEBUG_RO irrelevant, and hence it is removed. Likewise,
upgrade to ALIGN_DEBUG_RO_MIN(PAGE_SIZE) for _stext.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Bug: 30369029
Patchset: rework-pagetable

(cherry picked from commit fca082bfb543ccaaff864fc0892379ccaa1711cd)
Signed-off-by: Jeff Vander Stoep <jeffv@google.com>
Change-Id: If1a829aa5c363f2c76eb1a18209c3c00ee3ffd0a
---

diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S
index 1a056bb26633..763e5aab5752 100644
--- a/arch/arm64/kernel/vmlinux.lds.S
+++ b/arch/arm64/kernel/vmlinux.lds.S
@@ -95,7 +95,7 @@ SECTIONS
 		_text = .;
 		HEAD_TEXT
 	}
-	ALIGN_DEBUG_RO
+	ALIGN_DEBUG_RO_MIN(PAGE_SIZE)
 	.text : {			/* Real text segment		*/
 		_stext = .;		/* Text and read-only data	*/
 			__exception_text_start = .;
@@ -118,9 +118,9 @@ SECTIONS
 	RO_DATA(PAGE_SIZE)
 	EXCEPTION_TABLE(8)
 	NOTES
-	ALIGN_DEBUG_RO
 
 	ALIGN_DEBUG_RO_MIN(PAGE_SIZE)
+	_etext = .;			/* End of text and rodata section */
 	__init_begin = .;
 
 	INIT_TEXT_SECTION(8)