linux-kernel - [PATCH 09/15] arm64: Add page size to the kernel image header

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 15 Sep 2015 16:41:18 +0100
From:	"Suzuki K. Poulose" <suzuki.poulose@....com>
To:	linux-arm-kernel@...ts.infradead.org
Cc:	linux-kernel@...r.kernel.org, Catalin.Marinas@....com,
	Will.Deacon@....com, Mark.Rutland@....com, Marc.Zyngier@....com,
	kvmarm@...ts.cs.columbia.edu, kvm@...r.kernel.org,
	ard.biesheuvel@...aro.org, suzuki.poulose@....com
Subject: [PATCH 09/15] arm64: Add page size to the kernel image header

From: Ard Biesheuvel <ard.biesheuvel@...aro.org>

This patch adds the page size to the arm64 kernel image header
so that one can infer the PAGESIZE used by the kernel. This will
be helpful to diagnose failures to boot the kernel with page size
not supported by the CPU.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@...aro.org>
---
 Documentation/arm64/booting.txt |    7 ++++++-
 arch/arm64/kernel/image.h       |    5 ++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/Documentation/arm64/booting.txt b/Documentation/arm64/booting.txt
index 7d9d3c2..aaf6d77 100644
--- a/Documentation/arm64/booting.txt
+++ b/Documentation/arm64/booting.txt
@@ -104,7 +104,12 @@ Header notes:
 - The flags field (introduced in v3.17) is a little-endian 64-bit field
   composed as follows:
   Bit 0:	Kernel endianness.  1 if BE, 0 if LE.
-  Bits 1-63:	Reserved.
+  Bit 1-2:	Kernel Page size.
+			0 - Unspecified.
+			1 - 4K
+			2 - 16K
+			3 - 64K
+  Bits 3-63:	Reserved.
 
 - When image_size is zero, a bootloader should attempt to keep as much
   memory as possible free for use by the kernel immediately after the
diff --git a/arch/arm64/kernel/image.h b/arch/arm64/kernel/image.h
index 8fae075..73b736c 100644
--- a/arch/arm64/kernel/image.h
+++ b/arch/arm64/kernel/image.h
@@ -47,7 +47,10 @@
 #define __HEAD_FLAG_BE	0
 #endif
 
-#define __HEAD_FLAGS	(__HEAD_FLAG_BE << 0)
+#define __HEAD_FLAG_PAGE_SIZE ((PAGE_SHIFT - 10) / 2)
+
+#define __HEAD_FLAGS	(__HEAD_FLAG_BE << 0) |		\
+			(__HEAD_FLAG_PAGE_SIZE << 1)
 
 /*
  * These will output as part of the Image header, which should be little-endian
-- 
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/