linux-kernel - [PATCH v1 11/13] powerpc/kconfig: define CONFIG_DATA_SHIFT and CONFIG_ETEXT

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]

Message-Id: <aa90e128e9822dc0f43f42941f339ae5edca9c63.1543517818.git.christophe.leroy@c-s.fr>
Date:   Thu, 29 Nov 2018 19:00:32 +0000 (UTC)
From:   Christophe Leroy <christophe.leroy@....fr>
To:     Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Paul Mackerras <paulus@...ba.org>,
        Michael Ellerman <mpe@...erman.id.au>, j.neuschaefer@....net
Cc:     linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org
Subject: [PATCH v1 11/13] powerpc/kconfig: define CONFIG_DATA_SHIFT and
 CONFIG_ETEXT_SHIFT

CONFIG_STRICT_KERNEL_RWX requires a special alignment
for DATA for some subarches. Today it is just defined
as an #ifdef in vmlinux.lds.S

In order to get more flexibility, this patch moves the
definition of this alignment in Kconfig

On some subarches, CONFIG_STRICT_KERNEL_RWX will
require a special alignment of _etext.

This patch also adds a configuration item for it in Kconfig

Signed-off-by: Christophe Leroy <christophe.leroy@....fr>
---
 arch/powerpc/Kconfig              | 9 +++++++++
 arch/powerpc/kernel/vmlinux.lds.S | 9 +++------
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 4a81a80d0635..f3e420f3f1d7 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -728,6 +728,15 @@ config THREAD_SHIFT
 	  Used to define the stack size. The default is almost always what you
 	  want. Only change this if you know what you are doing.
 
+config ETEXT_SHIFT
+	int
+	default PPC_PAGE_SHIFT
+
+config DATA_SHIFT
+	int
+	default 24 if STRICT_KERNEL_RWX && PPC64
+	default PPC_PAGE_SHIFT
+
 config FORCE_MAX_ZONEORDER
 	int "Maximum zone order"
 	range 8 9 if PPC64 && PPC_64K_PAGES
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 1148c3c60c3b..d210dcfe915a 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -12,11 +12,8 @@
 #include <asm/cache.h>
 #include <asm/thread_info.h>
 
-#if defined(CONFIG_STRICT_KERNEL_RWX) && !defined(CONFIG_PPC32)
-#define STRICT_ALIGN_SIZE	(1 << 24)
-#else
-#define STRICT_ALIGN_SIZE	PAGE_SIZE
-#endif
+#define STRICT_ALIGN_SIZE	(1 << CONFIG_DATA_SHIFT)
+#define ETEXT_ALIGN_SIZE	(1 << CONFIG_ETEXT_SHIFT)
 
 ENTRY(_stext)
 
@@ -131,7 +128,7 @@ SECTIONS
 
 	} :kernel
 
-	. = ALIGN(PAGE_SIZE);
+	. = ALIGN(ETEXT_ALIGN_SIZE);
 	_etext = .;
 	PROVIDE32 (etext = .);
 
-- 
2.13.3