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@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Christophe Leroy 2019-02-21 19:08:47 +00:00 committed by Michael Ellerman
parent 555f4fdb93
commit 166d97d961
2 changed files with 12 additions and 6 deletions

View File

@ -721,6 +721,15 @@ 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

View File

@ -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 = .);