[ARM] nommu: uaccess tweaks
MMUless systems have only one address space for all threads, so
both the usual access_ok() checks, and the exception handling do
not make much sense.
Hence, discard the fixup and exception tables at link time, use
memcpy/memset for the user copy/clearing functions, and define
the permission check macros to be constants.
Some of this patch was derived from the equivalent patch by
Hyok S. Choi.
Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c
index f8bb7ab..da69e66 100644
--- a/arch/arm/kernel/armksyms.c
+++ b/arch/arm/kernel/armksyms.c
@@ -109,11 +109,13 @@
EXPORT_SYMBOL(__memzero);
/* user mem (segment) */
+EXPORT_SYMBOL(__strnlen_user);
+EXPORT_SYMBOL(__strncpy_from_user);
+
+#ifdef CONFIG_MMU
EXPORT_SYMBOL(__copy_from_user);
EXPORT_SYMBOL(__copy_to_user);
EXPORT_SYMBOL(__clear_user);
-EXPORT_SYMBOL(__strnlen_user);
-EXPORT_SYMBOL(__strncpy_from_user);
EXPORT_SYMBOL(__get_user_1);
EXPORT_SYMBOL(__get_user_2);
@@ -123,6 +125,7 @@
EXPORT_SYMBOL(__put_user_2);
EXPORT_SYMBOL(__put_user_4);
EXPORT_SYMBOL(__put_user_8);
+#endif
/* crypto hash */
EXPORT_SYMBOL(sha_transform);
diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S
index 2b254e8..2df9688 100644
--- a/arch/arm/kernel/vmlinux.lds.S
+++ b/arch/arm/kernel/vmlinux.lds.S
@@ -80,6 +80,10 @@
*(.exit.text)
*(.exit.data)
*(.exitcall.exit)
+#ifndef CONFIG_MMU
+ *(.fixup)
+ *(__ex_table)
+#endif
}
.text : { /* Real text segment */
@@ -87,7 +91,9 @@
*(.text)
SCHED_TEXT
LOCK_TEXT
+#ifdef CONFIG_MMU
*(.fixup)
+#endif
*(.gnu.warning)
*(.rodata)
*(.rodata.*)
@@ -142,7 +148,9 @@
*/
. = ALIGN(32);
__start___ex_table = .;
+#ifdef CONFIG_MMU
*(__ex_table)
+#endif
__stop___ex_table = .;
/*