[PATCH] flush icache in correct context

flush_icache_range() is used in two different situation - in binfmt_elf.c &
co for user space mappings and module.c for kernel modules.  On m68k
flush_icache_range() doesn't know which data to flush, as it has separate
address spaces and the pointer argument can be valid in either address
space.

First I considered splitting flush_icache_range(), but this patch is
simpler.  Setting the correct context gives flush_icache_range() enough
information to flush the correct data.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

kernel/module.c

@@ -1758,6 +1758,7 @@ sys_init_module(void __user *umod,
 		const char __user *uargs)
 {
 	struct module *mod;
+	mm_segment_t old_fs = get_fs();
 	int ret = 0;
 
 	/* Must have permission */
@@ -1775,6 +1776,9 @@ sys_init_module(void __user *umod,
 		return PTR_ERR(mod);
 	}
 
+	/* flush the icache in correct context */
+	set_fs(KERNEL_DS);
+
 	/* Flush the instruction cache, since we've played with text */
 	if (mod->module_init)
 		flush_icache_range((unsigned long)mod->module_init,
@@ -1783,6 +1787,8 @@ sys_init_module(void __user *umod,
 	flush_icache_range((unsigned long)mod->module_core,
 			   (unsigned long)mod->module_core + mod->core_size);
 
+	set_fs(old_fs);
+
 	/* Now sew it into the lists.  They won't access us, since
            strong_try_module_get() will fail. */
 	stop_machine_run(__link_module, mod, NR_CPUS);