[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>

1 files changed, 6 insertions, 0 deletions

diff --git a/kernel/module.c b/kernel/module.c
index 5734ab09d3f9..83b3d376708c 100644
--- a/kernel/module.c
+++ b/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);