[PATCH] flush icache in correct context

From: Roman Zippel
Date: Mon May 30 2005 - 17:30:17 EST


Hi,

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.

bye, Roman

---

kernel/module.c | 6 ++++++
1 files changed, 6 insertions(+)

Index: linux-2.6-mm/kernel/module.c
===================================================================
--- linux-2.6-mm.orig/kernel/module.c 2005-05-30 22:17:40.890503434 +0200
+++ linux-2.6-mm/kernel/module.c 2005-05-30 22:18:59.804961363 +0200
@@ -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);
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/