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Commit 378bac82 authored by Thomas Koeller's avatar Thomas Koeller Committed by Linus Torvalds
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[PATCH] flush icache early when loading module 



Change the sequence of operations performed during module loading to flush
the instruction cache before module parameters are processed.  If a module
has parameters of an unusual type that cannot be handled using the standard
accessor functions param_set_xxx and param_get_xxx, it has to to provide a
set of accessor functions for this type.  This requires module code to be
executed during parameter processing, which is of course only possible
after the icache has been flushed.

Signed-off-by: default avatarThomas Koeller <thomas@koeller.dyndns.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 19b4946c

kernel/module.c

+19 −14
Original line number Diff line number Diff line
@@ -1509,6 +1509,7 @@ static struct module *load_module(void __user *umod, 
	long err = 0;

	void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */

	struct exception_table_entry *extable;

	mm_segment_t old_fs;



	DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",

	       umod, len, uargs);
@@ -1779,6 +1780,24 @@ static struct module *load_module(void __user *umod, 
	if (err < 0)

		goto cleanup;



	/* flush the icache in correct context */

	old_fs = get_fs();

	set_fs(KERNEL_DS);



	/*

	 * Flush the instruction cache, since we've played with text.

	 * Do it before processing of module parameters, so the module

	 * can provide parameter accessor functions of its own.

	 */

	if (mod->module_init)

		flush_icache_range((unsigned long)mod->module_init,

				   (unsigned long)mod->module_init

				   + mod->init_size);

	flush_icache_range((unsigned long)mod->module_core,

			   (unsigned long)mod->module_core + mod->core_size);



	set_fs(old_fs);



	mod->args = args;

	if (obsparmindex) {

		err = obsolete_params(mod->name, mod->args,
@@ -1860,7 +1879,6 @@ 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 */
@@ -1878,19 +1896,6 @@ 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,

				   (unsigned long)mod->module_init

				   + mod->init_size);

	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);