From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Jessica Yu <jeyu@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>,
Petr Mladek <pmladek@suse.com>, Jiri Kosina <jikos@kernel.org>,
Miroslav Benes <mbenes@suse.cz>,
Joe Lawrence <joe.lawrence@redhat.com>,
linux-kernel@vger.kernel.org, live-patching@vger.kernel.org,
Johannes Erdfelt <johannes@erdfelt.com>,
Ingo Molnar <mingo@kernel.org>
Subject: [PATCH 2/3] module: Add text_mutex lockdep assertions for page attribute changes
Date: Thu, 13 Jun 2019 20:07:23 -0500 [thread overview]
Message-ID: <bb2b2c63c60e0b415ea1f78e6a0e3ed89ab82008.1560474114.git.jpoimboe@redhat.com> (raw)
In-Reply-To: <cover.1560474114.git.jpoimboe@redhat.com>
External callers of the module page attribute change functions now need
to have the text_mutex. Enforce that with lockdep assertions.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
kernel/module.c | 27 +++++++++++++++++++++------
1 file changed, 21 insertions(+), 6 deletions(-)
diff --git a/kernel/module.c b/kernel/module.c
index 6e6712b3aaf5..e43a90ee2d23 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -64,6 +64,7 @@
#include <linux/bsearch.h>
#include <linux/dynamic_debug.h>
#include <linux/audit.h>
+#include <linux/memory.h>
#include <uapi/linux/module.h>
#include "module-internal.h"
@@ -1943,6 +1944,8 @@ static void frob_writable_data(const struct module_layout *layout,
/* livepatching wants to disable read-only so it can frob module. */
void module_disable_ro(const struct module *mod)
{
+ lockdep_assert_held(&text_mutex);
+
if (!rodata_enabled)
return;
@@ -1953,7 +1956,7 @@ void module_disable_ro(const struct module *mod)
frob_rodata(&mod->init_layout, set_memory_rw);
}
-void module_enable_ro(const struct module *mod, bool after_init)
+void __module_enable_ro(const struct module *mod, bool after_init)
{
if (!rodata_enabled)
return;
@@ -1974,7 +1977,14 @@ void module_enable_ro(const struct module *mod, bool after_init)
frob_ro_after_init(&mod->core_layout, set_memory_ro);
}
-static void module_enable_nx(const struct module *mod)
+void module_enable_ro(const struct module *mod, bool after_init)
+{
+ lockdep_assert_held(&text_mutex);
+
+ __module_enable_ro(mod, after_init);
+}
+
+static void __module_enable_nx(const struct module *mod)
{
frob_rodata(&mod->core_layout, set_memory_nx);
frob_ro_after_init(&mod->core_layout, set_memory_nx);
@@ -1988,6 +1998,8 @@ void set_all_modules_text_rw(void)
{
struct module *mod;
+ lockdep_assert_held(&text_mutex);
+
if (!rodata_enabled)
return;
@@ -2007,6 +2019,8 @@ void set_all_modules_text_ro(void)
{
struct module *mod;
+ lockdep_assert_held(&text_mutex);
+
if (!rodata_enabled)
return;
@@ -2027,7 +2041,8 @@ void set_all_modules_text_ro(void)
mutex_unlock(&module_mutex);
}
#else
-static void module_enable_nx(const struct module *mod) { }
+static void __module_enable_ro(const struct module *mod, bool after_init) { }
+static void __module_enable_nx(const struct module *mod) { }
#endif
#ifdef CONFIG_LIVEPATCH
@@ -3519,7 +3534,7 @@ static noinline int do_init_module(struct module *mod)
/* Switch to core kallsyms now init is done: kallsyms may be walking! */
rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms);
#endif
- module_enable_ro(mod, true);
+ __module_enable_ro(mod, true);
mod_tree_remove_init(mod);
module_arch_freeing_init(mod);
mod->init_layout.base = NULL;
@@ -3626,8 +3641,8 @@ static int complete_formation(struct module *mod, struct load_info *info)
/* This relies on module_mutex for list integrity. */
module_bug_finalize(info->hdr, info->sechdrs, mod);
- module_enable_ro(mod, false);
- module_enable_nx(mod);
+ __module_enable_ro(mod, false);
+ __module_enable_nx(mod);
/* Mark state as coming so strong_try_module_get() ignores us,
* but kallsyms etc. can see us. */
--
2.20.1
next prev parent reply other threads:[~2019-06-14 1:08 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-14 1:07 [PATCH 0/3] module: Livepatch/ftrace fixes Josh Poimboeuf
2019-06-14 1:07 ` [PATCH 1/3] module: Fix livepatch/ftrace module text permissions race Josh Poimboeuf
2019-06-14 21:04 ` Steven Rostedt
2019-06-26 8:22 ` Miroslav Benes
2019-06-26 13:37 ` Petr Mladek
2019-06-26 14:44 ` Thomas Gleixner
2019-06-26 14:52 ` Josh Poimboeuf
2019-06-26 14:59 ` Steven Rostedt
2019-06-14 1:07 ` Josh Poimboeuf [this message]
2019-06-14 14:04 ` [PATCH 2/3] module: Add text_mutex lockdep assertions for page attribute changes Petr Mladek
2019-06-14 18:21 ` Josh Poimboeuf
2019-06-14 1:07 ` [PATCH 3/3] module: Improve module __ro_after_init handling Josh Poimboeuf
2019-06-14 14:14 ` Petr Mladek
2019-06-14 18:23 ` Josh Poimboeuf
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