[PATCH 4.19 46/50] modules: fix compile error if dont have strict module rwx

Greg Kroah-Hartman
2019-09-18T06:31:06Z

From: Yang Yingliang <yangyingliang@huawei.com>

commit 93651f80dcb616b8c9115cdafc8e57a781af22d0 upstream.

If CONFIG_ARCH_HAS_STRICT_MODULE_RWX is not defined,
we need stub for module_enable_nx() and module_enable_x().

If CONFIG_ARCH_HAS_STRICT_MODULE_RWX is defined, but
CONFIG_STRICT_MODULE_RWX is disabled, we need stub for
module_enable_nx.

Move frob_text() outside of the CONFIG_STRICT_MODULE_RWX,
because it is needed anyway.

Fixes: 2eef1399a866 ("modules: fix BUG when load module with rodata=n")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
kernel/module.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1884,7 +1884,7 @@ static void mod_sysfs_teardown(struct mo
mod_sysfs_fini(mod);
}

-#ifdef CONFIG_STRICT_MODULE_RWX
+#ifdef CONFIG_ARCH_HAS_STRICT_MODULE_RWX
/*
* LKM RO/NX protection: protect module's text/ro-data
* from modification and any data from execution.
@@ -1907,6 +1907,7 @@ static void frob_text(const struct modul
layout->text_size >> PAGE_SHIFT);
}

+#ifdef CONFIG_STRICT_MODULE_RWX
static void frob_rodata(const struct module_layout *layout,
int (*set_memory)(unsigned long start, int num_pages))
{
@@ -2039,17 +2040,21 @@ static void disable_ro_nx(const struct m
frob_writable_data(layout, set_memory_x);
}

-#else
+#else /* !CONFIG_STRICT_MODULE_RWX */
static void disable_ro_nx(const struct module_layout *layout) { }
static void module_enable_nx(const struct module *mod) { }
static void module_disable_nx(const struct module *mod) { }
-#endif
+#endif /* CONFIG_STRICT_MODULE_RWX */

static void module_enable_x(const struct module *mod)
{
frob_text(&mod->core_layout, set_memory_x);
frob_text(&mod->init_layout, set_memory_x);
}
+#else /* !CONFIG_ARCH_HAS_STRICT_MODULE_RWX */
+static void module_enable_nx(const struct module *mod) { }
+static void module_enable_x(const struct module *mod) { }
+#endif /* CONFIG_ARCH_HAS_STRICT_MODULE_RWX */

#ifdef CONFIG_LIVEPATCH
/*