summaryrefslogtreecommitdiff
path: root/kernel/module/strict_rwx.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/module/strict_rwx.c')
-rw-r--r--kernel/module/strict_rwx.c99
1 files changed, 18 insertions, 81 deletions
diff --git a/kernel/module/strict_rwx.c b/kernel/module/strict_rwx.c
index 14fbea66f12f..a2b656b4e3d2 100644
--- a/kernel/module/strict_rwx.c
+++ b/kernel/module/strict_rwx.c
@@ -11,82 +11,25 @@
#include <linux/set_memory.h>
#include "internal.h"
-/*
- * LKM RO/NX protection: protect module's text/ro-data
- * from modification and any data from execution.
- *
- * General layout of module is:
- * [text] [read-only-data] [ro-after-init] [writable data]
- * text_size -----^ ^ ^ ^
- * ro_size ------------------------| | |
- * ro_after_init_size -----------------------------| |
- * size -----------------------------------------------------------|
- *
- * These values are always page-aligned (as is base) when
- * CONFIG_STRICT_MODULE_RWX is set.
- */
+static void module_set_memory(const struct module *mod, enum mod_mem_type type,
+ int (*set_memory)(unsigned long start, int num_pages))
+{
+ const struct module_memory *mod_mem = &mod->mem[type];
+
+ set_vm_flush_reset_perms(mod_mem->base);
+ set_memory((unsigned long)mod_mem->base, mod_mem->size >> PAGE_SHIFT);
+}
/*
* Since some arches are moving towards PAGE_KERNEL module allocations instead
- * of PAGE_KERNEL_EXEC, keep frob_text() and module_enable_x() independent of
+ * of PAGE_KERNEL_EXEC, keep module_enable_x() independent of
* CONFIG_STRICT_MODULE_RWX because they are needed regardless of whether we
* are strict.
*/
-static void frob_text(const struct module_layout *layout,
- int (*set_memory)(unsigned long start, int num_pages))
-{
- set_memory((unsigned long)layout->base,
- PAGE_ALIGN(layout->text_size) >> PAGE_SHIFT);
-}
-
-static void frob_rodata(const struct module_layout *layout,
- int (*set_memory)(unsigned long start, int num_pages))
-{
- set_memory((unsigned long)layout->base + layout->text_size,
- (layout->ro_size - layout->text_size) >> PAGE_SHIFT);
-}
-
-static void frob_ro_after_init(const struct module_layout *layout,
- int (*set_memory)(unsigned long start, int num_pages))
-{
- set_memory((unsigned long)layout->base + layout->ro_size,
- (layout->ro_after_init_size - layout->ro_size) >> PAGE_SHIFT);
-}
-
-static void frob_writable_data(const struct module_layout *layout,
- int (*set_memory)(unsigned long start, int num_pages))
-{
- set_memory((unsigned long)layout->base + layout->ro_after_init_size,
- (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
-}
-
-static bool layout_check_misalignment(const struct module_layout *layout)
-{
- return WARN_ON(!PAGE_ALIGNED(layout->base)) ||
- WARN_ON(!PAGE_ALIGNED(layout->text_size)) ||
- WARN_ON(!PAGE_ALIGNED(layout->ro_size)) ||
- WARN_ON(!PAGE_ALIGNED(layout->ro_after_init_size)) ||
- WARN_ON(!PAGE_ALIGNED(layout->size));
-}
-
-bool module_check_misalignment(const struct module *mod)
-{
- if (!IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
- return false;
-
- return layout_check_misalignment(&mod->core_layout) ||
- layout_check_misalignment(&mod->data_layout) ||
- layout_check_misalignment(&mod->init_layout);
-}
-
void module_enable_x(const struct module *mod)
{
- if (!PAGE_ALIGNED(mod->core_layout.base) ||
- !PAGE_ALIGNED(mod->init_layout.base))
- return;
-
- frob_text(&mod->core_layout, set_memory_x);
- frob_text(&mod->init_layout, set_memory_x);
+ for_class_mod_mem_type(type, text)
+ module_set_memory(mod, type, set_memory_x);
}
void module_enable_ro(const struct module *mod, bool after_init)
@@ -98,16 +41,13 @@ void module_enable_ro(const struct module *mod, bool after_init)
return;
#endif
- set_vm_flush_reset_perms(mod->core_layout.base);
- set_vm_flush_reset_perms(mod->init_layout.base);
- frob_text(&mod->core_layout, set_memory_ro);
-
- frob_rodata(&mod->data_layout, set_memory_ro);
- frob_text(&mod->init_layout, set_memory_ro);
- frob_rodata(&mod->init_layout, set_memory_ro);
+ module_set_memory(mod, MOD_TEXT, set_memory_ro);
+ module_set_memory(mod, MOD_INIT_TEXT, set_memory_ro);
+ module_set_memory(mod, MOD_RODATA, set_memory_ro);
+ module_set_memory(mod, MOD_INIT_RODATA, set_memory_ro);
if (after_init)
- frob_ro_after_init(&mod->data_layout, set_memory_ro);
+ module_set_memory(mod, MOD_RO_AFTER_INIT, set_memory_ro);
}
void module_enable_nx(const struct module *mod)
@@ -115,11 +55,8 @@ void module_enable_nx(const struct module *mod)
if (!IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
return;
- frob_rodata(&mod->data_layout, set_memory_nx);
- frob_ro_after_init(&mod->data_layout, set_memory_nx);
- frob_writable_data(&mod->data_layout, set_memory_nx);
- frob_rodata(&mod->init_layout, set_memory_nx);
- frob_writable_data(&mod->init_layout, set_memory_nx);
+ for_class_mod_mem_type(type, data)
+ module_set_memory(mod, type, set_memory_nx);
}
int module_enforce_rwx_sections(Elf_Ehdr *hdr, Elf_Shdr *sechdrs,