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-rw-r--r--kernel/module.c105
1 files changed, 64 insertions, 41 deletions
diff --git a/kernel/module.c b/kernel/module.c
index 4d5c16aae74..795bdc7f5c3 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -57,6 +57,7 @@
#include <linux/kmemleak.h>
#include <linux/jump_label.h>
#include <linux/pfn.h>
+#include <linux/bsearch.h>
#define CREATE_TRACE_POINTS
#include <trace/events/module.h>
@@ -240,23 +241,24 @@ static bool each_symbol_in_section(const struct symsearch *arr,
struct module *owner,
bool (*fn)(const struct symsearch *syms,
struct module *owner,
- unsigned int symnum, void *data),
+ void *data),
void *data)
{
- unsigned int i, j;
+ unsigned int j;
for (j = 0; j < arrsize; j++) {
- for (i = 0; i < arr[j].stop - arr[j].start; i++)
- if (fn(&arr[j], owner, i, data))
- return true;
+ if (fn(&arr[j], owner, data))
+ return true;
}
return false;
}
/* Returns true as soon as fn returns true, otherwise false. */
-bool each_symbol(bool (*fn)(const struct symsearch *arr, struct module *owner,
- unsigned int symnum, void *data), void *data)
+bool each_symbol_section(bool (*fn)(const struct symsearch *arr,
+ struct module *owner,
+ void *data),
+ void *data)
{
struct module *mod;
static const struct symsearch arr[] = {
@@ -309,7 +311,7 @@ bool each_symbol(bool (*fn)(const struct symsearch *arr, struct module *owner,
}
return false;
}
-EXPORT_SYMBOL_GPL(each_symbol);
+EXPORT_SYMBOL_GPL(each_symbol_section);
struct find_symbol_arg {
/* Input */
@@ -323,15 +325,12 @@ struct find_symbol_arg {
const struct kernel_symbol *sym;
};
-static bool find_symbol_in_section(const struct symsearch *syms,
- struct module *owner,
- unsigned int symnum, void *data)
+static bool check_symbol(const struct symsearch *syms,
+ struct module *owner,
+ unsigned int symnum, void *data)
{
struct find_symbol_arg *fsa = data;
- if (strcmp(syms->start[symnum].name, fsa->name) != 0)
- return false;
-
if (!fsa->gplok) {
if (syms->licence == GPL_ONLY)
return false;
@@ -365,6 +364,30 @@ static bool find_symbol_in_section(const struct symsearch *syms,
return true;
}
+static int cmp_name(const void *va, const void *vb)
+{
+ const char *a;
+ const struct kernel_symbol *b;
+ a = va; b = vb;
+ return strcmp(a, b->name);
+}
+
+static bool find_symbol_in_section(const struct symsearch *syms,
+ struct module *owner,
+ void *data)
+{
+ struct find_symbol_arg *fsa = data;
+ struct kernel_symbol *sym;
+
+ sym = bsearch(fsa->name, syms->start, syms->stop - syms->start,
+ sizeof(struct kernel_symbol), cmp_name);
+
+ if (sym != NULL && check_symbol(syms, owner, sym - syms->start, data))
+ return true;
+
+ return false;
+}
+
/* Find a symbol and return it, along with, (optional) crc and
* (optional) module which owns it. Needs preempt disabled or module_mutex. */
const struct kernel_symbol *find_symbol(const char *name,
@@ -379,7 +402,7 @@ const struct kernel_symbol *find_symbol(const char *name,
fsa.gplok = gplok;
fsa.warn = warn;
- if (each_symbol(find_symbol_in_section, &fsa)) {
+ if (each_symbol_section(find_symbol_in_section, &fsa)) {
if (owner)
*owner = fsa.owner;
if (crc)
@@ -1607,27 +1630,28 @@ static void set_section_ro_nx(void *base,
}
}
-/* Setting memory back to RW+NX before releasing it */
-void unset_section_ro_nx(struct module *mod, void *module_region)
+static void unset_module_core_ro_nx(struct module *mod)
{
- unsigned long total_pages;
-
- if (mod->module_core == module_region) {
- /* Set core as NX+RW */
- total_pages = MOD_NUMBER_OF_PAGES(mod->module_core, mod->core_size);
- set_memory_nx((unsigned long)mod->module_core, total_pages);
- set_memory_rw((unsigned long)mod->module_core, total_pages);
+ set_page_attributes(mod->module_core + mod->core_text_size,
+ mod->module_core + mod->core_size,
+ set_memory_x);
+ set_page_attributes(mod->module_core,
+ mod->module_core + mod->core_ro_size,
+ set_memory_rw);
+}
- } else if (mod->module_init == module_region) {
- /* Set init as NX+RW */
- total_pages = MOD_NUMBER_OF_PAGES(mod->module_init, mod->init_size);
- set_memory_nx((unsigned long)mod->module_init, total_pages);
- set_memory_rw((unsigned long)mod->module_init, total_pages);
- }
+static void unset_module_init_ro_nx(struct module *mod)
+{
+ set_page_attributes(mod->module_init + mod->init_text_size,
+ mod->module_init + mod->init_size,
+ set_memory_x);
+ set_page_attributes(mod->module_init,
+ mod->module_init + mod->init_ro_size,
+ set_memory_rw);
}
/* Iterate through all modules and set each module's text as RW */
-void set_all_modules_text_rw()
+void set_all_modules_text_rw(void)
{
struct module *mod;
@@ -1648,7 +1672,7 @@ void set_all_modules_text_rw()
}
/* Iterate through all modules and set each module's text as RO */
-void set_all_modules_text_ro()
+void set_all_modules_text_ro(void)
{
struct module *mod;
@@ -1669,7 +1693,8 @@ void set_all_modules_text_ro()
}
#else
static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { }
-static inline void unset_section_ro_nx(struct module *mod, void *module_region) { }
+static void unset_module_core_ro_nx(struct module *mod) { }
+static void unset_module_init_ro_nx(struct module *mod) { }
#endif
/* Free a module, remove from lists, etc. */
@@ -1696,7 +1721,7 @@ static void free_module(struct module *mod)
destroy_params(mod->kp, mod->num_kp);
/* This may be NULL, but that's OK */
- unset_section_ro_nx(mod, mod->module_init);
+ unset_module_init_ro_nx(mod);
module_free(mod, mod->module_init);
kfree(mod->args);
percpu_modfree(mod);
@@ -1705,7 +1730,7 @@ static void free_module(struct module *mod)
lockdep_free_key_range(mod->module_core, mod->core_size);
/* Finally, free the core (containing the module structure) */
- unset_section_ro_nx(mod, mod->module_core);
+ unset_module_core_ro_nx(mod);
module_free(mod, mod->module_core);
#ifdef CONFIG_MPU
@@ -2030,11 +2055,8 @@ static const struct kernel_symbol *lookup_symbol(const char *name,
const struct kernel_symbol *start,
const struct kernel_symbol *stop)
{
- const struct kernel_symbol *ks = start;
- for (; ks < stop; ks++)
- if (strcmp(ks->name, name) == 0)
- return ks;
- return NULL;
+ return bsearch(name, start, stop - start,
+ sizeof(struct kernel_symbol), cmp_name);
}
static int is_exported(const char *name, unsigned long value,
@@ -2931,10 +2953,11 @@ SYSCALL_DEFINE3(init_module, void __user *, umod,
mod->symtab = mod->core_symtab;
mod->strtab = mod->core_strtab;
#endif
- unset_section_ro_nx(mod, mod->module_init);
+ unset_module_init_ro_nx(mod);
module_free(mod, mod->module_init);
mod->module_init = NULL;
mod->init_size = 0;
+ mod->init_ro_size = 0;
mod->init_text_size = 0;
mutex_unlock(&module_mutex);
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-12-03 04:30:08 +0000