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authorChristophe Leroy <christophe.leroy@csgroup.eu>2022-02-23 13:02:14 +0100
committerLuis Chamberlain <mcgrof@kernel.org>2022-04-05 08:43:05 -0700
commit01dc0386efb769056257410ba5754558384006a7 (patch)
tree482f7422adef2c1d7f9c5ac85a065be8edcff18d /kernel/module
parent6ab9942c44b2d213a16b2620e4baf0223122222f (diff)
module: Add CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
Add CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC to allow architectures to request having modules data in vmalloc area instead of module area. This is required on powerpc book3s/32 in order to set data non executable, because it is not possible to set executability on page basis, this is done per 256 Mbytes segments. The module area has exec right, vmalloc area has noexec. This can also be useful on other powerpc/32 in order to maximize the chance of code being close enough to kernel core to avoid branch trampolines. Cc: Jason Wessel <jason.wessel@windriver.com> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Cc: Douglas Anderson <dianders@chromium.org> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mcgrof: rebased in light of kernel/module/kdb.c move] Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Diffstat (limited to 'kernel/module')
-rw-r--r--kernel/module/internal.h3
-rw-r--r--kernel/module/kdb.c10
-rw-r--r--kernel/module/main.c58
-rw-r--r--kernel/module/procfs.c8
-rw-r--r--kernel/module/strict_rwx.c1
-rw-r--r--kernel/module/tree_lookup.c8
6 files changed, 82 insertions, 6 deletions
diff --git a/kernel/module/internal.h b/kernel/module/internal.h
index 0aabbf5cbcd1..3e23bef5884d 100644
--- a/kernel/module/internal.h
+++ b/kernel/module/internal.h
@@ -20,7 +20,9 @@
/* Maximum number of characters written by module_flags() */
#define MODULE_FLAGS_BUF_SIZE (TAINT_FLAGS_COUNT + 4)
+#ifndef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
#define data_layout core_layout
+#endif
/*
* Modules' sections will be aligned on page boundaries
@@ -154,6 +156,7 @@ struct mod_tree_root {
};
extern struct mod_tree_root mod_tree;
+extern struct mod_tree_root mod_data_tree;
#ifdef CONFIG_MODULES_TREE_LOOKUP
void mod_tree_insert(struct module *mod);
diff --git a/kernel/module/kdb.c b/kernel/module/kdb.c
index a446c699db0a..f4317f92e189 100644
--- a/kernel/module/kdb.c
+++ b/kernel/module/kdb.c
@@ -26,8 +26,11 @@ int kdb_lsmod(int argc, const char **argv)
if (mod->state == MODULE_STATE_UNFORMED)
continue;
- kdb_printf("%-20s%8u 0x%px ", mod->name,
- mod->core_layout.size, (void *)mod);
+ kdb_printf("%-20s%8u", mod->name, mod->core_layout.size);
+#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
+ kdb_printf("/%8u", mod->data_layout.size);
+#endif
+ kdb_printf(" 0x%px ", (void *)mod);
#ifdef CONFIG_MODULE_UNLOAD
kdb_printf("%4d ", module_refcount(mod));
#endif
@@ -38,6 +41,9 @@ int kdb_lsmod(int argc, const char **argv)
else
kdb_printf(" (Live)");
kdb_printf(" 0x%px", mod->core_layout.base);
+#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
+ kdb_printf("/0x%px", mod->data_layout.base);
+#endif
#ifdef CONFIG_MODULE_UNLOAD
{
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 78658283408d..84b828431dcb 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -78,6 +78,12 @@ struct mod_tree_root mod_tree __cacheline_aligned = {
.addr_min = -1UL,
};
+#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
+struct mod_tree_root mod_data_tree __cacheline_aligned = {
+ .addr_min = -1UL,
+};
+#endif
+
#define module_addr_min mod_tree.addr_min
#define module_addr_max mod_tree.addr_max
@@ -107,6 +113,9 @@ static void mod_update_bounds(struct module *mod)
__mod_update_bounds(mod->core_layout.base, mod->core_layout.size, &mod_tree);
if (mod->init_layout.size)
__mod_update_bounds(mod->init_layout.base, mod->init_layout.size, &mod_tree);
+#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
+ __mod_update_bounds(mod->data_layout.base, mod->data_layout.size, &mod_data_tree);
+#endif
}
static void module_assert_mutex_or_preempt(void)
@@ -940,6 +949,17 @@ static ssize_t show_coresize(struct module_attribute *mattr,
static struct module_attribute modinfo_coresize =
__ATTR(coresize, 0444, show_coresize, NULL);
+#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
+static ssize_t show_datasize(struct module_attribute *mattr,
+ struct module_kobject *mk, char *buffer)
+{
+ return sprintf(buffer, "%u\n", mk->mod->data_layout.size);
+}
+
+static struct module_attribute modinfo_datasize =
+ __ATTR(datasize, 0444, show_datasize, NULL);
+#endif
+
static ssize_t show_initsize(struct module_attribute *mattr,
struct module_kobject *mk, char *buffer)
{
@@ -968,6 +988,9 @@ struct module_attribute *modinfo_attrs[] = {
&modinfo_srcversion,
&modinfo_initstate,
&modinfo_coresize,
+#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
+ &modinfo_datasize,
+#endif
&modinfo_initsize,
&modinfo_taint,
#ifdef CONFIG_MODULE_UNLOAD
@@ -1194,6 +1217,9 @@ static void free_module(struct module *mod)
/* Finally, free the core (containing the module structure) */
module_memfree(mod->core_layout.base);
+#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
+ vfree(mod->data_layout.base);
+#endif
}
void *__symbol_get(const char *symbol)
@@ -2124,6 +2150,24 @@ static int move_module(struct module *mod, struct load_info *info)
} else
mod->init_layout.base = NULL;
+#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
+ /* Do the allocs. */
+ ptr = vmalloc(mod->data_layout.size);
+ /*
+ * The pointer to this block is stored in the module structure
+ * which is inside the block. Just mark it as not being a
+ * leak.
+ */
+ kmemleak_not_leak(ptr);
+ if (!ptr) {
+ module_memfree(mod->core_layout.base);
+ module_memfree(mod->init_layout.base);
+ return -ENOMEM;
+ }
+
+ memset(ptr, 0, mod->data_layout.size);
+ mod->data_layout.base = ptr;
+#endif
/* Transfer each section which specifies SHF_ALLOC */
pr_debug("final section addresses:\n");
for (i = 0; i < info->hdr->e_shnum; i++) {
@@ -2299,6 +2343,9 @@ static void module_deallocate(struct module *mod, struct load_info *info)
module_arch_freeing_init(mod);
module_memfree(mod->init_layout.base);
module_memfree(mod->core_layout.base);
+#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
+ vfree(mod->data_layout.base);
+#endif
}
int __weak module_finalize(const Elf_Ehdr *hdr,
@@ -3015,13 +3062,20 @@ bool is_module_address(unsigned long addr)
struct module *__module_address(unsigned long addr)
{
struct module *mod;
+ struct mod_tree_root *tree;
- if (addr < module_addr_min || addr > module_addr_max)
+ if (addr >= mod_tree.addr_min && addr <= mod_tree.addr_max)
+ tree = &mod_tree;
+#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
+ else if (addr >= mod_data_tree.addr_min && addr <= mod_data_tree.addr_max)
+ tree = &mod_data_tree;
+#endif
+ else
return NULL;
module_assert_mutex_or_preempt();
- mod = mod_find(addr, &mod_tree);
+ mod = mod_find(addr, tree);
if (mod) {
BUG_ON(!within_module(addr, mod));
if (mod->state == MODULE_STATE_UNFORMED)
diff --git a/kernel/module/procfs.c b/kernel/module/procfs.c
index 2717e130788e..9a8f4f0f6329 100644
--- a/kernel/module/procfs.c
+++ b/kernel/module/procfs.c
@@ -67,13 +67,17 @@ static int m_show(struct seq_file *m, void *p)
struct module *mod = list_entry(p, struct module, list);
char buf[MODULE_FLAGS_BUF_SIZE];
void *value;
+ unsigned int size;
/* We always ignore unformed modules. */
if (mod->state == MODULE_STATE_UNFORMED)
return 0;
- seq_printf(m, "%s %u",
- mod->name, mod->init_layout.size + mod->core_layout.size);
+ size = mod->init_layout.size + mod->core_layout.size;
+#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
+ size += mod->data_layout.size;
+#endif
+ seq_printf(m, "%s %u", mod->name, size);
print_unload_info(m, mod);
/* Informative for users. */
diff --git a/kernel/module/strict_rwx.c b/kernel/module/strict_rwx.c
index fe3c10891407..14fbea66f12f 100644
--- a/kernel/module/strict_rwx.c
+++ b/kernel/module/strict_rwx.c
@@ -75,6 +75,7 @@ bool module_check_misalignment(const struct module *mod)
return false;
return layout_check_misalignment(&mod->core_layout) ||
+ layout_check_misalignment(&mod->data_layout) ||
layout_check_misalignment(&mod->init_layout);
}
diff --git a/kernel/module/tree_lookup.c b/kernel/module/tree_lookup.c
index 995fe68059db..8ec5cfd60496 100644
--- a/kernel/module/tree_lookup.c
+++ b/kernel/module/tree_lookup.c
@@ -83,6 +83,11 @@ void mod_tree_insert(struct module *mod)
__mod_tree_insert(&mod->core_layout.mtn, &mod_tree);
if (mod->init_layout.size)
__mod_tree_insert(&mod->init_layout.mtn, &mod_tree);
+
+#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
+ mod->data_layout.mtn.mod = mod;
+ __mod_tree_insert(&mod->data_layout.mtn, &mod_data_tree);
+#endif
}
void mod_tree_remove_init(struct module *mod)
@@ -95,6 +100,9 @@ void mod_tree_remove(struct module *mod)
{
__mod_tree_remove(&mod->core_layout.mtn, &mod_tree);
mod_tree_remove_init(mod);
+#ifdef CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC
+ __mod_tree_remove(&mod->data_layout.mtn, &mod_data_tree);
+#endif
}
struct module *mod_find(unsigned long addr, struct mod_tree_root *tree)