#include <linux/jump_label.h>
#include <linux/pfn.h>
#include <linux/bsearch.h>
+#include <linux/dynamic_debug.h>
#include <uapi/linux/module.h>
#include "module-internal.h"
if (unlikely(!debug_locks))
return;
- WARN_ON(!rcu_read_lock_sched_held() &&
+ WARN_ON_ONCE(!rcu_read_lock_sched_held() &&
!lockdep_is_held(&module_mutex));
#endif
}
* from modification and any data from execution.
*
* General layout of module is:
- * [text] [read-only-data] [writable data]
- * text_size -----^ ^ ^
- * ro_size ------------------------| |
- * size -------------------------------------------|
+ * [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)
*/
(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))
+{
+ BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
+ BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
+ BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
+ 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))
{
BUG_ON((unsigned long)layout->base & (PAGE_SIZE-1));
- BUG_ON((unsigned long)layout->ro_size & (PAGE_SIZE-1));
+ BUG_ON((unsigned long)layout->ro_after_init_size & (PAGE_SIZE-1));
BUG_ON((unsigned long)layout->size & (PAGE_SIZE-1));
- set_memory((unsigned long)layout->base + layout->ro_size,
- (layout->size - layout->ro_size) >> PAGE_SHIFT);
+ set_memory((unsigned long)layout->base + layout->ro_after_init_size,
+ (layout->size - layout->ro_after_init_size) >> PAGE_SHIFT);
}
/* livepatching wants to disable read-only so it can frob module. */
{
frob_text(&mod->core_layout, set_memory_rw);
frob_rodata(&mod->core_layout, set_memory_rw);
+ frob_ro_after_init(&mod->core_layout, set_memory_rw);
frob_text(&mod->init_layout, set_memory_rw);
frob_rodata(&mod->init_layout, set_memory_rw);
}
-void module_enable_ro(const struct module *mod)
+void module_enable_ro(const struct module *mod, bool after_init)
{
frob_text(&mod->core_layout, set_memory_ro);
frob_rodata(&mod->core_layout, set_memory_ro);
frob_text(&mod->init_layout, set_memory_ro);
frob_rodata(&mod->init_layout, set_memory_ro);
+
+ if (after_init)
+ frob_ro_after_init(&mod->core_layout, set_memory_ro);
}
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);
frob_writable_data(&mod->core_layout, set_memory_nx);
frob_rodata(&mod->init_layout, set_memory_nx);
frob_writable_data(&mod->init_layout, set_memory_nx);
static void module_disable_nx(const struct module *mod)
{
frob_rodata(&mod->core_layout, set_memory_x);
+ frob_ro_after_init(&mod->core_layout, set_memory_x);
frob_writable_data(&mod->core_layout, set_memory_x);
frob_rodata(&mod->init_layout, set_memory_x);
frob_writable_data(&mod->init_layout, set_memory_x);
frob_text(layout, set_memory_rw);
frob_rodata(layout, set_memory_rw);
frob_rodata(layout, set_memory_x);
+ frob_ro_after_init(layout, set_memory_rw);
+ frob_ro_after_init(layout, set_memory_x);
frob_writable_data(layout, set_memory_x);
}
* finder in the two loops below */
{ SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
{ SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
+ { SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
{ SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL },
{ ARCH_SHF_SMALL | SHF_ALLOC, 0 }
};
mod->core_layout.size = debug_align(mod->core_layout.size);
mod->core_layout.ro_size = mod->core_layout.size;
break;
- case 3: /* whole core */
+ case 2: /* RO after init */
+ mod->core_layout.size = debug_align(mod->core_layout.size);
+ mod->core_layout.ro_after_init_size = mod->core_layout.size;
+ break;
+ case 4: /* whole core */
mod->core_layout.size = debug_align(mod->core_layout.size);
break;
}
mod->init_layout.size = debug_align(mod->init_layout.size);
mod->init_layout.ro_size = mod->init_layout.size;
break;
- case 3: /* whole init */
+ case 2:
+ /*
+ * RO after init doesn't apply to init_layout (only
+ * core_layout), so it just takes the value of ro_size.
+ */
+ mod->init_layout.ro_after_init_size = mod->init_layout.ro_size;
+ break;
+ case 4: /* whole init */
mod->init_layout.size = debug_align(mod->init_layout.size);
break;
}
return 0;
}
+/* module_blacklist is a comma-separated list of module names */
+static char *module_blacklist;
+static bool blacklisted(char *module_name)
+{
+ const char *p;
+ size_t len;
+
+ if (!module_blacklist)
+ return false;
+
+ for (p = module_blacklist; *p; p += len) {
+ len = strcspn(p, ",");
+ if (strlen(module_name) == len && !memcmp(module_name, p, len))
+ return true;
+ if (p[len] == ',')
+ len++;
+ }
+ return false;
+}
+core_param(module_blacklist, module_blacklist, charp, 0400);
+
static struct module *layout_and_allocate(struct load_info *info, int flags)
{
/* Module within temporary copy. */
struct module *mod;
+ unsigned int ndx;
int err;
mod = setup_load_info(info, flags);
if (IS_ERR(mod))
return mod;
+ if (blacklisted(mod->name))
+ return ERR_PTR(-EPERM);
+
err = check_modinfo(mod, info, flags);
if (err)
return ERR_PTR(err);
/* We will do a special allocation for per-cpu sections later. */
info->sechdrs[info->index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
+ /*
+ * Mark ro_after_init section with SHF_RO_AFTER_INIT so that
+ * layout_sections() can put it in the right place.
+ * Note: ro_after_init sections also have SHF_{WRITE,ALLOC} set.
+ */
+ ndx = find_sec(info, ".data..ro_after_init");
+ if (ndx)
+ info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
+
/* Determine total sizes, and put offsets in sh_entsize. For now
this is done generically; there doesn't appear to be any
special cases for the architectures. */
/* 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);
mod_tree_remove_init(mod);
disable_ro_nx(&mod->init_layout);
module_arch_freeing_init(mod);
mod->init_layout.base = NULL;
mod->init_layout.size = 0;
mod->init_layout.ro_size = 0;
+ mod->init_layout.ro_after_init_size = 0;
mod->init_layout.text_size = 0;
/*
* We want to free module_init, but be aware that kallsyms may be
/* This relies on module_mutex for list integrity. */
module_bug_finalize(info->hdr, info->sechdrs, mod);
- /* Set RO and NX regions */
- module_enable_ro(mod);
+ module_enable_ro(mod, false);
module_enable_nx(mod);
/* Mark state as coming so strong_try_module_get() ignores us,
projects / cascardo / linux.git / blobdiff