[PATCH v2 06/10] module: introduce MODULE_STATE_GONE
From: Mike Rapoport <rppt@kernel.org>
Date: 2025-01-21 09:58:58
Also in:
linux-kselftest, linux-mm, linux-modules, linux-um, live-patching, lkml
Subsystem:
kernel selftest framework, kernel unit testing framework (kunit), kgdb / kdb /debug_core, library code, live patching, module support, the rest, tracing · Maintainers:
Shuah Khan, Brendan Higgins, David Gow, Jason Wessel, Daniel Thompson, Andrew Morton, Josh Poimboeuf, Jiri Kosina, Miroslav Benes, Petr Mladek, Luis Chamberlain, Petr Pavlu, Daniel Gomez, Sami Tolvanen, Linus Torvalds, Steven Rostedt, Masami Hiramatsu
From: "Mike Rapoport (Microsoft)" <rppt@kernel.org> In order to use execmem's API for temporal remapping of the memory allocated from ROX cache as writable, there is a need to distinguish between the state when the module is being formed and the state when it is deconstructed and freed so that when module_memory_free() is called from error paths during module loading it could restore ROX mappings. Replace open coded checks for MODULE_STATE_UNFORMED with a helper function module_is_formed() and add a new MODULE_STATE_GONE that will be set when the module is deconstructed and freed. Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Daniel Thompson (RISCstar) <danielt@kernel.org> --- include/linux/module.h | 6 ++++++ kernel/module/kallsyms.c | 8 ++++---- kernel/module/kdb.c | 2 +- kernel/module/main.c | 19 +++++++++---------- kernel/module/procfs.c | 2 +- kernel/tracepoint.c | 2 ++ lib/kunit/test.c | 2 ++ samples/livepatch/livepatch-callbacks-demo.c | 1 + .../test_modules/test_klp_callbacks_demo.c | 1 + .../test_modules/test_klp_callbacks_demo2.c | 1 + .../livepatch/test_modules/test_klp_state.c | 1 + .../livepatch/test_modules/test_klp_state2.c | 1 + 12 files changed, 30 insertions(+), 16 deletions(-)
diff --git a/include/linux/module.h b/include/linux/module.h
index b3a643435357..624a5317d5a5 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h@@ -320,6 +320,7 @@ enum module_state { MODULE_STATE_COMING, /* Full formed, running module_init. */ MODULE_STATE_GOING, /* Going away. */ MODULE_STATE_UNFORMED, /* Still setting it up. */ + MODULE_STATE_GONE, /* Deconstructing and freeing. */ }; struct mod_tree_node {
@@ -620,6 +621,11 @@ static inline bool module_is_coming(struct module *mod) return mod->state == MODULE_STATE_COMING; } +static inline bool module_is_formed(struct module *mod) +{ + return mod->state < MODULE_STATE_UNFORMED; +} + struct module *__module_text_address(unsigned long addr); struct module *__module_address(unsigned long addr); bool is_module_address(unsigned long addr);
diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c
index bf65e0c3c86f..daf9a9b3740f 100644
--- a/kernel/module/kallsyms.c
+++ b/kernel/module/kallsyms.c@@ -361,7 +361,7 @@ int lookup_module_symbol_name(unsigned long addr, char *symname) preempt_disable(); list_for_each_entry_rcu(mod, &modules, list) { - if (mod->state == MODULE_STATE_UNFORMED) + if (!module_is_formed(mod)) continue; if (within_module(addr, mod)) { const char *sym;
@@ -389,7 +389,7 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, list_for_each_entry_rcu(mod, &modules, list) { struct mod_kallsyms *kallsyms; - if (mod->state == MODULE_STATE_UNFORMED) + if (!module_is_formed(mod)) continue; kallsyms = rcu_dereference_sched(mod->kallsyms); if (symnum < kallsyms->num_symtab) {
@@ -441,7 +441,7 @@ static unsigned long __module_kallsyms_lookup_name(const char *name) list_for_each_entry_rcu(mod, &modules, list) { unsigned long ret; - if (mod->state == MODULE_STATE_UNFORMED) + if (!module_is_formed(mod)) continue; ret = __find_kallsyms_symbol_value(mod, name); if (ret)
@@ -484,7 +484,7 @@ int module_kallsyms_on_each_symbol(const char *modname, list_for_each_entry(mod, &modules, list) { struct mod_kallsyms *kallsyms; - if (mod->state == MODULE_STATE_UNFORMED) + if (!module_is_formed(mod)) continue; if (modname && strcmp(modname, mod->name))
diff --git a/kernel/module/kdb.c b/kernel/module/kdb.c
index 995c32d3698f..14f14700ffc2 100644
--- a/kernel/module/kdb.c
+++ b/kernel/module/kdb.c@@ -23,7 +23,7 @@ int kdb_lsmod(int argc, const char **argv) kdb_printf("Module Size modstruct Used by\n"); list_for_each_entry(mod, &modules, list) { - if (mod->state == MODULE_STATE_UNFORMED) + if (!module_is_formed(mod)) continue; kdb_printf("%-20s%8u", mod->name, mod->mem[MOD_TEXT].size);
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 5399c182b3cb..ad8ef20c120f 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c@@ -153,7 +153,7 @@ EXPORT_SYMBOL(unregister_module_notifier); */ static inline int strong_try_module_get(struct module *mod) { - BUG_ON(mod && mod->state == MODULE_STATE_UNFORMED); + BUG_ON(mod && !module_is_formed(mod)); if (mod && mod->state == MODULE_STATE_COMING) return -EBUSY; if (try_module_get(mod))
@@ -361,7 +361,7 @@ bool find_symbol(struct find_symbol_arg *fsa) GPL_ONLY }, }; - if (mod->state == MODULE_STATE_UNFORMED) + if (!module_is_formed(mod)) continue; for (i = 0; i < ARRAY_SIZE(arr); i++)
@@ -386,7 +386,7 @@ struct module *find_module_all(const char *name, size_t len, list_for_each_entry_rcu(mod, &modules, list, lockdep_is_held(&module_mutex)) { - if (!even_unformed && mod->state == MODULE_STATE_UNFORMED) + if (!even_unformed && !module_is_formed(mod)) continue; if (strlen(mod->name) == len && !memcmp(mod->name, name, len)) return mod;
@@ -457,7 +457,7 @@ bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr) preempt_disable(); list_for_each_entry_rcu(mod, &modules, list) { - if (mod->state == MODULE_STATE_UNFORMED) + if (!module_is_formed(mod)) continue; if (!mod->percpu_size) continue;
@@ -1326,7 +1326,7 @@ static void free_module(struct module *mod) * that noone uses it while it's being deconstructed. */ mutex_lock(&module_mutex); - mod->state = MODULE_STATE_UNFORMED; + mod->state = MODULE_STATE_GONE; mutex_unlock(&module_mutex); /* Arch-specific cleanup. */
@@ -3048,8 +3048,7 @@ static int module_patient_check_exists(const char *name, if (old == NULL) return 0; - if (old->state == MODULE_STATE_COMING || - old->state == MODULE_STATE_UNFORMED) { + if (old->state == MODULE_STATE_COMING || !module_is_formed(old)) { /* Wait in case it fails to load. */ mutex_unlock(&module_mutex); err = wait_event_interruptible(module_wq,
@@ -3608,7 +3607,7 @@ char *module_flags(struct module *mod, char *buf, bool show_state) { int bx = 0; - BUG_ON(mod->state == MODULE_STATE_UNFORMED); + BUG_ON(!module_is_formed(mod)); if (!mod->taints && !show_state) goto out; if (mod->taints ||
@@ -3702,7 +3701,7 @@ struct module *__module_address(unsigned long addr) mod = mod_find(addr, &mod_tree); if (mod) { BUG_ON(!within_module(addr, mod)); - if (mod->state == MODULE_STATE_UNFORMED) + if (!module_is_formed(mod)) mod = NULL; } return mod;
@@ -3756,7 +3755,7 @@ void print_modules(void) /* Most callers should already have preempt disabled, but make sure */ preempt_disable(); list_for_each_entry_rcu(mod, &modules, list) { - if (mod->state == MODULE_STATE_UNFORMED) + if (!module_is_formed(mod)) continue; pr_cont(" %s%s", mod->name, module_flags(mod, buf, true)); }
diff --git a/kernel/module/procfs.c b/kernel/module/procfs.c
index 0a4841e88adb..2c617e6f8bc0 100644
--- a/kernel/module/procfs.c
+++ b/kernel/module/procfs.c@@ -79,7 +79,7 @@ static int m_show(struct seq_file *m, void *p) unsigned int size; /* We always ignore unformed modules. */ - if (mod->state == MODULE_STATE_UNFORMED) + if (!module_is_formed(mod)) return 0; size = module_total_size(mod);
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index 1848ce7e2976..e94247afb2c6 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c@@ -668,6 +668,8 @@ static int tracepoint_module_notify(struct notifier_block *self, break; case MODULE_STATE_UNFORMED: break; + case MODULE_STATE_GONE: + break; } return notifier_from_errno(ret); }
diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index 089c832e3cdb..54eaed92a2d3 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c@@ -836,6 +836,8 @@ static int kunit_module_notify(struct notifier_block *nb, unsigned long val, break; case MODULE_STATE_UNFORMED: break; + case MODULE_STATE_GONE: + break; } return 0;
diff --git a/samples/livepatch/livepatch-callbacks-demo.c b/samples/livepatch/livepatch-callbacks-demo.c
index 11c3f4357812..324bddaef9a6 100644
--- a/samples/livepatch/livepatch-callbacks-demo.c
+++ b/samples/livepatch/livepatch-callbacks-demo.c@@ -93,6 +93,7 @@ static const char *const module_state[] = { [MODULE_STATE_COMING] = "[MODULE_STATE_COMING] Full formed, running module_init", [MODULE_STATE_GOING] = "[MODULE_STATE_GOING] Going away", [MODULE_STATE_UNFORMED] = "[MODULE_STATE_UNFORMED] Still setting it up", + [MODULE_STATE_GONE] = "[MODULE_STATE_GONE] Deconstructing and freeing", }; static void callback_info(const char *callback, struct klp_object *obj)
diff --git a/tools/testing/selftests/livepatch/test_modules/test_klp_callbacks_demo.c b/tools/testing/selftests/livepatch/test_modules/test_klp_callbacks_demo.c
index 3fd8fe1cd1cc..8435e3254f85 100644
--- a/tools/testing/selftests/livepatch/test_modules/test_klp_callbacks_demo.c
+++ b/tools/testing/selftests/livepatch/test_modules/test_klp_callbacks_demo.c@@ -16,6 +16,7 @@ static const char *const module_state[] = { [MODULE_STATE_COMING] = "[MODULE_STATE_COMING] Full formed, running module_init", [MODULE_STATE_GOING] = "[MODULE_STATE_GOING] Going away", [MODULE_STATE_UNFORMED] = "[MODULE_STATE_UNFORMED] Still setting it up", + [MODULE_STATE_GONE] = "[MODULE_STATE_GONE] Deconstructing and freeing", }; static void callback_info(const char *callback, struct klp_object *obj)
diff --git a/tools/testing/selftests/livepatch/test_modules/test_klp_callbacks_demo2.c b/tools/testing/selftests/livepatch/test_modules/test_klp_callbacks_demo2.c
index 5417573e80af..78c1fff5d977 100644
--- a/tools/testing/selftests/livepatch/test_modules/test_klp_callbacks_demo2.c
+++ b/tools/testing/selftests/livepatch/test_modules/test_klp_callbacks_demo2.c@@ -16,6 +16,7 @@ static const char *const module_state[] = { [MODULE_STATE_COMING] = "[MODULE_STATE_COMING] Full formed, running module_init", [MODULE_STATE_GOING] = "[MODULE_STATE_GOING] Going away", [MODULE_STATE_UNFORMED] = "[MODULE_STATE_UNFORMED] Still setting it up", + [MODULE_STATE_GONE] = "[MODULE_STATE_GONE] Deconstructing and freeing", }; static void callback_info(const char *callback, struct klp_object *obj)
diff --git a/tools/testing/selftests/livepatch/test_modules/test_klp_state.c b/tools/testing/selftests/livepatch/test_modules/test_klp_state.c
index 57a4253acb01..bdebf1d24c98 100644
--- a/tools/testing/selftests/livepatch/test_modules/test_klp_state.c
+++ b/tools/testing/selftests/livepatch/test_modules/test_klp_state.c@@ -18,6 +18,7 @@ static const char *const module_state[] = { [MODULE_STATE_COMING] = "[MODULE_STATE_COMING] Full formed, running module_init", [MODULE_STATE_GOING] = "[MODULE_STATE_GOING] Going away", [MODULE_STATE_UNFORMED] = "[MODULE_STATE_UNFORMED] Still setting it up", + [MODULE_STATE_GONE] = "[MODULE_STATE_GONE] Deconstructing and freeing", }; static void callback_info(const char *callback, struct klp_object *obj)
diff --git a/tools/testing/selftests/livepatch/test_modules/test_klp_state2.c b/tools/testing/selftests/livepatch/test_modules/test_klp_state2.c
index c978ea4d5e67..1a55f84a8eb3 100644
--- a/tools/testing/selftests/livepatch/test_modules/test_klp_state2.c
+++ b/tools/testing/selftests/livepatch/test_modules/test_klp_state2.c@@ -18,6 +18,7 @@ static const char *const module_state[] = { [MODULE_STATE_COMING] = "[MODULE_STATE_COMING] Full formed, running module_init", [MODULE_STATE_GOING] = "[MODULE_STATE_GOING] Going away", [MODULE_STATE_UNFORMED] = "[MODULE_STATE_UNFORMED] Still setting it up", + [MODULE_STATE_GONE] = "[MODULE_STATE_GONE] Deconstructing and freeing", }; static void callback_info(const char *callback, struct klp_object *obj)
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2.45.2