From: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
Add __module_build_id() to find module by build_id. This also makes
module::build_id available with CONFIG_MODULE_BUILD_ID kconfig.
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
---
include/linux/module.h | 8 +++++++-
kernel/module/Kconfig | 3 +++
kernel/module/kallsyms.c | 4 ++--
kernel/module/main.c | 29 +++++++++++++++++++++++++++++
lib/Kconfig.debug | 1 +
5 files changed, 42 insertions(+), 3 deletions(-)
diff --git a/include/linux/module.h b/include/linux/module.h
index b3a643435357..e181056d6af6 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -416,7 +416,7 @@ struct module {
/* Unique handle for this module */
char name[MODULE_NAME_LEN];
-#ifdef CONFIG_STACKTRACE_BUILD_ID
+#ifdef CONFIG_MODULE_BUILD_ID
/* Module build ID */
unsigned char build_id[BUILD_ID_SIZE_MAX];
#endif
@@ -622,6 +622,7 @@ static inline bool module_is_coming(struct module *mod)
struct module *__module_text_address(unsigned long addr);
struct module *__module_address(unsigned long addr);
+struct module *__module_build_id(unsigned char *build_id, int size);
bool is_module_address(unsigned long addr);
bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr);
bool is_module_percpu_address(unsigned long addr);
@@ -791,6 +792,11 @@ static inline struct module *__module_text_address(unsigned long addr)
return NULL;
}
+static inline struct module *__module_build_id(unsigned char *build_id, int size)
+{
+ return NULL;
+}
+
static inline bool is_module_address(unsigned long addr)
{
return false;
diff --git a/kernel/module/Kconfig b/kernel/module/Kconfig
index 7b329057997a..5e81dea1afea 100644
--- a/kernel/module/Kconfig
+++ b/kernel/module/Kconfig
@@ -26,6 +26,9 @@ if MODULES
config MODULE_DEBUGFS
bool
+config MODULE_BUILD_ID
+ bool
+
config MODULE_DEBUG
bool "Module debugging"
depends on DEBUG_FS
diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c
index bf65e0c3c86f..98f2661c1da8 100644
--- a/kernel/module/kallsyms.c
+++ b/kernel/module/kallsyms.c
@@ -224,7 +224,7 @@ void add_kallsyms(struct module *mod, const struct load_info *info)
mod->core_kallsyms.num_symtab = ndst;
}
-#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
+#if IS_ENABLED(CONFIG_MODULE_BUILD_ID)
void init_build_id(struct module *mod, const struct load_info *info)
{
const Elf_Shdr *sechdr;
@@ -338,7 +338,7 @@ int module_address_lookup(unsigned long addr,
if (modname)
*modname = mod->name;
if (modbuildid) {
-#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
+#if IS_ENABLED(CONFIG_MODULE_BUILD_ID)
*modbuildid = mod->build_id;
#else
*modbuildid = NULL;
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 5399c182b3cb..fca9b6a692e3 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -3746,6 +3746,35 @@ struct module *__module_text_address(unsigned long addr)
return mod;
}
+/**
+ * __module_build_id() - get the module whose build_id start with an array.
+ * @build_id: the first part of the build_id.
+ * @size: the size of @build_id.
+ *
+ * Must be called with preempt disabled or module mutex held so that
+ * module doesn't get freed during this.
+ */
+struct module *__module_build_id(unsigned char *build_id, int size)
+{
+#ifdef CONFIG_MODULE_BUILD_ID
+ struct module *mod;
+
+ if (size < 0)
+ return NULL;
+
+ if (size > BUILD_ID_SIZE_MAX)
+ size = BUILD_ID_SIZE_MAX;
+
+ list_for_each_entry_rcu(mod, &modules, list) {
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
+ if (!memcmp(mod->build_id, build_id, size))
+ return mod;
+ }
+#endif
+ return NULL;
+}
+
/* Don't grab lock, we're oopsing. */
void print_modules(void)
{
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index cf2a41dc7682..2d3a2f656a86 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -38,6 +38,7 @@ config PRINTK_CALLER
config STACKTRACE_BUILD_ID
bool "Show build ID information in stacktraces"
depends on PRINTK
+ select MODULE_BUILD_ID if MODULES
help
Selecting this option adds build ID information for symbols in
stacktraces printed with the printk format '%p[SR]b'.
