Merge branch 'for-5.15-printk-index' into for-linus

1 files changed, 45 insertions, 8 deletions

diff --git a/kernel/module.c b/kernel/module.c
index 927d46cb8eb9..40ec9a030eec 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -13,6 +13,7 @@
 #include <linux/trace_events.h>
 #include <linux/init.h>
 #include <linux/kallsyms.h>
+#include <linux/buildid.h>
 #include <linux/file.h>
 #include <linux/fs.h>
 #include <linux/sysfs.h>
@@ -1018,8 +1019,7 @@ void __symbol_put(const char *symbol)
 	};
 
 	preempt_disable();
-	if (!find_symbol(&fsa))
-		BUG();
+	BUG_ON(!find_symbol(&fsa));
 	module_put(fsa.owner);
 	preempt_enable();
 }
@@ -1466,6 +1466,13 @@ resolve_symbol_wait(struct module *mod,
 	return ksym;
 }
 
+#ifdef CONFIG_KALLSYMS
+static inline bool sect_empty(const Elf_Shdr *sect)
+{
+	return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
+}
+#endif
+
 /*
  * /sys/module/foo/sections stuff
  * J. Corbet <corbet@lwn.net>
@@ -1473,11 +1480,6 @@ resolve_symbol_wait(struct module *mod,
 #ifdef CONFIG_SYSFS
 
 #ifdef CONFIG_KALLSYMS
-static inline bool sect_empty(const Elf_Shdr *sect)
-{
-	return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
-}
-
 struct module_sect_attr {
 	struct bin_attribute battr;
 	unsigned long address;
@@ -2798,6 +2800,26 @@ static void add_kallsyms(struct module *mod, const struct load_info *info)
 }
 #endif /* CONFIG_KALLSYMS */
 
+#if IS_ENABLED(CONFIG_KALLSYMS) && IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
+static void init_build_id(struct module *mod, const struct load_info *info)
+{
+	const Elf_Shdr *sechdr;
+	unsigned int i;
+
+	for (i = 0; i < info->hdr->e_shnum; i++) {
+		sechdr = &info->sechdrs[i];
+		if (!sect_empty(sechdr) && sechdr->sh_type == SHT_NOTE &&
+		    !build_id_parse_buf((void *)sechdr->sh_addr, mod->build_id,
+					sechdr->sh_size))
+			break;
+	}
+}
+#else
+static void init_build_id(struct module *mod, const struct load_info *info)
+{
+}
+#endif
+
 static void dynamic_debug_setup(struct module *mod, struct _ddebug *debug, unsigned int num)
 {
 	if (!debug)
@@ -3333,6 +3355,11 @@ static int find_module_sections(struct module *mod, struct load_info *info)
 						sizeof(unsigned long),
 						&mod->num_kprobe_blacklist);
 #endif
+#ifdef CONFIG_PRINTK_INDEX
+	mod->printk_index_start = section_objs(info, ".printk_index",
+					       sizeof(*mod->printk_index_start),
+					       &mod->printk_index_size);
+#endif
 #ifdef CONFIG_HAVE_STATIC_CALL_INLINE
 	mod->static_call_sites = section_objs(info, ".static_call_sites",
 					      sizeof(*mod->static_call_sites),
@@ -4022,6 +4049,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
 		goto free_arch_cleanup;
 	}
 
+	init_build_id(mod, info);
 	dynamic_debug_setup(mod, info->debug, info->num_debug);
 
 	/* Ftrace init must be called in the MODULE_STATE_UNFORMED state */
@@ -4255,6 +4283,7 @@ const char *module_address_lookup(unsigned long addr,
 			    unsigned long *size,
 			    unsigned long *offset,
 			    char **modname,
+			    const unsigned char **modbuildid,
 			    char *namebuf)
 {
 	const char *ret = NULL;
@@ -4265,6 +4294,13 @@ const char *module_address_lookup(unsigned long addr,
 	if (mod) {
 		if (modname)
 			*modname = mod->name;
+		if (modbuildid) {
+#if IS_ENABLED(CONFIG_STACKTRACE_BUILD_ID)
+			*modbuildid = mod->build_id;
+#else
+			*modbuildid = NULL;
+#endif
+		}
 
 		ret = find_kallsyms_symbol(mod, addr, size, offset);
 	}
@@ -4425,9 +4461,10 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
 			ret = fn(data, kallsyms_symbol_name(kallsyms, i),
 				 mod, kallsyms_symbol_value(sym));
 			if (ret != 0)
-				break;
+				goto out;
 		}
 	}
+out:
 	mutex_unlock(&module_mutex);
 	return ret;
 }