markers-revert-modpost-removal

markers revert modpost removal

commit a8773769d1a1e08d0ca15f890515401ab3860637
Author: Wenji Huang <wenji.huang@oracle.com>
Date:   Mon Nov 16 13:49:55 2009 +0800

    Kbuild: clear marker out of modpost
    
    Remove the unnecessary functions and variables.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

2 files changed, 167 insertions, 0 deletions

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 4b0d2a86b95..097d58047fe 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -481,6 +481,8 @@ static int parse_elf(struct elf_info *info, const char *filename)
 			info->export_unused_gpl_sec = i;
 		else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
 			info->export_gpl_future_sec = i;
+		else if (strcmp(secname, "__markers_strings") == 0)
+			info->markers_strings_sec = i;
 
 		if (sechdrs[i].sh_type == SHT_SYMTAB) {
 			unsigned int sh_link_idx;
@@ -1641,6 +1643,62 @@ static void check_sec_ref(struct module *mod, const char *modname,
 	}
 }
 
+static void get_markers(struct elf_info *info, struct module *mod)
+{
+	const Elf_Shdr *sh = &info->sechdrs[info->markers_strings_sec];
+	const char *strings = (const char *) info->hdr + sh->sh_offset;
+	const Elf_Sym *sym, *first_sym, *last_sym;
+	size_t n;
+
+	if (!info->markers_strings_sec)
+		return;
+
+	/*
+	 * First count the strings.  We look for all the symbols defined
+	 * in the __markers_strings section named __mstrtab_*.  For
+	 * these local names, the compiler puts a random .NNN suffix on,
+	 * so the names don't correspond exactly.
+	 */
+	first_sym = last_sym = NULL;
+	n = 0;
+	for (sym = info->symtab_start; sym < info->symtab_stop; sym++)
+		if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT &&
+		    sym->st_shndx == info->markers_strings_sec &&
+		    !strncmp(info->strtab + sym->st_name,
+			     "__mstrtab_", sizeof "__mstrtab_" - 1)) {
+			if (first_sym == NULL)
+				first_sym = sym;
+			last_sym = sym;
+			++n;
+		}
+
+	if (n == 0)
+		return;
+
+	/*
+	 * Now collect each name and format into a line for the output.
+	 * Lines look like:
+	 *	marker_name	vmlinux	marker %s format %d
+	 * The format string after the second \t can use whitespace.
+	 */
+	mod->markers = NOFAIL(malloc(sizeof mod->markers[0] * n));
+	mod->nmarkers = n;
+
+	n = 0;
+	for (sym = first_sym; sym <= last_sym; sym++)
+		if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT &&
+		    sym->st_shndx == info->markers_strings_sec &&
+		    !strncmp(info->strtab + sym->st_name,
+			     "__mstrtab_", sizeof "__mstrtab_" - 1)) {
+			const char *name = strings + sym->st_value;
+			const char *fmt = strchr(name, '\0') + 1;
+			char *line = NULL;
+			asprintf(&line, "%s\t%s\t%s\n", name, mod->name, fmt);
+			NOFAIL(line);
+			mod->markers[n++] = line;
+		}
+}
+
 static void read_symbols(char *modname)
 {
 	const char *symname;
@@ -1696,6 +1754,8 @@ static void read_symbols(char *modname)
 		get_src_version(modname, mod->srcversion,
 				sizeof(mod->srcversion)-1);
 
+	get_markers(&info, mod);
+
 	parse_elf_finish(&info);
 
 	/* Our trick to get versioning for module struct etc. - it's
@@ -2050,6 +2110,96 @@ static void write_dump(const char *fname)
 	write_if_changed(&buf, fname);
 }
 
+static void add_marker(struct module *mod, const char *name, const char *fmt)
+{
+	char *line = NULL;
+	asprintf(&line, "%s\t%s\t%s\n", name, mod->name, fmt);
+	NOFAIL(line);
+
+	mod->markers = NOFAIL(realloc(mod->markers, ((mod->nmarkers + 1) *
+						     sizeof mod->markers[0])));
+	mod->markers[mod->nmarkers++] = line;
+}
+
+static void read_markers(const char *fname)
+{
+	unsigned long size, pos = 0;
+	void *file = grab_file(fname, &size);
+	char *line;
+
+	if (!file)		/* No old markers, silently ignore */
+		return;
+
+	while ((line = get_next_line(&pos, file, size))) {
+		char *marker, *modname, *fmt;
+		struct module *mod;
+
+		marker = line;
+		modname = strchr(marker, '\t');
+		if (!modname)
+			goto fail;
+		*modname++ = '\0';
+		fmt = strchr(modname, '\t');
+		if (!fmt)
+			goto fail;
+		*fmt++ = '\0';
+		if (*marker == '\0' || *modname == '\0')
+			goto fail;
+
+		mod = find_module(modname);
+		if (!mod) {
+			mod = new_module(modname);
+			mod->skip = 1;
+		}
+		if (is_vmlinux(modname)) {
+			have_vmlinux = 1;
+			mod->skip = 0;
+		}
+
+		if (!mod->skip)
+			add_marker(mod, marker, fmt);
+	}
+	release_file(file, size);
+	return;
+fail:
+	fatal("parse error in markers list file\n");
+}
+
+static int compare_strings(const void *a, const void *b)
+{
+	return strcmp(*(const char **) a, *(const char **) b);
+}
+
+static void write_markers(const char *fname)
+{
+	struct buffer buf = { };
+	struct module *mod;
+	size_t i;
+
+	for (mod = modules; mod; mod = mod->next)
+		if ((!external_module || !mod->skip) && mod->markers != NULL) {
+			/*
+			 * Sort the strings so we can skip duplicates when
+			 * we write them out.
+			 */
+			qsort(mod->markers, mod->nmarkers,
+			      sizeof mod->markers[0], &compare_strings);
+			for (i = 0; i < mod->nmarkers; ++i) {
+				char *line = mod->markers[i];
+				buf_write(&buf, line, strlen(line));
+				while (i + 1 < mod->nmarkers &&
+				       !strcmp(mod->markers[i],
+					       mod->markers[i + 1]))
+					free(mod->markers[i++]);
+				free(mod->markers[i]);
+			}
+			free(mod->markers);
+			mod->markers = NULL;
+		}
+
+	write_if_changed(&buf, fname);
+}
+
 struct ext_sym_list {
 	struct ext_sym_list *next;
 	const char *file;
@@ -2061,6 +2211,8 @@ int main(int argc, char **argv)
 	struct buffer buf = { };
 	char *kernel_read = NULL, *module_read = NULL;
 	char *dump_write = NULL;
+	char *markers_read = NULL;
+	char *markers_write = NULL;
 	int opt;
 	int err;
 	struct ext_sym_list *extsym_iter;
@@ -2104,6 +2256,12 @@ int main(int argc, char **argv)
 		case 'w':
 			warn_unresolved = 1;
 			break;
+			case 'M':
+				markers_write = optarg;
+				break;
+			case 'K':
+				markers_read = optarg;
+				break;
 		default:
 			exit(1);
 		}
@@ -2158,5 +2316,11 @@ int main(int argc, char **argv)
 		     "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
 		     sec_mismatch_count);
 
+	if (markers_read)
+		read_markers(markers_read);
+
+	if (markers_write)
+		write_markers(markers_write);
+
 	return err;
 }
diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
index 0388cfccac8..dbde650961e 100644
--- a/scripts/mod/modpost.h
+++ b/scripts/mod/modpost.h
@@ -112,6 +112,8 @@ struct module {
 	int has_init;
 	int has_cleanup;
 	struct buffer dev_table_buf;
+	char **markers;
+	size_t nmarkers;
 	char	     srcversion[25];
 };
 
@@ -126,6 +128,7 @@ struct elf_info {
 	Elf_Section  export_gpl_sec;
 	Elf_Section  export_unused_gpl_sec;
 	Elf_Section  export_gpl_future_sec;
+	Elf_Section  markers_strings_sec;
 	const char   *strtab;
 	char	     *modinfo;
 	unsigned int modinfo_len;