1 files changed, 164 insertions, 106 deletions

diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index 91d0a5c014..6006154d36 100644
--- a/scripts/kconfig/confdata.c
+++ b/scripts/kconfig/confdata.c
@@ -1,12 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
- * Released under the terms of the GNU GPL v2.0.
  */
 
+#include <sys/mman.h>
 #include <sys/stat.h>
 #include <ctype.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <limits.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -35,6 +37,52 @@ static bool is_dir(const char *path)
 	return S_ISDIR(st.st_mode);
 }
 
+/* return true if the given two files are the same, false otherwise */
+static bool is_same(const char *file1, const char *file2)
+{
+	int fd1, fd2;
+	struct stat st1, st2;
+	void *map1, *map2;
+	bool ret = false;
+
+	fd1 = open(file1, O_RDONLY);
+	if (fd1 < 0)
+		return ret;
+
+	fd2 = open(file2, O_RDONLY);
+	if (fd2 < 0)
+		goto close1;
+
+	ret = fstat(fd1, &st1);
+	if (ret)
+		goto close2;
+	ret = fstat(fd2, &st2);
+	if (ret)
+		goto close2;
+
+	if (st1.st_size != st2.st_size)
+		goto close2;
+
+	map1 = mmap(NULL, st1.st_size, PROT_READ, MAP_PRIVATE, fd1, 0);
+	if (map1 == MAP_FAILED)
+		goto close2;
+
+	map2 = mmap(NULL, st2.st_size, PROT_READ, MAP_PRIVATE, fd2, 0);
+	if (map2 == MAP_FAILED)
+		goto close2;
+
+	if (bcmp(map1, map2, st1.st_size))
+		goto close2;
+
+	ret = true;
+close2:
+	close(fd2);
+close1:
+	close(fd1);
+
+	return ret;
+}
+
 /*
  * Create the parent directory of the given path.
  *
@@ -74,6 +122,47 @@ static int make_parent_dir(const char *path)
 	return 0;
 }
 
+static char depfile_path[PATH_MAX];
+static size_t depfile_prefix_len;
+
+/* touch depfile for symbol 'name' */
+static int conf_touch_dep(const char *name)
+{
+	int fd, ret;
+	const char *s;
+	char *d, c;
+
+	/* check overflow: prefix + name + ".h" + '\0' must fit in buffer. */
+	if (depfile_prefix_len + strlen(name) + 3 > sizeof(depfile_path))
+		return -1;
+
+	d = depfile_path + depfile_prefix_len;
+	s = name;
+
+	while ((c = *s++))
+		*d++ = (c == '_') ? '/' : tolower(c);
+	strcpy(d, ".h");
+
+	/* Assume directory path already exists. */
+	fd = open(depfile_path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+	if (fd == -1) {
+		if (errno != ENOENT)
+			return -1;
+
+		ret = make_parent_dir(depfile_path);
+		if (ret)
+			return ret;
+
+		/* Try it again. */
+		fd = open(depfile_path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+		if (fd == -1)
+			return -1;
+	}
+	close(fd);
+
+	return 0;
+}
+
 struct conf_printer {
 	void (*print_symbol)(FILE *, struct symbol *, const char *, void *);
 	void (*print_comment)(FILE *, const char *, void *);
@@ -137,7 +226,7 @@ const char *conf_get_configname(void)
 	return name ? name : ".config";
 }
 
-const char *conf_get_autoconfig_name(void)
+static const char *conf_get_autoconfig_name(void)
 {
 	char *name = getenv("KCONFIG_AUTOCONFIG");
 
@@ -152,7 +241,7 @@ char *conf_get_default_confname(void)
 	name = expand_string(conf_defname);
 	env = getenv(SRCTREE);
 	if (env) {
-		sprintf(fullname, "%s/%s", env, name);
+		snprintf(fullname, sizeof(fullname), "%s/%s", env, name);
 		if (is_present(fullname))
 			return fullname;
 	}
@@ -186,14 +275,6 @@ static int conf_set_sym_val(struct symbol *sym, int def, int def_flags, char *p)
 			conf_warning("symbol value '%s' invalid for %s",
 				     p, sym->name);
 		return 1;
-	case S_OTHER:
-		if (*p != '"') {
-			for (p2 = p; *p2 && !isspace(*p2); p2++)
-				;
-			sym->type = S_STRING;
-			goto done;
-		}
-		/* fall through */
 	case S_STRING:
 		if (*p++ != '"')
 			break;
@@ -212,7 +293,6 @@ static int conf_set_sym_val(struct symbol *sym, int def, int def_flags, char *p)
 		/* fall through */
 	case S_INT:
 	case S_HEX:
-	done:
 		if (sym_string_valid(sym, p)) {
 			sym->def[def].val = xstrdup(p);
 			sym->flags |= def_flags;
@@ -363,7 +443,7 @@ load:
 				sym = sym_find(line + 2 + strlen(CONFIG_));
 				if (!sym) {
 					sym_add_change_count(1);
-					goto setsym;
+					continue;
 				}
 			} else {
 				sym = sym_lookup(line + 2 + strlen(CONFIG_), 0);
@@ -393,17 +473,22 @@ load:
 				if (*p2 == '\r')
 					*p2 = 0;
 			}
-			if (def == S_DEF_USER) {
-				sym = sym_find(line + strlen(CONFIG_));
-				if (!sym) {
+
+			sym = sym_find(line + strlen(CONFIG_));
+			if (!sym) {
+				if (def == S_DEF_AUTO)
+					/*
+					 * Reading from include/config/auto.conf
+					 * If CONFIG_FOO previously existed in
+					 * auto.conf but it is missing now,
+					 * include/config/foo.h must be touched.
+					 */
+					conf_touch_dep(line + strlen(CONFIG_));
+				else
 					sym_add_change_count(1);
-					goto setsym;
-				}
-			} else {
-				sym = sym_lookup(line + strlen(CONFIG_), 0);
-				if (sym->type == S_UNKNOWN)
-					sym->type = S_OTHER;
+				continue;
 			}
+
 			if (sym->flags & def_flags) {
 				conf_warning("override: reassigning to symbol %s", sym->name);
 			}
@@ -416,7 +501,7 @@ load:
 
 			continue;
 		}
-setsym:
+
 		if (sym && sym_is_choice_value(sym)) {
 			struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
 			switch (sym->def[def].tri) {
@@ -669,7 +754,6 @@ static void conf_write_symbol(FILE *fp, struct symbol *sym,
 	const char *str;
 
 	switch (sym->type) {
-	case S_OTHER:
 	case S_UNKNOWN:
 		break;
 	case S_STRING:
@@ -780,40 +864,35 @@ int conf_write(const char *name)
 	FILE *out;
 	struct symbol *sym;
 	struct menu *menu;
-	const char *basename;
 	const char *str;
-	char dirname[PATH_MAX+1], tmpname[PATH_MAX+22], newname[PATH_MAX+8];
+	char tmpname[PATH_MAX + 1], oldname[PATH_MAX + 1];
 	char *env;
+	bool need_newline = false;
+
+	if (!name)
+		name = conf_get_configname();
+
+	if (!*name) {
+		fprintf(stderr, "config name is empty\n");
+		return -1;
+	}
+
+	if (is_dir(name)) {
+		fprintf(stderr, "%s: Is a directory\n", name);
+		return -1;
+	}
+
+	if (make_parent_dir(name))
+		return -1;
 
-	dirname[0] = 0;
-	if (name && name[0]) {
-		char *slash;
-
-		if (is_dir(name)) {
-			strcpy(dirname, name);
-			strcat(dirname, "/");
-			basename = conf_get_configname();
-		} else if ((slash = strrchr(name, '/'))) {
-			int size = slash - name + 1;
-			memcpy(dirname, name, size);
-			dirname[size] = 0;
-			if (slash[1])
-				basename = slash + 1;
-			else
-				basename = conf_get_configname();
-		} else
-			basename = name;
-	} else
-		basename = conf_get_configname();
-
-	sprintf(newname, "%s%s", dirname, basename);
 	env = getenv("KCONFIG_OVERWRITECONFIG");
-	if (!env || !*env) {
-		sprintf(tmpname, "%s.tmpconfig.%d", dirname, (int)getpid());
-		out = fopen(tmpname, "w");
-	} else {
+	if (env && *env) {
 		*tmpname = 0;
-		out = fopen(newname, "w");
+		out = fopen(name, "w");
+	} else {
+		snprintf(tmpname, sizeof(tmpname), "%s.%d.tmp",
+			 name, (int)getpid());
+		out = fopen(tmpname, "w");
 	}
 	if (!out)
 		return 1;
@@ -834,12 +913,16 @@ int conf_write(const char *name)
 				     "#\n"
 				     "# %s\n"
 				     "#\n", str);
+			need_newline = false;
 		} else if (!(sym->flags & SYMBOL_CHOICE)) {
 			sym_calc_value(sym);
 			if (!(sym->flags & SYMBOL_WRITE))
 				goto next;
+			if (need_newline) {
+				fprintf(out, "\n");
+				need_newline = false;
+			}
 			sym->flags &= ~SYMBOL_WRITE;
-
 			conf_write_symbol(out, sym, &kconfig_printer_cb, NULL);
 		}
 
@@ -851,6 +934,12 @@ next:
 		if (menu->next)
 			menu = menu->next;
 		else while ((menu = menu->parent)) {
+			if (!menu->sym && menu_is_visible(menu) &&
+			    menu != &rootmenu) {
+				str = menu_get_prompt(menu);
+				fprintf(out, "# end of %s\n", str);
+				need_newline = true;
+			}
 			if (menu->next) {
 				menu = menu->next;
 				break;
@@ -860,14 +949,20 @@ next:
 	fclose(out);
 
 	if (*tmpname) {
-		strcat(dirname, basename);
-		strcat(dirname, ".old");
-		rename(newname, dirname);
-		if (rename(tmpname, newname))
+		if (is_same(name, tmpname)) {
+			conf_message("No change to %s", name);
+			unlink(tmpname);
+			sym_set_change_count(0);
+			return 0;
+		}
+
+		snprintf(oldname, sizeof(oldname), "%s.old", name);
+		rename(name, oldname);
+		if (rename(tmpname, name))
 			return 1;
 	}
 
-	conf_message("configuration written to %s", newname);
+	conf_message("configuration written to %s", name);
 
 	sym_set_change_count(0);
 
@@ -880,8 +975,6 @@ static int conf_write_dep(const char *name)
 	struct file *file;
 	FILE *out;
 
-	if (!name)
-		name = ".kconfig.d";
 	out = fopen("..config.tmp", "w");
 	if (!out)
 		return 1;
@@ -906,24 +999,19 @@ static int conf_write_dep(const char *name)
 	return 0;
 }
 
-static int conf_split_config(void)
+static int conf_touch_deps(void)
 {
 	const char *name;
-	char path[PATH_MAX+1];
-	char *s, *d, c;
 	struct symbol *sym;
-	int res, i, fd;
+	int res, i;
+
+	strcpy(depfile_path, "include/config/");
+	depfile_prefix_len = strlen(depfile_path);
 
 	name = conf_get_autoconfig_name();
 	conf_read_simple(name, S_DEF_AUTO);
 	sym_calc_value(modules_sym);
 
-	if (make_parent_dir("include/config/foo.h"))
-		return 1;
-	if (chdir("include/config"))
-		return 1;
-
-	res = 0;
 	for_all_symbols(i, sym) {
 		sym_calc_value(sym);
 		if ((sym->flags & SYMBOL_NO_WRITE) || !sym->name)
@@ -975,42 +1063,12 @@ static int conf_split_config(void)
 		 *	different from 'no').
 		 */
 
-		/* Replace all '_' and append ".h" */
-		s = sym->name;
-		d = path;
-		while ((c = *s++)) {
-			c = tolower(c);
-			*d++ = (c == '_') ? '/' : c;
-		}
-		strcpy(d, ".h");
-
-		/* Assume directory path already exists. */
-		fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
-		if (fd == -1) {
-			if (errno != ENOENT) {
-				res = 1;
-				break;
-			}
-
-			if (make_parent_dir(path)) {
-				res = 1;
-				goto out;
-			}
-
-			/* Try it again. */
-			fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
-			if (fd == -1) {
-				res = 1;
-				break;
-			}
-		}
-		close(fd);
+		res = conf_touch_dep(sym->name);
+		if (res)
+			return res;
 	}
-out:
-	if (chdir("../.."))
-		return 1;
 
-	return res;
+	return 0;
 }
 
 int conf_write_autoconf(int overwrite)
@@ -1028,7 +1086,7 @@ int conf_write_autoconf(int overwrite)
 
 	conf_write_dep("include/config/auto.conf.cmd");
 
-	if (conf_split_config())
+	if (conf_touch_deps())
 		return 1;
 
 	out = fopen(".tmpconfig", "w");