X-Git-Url: https://jxself.org/git/?p=carl9170fw.git;a=blobdiff_plain;f=config%2Fconfdata.c;h=f6461a6af4bc9a573305b7d1b6e8af5b0997980d;hp=f6168f2aaeacda3113fd117ddfc710f41721ae55;hb=a57a7e78baeede9c999a67dcd812fbfc711463fa;hpb=8aac74167ad25956a35b6d5b04cc97cc1ed6ce04

diff --git a/config/confdata.c b/config/confdata.c
index f6168f2..f6461a6 100644
--- a/config/confdata.c
+++ b/config/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.
  *
@@ -862,40 +910,34 @@ 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;
 
-	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);
+	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;
+
 	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;
@@ -942,14 +984,20 @@ 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);
 
@@ -962,8 +1010,6 @@ 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;
@@ -1060,13 +1106,17 @@ static int conf_touch_deps(void)
 	return 0;
 }
 
-int conf_write_autoconf(void)
+int conf_write_autoconf(int overwrite)
 {
 	struct symbol *sym;
 	const char *name;
+	const char *autoconf_name = conf_get_autoconfig_name();
 	FILE *out, *tristate, *out_h, *out_c;
 	int i;
 
+	if (!overwrite && is_present(autoconf_name))
+		return 0;
+
 	sym_clear_all_valid();
 
 	conf_write_dep("include/generated/auto.conf.cmd");
@@ -1141,6 +1191,9 @@ int conf_write_autoconf(void)
 	if (rename(".tmpconfig_tristate", name))
 		return 1;
 
+	if (make_parent_dir(autoconf_name))
+		return 1;
+
 	name = getenv("KCONFIG_CMAKE");
 	if (!name)
 		name = "config.cmake";
@@ -1149,15 +1202,11 @@ int conf_write_autoconf(void)
 	if (rename(".tmpconfig.cmake", name))
 		return 1;
 
-	name = conf_get_autoconfig_name();
-	if (make_parent_dir(name))
-		return 1;
-
 	/*
 	 * This must be the last step, kbuild has a dependency on auto.conf
 	 * and this marks the successful completion of the previous steps.
 	 */
-	if (rename(".tmpconfig", name))
+	if (rename(".tmpconfig", autoconf_name))
 		return 1;
 
 	return 0;