diff options
| -rw-r--r-- | scripts/kconfig/confdata.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c index 9fd6430c93d2..399973e35533 100644 --- a/scripts/kconfig/confdata.c +++ b/scripts/kconfig/confdata.c @@ -3,6 +3,7 @@ * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org> */ +#include <sys/mman.h> #include <sys/stat.h> #include <ctype.h> #include <errno.h> @@ -36,6 +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. * @@ -888,6 +935,13 @@ next: fclose(out); if (*tmpname) { + 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)) |