From 1399c5ad53f380ebf4e465892bfd0c8b82b12aeb Mon Sep 17 00:00:00 2001 From: Yauheni Kaliuta Date: Tue, 9 May 2017 22:09:22 +0300 Subject: [PATCH] depmod: rewrite depmod modules search with scratchbuf The recursive search code used used pretty big, PATH_MAX, automatic storage buffer for the module directory scanning. Some time ago there was scratchbuf implemented, which dynamically reallocates its buffer on demand. The patch takes it in use for the scanning code also. The initial size is hardcoded to 256 bytes which sounds good enough for most usecases so there should be not many reallocations. Signed-off-by: Yauheni Kaliuta --- tools/depmod.c | 33 +++++++++++++++++++++------------ 1 file changed, 21 insertions(+), 12 deletions(-) diff --git a/tools/depmod.c b/tools/depmod.c index cfed864..a9a02bb 100644 --- a/tools/depmod.c +++ b/tools/depmod.c @@ -1108,10 +1108,11 @@ add: return 0; } -static int depmod_modules_search_dir(struct depmod *depmod, DIR *d, size_t baselen, char *path) +static int depmod_modules_search_dir(struct depmod *depmod, DIR *d, size_t baselen, struct scratchbuf *s_path) { struct dirent *de; int err = 0, dfd = dirfd(d); + char *path; while ((de = readdir(d)) != NULL) { const char *name = de->d_name; @@ -1124,11 +1125,13 @@ static int depmod_modules_search_dir(struct depmod *depmod, DIR *d, size_t basel if (streq(name, "build") || streq(name, "source")) continue; namelen = strlen(name); - if (baselen + namelen + 2 >= PATH_MAX) { - path[baselen] = '\0'; - ERR("path is too long %s%s\n", path, name); + if (scratchbuf_alloc(s_path, baselen + namelen + 2) < 0) { + err = -ENOMEM; + ERR("No memory\n"); continue; } + + path = scratchbuf_str(s_path); memcpy(path + baselen, name, namelen + 1); if (de->d_type == DT_REG) @@ -1154,10 +1157,6 @@ static int depmod_modules_search_dir(struct depmod *depmod, DIR *d, size_t basel if (is_dir) { int fd; DIR *subdir; - if (baselen + namelen + 2 + NAME_MAX >= PATH_MAX) { - ERR("directory path is too long %s\n", path); - continue; - } fd = openat(dfd, name, O_RDONLY); if (fd < 0) { ERR("openat(%d, %s, O_RDONLY): %m\n", @@ -1174,7 +1173,7 @@ static int depmod_modules_search_dir(struct depmod *depmod, DIR *d, size_t basel path[baselen + namelen + 1] = '\0'; err = depmod_modules_search_dir(depmod, subdir, baselen + namelen + 1, - path); + s_path); closedir(subdir); } else { err = depmod_modules_search_file(depmod, baselen, @@ -1187,14 +1186,16 @@ static int depmod_modules_search_dir(struct depmod *depmod, DIR *d, size_t basel err = 0; /* ignore errors */ } } - return err; } static int depmod_modules_search_path(struct depmod *depmod, const char *path) { - char path_buf[PATH_MAX]; + char buf[256]; + _cleanup_(scratchbuf_release) struct scratchbuf s_path_buf = + SCRATCHBUF_INITIALIZER(buf); + char *path_buf; DIR *d; size_t baselen; int err; @@ -1207,12 +1208,20 @@ static int depmod_modules_search_path(struct depmod *depmod, } baselen = strlen(path); + + if (scratchbuf_alloc(&s_path_buf, baselen + 2) < 0) { + err = -ENOMEM; + goto out; + } + path_buf = scratchbuf_str(&s_path_buf); + memcpy(path_buf, path, baselen); path_buf[baselen] = '/'; baselen++; path_buf[baselen] = '\0'; - err = depmod_modules_search_dir(depmod, d, baselen, path_buf); + err = depmod_modules_search_dir(depmod, d, baselen, &s_path_buf); +out: closedir(d); return err; } -- 2.7.4