From 6e3c6dcf922e30282d2c49a643253e58fffab362 Mon Sep 17 00:00:00 2001 From: Yousong Zhou Date: Sat, 14 Jan 2017 01:00:34 +0800 Subject: [PATCH] kmodloader: add module alias awareness To achieve this, the following changes are made - scan module folders before scaning loaded modules - struct module was splited into struct module_node for the avl tree and struct module for storing actual info about modules The other minor fix is that module.opts is now freed in free_modules() when appliable Signed-off-by: Yousong Zhou --- kmodloader.c | 152 +++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 129 insertions(+), 23 deletions(-) diff --git a/kmodloader.c b/kmodloader.c index c780379..bcb213b 100644 --- a/kmodloader.c +++ b/kmodloader.c @@ -45,22 +45,31 @@ enum { }; struct module { - struct avl_node avl; - char *name; char *depends; char *opts; + char **aliases; + int naliases; int size; int usage; int state; int error; + int refcnt; /* number of references from module_node.m */ +}; + +struct module_node { + struct avl_node avl; + struct module *m; + bool is_alias; }; static struct avl_tree modules; static char **module_folders = NULL; +static void free_module(struct module *m); + static int init_module_folders(void) { int n = 0; @@ -106,16 +115,26 @@ static int init_module_folders(void) static struct module *find_module(const char *name) { - struct module *m; - return avl_find_element(&modules, name, m, avl); + struct module_node *mn; + mn = avl_find_element(&modules, name, mn, avl); + if (mn) + return mn->m; + else + return NULL; } static void free_modules(void) { - struct module *m, *tmp; + struct module_node *mn, *tmp; + + avl_remove_all_elements(&modules, mn, avl, tmp) { + struct module *m = mn->m; - avl_remove_all_elements(&modules, m, avl, tmp) - free(m); + m->refcnt -= 1; + if (m->refcnt == 0) + free_module(m); + free(mn); + } } static char* get_module_path(char *name) @@ -208,19 +227,43 @@ static int elf_find_section(char *map, const char *section, unsigned int *offset return -1; } +static struct module_node * +alloc_module_node(const char *name, struct module *m, bool is_alias) +{ + struct module_node *mn; + char *_name; + + mn = calloc_a(sizeof(*mn), + &_name, strlen(name) + 1); + if (mn) { + mn->avl.key = strcpy(_name, name); + mn->m = m; + mn->is_alias = is_alias; + avl_insert(&modules, &mn->avl); + m->refcnt += 1; + } + return mn; +} + static struct module * -alloc_module(const char *name, const char *depends, int size) +alloc_module(const char *name, const char * const *aliases, int naliases, const char *depends, int size) { struct module *m; char *_name, *_dep; + char **_aliases; + int i, len_aliases; + len_aliases = naliases * sizeof(aliases[0]); + for (i = 0; i < naliases; i++) + len_aliases += strlen(aliases[i]) + 1; m = calloc_a(sizeof(*m), &_name, strlen(name) + 1, - &_dep, depends ? strlen(depends) + 2 : 0); + &_dep, depends ? strlen(depends) + 2 : 0, + &_aliases, len_aliases); if (!m) return NULL; - m->avl.key = m->name = strcpy(_name, name); + m->name = strcpy(_name, name); m->opts = 0; if (depends) { @@ -231,13 +274,40 @@ alloc_module(const char *name, const char *depends, int size) _dep++; } } - m->size = size; - avl_insert(&modules, &m->avl); + m->naliases = naliases; + if (naliases == 0) + m->aliases = NULL; + else { + char *ptr = (char *)_aliases + naliases * sizeof(_aliases[0]); + int len; + + i = 0; + do { + len = strlen(aliases[i]) + 1; + memcpy(ptr, aliases[i], len); + _aliases[i] = ptr; + ptr += len; + i++; + } while (i < naliases); + m->aliases = _aliases; + } + + m->refcnt = 0; + alloc_module_node(m->name, m, false); + for (i = 0; i < m->naliases; i++) + alloc_module_node(m->aliases[i], m, true); return m; } +static void free_module(struct module *m) +{ + if (m->opts) + free(m->opts); + free(m); +} + static int scan_loaded_modules(void) { size_t buf_len = 0; @@ -262,7 +332,11 @@ static int scan_loaded_modules(void) if (!m.name || !m.depends) continue; - n = alloc_module(m.name, m.depends, m.size); + n = find_module(m.name); + if (!n) { + /* possibly a module outside /lib/modules// */ + n = alloc_module(m.name, NULL, 0, m.depends, m.size); + } n->usage = m.usage; n->state = LOADED; } @@ -277,6 +351,8 @@ static struct module* get_module_info(const char *module, const char *name) int fd = open(module, O_RDONLY); unsigned int offset, size; char *map = MAP_FAILED, *strings, *dep = NULL; + const char *aliases[32]; + int naliases = 0; struct module *m = NULL; struct stat s; @@ -317,10 +393,17 @@ static struct module* get_module_info(const char *module, const char *name) sep++; if (!strncmp(strings, "depends=", len + 1)) dep = sep; + else if (!strncmp(strings, "alias=", len + 1)) { + if (naliases < ARRAY_SIZE(aliases)) + aliases[naliases++] = sep; + else + ULOG_WARN("module %s has more than %d aliases: truncated", + name, ARRAY_SIZE(aliases)); + } strings = &sep[strlen(sep)]; } - m = alloc_module(name, dep, s.st_size); + m = alloc_module(name, aliases, naliases, dep, s.st_size); if (m) m->state = SCANNED; @@ -530,16 +613,24 @@ static int iterations = 0; static int load_modprobe(void) { int loaded, todo; + struct module_node *mn; struct module *m; - avl_for_each_element(&modules, m, avl) + avl_for_each_element(&modules, mn, avl) { + if (mn->is_alias) + continue; + m = mn->m; if (m->state == PROBE) load_moddeps(m); + } do { loaded = 0; todo = 0; - avl_for_each_element(&modules, m, avl) { + avl_for_each_element(&modules, mn, avl) { + if (mn->is_alias) + continue; + m = mn->m; if ((m->state == PROBE) && (!deps_available(m, 0))) { if (!insert_module(get_module_path(m->name), (m->opts) ? (m->opts) : (""))) { m->state = LOADED; @@ -663,13 +754,17 @@ static int main_rmmod(int argc, char **argv) static int main_lsmod(int argc, char **argv) { + struct module_node *mn; struct module *m; char *dep; if (scan_loaded_modules()) return -1; - avl_for_each_element(&modules, m, avl) + avl_for_each_element(&modules, mn, avl) { + if (mn->is_alias) + continue; + m = mn->m; if (m->state == LOADED) { printf("%-20s%8d%3d ", m->name, m->size, m->usage); @@ -684,6 +779,7 @@ static int main_lsmod(int argc, char **argv) } printf("\n"); } + } free_modules(); @@ -721,6 +817,7 @@ static int main_modinfo(int argc, char **argv) static int main_modprobe(int argc, char **argv) { + struct module_node *mn; struct module *m; char *name; char *mod = NULL; @@ -734,10 +831,10 @@ static int main_modprobe(int argc, char **argv) if (!mod) return print_usage("modprobe"); - if (scan_loaded_modules()) + if (scan_module_folders()) return -1; - if (scan_module_folders()) + if (scan_loaded_modules()) return -1; name = get_module_name(mod); @@ -758,9 +855,13 @@ static int main_modprobe(int argc, char **argv) ULOG_ERR("%d module%s could not be probed\n", fail, (fail == 1) ? ("") : ("s")); - avl_for_each_element(&modules, m, avl) + avl_for_each_element(&modules, mn, avl) { + if (mn->is_alias) + continue; + m = mn->m; if ((m->state == PROBE) || m->error) ULOG_ERR("- %s\n", m->name); + } } } @@ -773,6 +874,7 @@ static int main_loader(int argc, char **argv) { int gl_flags = GLOB_NOESCAPE | GLOB_MARK; char *dir = "/etc/modules.d/"; + struct module_node *mn; struct module *m; glob_t gl; char *path; @@ -785,12 +887,12 @@ static int main_loader(int argc, char **argv) strcpy(path, dir); strcat(path, "*"); - if (scan_loaded_modules()) { + if (scan_module_folders()) { free (path); return -1; } - if (scan_module_folders()) { + if (scan_loaded_modules()) { free (path); return -1; } @@ -843,9 +945,13 @@ static int main_loader(int argc, char **argv) ULOG_ERR("%d module%s could not be probed\n", fail, (fail == 1) ? ("") : ("s")); - avl_for_each_element(&modules, m, avl) + avl_for_each_element(&modules, mn, avl) { + if (mn->is_alias) + continue; + m = mn->m; if ((m->state == PROBE) || (m->error)) ULOG_ERR("- %s - %d\n", m->name, deps_available(m, 1)); + } } else { ULOG_INFO("done loading kernel modules from %s\n", path); } -- 2.30.2