modprobe-small: (un)load all modules which match the alias, not only first one

Closes 627 and 7034.

Commonly seen case is (un)loading of an alias
which matches ata_generic and a more specific ata module.

For example:

modprobe [-r] pci:v00008086d00007010sv00000000sd00000000bc01sc01i80
(ata_generic and pata_acpi)

modprobe [-r] pci:v00001106d00000571sv00001509sd00009022bc01sc01i8a
(ata_generic and pata_via)

function                                             old     new   delta
process_module                                       615     728    +113
parse_module                                         309     395     +86
find_alias                                           621     653     +32
pathname_matches_modname                              78      79      +1
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 4/0 up/down: 232/0)             Total: 232 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 101 insertions, 61 deletions

diff --git a/modutils/modprobe-small.c b/modutils/modprobe-small.c
index 223eba915..91e0c1380 100644
--- a/modutils/modprobe-small.c
+++ b/modutils/modprobe-small.c
@@ -22,6 +22,9 @@
 extern int init_module(void *module, unsigned long len, const char *options);
 extern int delete_module(const char *module, unsigned flags);
 extern int query_module(const char *name, int which, void *buf, size_t bufsize, size_t *ret);
+/* linux/include/linux/module.h has limit of 64 chars on module names */
+#undef MODULE_NAME_LEN
+#define MODULE_NAME_LEN 64
 
 
 #if 1
@@ -143,6 +146,19 @@ static void replace(char *s, char what, char with)
         }
 }
 
+static char *filename2modname(const char *filename, char *modname)
+{
+        int i;
+        char *from;
+
+        from = bb_get_last_path_component_nostrip(filename);
+        for (i = 0; i < (MODULE_NAME_LEN-1) && from[i] != '\0' && from[i] != '.'; i++)
+                modname[i] = (from[i] == '-') ? '_' : from[i];
+        modname[i] = '\0';
+
+        return modname;
+}
+
 /* Take "word word", return malloced "word",NUL,"word",NUL,NUL */
 static char* str_2_list(const char *str)
 {
@@ -277,14 +293,13 @@ static void parse_module(module_info *info, const char *pathname)
 
 static int pathname_matches_modname(const char *pathname, const char *modname)
 {
+        int r;
+        char name[MODULE_NAME_LEN];
         const char *fname = bb_get_last_path_component_nostrip(pathname);
         const char *suffix = strrstr(fname, ".ko");
-//TODO: can do without malloc?
-        char *name = xstrndup(fname, suffix - fname);
-        int r;
+        safe_strncpy(name, fname, suffix - fname);
         replace(name, '-', '_');
         r = (strcmp(name, modname) == 0);
-        free(name);
         return r;
 }
 
@@ -447,11 +462,12 @@ static void write_out_dep_bb(int fd)
         }
 }
 
-static module_info* find_alias(const char *alias)
+static module_info** find_alias(const char *alias)
 {
         int i;
         int dep_bb_fd;
-        module_info *result;
+        int infoidx;
+        module_info **infovec;
         dbg1_error_msg("find_alias('%s')", alias);
 
  try_again:
@@ -464,7 +480,9 @@ static module_info* find_alias(const char *alias)
                         if (!modinfo[i].aliases) {
                                 parse_module(&modinfo[i], modinfo[i].pathname);
                         }
-                        return &modinfo[i];
+                        infovec = xzalloc(2 * sizeof(infovec[0]));
+                        infovec[0] = &modinfo[i];
+                        return infovec;
                 }
                 i++;
         }
@@ -477,16 +495,13 @@ static module_info* find_alias(const char *alias)
 
         /* Scan all module bodies, extract modinfo (it contains aliases) */
         i = 0;
-        result = NULL;
+        infoidx = 0;
+        infovec = NULL;
         while (modinfo[i].pathname) {
                 char *desc, *s;
                 if (!modinfo[i].aliases) {
                         parse_module(&modinfo[i], modinfo[i].pathname);
                 }
-                if (result) {
-                        i++;
-                        continue;
-                }
                 /* "alias1 symbol:sym1 alias2 symbol:sym2" */
                 desc = str_2_list(modinfo[i].aliases);
                 /* Does matching substring exist? */
@@ -498,13 +513,12 @@ static module_info* find_alias(const char *alias)
                         if (fnmatch(s, alias, 0) == 0) {
                                 dbg1_error_msg("found alias '%s' in module '%s'",
                                                 alias, modinfo[i].pathname);
-                                result = &modinfo[i];
+                                infovec = xrealloc_vector(infovec, 1, infoidx);
+                                infovec[infoidx++] = &modinfo[i];
                                 break;
                         }
                 }
                 free(desc);
-                if (result && dep_bb_fd < 0)
-                        return result;
                 i++;
         }
 
@@ -513,8 +527,8 @@ static module_info* find_alias(const char *alias)
                 write_out_dep_bb(dep_bb_fd);
         }
 
-        dbg1_error_msg("find_alias '%s' returns %p", alias, result);
-        return result;
+        dbg1_error_msg("find_alias '%s' returns %d results", alias, infoidx);
+        return infovec;
 }
 
 #if ENABLE_FEATURE_MODPROBE_SMALL_CHECK_ALREADY_LOADED
@@ -550,14 +564,23 @@ static int already_loaded(const char *name)
 static void process_module(char *name, const char *cmdline_options)
 {
         char *s, *deps, *options;
+        module_info **infovec;
         module_info *info;
+        int infoidx;
         int is_rmmod = (option_mask32 & OPT_r) != 0;
+
         dbg1_error_msg("process_module('%s','%s')", name, cmdline_options);
 
         replace(name, '-', '_');
 
         dbg1_error_msg("already_loaded:%d is_rmmod:%d", already_loaded(name), is_rmmod);
-        if (already_loaded(name) != is_rmmod) {
+        /*
+         * We used to have "is_rmmod != already_loaded(name)" check here, but
+         *  modprobe -r pci:v00008086d00007010sv00000000sd00000000bc01sc01i80
+         * won't unload modules (there are more than one)
+         * which have this alias.
+         */
+        if (!is_rmmod && already_loaded(name)) {
                 dbg1_error_msg("nothing to do for '%s'", name);
                 return;
         }
@@ -586,39 +609,51 @@ static void process_module(char *name, const char *cmdline_options)
         if (!module_count) {
                 /* Scan module directory. This is done only once.
                  * It will attempt module load, and will exit(EXIT_SUCCESS)
-                 * on success. */
+                 * on success.
+                 */
                 module_found_idx = -1;
                 recursive_action(".",
                         ACTION_RECURSE, /* flags */
                         fileAction, /* file action */
                         NULL, /* dir action */
                         name, /* user data */
-                        0); /* depth */
+                        0 /* depth */
+                );
                 dbg1_error_msg("dirscan complete");
                 /* Module was not found, or load failed, or is_rmmod */
                 if (module_found_idx >= 0) { /* module was found */
-                        info = &modinfo[module_found_idx];
+                        infovec = xzalloc(2 * sizeof(infovec[0]));
+                        infovec[0] = &modinfo[module_found_idx];
                 } else { /* search for alias, not a plain module name */
-                        info = find_alias(name);
+                        infovec = find_alias(name);
                 }
         } else {
-                info = find_alias(name);
+                infovec = find_alias(name);
         }
 
-// Problem here: there can be more than one module
-// for the given alias. For example,
-// "pci:v00008086d00007010sv00000000sd00000000bc01sc01i80" matches
-// ata_piix because it has an alias "pci:v00008086d00007010sv*sd*bc*sc*i*"
-// and ata_generic, it has an alias "pci:v*d*sv*sd*bc01sc01i*"
-// Standard modprobe would load them both.
-// In this code, find_alias() returns only the first matching module.
+        /* There can be more than one module for the given alias. For example,
+         * "pci:v00008086d00007010sv00000000sd00000000bc01sc01i80" matches
+         * ata_piix because it has alias "pci:v00008086d00007010sv*sd*bc*sc*i*"
+         * and ata_generic, it has alias "pci:v*d*sv*sd*bc01sc01i*"
+         * Standard modprobe loads them both. We achieve it by returning
+         * a *list* of modinfo pointers from find_alias().
+         */
 
-        /* rmmod? unload it by name */
+        /* rmmod or modprobe -r? unload module(s) */
         if (is_rmmod) {
-                if (delete_module(name, O_NONBLOCK | O_EXCL) != 0) {
-                        if (!(option_mask32 & OPT_q))
-                                bb_perror_msg("remove '%s'", name);
-                        goto ret;
+                infoidx = 0;
+                while ((info = infovec[infoidx++]) != NULL) {
+                        int r;
+                        char modname[MODULE_NAME_LEN];
+
+                        filename2modname(info->pathname, modname);
+                        r = delete_module(modname, O_NONBLOCK | O_EXCL);
+                        dbg1_error_msg("delete_module('%s', O_NONBLOCK | O_EXCL):%d", modname, r);
+                        if (r != 0) {
+                                if (!(option_mask32 & OPT_q))
+                                        bb_perror_msg("remove '%s'", modname);
+                                goto ret;
+                        }
                 }
 
                 if (applet_name[0] == 'r') {
@@ -634,7 +669,7 @@ static void process_module(char *name, const char *cmdline_options)
                  */
         }
 
-        if (!info) {
+        if (!infovec) {
                 /* both dirscan and find_alias found nothing */
                 if (!is_rmmod && applet_name[0] != 'd') /* it wasn't rmmod or depmod */
                         bb_error_msg("module '%s' not found", name);
@@ -642,36 +677,41 @@ static void process_module(char *name, const char *cmdline_options)
                 goto ret;
         }
 
-        /* Iterate thru dependencies, trying to (un)load them */
-        deps = str_2_list(info->deps);
-        for (s = deps; *s; s += strlen(s) + 1) {
-                //if (strcmp(name, s) != 0) // N.B. do loops exist?
-                dbg1_error_msg("recurse on dep '%s'", s);
-                process_module(s, NULL);
-                dbg1_error_msg("recurse on dep '%s' done", s);
-        }
-        free(deps);
+        infoidx = 0;
+        while ((info = infovec[infoidx++]) != NULL) {
+                /* Iterate thru dependencies, trying to (un)load them */
+                deps = str_2_list(info->deps);
+                for (s = deps; *s; s += strlen(s) + 1) {
+                        //if (strcmp(name, s) != 0) // N.B. do loops exist?
+                        dbg1_error_msg("recurse on dep '%s'", s);
+                        process_module(s, NULL);
+                        dbg1_error_msg("recurse on dep '%s' done", s);
+                }
+                free(deps);
 
-        /* modprobe -> load it */
-        if (!is_rmmod) {
-                if (!options || strstr(options, "blacklist") == NULL) {
-                        errno = 0;
-                        if (load_module(info->pathname, options) != 0) {
-                                if (EEXIST != errno) {
-                                        bb_error_msg("'%s': %s",
-                                                info->pathname,
-                                                moderror(errno));
-                                } else {
-                                        dbg1_error_msg("'%s': %s",
-                                                info->pathname,
-                                                moderror(errno));
-                                }
-                        }
-                } else {
+                if (is_rmmod)
+                        continue;
+
+                /* We are modprobe: load it */
+                if (options && strstr(options, "blacklist")) {
                         dbg1_error_msg("'%s': blacklisted", info->pathname);
+                        continue;
+                }
+                errno = 0;
+                if (load_module(info->pathname, options) != 0) {
+                        if (EEXIST != errno) {
+                                bb_error_msg("'%s': %s",
+                                        info->pathname,
+                                        moderror(errno));
+                        } else {
+                                dbg1_error_msg("'%s': %s",
+                                        info->pathname,
+                                        moderror(errno));
+                        }
                 }
         }
  ret:
+        free(infovec);
         free(options);
 //TODO: return load attempt result from process_module.
 //If dep didn't load ok, continuing makes little sense.