* [PATCH] Re: modprobe documentation discrepancy (modules.dep support)
2014-02-26 8:18 modprobe documentation discrepancy (modules.dep support) Andrej Krutak
@ 2014-02-26 16:19 ` Andrej Krutak
2014-02-26 20:06 ` Lucas De Marchi
0 siblings, 1 reply; 3+ messages in thread
From: Andrej Krutak @ 2014-02-26 16:19 UTC (permalink / raw)
To: linux-modules
Hi again,
below is a patch to (re-)add support for modules.dep (in addition to
modules.dep.bin), in a very dirty way. Basically I just took parts of the
original code from module-init-tools...
Also, it fixes the CHECK_ERR_AND_FINISH macro.
However, this doesn't fix the whole "problem" - 'modprobe nonexistingmodule'
is called, no error is printed, because of the faulty processing of subsequent
non-existent files (like modules.builtin.bin etc. - which depmod.pl doesn't
generate).
To fully fix this, one would have to also add support for the other
legacy files. Well, at least a support to handle the missing files gracefully.
Fixing this is important for when you want to cross-compile the kernel in a
non-linux environment. I didn't find find any other tool than depmod.pl that
could generate all the files required by modprobe (but depmod.pl, as mentioned
before, doesn't generate other .bin files) - and kmod/module-init-tools can't
be cross-compiled for cygwin/mingw32...
Best regards,
Andrej Krutak
SYSGO
---
libkmod/libkmod-module.c | 4 +-
libkmod/libkmod.c | 107
+++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 107 insertions(+), 4 deletions(-)
diff --git a/libkmod/libkmod-module.c b/libkmod/libkmod-module.c
index 3d3325f..e737d30 100644
--- a/libkmod/libkmod-module.c
+++ b/libkmod/libkmod-module.c
@@ -473,7 +473,7 @@ KMOD_EXPORT struct kmod_module *kmod_module_ref(struct
kmod_module *mod)
if ((_err) < 0) \
goto _label_err; \
if (*(_list) != NULL) \
- goto finish; \
+ goto label_finish; \
} while (0)
/**
@@ -553,7 +553,7 @@ finish:
DBG(ctx, "lookup %s=%d, list=%p\n", alias, err, *list);
return err;
fail:
- DBG(ctx, "Failed to lookup %s\n", alias);
+ DBG(ctx, "Failed to lookup %s (%d)\n", alias, err);
kmod_module_unref_list(*list);
*list = NULL;
return err;
diff --git a/libkmod/libkmod.c b/libkmod/libkmod.c
index ef83e31..4a60416 100644
--- a/libkmod/libkmod.c
+++ b/libkmod/libkmod.c
@@ -533,11 +533,106 @@ finish:
return err;
}
+/**
+ * modname_equal - compare module names (up to len), with '_' and '-' equal
+ *
+ * @a: first module name
+ * @b: second module name
+ * @len: length to compare
+ *
+ */
+static int modname_equal(const char *a, const char *b, unsigned int len)
+{
+ unsigned int i;
+
+ if (strlen(b) != len)
+ return 0;
+
+ for (i = 0; i < len; i++) {
+ if ((a[i] == '_' || a[i] == '-')
+ && (b[i] == '_' || b[i] == '-'))
+ continue;
+ if (a[i] != b[i])
+ return 0;
+ }
+ return 1;
+}
+
+static char *my_basename(const char *path)
+{
+ const char *base = strrchr(path, '/');
+ if (base)
+ return (char *) base + 1;
+ return (char *) path;
+}
+
+
+/**
+ * add_modules_dep_line - parse a dep line from the module.dep[.bin] file
+ *
+ * @line: input file line
+ * @name: module name
+ *
+ * Add dependency information if this line of the dep file matches mod name
+ */
+static int is_module_line(char *line,
+ const char *name)
+{
+ char *ptr;
+ int len;
+ char *modname;
+ int rv;
+
+ line = strdup(line);
+
+ /* Ignore lines without : or which start with a # */
+ ptr = strchr(line, ':');
+ if (ptr == NULL || line[strspn(line, "\t ")] == '#') {
+ free(line);
+ return 0;
+ }
+
+ /* Is this the module we are looking for? */
+ *ptr = '\0';
+ modname = my_basename(line);
+
+ len = strlen(modname);
+ if (strchr(modname, '.'))
+ len = strchr(modname, '.') - modname;
+
+ rv = modname_equal(modname, name, len);
+
+ free(line);
+ return rv;
+}
+
+static char *kmod_search_moddep_legacy(struct kmod_ctx *ctx, const char
*name, const char *fn)
+{
+ char *line;
+ FILE *modules_dep;
+
+ modules_dep = fopen(fn, "r");
+ if (!modules_dep)
+ return NULL;
+
+ /* Stop at first line, as we can have duplicates (eg. symlinks
+ from boot/ */
+ while ((line = getline_wrapped(modules_dep, NULL)) != NULL) {
+ if (is_module_line(line, name))
+ break;
+ free(line);
+ }
+ fclose(modules_dep);
+
+ return line;
+}
+
char *kmod_search_moddep(struct kmod_ctx *ctx, const char *name)
{
struct index_file *idx;
char fn[PATH_MAX];
char *line;
+
if (ctx->indexes[KMOD_INDEX_MODULES_DEP]) {
DBG(ctx, "use mmaped index '%s' modname=%s\n",
@@ -553,8 +648,16 @@ char *kmod_search_moddep(struct kmod_ctx *ctx, const char
*name)
idx = index_file_open(fn);
if (idx == NULL) {
- DBG(ctx, "could not open moddep file '%s'\n", fn);
- return NULL;
+ struct stat st;
+
+ snprintf(fn, sizeof(fn), "%s/%s", ctx->dirname,
+ index_files[KMOD_INDEX_MODULES_DEP].fn);
+ if (stat(fn, &st) != 0) {
+ DBG(ctx, "could not open moddep file '%s[.bin]'\n", fn);
+ return NULL;
+ }
+
+ return kmod_search_moddep_legacy(ctx, name, fn);
}
line = index_search(idx, name);
--
1.7.9.5
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