[PATCH v2 0/4] Add modules.builtin.modinfo support

[PATCH v2 0/4] Add modules.builtin.modinfo support

[Alexey Gladkov]

The kernel since version v5.2-rc1 exports information about built-in
modules in the modules.builtin.modinfo. Now, kmod can show complete information
about the built-in modules as well as about external modules. Also kmod can
understand aliases of built-in modules.

Before:

$ modinfo block-major-9-1
modinfo: ERROR: Module block-major-9-1 not found.

After:

$ modinfo block-major-9-1
name:           md_mod
filename:       (builtin)
alias:          block-major-9-*
alias:          md
description:    MD RAID framework
license:        GPL
parm:           start_dirty_degraded:int
parm:           create_on_open:bool

v2:

* Don't use kmod_file() to parse modules.builtin.modinfo. Instead, parser reads
the file into the buffer by chunks, which reduces the amount of memory.

Alexey Gladkov (4):
  libkmod: Add parser for modules.builtin.modinfo
  libkmod: Add function to get list of built-in modules
  Lookup aliases in the modules.builtin.modinfo
  modinfo: Show information about built-in modules

 Makefile.am                |   1 +
 libkmod/libkmod-builtin.c  | 329 +++++++++++++++++++++++++++++++++++++
 libkmod/libkmod-internal.h |  10 ++
 libkmod/libkmod-module.c   |  73 +++++++-
 libkmod/libkmod.c          |  25 +++
 libkmod/libkmod.h          |   1 +
 tools/depmod.c             |  63 +++++++
 tools/modinfo.c            |  39 +++--
 8 files changed, 514 insertions(+), 27 deletions(-)
 create mode 100644 libkmod/libkmod-builtin.c

-- 
2.21.0

[PATCH v2 1/4] libkmod: Add parser for modules.builtin.modinfo

[Alexey Gladkov]

The kernel since version v5.2-rc1 exports information about built-in
modules in the modules.builtin.modinfo. Information is stored in
the same format as in the separate modules (null-terminated string
array). The module name is a prefix for each line.

$ tr '\0' '\n' < modules.builtin.modinfo
ext4.softdep=pre: crc32c
ext4.license=GPL
ext4.description=Fourth Extended Filesystem
ext4.author=Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others
ext4.alias=fs-ext4
ext4.alias=ext3
ext4.alias=fs-ext3
ext4.alias=ext2
ext4.alias=fs-ext2
md_mod.alias=block-major-9-*
md_mod.alias=md
md_mod.description=MD RAID framework
md_mod.license=GPL
md_mod.parmtype=create_on_open:bool
md_mod.parmtype=start_dirty_degraded:int
...

Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com>
---
 Makefile.am                |   1 +
 libkmod/libkmod-builtin.c  | 329 +++++++++++++++++++++++++++++++++++++
 libkmod/libkmod-internal.h |   8 +
 3 files changed, 338 insertions(+)
 create mode 100644 libkmod/libkmod-builtin.c

diff --git a/Makefile.am b/Makefile.am
index c5c2f06..176dcfc 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -68,6 +68,7 @@ libkmod_libkmod_la_SOURCES = \
 	libkmod/libkmod.h \
 	libkmod/libkmod-internal.h \
 	libkmod/libkmod.c \
+	libkmod/libkmod-builtin.c \
 	libkmod/libkmod-list.c \
 	libkmod/libkmod-config.c \
 	libkmod/libkmod-index.c \
diff --git a/libkmod/libkmod-builtin.c b/libkmod/libkmod-builtin.c
new file mode 100644
index 0000000..c7b888a
--- /dev/null
+++ b/libkmod/libkmod-builtin.c
@@ -0,0 +1,329 @@
+/*
+ * libkmod - interface to kernel built-in modules
+ *
+ * Copyright (C) 2019  Alexey Gladkov <gladkov.alexey@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include "libkmod.h"
+#include "libkmod-internal.h"
+
+#define MODULES_BUILTIN_MODINFO "modules.builtin.modinfo"
+
+struct kmod_builtin_iter {
+	struct kmod_ctx *ctx;
+
+	// The file descriptor.
+	int file;
+
+	// The total size in bytes.
+	ssize_t size;
+
+	// The offset of current module.
+	off_t pos;
+
+	// The offset at which the next module is located.
+	off_t next;
+
+	// Number of strings in the current block.
+	ssize_t nstrings;
+
+	// Internal buffer and its size.
+	size_t bufsz;
+	char *buf;
+};
+
+struct kmod_builtin_iter *kmod_builtin_iter_new(struct kmod_ctx *ctx)
+{
+	char path[PATH_MAX];
+	int file, sv_errno;
+	struct stat sb;
+	struct kmod_builtin_iter *iter = NULL;
+	const char *dirname = kmod_get_dirname(ctx);
+	size_t len = strlen(dirname);
+
+	file = -1;
+
+	if ((len + 1 + strlen(MODULES_BUILTIN_MODINFO) + 1) >= PATH_MAX) {
+		sv_errno = ENAMETOOLONG;
+		goto fail;
+	}
+
+	snprintf(path, PATH_MAX, "%s/%s", dirname, MODULES_BUILTIN_MODINFO);
+
+	file = open(path, O_RDONLY|O_CLOEXEC);
+	if (file < 0) {
+		sv_errno = errno;
+		goto fail;
+	}
+
+	if (fstat(file, &sb) < 0) {
+		sv_errno = errno;
+		goto fail;
+	}
+
+	iter = malloc(sizeof(*iter));
+	if (!iter) {
+		sv_errno = ENOMEM;
+		goto fail;
+	}
+
+	iter->ctx = ctx;
+	iter->file = file;
+	iter->size = sb.st_size;
+	iter->nstrings = 0;
+	iter->pos = 0;
+	iter->next = 0;
+	iter->bufsz = 0;
+	iter->buf = NULL;
+
+	return iter;
+fail:
+	if (file >= 0)
+		close(file);
+
+	errno = sv_errno;
+
+	return iter;
+}
+
+void kmod_builtin_iter_free(struct kmod_builtin_iter *iter)
+{
+	close(iter->file);
+	free(iter->buf);
+	free(iter);
+}
+
+static off_t get_string(struct kmod_builtin_iter *iter, off_t offset,
+			char **line, size_t *size)
+{
+	int sv_errno;
+	char *nullp = NULL;
+	size_t linesz = 0;
+
+	while (!nullp) {
+		char buf[BUFSIZ];
+		ssize_t sz;
+		size_t partsz;
+
+		sz = pread(iter->file, buf, BUFSIZ, offset);
+		if (sz < 0) {
+			sv_errno = errno;
+			goto fail;
+		} else if (sz == 0) {
+			offset = 0;
+			break;
+		}
+
+		nullp = memchr(buf, '\0', (size_t) sz);
+		partsz = (size_t)((nullp) ? (nullp - buf) + 1 : sz);
+		offset += (off_t) partsz;
+
+		if (iter->bufsz < linesz + partsz) {
+			iter->bufsz = linesz + partsz;
+			iter->buf = realloc(iter->buf, iter->bufsz);
+
+			if (!iter->buf) {
+				sv_errno = errno;
+				goto fail;
+			}
+		}
+
+		strncpy(iter->buf + linesz, buf, partsz);
+		linesz += partsz;
+	}
+
+	if (linesz) {
+		*line = iter->buf;
+		*size = linesz;
+	}
+
+	return offset;
+fail:
+	errno = sv_errno;
+	return -1;
+}
+
+bool kmod_builtin_iter_next(struct kmod_builtin_iter *iter)
+{
+	char *line,  *modname;
+	size_t linesz;
+	off_t pos, offset, modlen;
+
+	modname = NULL;
+
+	iter->nstrings = 0;
+	offset = pos = iter->next;
+
+	while (offset < iter->size) {
+		char *dot;
+		off_t len;
+
+		offset = get_string(iter, pos, &line, &linesz);
+		if (offset <= 0) {
+			if (offset)
+				ERR(iter->ctx, "get_string: %s\n", strerror(errno));
+			pos = iter->size;
+			break;
+		}
+
+		dot = strchr(line, '.');
+		if (!dot) {
+			ERR(iter->ctx, "kmod_builtin_iter_next: unexpected string without modname prefix\n");
+			pos = iter->size;
+			break;
+		}
+
+		len = dot - line;
+
+		if (!modname) {
+			modname = strdup(line);
+			modlen = len;
+		} else if (modlen != len || strncmp(modname, line, len)) {
+			break;
+		}
+
+		iter->nstrings++;
+		pos = offset;
+	}
+
+	iter->pos = iter->next;
+	iter->next = pos;
+
+	free(modname);
+
+	return (iter->pos < iter->size);
+}
+
+bool kmod_builtin_iter_get_modname(struct kmod_builtin_iter *iter,
+				char modname[static PATH_MAX])
+{
+	int sv_errno;
+	char *line, *dot;
+	size_t linesz, len;
+	off_t offset;
+
+	if (iter->pos == iter->size)
+		return false;
+
+	line = NULL;
+
+	offset = get_string(iter, iter->pos, &line, &linesz);
+	if (offset <= 0) {
+		sv_errno = errno;
+		if (offset)
+			ERR(iter->ctx, "get_string: %s\n", strerror(errno));
+		goto fail;
+	}
+
+	dot = strchr(line, '.');
+	if (!dot) {
+		sv_errno = errno;
+		ERR(iter->ctx, "kmod_builtin_iter_get_modname: unexpected string without modname prefix\n");
+		goto fail;
+	}
+
+	len = dot - line;
+
+	if (len > PATH_MAX) {
+		sv_errno = ENAMETOOLONG;
+		goto fail;
+	}
+
+	strncpy(modname, line, len);
+	modname[len] = '\0';
+
+	return true;
+fail:
+	errno = sv_errno;
+	return false;
+}
+
+/* array will be allocated with strings in a single malloc, just free *array */
+ssize_t kmod_builtin_get_modinfo(struct kmod_ctx *ctx, const char *modname,
+				char ***modinfo)
+{
+	ssize_t count = 0;
+	char *s, *line = NULL;
+	size_t i, n, linesz, modlen, size;
+	off_t pos, offset;
+
+	char *name = NULL;
+	char buf[PATH_MAX];
+
+	struct kmod_builtin_iter *iter = kmod_builtin_iter_new(ctx);
+
+	if (!iter)
+		return -1;
+
+	while (!name && kmod_builtin_iter_next(iter)) {
+		if (!kmod_builtin_iter_get_modname(iter, buf)) {
+			count = -errno;
+			goto fail;
+		}
+
+		if (strcmp(modname, buf))
+			continue;
+
+		name = buf;
+	}
+
+	if (!name) {
+		count = -ENOSYS;
+		goto fail;
+	}
+
+	modlen = strlen(modname) + 1;
+	count = iter->nstrings;
+	size = iter->next - iter->pos - (modlen * count);
+
+	*modinfo = malloc(size + sizeof(char *) * (count + 1));
+	if (!*modinfo) {
+		count = -errno;
+		goto fail;
+	}
+
+	s = (char *)(*modinfo + count + 1);
+	i = 0;
+
+	n = 0;
+	offset = pos = iter->pos;
+
+	while (offset < iter->next) {
+		offset = get_string(iter, pos, &line, &linesz);
+		if (offset <= 0) {
+			count = (offset) ? -errno : -EOF;
+			goto fail;
+		}
+
+		strcpy(s + i, line + modlen);
+		(*modinfo)[n++] = s + i;
+		i += linesz - modlen;
+
+		pos = offset;
+	}
+fail:
+	kmod_builtin_iter_free(iter);
+	return count;
+}
diff --git a/libkmod/libkmod-internal.h b/libkmod/libkmod-internal.h
index a65ddd1..df01df1 100644
--- a/libkmod/libkmod-internal.h
+++ b/libkmod/libkmod-internal.h
@@ -193,3 +193,11 @@ struct kmod_signature_info {
 };
 bool kmod_module_signature_info(const struct kmod_file *file, struct kmod_signature_info *sig_info) _must_check_ __attribute__((nonnull(1, 2)));
 void kmod_module_signature_info_free(struct kmod_signature_info *sig_info) __attribute__((nonnull));
+
+/* libkmod-builtin.c */
+struct kmod_builtin_iter;
+struct kmod_builtin_iter *kmod_builtin_iter_new(struct kmod_ctx *ctx) __attribute__((nonnull(1)));
+void kmod_builtin_iter_free(struct kmod_builtin_iter *iter) __attribute__((nonnull(1)));
+bool kmod_builtin_iter_next(struct kmod_builtin_iter *iter) __attribute__((nonnull(1)));
+bool kmod_builtin_iter_get_modname(struct kmod_builtin_iter *iter, char modname[static PATH_MAX]) __attribute__((nonnull(1, 2)));
+ssize_t kmod_builtin_get_modinfo(struct kmod_ctx *ctx, const char *modname, char ***modinfo) __attribute__((nonnull(1, 2, 3)));
-- 
2.21.0

[PATCH v2 2/4] libkmod: Add function to get list of built-in modules

[Alexey Gladkov]

Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com>
---
 libkmod/libkmod-internal.h |  1 +
 libkmod/libkmod-module.c   | 40 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+)

diff --git a/libkmod/libkmod-internal.h b/libkmod/libkmod-internal.h
index df01df1..ee4b97b 100644
--- a/libkmod/libkmod-internal.h
+++ b/libkmod/libkmod-internal.h
@@ -145,6 +145,7 @@ void kmod_module_set_visited(struct kmod_module *mod, bool visited) __attribute_
 void kmod_module_set_builtin(struct kmod_module *mod, bool builtin) __attribute__((nonnull((1))));
 void kmod_module_set_required(struct kmod_module *mod, bool required) __attribute__((nonnull(1)));
 bool kmod_module_is_builtin(struct kmod_module *mod) __attribute__((nonnull(1)));
+int kmod_module_get_builtin(struct kmod_ctx *ctx, struct kmod_list **list) __attribute__((nonnull(1, 2)));
 
 /* libkmod-file.c */
 struct kmod_file *kmod_file_open(const struct kmod_ctx *ctx, const char *filename) _must_check_ __attribute__((nonnull(1,2)));
diff --git a/libkmod/libkmod-module.c b/libkmod/libkmod-module.c
index bffe715..8fbabd2 100644
--- a/libkmod/libkmod-module.c
+++ b/libkmod/libkmod-module.c
@@ -2866,3 +2866,43 @@ KMOD_EXPORT void kmod_module_dependency_symbols_free_list(struct kmod_list *list
 		list = kmod_list_remove(list);
 	}
 }
+
+/**
+ * kmod_module_get_builtin:
+ * @ctx: kmod library context
+ * @list: where to save the builtin module list
+ *
+ * Returns: 0 on success or < 0 otherwise.
+ */
+int kmod_module_get_builtin(struct kmod_ctx *ctx, struct kmod_list **list)
+{
+	struct kmod_builtin_iter *iter;
+	int err = 0;
+
+	iter = kmod_builtin_iter_new(ctx);
+	if (!iter)
+		return -errno;
+
+	while (kmod_builtin_iter_next(iter)) {
+		struct kmod_module *mod = NULL;
+		char modname[PATH_MAX];
+
+		if (!kmod_builtin_iter_get_modname(iter, modname)) {
+			err = -errno;
+			goto fail;
+		}
+
+		kmod_module_new_from_name(ctx, modname, &mod);
+		kmod_module_set_builtin(mod, true);
+
+		*list = kmod_list_append(*list, mod);
+	}
+
+	kmod_builtin_iter_free(iter);
+	return err;
+fail:
+	kmod_builtin_iter_free(iter);
+	kmod_module_unref_list(*list);
+	*list = NULL;
+	return err;
+}
-- 
2.21.0

[PATCH v2 3/4] Lookup aliases in the modules.builtin.modinfo

[Alexey Gladkov]

New modules.builtin.modinfo duplicates modules.builtin in the built-in
module name search. If it exists, then we can use this file, but if not,
then we need to fallback to the old file.

Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com>
---
 libkmod/libkmod-internal.h |  1 +
 libkmod/libkmod-module.c   | 10 ++++--
 libkmod/libkmod.c          | 25 +++++++++++++++
 libkmod/libkmod.h          |  1 +
 tools/depmod.c             | 63 ++++++++++++++++++++++++++++++++++++++
 5 files changed, 98 insertions(+), 2 deletions(-)

diff --git a/libkmod/libkmod-internal.h b/libkmod/libkmod-internal.h
index ee4b97b..b22ac2a 100644
--- a/libkmod/libkmod-internal.h
+++ b/libkmod/libkmod-internal.h
@@ -89,6 +89,7 @@ int kmod_lookup_alias_from_config(struct kmod_ctx *ctx, const char *name, struct
 int kmod_lookup_alias_from_symbols_file(struct kmod_ctx *ctx, const char *name, struct kmod_list **list) __attribute__((nonnull(1, 2, 3)));
 int kmod_lookup_alias_from_aliases_file(struct kmod_ctx *ctx, const char *name, struct kmod_list **list) __attribute__((nonnull(1, 2, 3)));
 int kmod_lookup_alias_from_moddep_file(struct kmod_ctx *ctx, const char *name, struct kmod_list **list) __attribute__((nonnull(1, 2, 3)));
+int kmod_lookup_alias_from_kernel_builtin_file(struct kmod_ctx *ctx, const char *name, struct kmod_list **list) __attribute__((nonnull(1, 2, 3)));
 int kmod_lookup_alias_from_builtin_file(struct kmod_ctx *ctx, const char *name, struct kmod_list **list) __attribute__((nonnull(1, 2, 3)));
 bool kmod_lookup_alias_is_builtin(struct kmod_ctx *ctx, const char *name) __attribute__((nonnull(1, 2)));
 int kmod_lookup_alias_from_commands(struct kmod_ctx *ctx, const char *name, struct kmod_list **list) __attribute__((nonnull(1, 2, 3)));
diff --git a/libkmod/libkmod-module.c b/libkmod/libkmod-module.c
index 8fbabd2..ee7e6bd 100644
--- a/libkmod/libkmod-module.c
+++ b/libkmod/libkmod-module.c
@@ -575,10 +575,16 @@ KMOD_EXPORT int kmod_module_new_from_lookup(struct kmod_ctx *ctx,
 	err = kmod_lookup_alias_from_aliases_file(ctx, alias, list);
 	CHECK_ERR_AND_FINISH(err, fail, list, finish);
 
-	DBG(ctx, "lookup modules.builtin %s\n", alias);
-	err = kmod_lookup_alias_from_builtin_file(ctx, alias, list);
+	DBG(ctx, "lookup modules.builtin.modinfo %s\n", alias);
+	err = kmod_lookup_alias_from_kernel_builtin_file(ctx, alias, list);
 	CHECK_ERR_AND_FINISH(err, fail, list, finish);
 
+	if (err == 0) {
+		DBG(ctx, "lookup modules.builtin %s\n", alias);
+		err = kmod_lookup_alias_from_builtin_file(ctx, alias, list);
+		CHECK_ERR_AND_FINISH(err, fail, list, finish);
+	}
+
 finish:
 	DBG(ctx, "lookup %s=%d, list=%p\n", alias, err, *list);
 	return err;
diff --git a/libkmod/libkmod.c b/libkmod/libkmod.c
index 69fe431..c9d9e2a 100644
--- a/libkmod/libkmod.c
+++ b/libkmod/libkmod.c
@@ -57,6 +57,7 @@ static struct _index_files {
 	[KMOD_INDEX_MODULES_DEP] = { .fn = "modules.dep", .prefix = "" },
 	[KMOD_INDEX_MODULES_ALIAS] = { .fn = "modules.alias", .prefix = "alias " },
 	[KMOD_INDEX_MODULES_SYMBOL] = { .fn = "modules.symbols", .prefix = "alias "},
+	[KMOD_INDEX_MODULES_BUILTIN_ALIAS] = { .fn = "modules.builtin.alias", .prefix = "" },
 	[KMOD_INDEX_MODULES_BUILTIN] = { .fn = "modules.builtin", .prefix = ""},
 };
 
@@ -522,6 +523,30 @@ static char *lookup_builtin_file(struct kmod_ctx *ctx, const char *name)
 	return line;
 }
 
+int kmod_lookup_alias_from_kernel_builtin_file(struct kmod_ctx *ctx,
+						const char *name,
+						struct kmod_list **list)
+{
+	struct kmod_list *l;
+	int ret = kmod_lookup_alias_from_alias_bin(ctx,
+						KMOD_INDEX_MODULES_BUILTIN_ALIAS,
+						name, list);
+	if (ret > 0) {
+		kmod_list_foreach(l, *list) {
+			struct kmod_module *mod = l->data;
+			kmod_module_set_builtin(mod, true);
+		}
+	} else if (ret == -ENOSYS) {
+		/*
+		 * If the system does not support this yet, then
+		 * there is no need to return an error.
+		 */
+		ret = 0;
+	}
+
+	return ret;
+}
+
 int kmod_lookup_alias_from_builtin_file(struct kmod_ctx *ctx, const char *name,
 						struct kmod_list **list)
 {
diff --git a/libkmod/libkmod.h b/libkmod/libkmod.h
index 352627e..3cab2e5 100644
--- a/libkmod/libkmod.h
+++ b/libkmod/libkmod.h
@@ -70,6 +70,7 @@ enum kmod_index {
 	KMOD_INDEX_MODULES_DEP = 0,
 	KMOD_INDEX_MODULES_ALIAS,
 	KMOD_INDEX_MODULES_SYMBOL,
+	KMOD_INDEX_MODULES_BUILTIN_ALIAS,
 	KMOD_INDEX_MODULES_BUILTIN,
 	/* Padding to make sure enum is not mapped to char */
 	_KMOD_INDEX_PAD = 1U << 31,
diff --git a/tools/depmod.c b/tools/depmod.c
index 391afe9..fbbce10 100644
--- a/tools/depmod.c
+++ b/tools/depmod.c
@@ -2402,6 +2402,68 @@ static int output_devname(struct depmod *depmod, FILE *out)
 	return 0;
 }
 
+static int output_builtin_alias_bin(struct depmod *depmod, FILE *out)
+{
+	int ret = 0, count = 0;
+	struct index_node *idx;
+	struct kmod_list *l, *builtin = NULL;
+
+	idx = index_create();
+
+	if (idx == NULL) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	ret = kmod_module_get_builtin(depmod->ctx, &builtin);
+	if (ret < 0) {
+		if (ret == -ENOENT)
+			ret = 0;
+		goto fail;
+	}
+
+	kmod_list_foreach(l, builtin) {
+		struct kmod_list *ll, *info_list = NULL;
+		struct kmod_module *mod = l->data;
+		const char *modname = kmod_module_get_name(mod);
+
+		ret = kmod_module_get_info(mod, &info_list);
+		if (ret < 0)
+			goto fail;
+
+		kmod_list_foreach(ll, info_list) {
+			char alias[PATH_MAX];
+			const char *key = kmod_module_info_get_key(ll);
+			const char *value = kmod_module_info_get_value(ll);
+
+			if (!streq(key, "alias"))
+				continue;
+
+			alias[0] = '\0';
+			if (alias_normalize(value, alias, NULL) < 0) {
+				WRN("Unmatched bracket in %s\n", value);
+				continue;
+			}
+
+			index_insert(idx, alias, modname, 0);
+		}
+
+		kmod_module_info_free_list(info_list);
+
+		index_insert(idx, modname, modname, 0);
+		count++;
+	}
+
+	if (count)
+		index_write(idx, out);
+	index_destroy(idx);
+fail:
+	if (builtin)
+		kmod_module_unref_list(builtin);
+
+	return ret;
+}
+
 static int depmod_output(struct depmod *depmod, FILE *out)
 {
 	static const struct depfile {
@@ -2416,6 +2478,7 @@ static int depmod_output(struct depmod *depmod, FILE *out)
 		{ "modules.symbols", output_symbols },
 		{ "modules.symbols.bin", output_symbols_bin },
 		{ "modules.builtin.bin", output_builtin_bin },
+		{ "modules.builtin.alias.bin", output_builtin_alias_bin },
 		{ "modules.devname", output_devname },
 		{ }
 	};
-- 
2.21.0

[PATCH v2 4/4] modinfo: Show information about built-in modules

[Alexey Gladkov]

Signed-off-by: Alexey Gladkov <gladkov.alexey@gmail.com>
---
 libkmod/libkmod-builtin.c |  2 +-
 libkmod/libkmod-module.c  | 23 ++++++++++++++++-------
 tools/modinfo.c           | 39 +++++++++++++++++++++------------------
 3 files changed, 38 insertions(+), 26 deletions(-)

diff --git a/libkmod/libkmod-builtin.c b/libkmod/libkmod-builtin.c
index c7b888a..6b4651c 100644
--- a/libkmod/libkmod-builtin.c
+++ b/libkmod/libkmod-builtin.c
@@ -275,7 +275,7 @@ ssize_t kmod_builtin_get_modinfo(struct kmod_ctx *ctx, const char *modname,
 	struct kmod_builtin_iter *iter = kmod_builtin_iter_new(ctx);
 
 	if (!iter)
-		return -1;
+		return -errno;
 
 	while (!name && kmod_builtin_iter_next(iter)) {
 		if (!kmod_builtin_iter_get_modname(iter, buf)) {
diff --git a/libkmod/libkmod-module.c b/libkmod/libkmod-module.c
index ee7e6bd..8044a8f 100644
--- a/libkmod/libkmod-module.c
+++ b/libkmod/libkmod-module.c
@@ -2286,13 +2286,22 @@ KMOD_EXPORT int kmod_module_get_info(const struct kmod_module *mod, struct kmod_
 
 	assert(*list == NULL);
 
-	elf = kmod_module_get_elf(mod);
-	if (elf == NULL)
-		return -errno;
+	/* remove const: this can only change internal state */
+	if (kmod_module_is_builtin((struct kmod_module *)mod)) {
+		count = kmod_builtin_get_modinfo(mod->ctx,
+						kmod_module_get_name(mod),
+						&strings);
+		if (count < 0)
+			return count;
+	} else {
+		elf = kmod_module_get_elf(mod);
+		if (elf == NULL)
+			return -errno;
 
-	count = kmod_elf_get_strings(elf, ".modinfo", &strings);
-	if (count < 0)
-		return count;
+		count = kmod_elf_get_strings(elf, ".modinfo", &strings);
+		if (count < 0)
+			return count;
+	}
 
 	for (i = 0; i < count; i++) {
 		struct kmod_list *n;
@@ -2316,7 +2325,7 @@ KMOD_EXPORT int kmod_module_get_info(const struct kmod_module *mod, struct kmod_
 			goto list_error;
 	}
 
-	if (kmod_module_signature_info(mod->file, &sig_info)) {
+	if (mod->file && kmod_module_signature_info(mod->file, &sig_info)) {
 		struct kmod_list *n;
 
 		n = kmod_module_info_append(list, "sig_id", strlen("sig_id"),
diff --git a/tools/modinfo.c b/tools/modinfo.c
index 86ac04b..0231bb0 100644
--- a/tools/modinfo.c
+++ b/tools/modinfo.c
@@ -172,18 +172,33 @@ static int modinfo_do(struct kmod_module *mod)
 {
 	struct kmod_list *l, *list = NULL;
 	struct param *params = NULL;
-	int err;
+	int err, is_builtin;
+	const char *filename = kmod_module_get_path(mod);
+
+	is_builtin = (filename == NULL);
+
+	if (is_builtin) {
+		printf("%-16s%s%c", "name:", kmod_module_get_name(mod), separator);
+		filename = "(builtin)";
+	}
 
 	if (field != NULL && streq(field, "filename")) {
-		printf("%s%c", kmod_module_get_path(mod), separator);
+		printf("%s%c", filename, separator);
 		return 0;
 	} else if (field == NULL) {
 		printf("%-16s%s%c", "filename:",
-		       kmod_module_get_path(mod), separator);
+		       filename, separator);
 	}
 
 	err = kmod_module_get_info(mod, &list);
 	if (err < 0) {
+		if (is_builtin && err == -ENOENT) {
+			/*
+			 * This is an old kernel that does not have a file
+			 * with information about built-in modules.
+			 */
+			return 0;
+		}
 		ERR("could not get modinfo from '%s': %s\n",
 			kmod_module_get_name(mod), strerror(-err));
 		return err;
@@ -276,7 +291,7 @@ static int modinfo_path_do(struct kmod_ctx *ctx, const char *path)
 
 static int modinfo_alias_do(struct kmod_ctx *ctx, const char *alias)
 {
-	struct kmod_list *l, *filtered, *list = NULL;
+	struct kmod_list *l, *list = NULL;
 	int err = kmod_module_new_from_lookup(ctx, alias, &list);
 	if (err < 0) {
 		ERR("Module alias %s not found.\n", alias);
@@ -288,26 +303,14 @@ static int modinfo_alias_do(struct kmod_ctx *ctx, const char *alias)
 		return -ENOENT;
 	}
 
-	err = kmod_module_apply_filter(ctx, KMOD_FILTER_BUILTIN, list, &filtered);
-	kmod_module_unref_list(list);
-	if (err < 0) {
-		ERR("Failed to filter list: %m\n");
-		return err;
-	}
-
-	if (filtered == NULL) {
-		ERR("Module %s not found.\n", alias);
-		return -ENOENT;
-	}
-
-	kmod_list_foreach(l, filtered) {
+	kmod_list_foreach(l, list) {
 		struct kmod_module *mod = kmod_module_get_module(l);
 		int r = modinfo_do(mod);
 		kmod_module_unref(mod);
 		if (r < 0)
 			err = r;
 	}
-	kmod_module_unref_list(filtered);
+	kmod_module_unref_list(list);
 	return err;
 }
 
-- 
2.21.0

Re: [PATCH v2 0/4] Add modules.builtin.modinfo support

[Alexey Gladkov]

On Fri, Nov 08, 2019 at 06:25:19PM +0100, Alexey Gladkov wrote:
> The kernel since version v5.2-rc1 exports information about built-in
> modules in the modules.builtin.modinfo. Now, kmod can show complete information
> about the built-in modules as well as about external modules. Also kmod can
> understand aliases of built-in modules.

How about this version ?

> Before:
> 
> $ modinfo block-major-9-1
> modinfo: ERROR: Module block-major-9-1 not found.
> 
> After:
> 
> $ modinfo block-major-9-1
> name:           md_mod
> filename:       (builtin)
> alias:          block-major-9-*
> alias:          md
> description:    MD RAID framework
> license:        GPL
> parm:           start_dirty_degraded:int
> parm:           create_on_open:bool
> 
> v2:
> 
> * Don't use kmod_file() to parse modules.builtin.modinfo. Instead, parser reads
> the file into the buffer by chunks, which reduces the amount of memory.
> 
> Alexey Gladkov (4):
>   libkmod: Add parser for modules.builtin.modinfo
>   libkmod: Add function to get list of built-in modules
>   Lookup aliases in the modules.builtin.modinfo
>   modinfo: Show information about built-in modules
> 
>  Makefile.am                |   1 +
>  libkmod/libkmod-builtin.c  | 329 +++++++++++++++++++++++++++++++++++++
>  libkmod/libkmod-internal.h |  10 ++
>  libkmod/libkmod-module.c   |  73 +++++++-
>  libkmod/libkmod.c          |  25 +++
>  libkmod/libkmod.h          |   1 +
>  tools/depmod.c             |  63 +++++++
>  tools/modinfo.c            |  39 +++--
>  8 files changed, 514 insertions(+), 27 deletions(-)
>  create mode 100644 libkmod/libkmod-builtin.c
> 
> -- 
> 2.21.0
> 

-- 
Rgrds, legion

Re: [PATCH v2 0/4] Add modules.builtin.modinfo support

[Alexey Gladkov]

On Fri, Nov 08, 2019 at 06:25:19PM +0100, Alexey Gladkov wrote:
> The kernel since version v5.2-rc1 exports information about built-in
> modules in the modules.builtin.modinfo. Now, kmod can show complete information
> about the built-in modules as well as about external modules. Also kmod can
> understand aliases of built-in modules.
> 
> Before:
> 
> $ modinfo block-major-9-1
> modinfo: ERROR: Module block-major-9-1 not found.
> 
> After:
> 
> $ modinfo block-major-9-1
> name:           md_mod
> filename:       (builtin)
> alias:          block-major-9-*
> alias:          md
> description:    MD RAID framework
> license:        GPL
> parm:           start_dirty_degraded:int
> parm:           create_on_open:bool
> 
> v2:
> 
> * Don't use kmod_file() to parse modules.builtin.modinfo. Instead, parser reads
> the file into the buffer by chunks, which reduces the amount of memory.
> 
> Alexey Gladkov (4):
>   libkmod: Add parser for modules.builtin.modinfo
>   libkmod: Add function to get list of built-in modules
>   Lookup aliases in the modules.builtin.modinfo
>   modinfo: Show information about built-in modules

ping.

>  Makefile.am                |   1 +
>  libkmod/libkmod-builtin.c  | 329 +++++++++++++++++++++++++++++++++++++
>  libkmod/libkmod-internal.h |  10 ++
>  libkmod/libkmod-module.c   |  73 +++++++-
>  libkmod/libkmod.c          |  25 +++
>  libkmod/libkmod.h          |   1 +
>  tools/depmod.c             |  63 +++++++
>  tools/modinfo.c            |  39 +++--
>  8 files changed, 514 insertions(+), 27 deletions(-)
>  create mode 100644 libkmod/libkmod-builtin.c
> 
> -- 
> 2.21.0
> 

-- 
Rgrds, legion

Re: [PATCH v2 0/4] Add modules.builtin.modinfo support

[Lucas De Marchi]

On Wed, Dec 4, 2019 at 7:27 AM Alexey Gladkov <gladkov.alexey@gmail.com> wrote:
>
> On Fri, Nov 08, 2019 at 06:25:19PM +0100, Alexey Gladkov wrote:
> > The kernel since version v5.2-rc1 exports information about built-in
> > modules in the modules.builtin.modinfo. Now, kmod can show complete information
> > about the built-in modules as well as about external modules. Also kmod can
> > understand aliases of built-in modules.
> >
> > Before:
> >
> > $ modinfo block-major-9-1
> > modinfo: ERROR: Module block-major-9-1 not found.
> >
> > After:
> >
> > $ modinfo block-major-9-1
> > name:           md_mod
> > filename:       (builtin)
> > alias:          block-major-9-*
> > alias:          md
> > description:    MD RAID framework
> > license:        GPL
> > parm:           start_dirty_degraded:int
> > parm:           create_on_open:bool
> >
> > v2:
> >
> > * Don't use kmod_file() to parse modules.builtin.modinfo. Instead, parser reads
> > the file into the buffer by chunks, which reduces the amount of memory.
> >
> > Alexey Gladkov (4):
> >   libkmod: Add parser for modules.builtin.modinfo
> >   libkmod: Add function to get list of built-in modules
> >   Lookup aliases in the modules.builtin.modinfo
> >   modinfo: Show information about built-in modules
>
> ping.

sorry for the delay, it took me some time to go through it and review.

Applied,
thanks

Lucas De Marchi

>
> >  Makefile.am                |   1 +
> >  libkmod/libkmod-builtin.c  | 329 +++++++++++++++++++++++++++++++++++++
> >  libkmod/libkmod-internal.h |  10 ++
> >  libkmod/libkmod-module.c   |  73 +++++++-
> >  libkmod/libkmod.c          |  25 +++
> >  libkmod/libkmod.h          |   1 +
> >  tools/depmod.c             |  63 +++++++
> >  tools/modinfo.c            |  39 +++--
> >  8 files changed, 514 insertions(+), 27 deletions(-)
> >  create mode 100644 libkmod/libkmod-builtin.c
> >
> > --
> > 2.21.0
> >
>
> --
> Rgrds, legion
>


-- 
Lucas De Marchi