From: Emil Velikov <emil.l.velikov@gmail.com>
Date: Wed, 7 May 2025 17:58:11 +0000 (+0100)
Subject: libkmod: update remaining function to return the error code
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5cd2a2a4874154bab15de6ad8be85d0571dfc2b8;p=thirdparty%2Fkmod.git

libkmod: update remaining function to return the error code

Rework the function signature and return the error code instead of the
stripped module. Thus we no longer explicitly set errno.

v2:
 - kmod_file_open() - use _cleanup_free_, return errno instead of ENOMEM

Reference: https://github.com/kmod-project/kmod/issues/244
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://github.com/kmod-project/kmod/pull/346
Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>
---

diff --git a/libkmod/libkmod-file.c b/libkmod/libkmod-file.c
index 23057fa6..d651fa2e 100644
--- a/libkmod/libkmod-file.c
+++ b/libkmod/libkmod-file.c
@@ -58,57 +58,53 @@ static const struct comp_type {
 	// clang-format on
 };
 
-struct kmod_elf *kmod_file_get_elf(struct kmod_file *file)
+int kmod_file_get_elf(struct kmod_file *file, struct kmod_elf **elf)
 {
-	int err;
-
-	if (file->elf)
-		return file->elf;
-
-	err = kmod_file_load_contents(file);
-	if (err) {
-		errno = -err;
-		return NULL;
+	if (!file->elf) {
+		int err = kmod_file_load_contents(file);
+		if (err)
+			return err;
+
+		err = kmod_elf_new(file->memory, file->size, &file->elf);
+		if (err)
+			return err;
 	}
 
-	err = kmod_elf_new(file->memory, file->size, &file->elf);
-	if (err) {
-		errno = -err;
-		return NULL;
-	}
-	return file->elf;
+	*elf = file->elf;
+	return 0;
 }
 
-struct kmod_file *kmod_file_open(const struct kmod_ctx *ctx, const char *filename)
+int kmod_file_open(const struct kmod_ctx *ctx, const char *filename,
+		   struct kmod_file **out_file)
 {
-	struct kmod_file *file;
+	_cleanup_free_ struct kmod_file *file;
 	char buf[7];
 	ssize_t sz;
+	int ret;
 
 	assert_cc(sizeof(magic_zstd) < sizeof(buf));
 	assert_cc(sizeof(magic_xz) < sizeof(buf));
 	assert_cc(sizeof(magic_zlib) < sizeof(buf));
 
 	file = calloc(1, sizeof(struct kmod_file));
-	if (file == NULL)
-		return NULL;
+	if (file == NULL) {
+		file = NULL;
+		return -ENOMEM;
+	}
 
 	file->fd = open(filename, O_RDONLY | O_CLOEXEC);
-	if (file->fd < 0) {
-		free(file);
-		return NULL;
-	}
+	if (file->fd < 0)
+		return -errno;
 
 	sz = pread_str_safe(file->fd, buf, sizeof(buf), 0);
 	if (sz != (sizeof(buf) - 1)) {
 		if (sz < 0)
-			errno = -sz;
+			ret = (int)sz;
 		else
-			errno = EINVAL;
+			ret = -EINVAL;
 
 		close(file->fd);
-		free(file);
-		return NULL;
+		return ret;
 	}
 
 	for (unsigned int i = 0; i < ARRAY_SIZE(comp_types); i++) {
@@ -124,7 +120,9 @@ struct kmod_file *kmod_file_open(const struct kmod_ctx *ctx, const char *filenam
 
 	file->ctx = ctx;
 
-	return file;
+	*out_file = file;
+	file = NULL;
+	return 0;
 }
 
 /*
diff --git a/libkmod/libkmod-internal.h b/libkmod/libkmod-internal.h
index 17e6e5f5..c4c24e6f 100644
--- a/libkmod/libkmod-internal.h
+++ b/libkmod/libkmod-internal.h
@@ -135,8 +135,10 @@ _nonnull_(1) void kmod_module_set_required(struct kmod_module *mod, bool require
 _nonnull_all_ bool kmod_module_is_builtin(struct kmod_module *mod);
 
 /* libkmod-file.c */
-_must_check_ _nonnull_all_ struct kmod_file *kmod_file_open(const struct kmod_ctx *ctx, const char *filename);
-_nonnull_all_ struct kmod_elf *kmod_file_get_elf(struct kmod_file *file);
+struct kmod_file;
+struct kmod_elf;
+_must_check_ _nonnull_all_ int kmod_file_open(const struct kmod_ctx *ctx, const char *filename, struct kmod_file **file);
+_must_check_ _nonnull_all_ int kmod_file_get_elf(struct kmod_file *file, struct kmod_elf **elf);
 _nonnull_all_ int kmod_file_load_contents(struct kmod_file *file);
 _must_check_ _nonnull_all_ const void *kmod_file_get_contents(const struct kmod_file *file);
 _must_check_ _nonnull_all_ off_t kmod_file_get_size(const struct kmod_file *file);
@@ -145,7 +147,6 @@ _must_check_ _nonnull_all_ int kmod_file_get_fd(const struct kmod_file *file);
 _nonnull_all_ void kmod_file_unref(struct kmod_file *file);
 
 /* libkmod-elf.c */
-struct kmod_elf;
 struct kmod_modversion {
 	uint64_t crc;
 	enum kmod_symbol_bind bind;
diff --git a/libkmod/libkmod-module.c b/libkmod/libkmod-module.c
index 5fc40a40..796dafa1 100644
--- a/libkmod/libkmod-module.c
+++ b/libkmod/libkmod-module.c
@@ -656,11 +656,9 @@ static int do_init_module(struct kmod_module *mod, unsigned int flags, const cha
 	int err;
 
 	if (flags & (KMOD_INSERT_FORCE_VERMAGIC | KMOD_INSERT_FORCE_MODVERSION)) {
-		elf = kmod_file_get_elf(mod->file);
-		if (elf == NULL) {
-			err = -errno;
+		err = kmod_file_get_elf(mod->file, &elf);
+		if (err)
 			return err;
-		}
 
 		err = kmod_elf_strip(elf, flags, &stripped);
 		if (err) {
@@ -702,11 +700,9 @@ KMOD_EXPORT int kmod_module_insert_module(struct kmod_module *mod, unsigned int
 	}
 
 	if (!mod->file) {
-		mod->file = kmod_file_open(mod->ctx, path);
-		if (mod->file == NULL) {
-			err = -errno;
+		err = kmod_file_open(mod->ctx, path, &mod->file);
+		if (err)
 			return err;
-		}
 	}
 
 	err = do_finit_module(mod, flags, args);
@@ -1736,22 +1732,21 @@ KMOD_EXPORT void kmod_module_section_free_list(struct kmod_list *list)
 	kmod_list_release(list, kmod_module_section_free);
 }
 
-static struct kmod_elf *kmod_module_get_elf(const struct kmod_module *mod)
+static int kmod_module_get_elf(const struct kmod_module *mod, struct kmod_elf **elf)
 {
 	if (mod->file == NULL) {
 		const char *path = kmod_module_get_path(mod);
+		int ret;
 
-		if (path == NULL) {
-			errno = ENOENT;
-			return NULL;
-		}
+		if (path == NULL)
+			return -ENOENT;
 
-		((struct kmod_module *)mod)->file = kmod_file_open(mod->ctx, path);
-		if (mod->file == NULL)
-			return NULL;
+		ret = kmod_file_open(mod->ctx, path, &((struct kmod_module *)mod)->file);
+		if (ret)
+			return ret;
 	}
 
-	return kmod_file_get_elf(mod->file);
+	return kmod_file_get_elf(mod->file, elf);
 }
 
 struct kmod_module_info {
@@ -1872,9 +1867,9 @@ KMOD_EXPORT int kmod_module_get_info(const struct kmod_module *mod,
 		if (count < 0)
 			return count;
 	} else {
-		elf = kmod_module_get_elf(mod);
-		if (elf == NULL)
-			return -errno;
+		ret = kmod_module_get_elf(mod, &elf);
+		if (ret)
+			return ret;
 
 		count = kmod_elf_get_modinfo_strings(elf, &strings);
 		if (count < 0)
@@ -2020,9 +2015,9 @@ KMOD_EXPORT int kmod_module_get_versions(const struct kmod_module *mod,
 
 	assert(*list == NULL);
 
-	elf = kmod_module_get_elf(mod);
-	if (elf == NULL)
-		return -errno;
+	ret = kmod_module_get_elf(mod, &elf);
+	if (ret)
+		return ret;
 
 	count = kmod_elf_get_modversions(elf, &versions);
 	if (count < 0)
@@ -2121,9 +2116,9 @@ KMOD_EXPORT int kmod_module_get_symbols(const struct kmod_module *mod,
 
 	assert(*list == NULL);
 
-	elf = kmod_module_get_elf(mod);
-	if (elf == NULL)
-		return -errno;
+	ret = kmod_module_get_elf(mod, &elf);
+	if (ret)
+		return ret;
 
 	count = kmod_elf_get_symbols(elf, &symbols);
 	if (count < 0)
@@ -2227,9 +2222,9 @@ KMOD_EXPORT int kmod_module_get_dependency_symbols(const struct kmod_module *mod
 
 	assert(*list == NULL);
 
-	elf = kmod_module_get_elf(mod);
-	if (elf == NULL)
-		return -errno;
+	ret = kmod_module_get_elf(mod, &elf);
+	if (ret)
+		return ret;
 
 	count = kmod_elf_get_dependency_symbols(elf, &symbols);
 	if (count < 0)